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Imana, Eyosias Yoseph. "Cognitive RF Front-end Control." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/51121.
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This research addresses the performance degradation in receivers due to poor selectivity. Poor selectivity is expected to be a primary limitation on the performance of Dynamic-Spectrum-Access (DSA) and millimeter wave (mmWave) technologies. Both DSA and mmWave are highly desired technologies because they can address the spectrum-deficit problem that is currently challenging the wireless industry. Accordingly, addressing poor receiver selectivity is necessary to expedite the adoption of these technologies into the main street of wireless. This research develops two receiver design concepts to enhance the performance of poorly-selective receivers.
The first concept is called cognitive RF front-end control (CogRF). CogRF operates by cognitively controlling the local-oscillator and sampling frequencies in receivers. This research shows that CogRF can fulfil the objective of pre-selectors by minimizing the effects of weak and moderately-powered neighboring-channel signals on the desired signal. This research shows that CogRF can be an alternative to high-performance pre-selectors, and hence, CogRF is a viable architecture to implement reliable DSA and mmWave receivers. The theoretical design and hardware implementation of a cognitive engine and a spectrum sensor of CogRF are reported in this dissertation. Measurement results show that CogRF significantly reduces the rate of communication outage due to interference from neighboring-channel signals in poorly-selective receivers. The results also indicate that CogRF can enable a poorly-selective receiver to behave like a highly-selective receiver.
The second receiver design concept addresses very strong neighboring-channel signals. The performance of poorly selective receivers can easily suffer due to a strong, unfiltered neighboring-channel signal. A strong neighboring-channel signal is likely for a DSA radio that is operating in military radar bands. Traditionally, strong neighboring signals are addressed using an Automatic-Gain-Control (AGC) that attempt to accommodate the strong received signal into the dynamic range of the receiver. However, this technique potentially desensitizes the receiver because it sacrifices the Signal-to-Noise-Ratio (SNR) of the desired signal. This research proposes the use of auxiliary-receive path to address strong neighboring-channel signals with minimal penalty on the SNR of the desired signal. Through simulation based analysis, and hardware-based measurement, this research shows that the proposed technique can provide significant improvement in the neighboring-channel-interference handling capability of the receiver.Ph. D.
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Karlsson, Magnus. "Ultra-wideband Antenna and Radio Front-end Systems." Doctoral thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10338.
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The number of wireless communication applications increase steadily, leading to the competition for currently allocated frequency bands. Pressure on authorities around the world to permit communications in higher and wider frequency ranges to achieve higher wireless capacity than those existed in the past has resulted in several new specifications. The federal communication commission (FCC) in USA has unleashed the band 3.1-10.6 GHz for ultra-wideband radio (UWB) communications. The release has triggered a worldwide interest for UWB. Other regulatory instances throughout the world have issued use of UWB techniques as well. Capacity issues in form of data rate and latency have always been a bottleneck for broadened wireless-communication usages. New communication systems like UWB require larger bandwidth than what is normally utilized with traditional antenna techniques. The interest for compact consumer electronics is growing in the meantime, creating a demand on efficient and low profile antennas which can be integrated on a printed circuit board. In this thesis, some methods to extend the bandwidth and other antenna parameters associated with wideband usages are studied. Furthermore, methods on how to enhance the performance when one antenna-element is not enough are studied as well. The principle of antenna parallelism is demonstrated using both microstrip patch antennas and inverted-F antennas. Several techniques to combine the antennas in parallel have been evaluated. Firstly, a solution using power-splitters to form sub-arrays that covers one 500-MHz multi-band orthogonal frequency division multiplexing (OFDM) UWB is shown in Paper I. It is then proposed that the sub-bands are selected with a switching network. A more convenient method is to use the later developed frequency multiplexing technique as described in Paper V and VIII. Using the frequency multiplexing technique, selective connection of any number of antennas to a common junction is possible. The characteristic impedance is chosen freely, typically using a 50-Ω feed-line. Secondly, in Paper VIII a frequency-triplexed inverted-F antenna system is investigated to cover the Mode 1 multi-band UWB bandwidth 3.1-4.8 GHz. The antenna system is composed of three inverted-F antennas and a frequency triplexer including three 5th order bandpass filters. In Paper VI a printed circuit board integrated-triplexer for multi-band UWB radio is presented. The triplexer utilizes a microstrip network and three combined broadside- and edge-coupled filters. The triplexer is fully integrated in a four metal-layer printed circuit board with the minimum requirement on process tolerances. Furthermore, the system is built completely with distributed microstrips, i.e., no discrete components. Using the proposed solution an equal performance between the sub-bands is obtained. Finally suitable monopoles and dipoles are discussed and evaluated for UWB. In Paper X circular monopole and dipole antennas for UWB utilizing the flex-rigid concept are proposed. The flex-rigid concept combines flexible polyimide materials with the regular printed circuit board material. The antennas are placed entirely on the flexible part while the antenna ground plane and the dipole antenna balun are placed in the rigid part.
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Karlsson, Magnus. "Ultra-wideband antenna and radio front-end systems /." Norrköping : Department of Science and technology, Linköpings universitet, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10338.
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Magalhães, José Pedro da Rocha. "Desenvolvimento de um front-end para cognitive radio." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/8817.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesNesta tese de mestrado é apresentada uma proposta para novos Front-Ends em Software De ned Radio (SDR) baseado na teoria dos Bancos de Filtros Híbridos (HFB) e que permite aumentar a largura de banda de operação do rádio sem perdas em resolução e gama dinâmica. Para prova de conceito, são apresentados dois Front-Ends que dividem o sinal de entrada (da antena) em 8 ou 64 bandas contíguas em frequência. Ambos os casos permitem a operação para uma largura de banda de 400MHz e com resolução de 16 bits. A divisão do sinal de entrada em múltiplas bandas contíguas em frequência é o ponto fundamental no desenvolvimento deste receptor. Nos artigos de investigação de HFBs nunca foi abordada a forma como na prática o sinal de entrada é dividido. Nesta tese, é sugerido o multiplexer como o elemento que realiza essa divisão. Infelizmente, também o estado da arte dos multiplexers é muito limitado, estando o estudo dessa tecnologia restringido a realizações com Guias de Onda ou Filtros de Cavidades, con gurações que pecam pelas excessivas dimensões e peso. Assim, o objectivo fundamental desta tese passa pela criação de novos multiplexers de reduzidas dimensões, grande número de canais, simplicidade de sintonização e facilidade de replicação. São propostas versões em tecnologia planar e discreta que permitem a divisão do sinal de entrada em 4, 8 ou 16 bandas contíguas em frequência. Para cada multiplexer criado é depois analisado o seu enquadramento num Banco de Filtros Híbridos, isto é, são analisados os custos de distorção e aliasing associados à divisão e posterior reconstrução do sinal no domínio digital. Para esse efeito é usado um método que permite o cálculo dos ltros digitais de síntese a partir dos multiplexers analógicos desenhados, minimizando assim os erros na reconstrução do sinal. Para os casos dos multiplexers de 8 canais criados, os resultados em distorção e aliasing obtidos rondam valores médios entre 80dB e 100dB o que valida a proposta de Front-End de SDR com 8 canais. Para terminar, é sugerido uma nova estratégia para a gestão de espectro em Cognitive Radio que melhor se coaduna com a arquitectura do Front-End proposto e que permitirá uma melhor gestão do consumo de potência em dispositivos móveis que funcionem a bateria - caso crítico no Software Radio e Cognitive Radio. Em suma, os objectivos desta tese são a criação de novos multiplexers que facilitem o projecto de Front-Ends baseados na teoria dos Bancos de Filtros Híbridos, e que permitam um aumento da resolução e gama dinâmica do Software Radio relativamente aos padrões actuais da tecnologia.
In this master dissertation, a new Front-End for Sofware-De ned Radio (SDR) based on the Hybrid Filter Bank theory is proposed. This new Front-End has the ability to increase the radio operational bandwith without losing in resolution or dynamic range. For proof of concept, two Radio Front-Ends are proposed, splitting the incoming signal in 8 or 64 channels that are frequency contiguous. In both cases, a total bandwidth of 400 MHz and a resolution of 16 bits is achieved. The input signal splitting is the fundamental point of the radio's development. In scienti c publications on Hybrid Filter Banks it has never been revealed how in practice the signal is splited in contiguous bands. In this master dissertation it is sugested the use of frequency multiplexers to achieve that goal. Unfortunately, there is not much scienti c research on frequency multiplexers, as those studies are mostly based on Cavity Filters and Wave Guides whose dimentions are not proper for mobility purposes. Therefore, the main goal of this dissertation is to develop Frequency Multiplexers with reduced dimentions, a large number of channels, easy to tune and easy to replicate. It is proposed new multiplexers in planar and discrete technology with 4, 8 or 16 channels that are contiguous in frequency. For each developed multiplexer, the behaviour on a Hybrid Filter Bank system is tested. By analysing the distortion and aliasing results attached to the analogic deconstruction and digital reconstruction of the signal, one can conclude if the system is suitable for a radio aplication or not. To obtain better results, it is used a Hybrid Filter Bank method that automatically designs the synthesis (digital) lters by knowing only the analogic lters response. Using this method we can reduce the aliasing and distortion costs of the Hybrid Filter Bank. For the 8 channel Multiplexers, the aliasing and distortion measured was placed between -80dB and -100dB which validates the usage of those systems in a actual Software De ned Radio designs. Finally, a new strategy for spectrum management in Cognitive Radio that allows to reduce the power consup- tion of mobile devices is proposed. In short words, the main goal of this dissertation is to develop new multiplexers that will ease the design of new Software Radio Front-End based on the Hybrid Filter Bank theory.
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Kim, Hyung Joon. "Multi-standard radio transceiver architectures and radio frequency front-end design." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1110399471.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 128 p.; also includes graphics (some col.). Includes bibliographical references (p. 125-128). Available online via OhioLINK's ETD Center
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Brisebois, Terrence. "Wideband RF Front End Daughterboard Based on the Motorola RFIC." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33943.
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The goal of software-defined radio (SDR) is to move the processing of radio signals from the analog domain to the digital domain â to use digital microchips instead of analog circuit components. Until faster, higher-precision analog-to-digital (ADCs) and digital-to-analog converters (DACs) become affordable, however, some analog signal processing will be necessary. We still need to convert high-radio frequency (RF) signals that we receive to low intermediate-frequency (IF) or baseband (centered on zero Hz) signals in order for ADCs to sample them and feed them into microchips for processing. The reverse is true when we transmit. Amplification is also needed on the receive side to fully utilize the dynamic range of the ADC and power amplification is needed on the transmit side to increase the power output from the DAC for transmission. Analog filtering is also needed to avoid saturating the ADC or to filter out interference when receiving and to avoid transmitting spurs. The analog frequency conversion, amplification and filtering section of a radio is called the RF front end. This thesis describes work on a new RF front end daughterboard for the Universal Software Radio Peripheral, or USRP. The USRP is a software-radio hardware platform designed to be used with the GNU Radio software radio software package. Using the Motorola RFIC4 chip, the new daughterboard receives RF signals, converts them to baseband and does analog filtering and amplification before feeding the signal into the USRP for processing. The chip also takes transmit signals from the USRP, converts them from baseband to RF and amplifies and filters them. The board was designed and laid out by Randall Nealy. I wrote the software driver for GNU Radio. The driver defines the interface between the USRP and the RFIC chip, controls the physical settings, and calculates and sets the hundreds of variables necessary to operate this extremely complex chip correctly. It allows plug-and-play compatibility with the current USRP daughterboards and supplies additional functions not available in any other daughterboard.Master of Science
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Abu-Al-Saud, Wajih Abdul-Elah. "Efficient Wideband Digital Front-End Transceivers for Software Radio Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5257.
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Software radios (SWR) have been proposed for wireless communication systems to enable them to operate according to incompatible wireless communication standards by implementing most analog functions in the digital section on software-reprogrammable hardware. However, this significantly increases the required computations for SWR functionality, mainly because of the digital front-end computationally intensive filtering functions, such as sample rate conversion (SRC), channelization, and equalization. For increasing the computational efficiency of SWR systems, two new SRC methods with better performance than conventional SRC methods are presented. In the first SRC method, we modify the conventional CIC filters to enable them to perform SRC on slightly oversampled signals efficiently. We also describe a SRC method with high efficiency for SRC by factors greater than unity at which SRC in SWR systems may be computationally demanding. This SRC method efficiently increases the sample rate of wideband signals, especially in SWR base station transmitters, by applying Lagrange interpolation for evaluating output samples hierarchically using a low-rate signal that is computed with low cost from the input signal.
A new channelizer/synthesizer is also developed for extracting/combining frequency multiplexed channels in SWR transceivers. The efficiency of this channelizer/synthesizer, which uses modulated perfect reconstruction (PR) filter banks, is higher than polyphase filter banks (when applicable) for processing few channels, and significantly higher than discrete filter banks for processing any number of variable-bandwidth channels where polyphase filter banks are inapplicable. Because the available methods for designing modulated PR filter banks are inapplicable due to the required number of subchannels and stopband attenuation of the prototype filters, a new design method for these filter banks is introduced. This method is reliable and significantly faster than the existing methods.
Modulated PR filter banks are also considered for implementing a frequency-domain block blind equalizer capable of equalizing SWR signals transmitted though channels with long impulse responses and severe intersymbol interference (ISI). This blind equalizer adapts by using separate sets of weights to correct for the magnitude and phase distortion of the channel. The adaptation of this blind equalizer is significantly more reliable and its computational requirements increase at a lower rate compared to conventional time-domain equalizers making it efficient for equalizing long channels that exhibit severe ISI.
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Backström, Anders, and Mats Ågesjö. "Design and implementation of a 5GHz radio front-end module." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2635.
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The overall goal of this diploma work is to produce a design of a 5 GHz radio frontend using Agilent Advanced Design System (ADS) and then build a working prototype. Using this prototype to determine if RF circuits at 5 GHz can be successfully produced using distributed components on a laminate substrate.
The design process for the radio front-end consists of two stages. In the first stage the distributed components are designed and simulated, and in the second stage all components are merged into a PCB. This PCB is then manufactured and assembled. All measurements on the radio front-end and the test components are made using a network analyser, in order to measure the S-parameters.
This diploma work has resulted in a functional design and prototype, which has proved that designing systems for 5 GHz on a laminate substrate is possible but by no means trivial.
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Long, John R. (John Robert) Carleton University Dissertation Engineering Electronics. "A Narrowband radio receiver front-end for portable communications applications." Ottawa, 1996.
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Gopalan, Anand. "Built-in-self-test of RF front-end circuitry /." Link to online version, 2005. https://ritdml.rit.edu/dspace/handle/1850/942.
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Cha, Jeongwon. "A CMOS radio-frequency front-end for multi-standard wireless communications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37250.
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The explosive growth of wireless communication market has led the development of low-cost, highly-integrated wireless communication systems. Even though most blocks in the front-end have successfully been integrated by using the CMOS technology, it is still a formidable challenge to integrate the entire front-end. Thus, the objective of this research is to demonstrate the feasibility of the integrated front-end by using improved circuit techniques as well as the improved process technologies. This dissertation proposes an improved control scheme to enhance the high-power handling capability of an antenna switch.
As a part of this research, an antenna switch controller for a GaAs antenna switch was first developed to enhance the performances of the GaAs antenna switch by using the boosted control voltage. To enhance the efficiency of the front-end, efficiency improvement techniques for the antenna switch controller has also been studied. With the suggested efficiency improvement techniques, a fully-integrated antenna switch was implemented using the SOI technology, and exceeding performances over many commercial products for watt-level high-power applications have been successfully demonstrated. As an effort to improve the efficiency of a power amplifier, a linear envelope detector was also implemented, and the results show that the envelope detector is suitable for dynamic biasing of the power amplifier. The research presented in this dissertation, thus, provides a low-cost and high-performance solution for highly-integrated RF front-end used in various wireless communication systems.
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Chen, Chih-Hung. "CMOS RF front-end design of a very narrowband transceiver with 0.18[micrometers]." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Hasan, S. M. Shajedul. "New Concepts in Front End Design for Receivers with Large, Multiband Tuning Ranges." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/37624.
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This dissertation presents new concepts in front end design for receivers with large, multiband tuning ranges. Such receivers are required to support large bandwidths (up to 10's of MHz) over very large tuning ranges (30:1 and beyond) with antennas that are usually narrowband, or which at best support multiple narrow bandwidths. Traditional techniques to integrate a single antenna with such receivers are limited in their ability to handle simultaneous channels distributed over very large tuning ranges, which is important for frequency-agile cognitive radio, surveillance, and other applications requiring wideband or multiband monitoring. Direct conversion architecture is gaining popularity due to the recent advancements in CMOS--based RFIC technology. The possibility of multiple parallel transceivers in RF CMOS suggests an approach to antenna--receiver integration using multiplexers. This dissertation describes an improved use of multiplexers to integrate antennas to receivers. First, the notion of sensitivity--constrained design is considered. In this approach, the goal is first to achieve sensitivity which is nominally dominated by external (environmental) noise, and then secondly to improve bandwidth to the maximum possible consistent with this goal. Next, a procedure is developed for designing antenna-multiplexer-preamplifier assemblies using this philosophy. It is shown that the approach can significantly increase the usable bandwidth and number of bands that can be supported by a single, traditional antenna. This performance is verified through field experiments. A prototype multiband multimode radio for public safety applications using these concepts is designed and demonstrated.Ph. D.
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González, José Luis Alcaraz. "Design of an Ultra Wideband Radio Front-End for Multi-band Communications." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-96288.
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Application of multiband systems with a variety of frequency band combinations is accelerating since the communication capacity is increasing and new functions like GPS or Bluetooth are being added. It is expected, therefore, that all the handsets will probably become compatible with multibands in the near future. In such multiband systems, a multiband antenna is definitely one of the key devices since it is compatible with all the frequency bands without resort to multiple antennas as is usual in today´s practices. This project deals with design of a single antenna module for different standards, i.e., to design an ultra-wideband antenna together with frequency multiplexer. The thesis focuses on the wideband antenna design. In principle, the module must be able to work with GPS, GSM, UMTS, ZigBee, Bluetooth and Wi-Fi in the 1.5-2.5 GHz band. The antenna type chosen was the dipole antenna and it was implemented using a four metal layer PCB structure wich includes a flexible material. Two different shapes were used for the dipole, square and circular. The design process is mainly carried out in two steps. In the first step dimensions of the antennas were calculated and some results were verified in Linecalc. Then, in the second step, dimensions were experimentally tuned until simulation results fulfilled the demands of the design specifications. Evaluation was done by looking at impedance bandwidth and radiation characteristics. Simulation results showed that with perfect circular discs a correct adaptation could not be obtained in the specificated frequency band and because of this an improved circular discs antenna was designed. With this new design a good result was obtained, the voltage standing wave ratio was under 3 in the whole band. With the rectangular antenna a good result was also obtained, too. In both cases, the worst behaviour was in the middle of the bandwidth. The multiplexer structure came from a theorical design. Initial transmission line parameters were calculated in Linecalc and filters are implemented with the ADS tool. Finally, the design is experimentally tuned until good simulations results were obtained. The network insertion loss is under 2.3 dB between input port and all output ports and isolation behavior between all the different ports is satisfactory. In the end, the complete Multi-band Front-end was simulated using both antennas obtaining good behaviour for isolation and return loss parameters. In conclusion, a planar ultra wide-band front-end for GPS, GSM, UMTS, Bluetooth, WiFi, and ZigBee standards in the 1.5-2.5 GHz band using planar dipole antenna and microstrips has been designed with good simulation results.
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Erixon, Mats. "Design of a Direct-conversion Radio Receiver Front-end in CMOS Technology." Thesis, Linköping University, Department of Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1197.
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In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology.
Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch. This implies very high demands on the DCR front-end.
The front-end comprises a low-noise amplifier (LNA) and a mixer. Different LNA and mixer architectures has been studied and from the mentioned inherited problems with direct conversion, one proposal for a solution is a differential source degenerated LNA and a differential harmonic mixer, which has been designed and simulated.
The LNA has a gain of 12dB, a noise figure of 3.6dB and provides a return loss better than -15dB. The overall noise figure of the signal path is 8dB and the overall IIP3 and IIP2 is -12dBm and 31dBm, respectively.
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Hedberg, Anders. "Design of CMOS RF-Switches for a Multi-Band Radio Front-End." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2037.
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A study has been made in CMOS RF-switches that can be used in the front-end of a multi-band radio targeting the 802.11a,b,g and W-CDMA standards and working in the frequency range 2.4-5.5GHz. Especially, one single-transistor switch and two types of transmission gates have been analyzed, simulated and compared with respect to loss, linearity, compression point and noise. From this, five different single-transistor switches have been designed for on-chip probing measurements. Special consideration has been taken to accommodate on-chip testing, thus additional structures have been designed. The simulations and design has been performed with Chartered 0.18um RF-CMOS process.
The results from the simulations show that the single-transistor switch has better performance in loss, linearity, compression point and noise compared to the transmission gates. However, for the transmission gates the linearity can be increased beyond the linearity of the single-transistor switch if the widths of the transistors are made sufficiently large.
For the single-transistor switch, simulation results show that the transistor length shall be kept to its minimum for best performance and that the number of fingers does not influence significantly. Also, there are optimum values for the loss in on-mode, the noise and the linearity and worst-case values for the loss in off-mode when the transistor width is varied. Consequently, the single- transistor switch can be tuned by its transistor width to accommodate desired performances.
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Lohmiller, Peter [Verfasser]. "Spectrum Sensing RF Front-End Module for Cognitive Radio Applications / Peter Lohmiller." Berlin : epubli, 2017. http://d-nb.info/1123330557/34.
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Park, Sanghoon. "Detection technique and front-end RF tunable filter for cognitive radio systems." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p3389416.
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Thesis (Ph. D.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed February 17, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 102-114).
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Malafaia, Daniel Filipe Simões. "Real time front-end for cognitive radio inspired by the human cochlea." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/10944.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesNesta tese vamos discutir a implementação e desenvolvimento de um frontend inspirado na cóclea humana que é capaz de amostrar sinais RF com uma larga largura de banda e gama dinâmica. Este front-end usa um multiplexer de RF de 8 canais amostrado por uma placa com 8 ADCs a funcionar a 250MSPS. Uma placa de desenvolvimento com uma FPGA controla a ADC e implementa os ltros de síntese digitais e liga a um computador pessoal para transferir toda a informação e mudar os coe cientes dos ltros em tempo real.
In this thesis it will be discussed the real time implementation and development of a front-end inspired by the Human Cochlea that is able to sample RF signals with a large bandwidth and dynamic range. This front-end uses an 8 channel RF multiplexer sampled by an 8 channel 250MSPS ADC board. A FPGA board controls the ADC, implements the digital synthesis lter bank and connects to a personal computer to transfer the data and to change the lters in real-time.
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Escobar, Kenny E. "Photonic front-end and comparator processor for a sigma-delta modulator." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Sept/08Sep%5FEscobar.pdf.
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Thesis (M.S. in Electrincal Engineering)--Naval Postgraduate School, September 2008.Thesis Advisor(s): Pace, Phillip E. "September 2008." Description based on title screen as viewed on November 4, 2008. Includes bibliographical references (p. 65-66). Also available in print.
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Blair, Arthur Paul Jr. "A broadband Microwave Transceiver Front-end for an Airborne Software Defined Radio Experiment." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51226.
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This document describes the design, simulation, construction, and test of a wideband analog transceiver front-end for use in an airborne software defined radio (SDR) experiment. The transceiver must operate in the GSM-1800 and IEEE 802.11b/g WiFi frequency bands and accommodate beamforming. It consists of a transmitter and dual band receiver. The receiver input is fed by a helical antenna and the outputs are digitized for use in the SDR. The transmitter is fed by a complex baseband output from a Digital-to-Analog Converter (DAC) and its output fed to another helical antenna. The requirements for the transceiver were driven by a spectral survey of the operating environment and the physical and electrical limitations of the platform. The spectral survey showed a great disparity in the received power levels between the signals of interest and potential interferers. Simulations of several candidate receiver architectures showed that meeting the needs of the experiment would require a high degree of linearity and filtering. It was found that the receiver requirements could be met by a single downconversion with high order filters and passband sampling. A series of analyses determined the requirements of the individual components that make up the system. Performance was verified by simulations using measured data of the individual components and lab tests of the assembled hardware. Suggestions for improved performance and expanded operation are made.Master of Science
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Li, Xiaopeng. "System and circuit design techniques for CMOS soft-ware radio receiver front-end /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu148639852855606.
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Duo, Xinzhong. "System-on-package solutions for multi-band RF front end." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-482.
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Jackson, Kevin. "Blind Front-end Processing of Dynamic Multi-channel Wideband Signals." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4692.
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In wireless digital communications, the sender and receiver typically know the modulation scheme with which they will be communicating. Automatic modulation identification is the ability to identify the modulation in a communication system with little to no prior knowledge of the modulation scheme. Many techniques for modulation identification operate on many assumptions including that the input signal is base-banded, the carrier frequency is known and that the signal is narrow-band (i.e. neighboring signals in the wide-band are excluded). This work provides the blind processing of an arbitrary wide-band signal to allow such assumptions. The challenges of such a front-end or pre-processor include detecting signals which can appear at any frequency, with any band-width at any given time and for any arbitrary duration. This work takes as its input a wide-band signal with a random number of sub-signals, each turning on and o at random times and each at random locations in the frequency domain. The output of the system is a collection of signals corresponding to each sub-signal brought down to base-band, isolated in the frequency and time domains, nominally sampled and with estimates of key parameters.
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Tsui, Hau Yiu. "A 5 GHz integrated low-power CMOS RF front-end IC design /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20TSUI.
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Liu, Xiaoqun. "Design of multi-channel radio-frequency front-end for 200mhz parallel magnetic resonance imaging." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3159.
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Malz, Stefan [Verfasser]. "Silicon Integrated Radio Front-End Design for 100 Gbit/s and Beyond / Stefan Malz." Wuppertal : Universitätsbibliothek Wuppertal, 2020. http://d-nb.info/1214389716/34.
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Papageorgiou, Nikolaos A. "Development of RF front end prototype compliant with the 802.11a standard for wireless applications." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04072004-180131/unrestricted/papageorgiou%5Fnikolaos%5Fa%5F200312%5Fms.pdf.
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Semlali, Hayat. "Développement de nouvelles structures et d'algorithmes appliquant l’échantillonnage aléatoire pour des systèmes de type radio logicielle et radio cognitive." Nantes, 2015. http://archive.bu.univ-nantes.fr/pollux/show.action?id=50ca55df-b56d-4c7c-817c-8976af7c725b.
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Dans ce travail, nous cherchons à appliquer l’échantillonnage aléatoire dans des architectures de types radio logicielle et radio cognitive en vue de les optimiser. L’échantillonnage aléatoire permet de réduire les contraintes de repliement de spectre du signal échantillonné et de s'affranchir des contraintes de bandes interdites. La première partie du travail est consacrée à l’élément clé de la radio logicielle qui est le front-end numérique. Nous présentons différentes méthodes de reconstruction des signaux aléatoirement échantillonnés et de filtrage de canal. Nous nous intéressons plus particulièrement aux méthodes itératives en raison de leur flexibilité et de leur rapidité de convergence. Nous proposons une nouvelle structure du front-end numérique basée sur la méthode itérative ADPW-GC pour la sélection de canal. Les performances de cette méthode sont analysées en termes de complexité, de qualité du signal reconstruit et de robustesse et sont comparées à des structures plus classiques. Nous nous sommes ensuite intéressés à la fonction clé de la radio cognitive à savoir la détection spectrale. Nous avons étudié trois structures puis étudié leurs performances. Les études théoriques et de simulation ont été complétées par quelques applications dans un contexte de la radio logicielle et de la radio cognitive en se basant sur des signaux réelsIn this work we apply random sampling in the context of software radio and cognitive radio. The use of random sampling makes it possible to overcome the aliasing constraint imposed by the uniform sampling case. The first part is dedicated to the key element of software radio systems which is the digital front-end. We present different methods for randomly sampled signals reconstruction and for channel filtering. We are interested by iterative methods due to their flexibility and convergence speed. Later we propose a new structure of the digital front-end based on the ADPW-GC iterative method for channel selection by applying random sampling in a software radio context. The performance of this method is analyzed in terms of complexity, quality of reconstructed signal and robustness and compared with classical structures. The second part, deals with the spectrum sensing which is one of the main functions of cognitive radio. The performance of these structures are evaluated and compared to the case of uniform sampling. After the theoretical and simulation studies, some applications are given in the context of software defined radio and cognitive radio based on real FM radio signals
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Viswanatha, Raghunath. "Design and Simulation of Multi-Frequency Global Navigation Satellite System Receiver Radio Frequency Front-End." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1227298677.
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Kim, Jihwan. "High performance radio-frequency and millimeter-wave front-end integrated circuits design in silicon-based technologies." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44704.
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Design techniques and procedures to improve performances of radio-frequency and millimeter-wave front-end integrated circuits were developed. Power amplifiers for high data-rate wireless communication applications were designed using CMOS technology employing a novel device resizing and concurrent power-combining technique to implement a multi-mode operation. Comprehensive analysis on the efficiency degradation effect of multi-input-single-output combining transformers with idle input terminals was performed. The proposed discrete resizing and power-combining technique effectively enhanced the efficiency of a linear CMOS power amplifier at back-off power levels. In addition, a novel power-combining transformer that is suitable to generate multi-watt-level output power was proposed and implemented. Employing the proposed power-combining transformer, a high-power linear CMOS power amplifier was designed. Furthermore, receiver building blocks such as a low-noise amplifier, a down-conversion mixer, and a passive balun were implemented using SiGe technology for W-band applications.
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Arriagada, Anton. "A wideband high dynamic range frequency hopping hardware front-end for the joint tactical radio system." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/fullcit?p1477881.
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Thesis (M.S.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed July 13, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (leaf 63).
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Monk, Andrew Michael. "Exploration into the Use of a Software Defined Radio as a Low-Cost Radar Front-End." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8742.
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Inspection methods for satellites post-launch are currently expensive and/or dangerous. To address this, BYU, in conjunction with NASA, is designing a series of small satellites called CubeSATs. These small satellites are designed to be launched from a satellite and to visually inspect the launching body. The current satellite revision passively tumbles through space and is appropriately named the passive inspection cube satellite (PICS). The next revision actively maintains translation and rotation relative to the launching satellite and is named the translation, rotation inspection cube satellite (TRICS). One of the necessary sensors aboard this next revision is the means to detect distance. This work explores the feasibility of using a software defined radio as a small, low-cost front end for a ranging radar to fulfill this need. For this work, the LimeSDR-Mini is selected due to its low-cost, small form factor, full duplex operation, and open-source hardware/software. Additionally, due to the the channel characteristics of space, the linear frequency modulated continuous-wave (LFMCW) radar is selected as the radar architecture due to its ranging capabilities and simplicity. The LFMCW radar theory and simulation are presented. Two programming methods for the LimeSDR-Mini are considered: GNU Radio Companion and the pyLMS7002Soapy API. GNU Radio Companion is used for initial exploration of the LimeSDR-Mini and confirms its data streaming (RX and TX) and full duplex capabilities. The pyLMS7002Soapy API demonstrates further refined control over the LimeSDR-Mini while providing platform independence and deployability. This work concludes that the LimeSDR-Mini is capable of acting as the front end for a ranging radar aboard a small satellite provided the pyLMS7002Soapy API is used for configuration and control. GNU Radio Companion is not recommended as a programming platform for the LimeSDR-Mini and the pyLMS7002Soapy API requires further research to fine tune the SDR's performance.
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Jun, Minhee. "Reconfigurable Radio Frequency (RF) Front-end and its Fast Optimization for Adapting to Dynamic Communication Environments." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/866.
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In order to support a multi-standard platform using a Software Defined Radio (SDR), the novel idea of reconfigurable Radio Frequency (RF) frontends have recently been proposed by the U.S. Defense Advanced Research Projects Agency (DARPA). A reconfigurable RF front-end has RF components that are reconfigured separately in order to satisfy the requirement of a particular communication standard. The reconfigurable RF front-end is a more reliable front-end for SDR than the currently used fixed wide-band RF front-ends, which have degraded system performance by passing more interference signals spread out in a wide range of frequency band. In order to realize the reconfigurable RF front-end, this thesis investigates the optimization method to select from the available configurations in radio environments with interference. In order to select an optimal configuration, we propose the Environment-Adaptable Fast (EAF) optimization algorithm for a reconfigurable RF front-end. A reconfigurable RF front-end not only needs to select an appropriate configuration that can operate for a given standard, but also needs to adapt quickly to a dynamic communication condition. This is difficult since there may be millions of available configurations. First, we studied RF impairment estimation for reconfigurable RF front-ends. Nonlinearity, phase noise, noise figure as well as frequency offset are RF impairments most likely to affect a particular standard. Second, we formulated the Signal-to-Interference-and-Noise Ratio (SINR) calculation which hastens the optimization process. We demonstrate the performance of the EAF optimization method in an exemplary scenario using Matlab Simulink. Finally, we designed the EAF optimization algorithm as a heuristic to select a configuration from the available ones. These simulation results demonstrate that while finding an optimal configuration, the EAF optimization significantly reduces simulation time compared to the four other previously proposed optimization methods. Thus, we expect that a reconfigurable RF front-end would be useful in real-time communication environments, since it would need significantly fewer reconfigurations to find an adequate configurations.
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Wilder, Ali, Randeep Pannu, and Amr Haj-Omar. "The Process of Implementing a RF Front-End Transceiver for NASA's Space Network." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581854.
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Software defined radio (SDR) introduces endless possibilities for future communication technologies. Instead of being limited to a static segment of the radio spectrum, SDR allows RF front-ends to be more flexible by using digital signal processing (DSP) and cognitive techniques to integrate adaptive hardware with dynamic software. We present the design and implementation of an innovative RF front-end transceiver architecture for application into a SDR test-bed platform. System-level requirements were extracted from the Space Network User Guide (SNUG). Initial system characterization demonstrated image leakage due to poor filtering and mixer isolation issues. Hence, the RF front-end design was re-implemented using the Weaver architecture for improved image rejection performance.
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Kim, Hyun-Woong. "CMOS RF transmitter front-end module for high-power mobile applications." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47592.
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With the explosive growth of the wireless market, the demand for low-cost and highly-integrated radio frequency (RF) transceiver has been increased. Keeping up with this trend, complimentary metal-oxide-semiconductor (CMOS) has been spotlighted by virtue of its superior characteristics. However, there are challenges in achieving this goal, especially designing the transmitter portion. The objective of this research is to demonstrate the feasibility of fully integrated CMOS transmitter module which includes power amplifier (PA) and transmit/receive (T/R) switch by compensating for the intrinsic drawbacks of CMOS technology.
As an effort to overcome the challenges, the high-power handling T/R switches are introduced as the first part of this dissertation. The proposed differential switch topology and feed-forward capacitor helps reducing the voltage stress over the switch devices, enabling a linear power transmission. With the high-power T/R switches, a new transmitter front-end topology - differential PA and T/R switch topology with the multi-section PA output matching network - is also proposed. The multi-stage PA output matching network assists to relieve the voltage stress over the switch device even more, by providing a low switch operating impedance. By analyzing the power performance and efficiency of entire transmitter module, design methodology for the high-power handling and efficient transmitter module is established. Finally, the research in this dissertation provides low-cost, high-power handling, and efficient CMOS RF transmitter module for wireless applications.
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Izquierdo, Christian. "Conception et réalisation d’un front-end analogique pour un récepteur multistandard multi-mode." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10013/document.
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L‘objectif de la thèse est la conception d’un front-end analogique RF large bande pour récepteurs cellulaires multistandard multi-mode. La principale limitation des récepteurs actuels par rapport à cet objectif est la nécessité d’un filtre SAW externe afin de protéger le LNA et le mélangeur des bloqueurs hors bande. Nous proposons dans cette thèse une technique de contre-réaction positive, basée sur la transposition de fréquences, qui permet un filtrage RF sélectif dès l’entrée du récepteur. Cette architecture diminue les contraintes de linéarité dès l’entrée du LNA. Ce filtrage est en plus reconfigurable en fréquence et en largeur de bande. Un circuit expérimental a été réalisé en technologie CMOS 65nm. La contre-réaction permet une amélioration de 17dB de l’IIP3 hors bande de l’amplificateur faible bruit. La fréquence centrale est accordable de 1,3GHz à 2,85GHz ; la consommation est de 30 mW pour un facteur de bruit maximal de 6,5dBThe aim of this thesis is the design of a wide-band RF analogue front-end for a cellular multi-standard and multiband receiver. The main limitation of receivers today is the need of external SAW filters to protect the LNA and mixer from out-of-band interferers. In this thesis we propose a new technique of positive feed-back which transposes the filters transfer function in RF. Thus, a selective RF filter is created in the LNA input to improve non-linearity performances of the receiver. This RF filter is also configurable in bandwidth and center frequency. An experimental prototype has been made in 65nm CMOS technology. The positive feed-back improves the LNA out-of-band IIP3 by 17dB. The center frequency is configurable from 1.3GHZ to 2.85GHz. Power consumption is of 30mW, while maximal NF is of 6.5dB
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Gong, Fei. "Front End Circuit Module Designs for A Digitally Controlled Channelized SDR Receiver Architecture." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322606039.
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Lombard, Philippe. "Étude de l'impact du filtrage et des non-linéarités sur les signaux ULB dans les front-end-radio-frequence et les réseaux hybrides optique-radio." Grenoble 1, 2007. http://www.theses.fr/2007GRE10297.
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Les systèmes Ultra Larges Bandes (ULB) représentent une nouvelle technologie de communication sans fil pour la transmission d’informations à très hauts débits. Avec une Densité Spectrale de Puissance (DSP) inférieure à -41. 3 dBm/MHz, les distances de propagation sont considérablement restreintes (< 20 m). C’est en février 2002, que la commission fédérale de communication des Etats-Unis (FCC) a alloué pour les systèmes ULB une bande de fréquence comprise entre 3,1 et 10,6 GHz. Depuis, de nombreuses divergences sont apparues suivant les grandes zones géographiques de normalisation. Au travers des nombreuses techniques de transmission ULB, nous étudions la modulation multi-bandes à répétition en fréquence orthogonale (MB-OFDM) qui a été proposée par l’European Computing Machineries Association (ECMA) en temps que standard en 2005. L’efficacité des signaux Impulsionnel Radio (IR), précurseur à l’ULB, a cependant été montrée. Nous présentons à ce titre une topologieDans le cadre de cette thèse, nous développons un outil de simulation système (SST) afin d’analyser les performances d’un système ULB-OFDM. Nous étudions l’influence sur le taux d’erreur binaire (BER) des non-linéarités du front-end de réception Radio-Fréquence (RF) et de l’amplification de puissance faible bruit (LNA) dans une chaîne de transmission globaleDans le cadre des systèmes MB-OOK, différents types de filtres sont envisagés. L’impact sur le BER est étudié afin de connaître les propriétés prédominantes des filtres sur les performances de transmission. Le domaine de l’optique peut également être avantageusement employé dans des processus de transmission ULB. Les réseaux larges bandes radio sur fibres (RoF) présentent de nombreux intérêts pour fournir à moindre coût la distribution du signal mais également la possibilité de pouvoir le traiter directement. Dans ce sens, Nous évaluons les possibilités de convertir fréquentiellement des signaux de type ULB-OFDM, ainsi que d’évaluer l’impact de transmetteurs Electrique/Optique (E/O) sur les performances d’un système ULB sur fibre à partir des valeurs du vecteur d’erreur d’amplitude (EVM)Ultra Wide Band (UWB) systems are a new wireless technology capable of transmitting high data rate over a wide frequency spectrum for short distances (< 20 m) for wireless applications. The Power Spectrum Density (PSD) of the emitted signals must be as low as -41. 3 dBm/MHz. In February 2002, the Federal Communication Commission (FCC) has allocated a band from 3. 1 to 10. 6 GHz for UWB communications. From that time, some differences appear depending on the country. Among all the various transmission techniques using UWB labelled modulations, we study the Multi-Band-Orthogonal Frequency Division Multiplexing (MB-OFDM) modulation which has been proposed by the European Computing Machineries Association (ECMA) in 2005. However, the efficiency of Impulse Radio (IR) was pointed out. In this way, an original topology known as Multi-Band On-Off Keying (MB-OOK) is also presented. In this thesis, we develop a System Simulation Tool (SST) to analyze the performances of UWB-OFDM system. The impact of the Radio-Frequency (RF) front-end and Low Noise Amplifier (LNA) non-linearity is studied on the Bit Error Rate (BER) of the overall receiver. In the MB-OOK transmission chain, different filters are introduced. BER is studied in order to know which properties of the filters have the main impact on the MB-OOK transmission performances. The optical domain can also be advantageously used to provide broadband optical UWB signal processing functions. Broadband Radio-over-Fiber (RoF) networks are raising great interest to provide both low cost optical intra-building distribution and signal processing of UWB signals. We investigate, from Error Vector Magnitude (EVM), optical transmission and frequency up-conversion of UWB-OFDM signals. In this proof of concept, a specific study is carried out to evaluate the capability to up-convert a MB-OFDM signal, and the impact of the Electronic/Optical (E/O) transceiver on the performance of the UWB-over-fiber system
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Coen, Christopher T. "Development and integration of silicon-germanium front-end electronics for active phased-array antennas." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48990.
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The research presented in this thesis leverages silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technology to develop microwave front-end electronics for active phased-array antennas. The highly integrated electronics will reduce costs and improve the feasibility of snow measurements from airborne and space-borne platforms. Chapter 1 presents the motivation of this research, focusing on the technological needs of snow measurement missions. The fundamentals and benefits of SiGe HBTs and phased-array antennas for these missions are discussed as well. Chapter 2 discusses SiGe power amplifier design considerations for radar systems. Basic power amplifier design concepts, power limitations in SiGe HBTs, and techniques for increasing the output power of SiGe HBT PAs are reviewed. Chapter 3 presents the design and characterization of a robust medium power X-band SiGe power amplifier for integration into a SiGe transmit/receive module. The PA design process applies the concepts presented in Chapter 2. A detailed investigation into measurement-to-simulation discrepancies is outlined as well. Chapter 4 discusses the development and characterization of a single-chip X-band SiGe T/R module for integration into a very thin, lightweight active phased array antenna panel. The system-on-package antenna combines the high performance and integration potential of SiGe technologies with advanced substrates and packaging techniques to develop a high performance scalable antenna panel using relatively low-cost materials and silicon-based electronics. The antenna panel presented in this chapter will enable airborne SCLP measurements and advance the technology towards an eventual space-based SCLP measurement instrument that will satisfy a critical Earth science need. Finally, Chapter 5 provides concluding remarks and discusses future research directions.
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Banerjee, Debashis. "Intelligent real-time environment and process adaptive radio frequency front-ends for ultra low power applications." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53882.
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In the thesis the design of process tolerant, use-aware radio-frequency front-ends were explored. First, the design of fuzzy logic and equation based controllers, which can adapt to multi-dimensional channel conditions, are proposed. Secondly, the thesis proves that adaptive systems can have multiple modes of operation depending upon the throughput requirements of the system. Two such modes were demonstrated: one optimizing the energy-per-bit (energy priority mode) and another achieving the lowest power consumption at the highest throughput (data priority mode). Finally, to achieve process tolerant channel adaptive operation a self-learning methodology is proposed which learns the optimal re-configuration setting for the system on-the-fly. Implications of the research are discussed and future avenues of further research are proposed.
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Kraemer, Michael M. "Design of a low-power 60 GHz transceiver front-end and behavioral modeling and implementation of its key building blocks in 65 nm CMOS." Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0027/document.
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La réglementation mondiale, pour des appareils de courte portée, permet l’utilisation sans licence de plusieurs Gigahertz de bande autour de 60 GHz. La bande des 60 GHz répond aux besoins des applications telles que les réseaux de capteurs très haut débit autonome en énergie,ou les transmissions à plusieurs Gbit/s avec des contraintes de consommation d’énergie. Il y a encore peu de temps, les interfaces radios fonctionnant dans la bande millimétrique n’étaient réalisables qu’en utilisant des technologies III-V couteuses. Aujourd’hui, les avancées des technologies CMOS nanométriques permettent la conception et la production en masse des circuits intégrées radiofréquences (RFIC) à faible coût.Cette thèse s’inscrit dans des travaux de recherches dédiés à la réalisation d’un système dans un boîtier (SiP, System in Package) à 60 GHz contenant à la fois l’interface radio (bande de base et circuits RF) ainsi qu’un réseau d’antennes. La première partie de cette thèse est dédiée la conception de la tête RF de l’émetteur-récepteur à faible consommation pour l’interface radio. Les blocs clefs de cette tête RF (amplificateurs, mélangeurs et un oscillateur commandé en tension) sont conçus, réalisés et mesurés en utilisant la technologie CMOS 65 nm de ST Microelectronics. Des éléments actifs et passifs sont développés spécifiquement pour l’utilisation au sein de ces blocs. Une étape importante vers l’intégration de la tête RF complète de l’émetteur-récepteur est l’assemblage de ces blocs de base afin de réaliser une puce émetteur et une puce récepteur. A ce but, une tête RF pour le récepteur a été réalisée. Ce circuit présent une consommation et un encombrement plus réduit que l’état de l’art.La deuxième partie de cette thèse présente le développement des modèles comportementaux des blocs de base conçus. Ces modèles au niveau système sont nécessaires afin de simuler le comportement du SIP, qui devient trop complexe si des modèles détaillés du niveau circuitsont utilisés. Dans cette thèse, une nouvelle technique modélisant le comportement en régime transitoire et régime permanent ainsi que le bruit de phase des oscillateurs commandés en tension est proposée. Ce modèle est implémenté dans le langage de description de matérielVHDL-AMS. La technique proposée utilise des réseaux de neurones artificiels pour approximer la caractéristique non linéaire du circuit. La dynamique est décrite dans l’espace d’état. Grâce à ce modèle, il est possible de réduire d’une façon drastique le temps de calcul des simulations système tout en conservant une excellente précisionWorldwide regulations for short range communication devices allow the unlicensed use of several Gigahertz of bandwidth in the frequency band around 60GHz. This 60GHz band is ideally suited for applications like very high data rate, energy-autonomous wireless sensor networks or Gbit/s multimedia links with low power constraints. Not long ago, radio interfaces that operate in the millimeter-wave frequency range could only be realized using expensive compound semiconductor technologies. Today, the latest sub-micron CMOS technologies can be used to design 60GHz radio frequency integrated circuits (RFICs)at very low cost in mass production. This thesis is part of an effort to realize a low power System in Package (SiP) including both the radio interface (with baseband and RF circuitry) and an antenna array to directly transmit and receive a 60GHz signal. The first part of this thesis deals with the design of the low power RF transceiver front-end for the radio interface. The key building blocks of this RF front-end (amplifiers, mixers and a voltage controlled oscillator (VCO)) are designed, realized and measured using the 65nm CMOS technology of ST Microelectronics. Full custom active and passive devices are developed for the use within these building blocks. An important step towards the full integration of the RF transceiver front-end is the assembly of these building blocks to form basic transmitter and receiver chips. Circuits with small chip size and low power consumption compared to the state of the art have been accomplished.The second part of this thesis concerns the development of behavioral models for the designed building blocks. These system level models are necessary to simulate the behavior of the entire SiP, which becomes too complex when using detailed circuit level models. In particular, a novel technique to model the transient, steady state and phase noise behavior of the VCO in the hardware description language VHDL-AMS is proposed and implemented. The model uses a state space description to describe the dynamic behavior of the VCO. Its nonlinearity is approximated by artificial neural networks. A drastic reduction of simulation time with respect to the circuit level model has been achieved, while at the same time maintaining a very high level of accuracy
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Abbasi, Mahdi. "Characterization of a 5GHz Modular Radio Frontend for WLAN Based on IEEE 802.11p." Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-3408.
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The number of vehicles has increased significantly in recent years, which causeshigh density in traffic and further problems like accidents and road congestions.A solution regarding to this problem is vehicle-to-vehicle communication, wherevehicles are able to communicate with their neighboring vehicles even in the absenceof a central base station, to provide safer and more efficient roads and toincrease passenger safety.The goal of this thesis is to investigate basic physical layer parameters of ainter-vehicle communication system, like emission power, spectral emission, errorvector magnitude, guard interval, ramp-up/down time, and third order interceptpoint. I also studied the intelligent transportation system’s channel layout inEurope, how the interference of other systems are working in co-channel and adjacentchannels, and some proposals to use the allocated frequency bands. On theother hand, the fundamentals of OFDM transmission and definitions of OFDMkey parameters in IEEE 802.11p are investigated.The focus of this work is on the measurement of transmitter frontend parametersof a new testbed designed and fabricated in order to be used at inter-vehiclecommunication based on IEEE 802.11p.
Road safety applications, Vehicle-to-Vehicle communication
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Mina, Rayan. "Etude des architectures échantillonnées de réception radio en technologies CMOS submicroniques avancées." Phd thesis, Télécom ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00005928.
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Avec l'arrivée des systèmes radio mobiles de troisième et de quatrième génération, les standards de communications ont tendance à occuper plus de bande pour pouvoir assurer des services de voix, de données et de multimédia. En parallèle, le terminal mobile doit être reconfigurable pour couvrir à la fois le service cellulaire et la connectivité de données. Dans ce contexte, la tendance est d'intégrer les fonctions radio et bandes de base sur le même substrat en utilisant la technologie CMOS afin de réduire la surface, le coût de fabrication et la consommation des terminaux sans fils. Récemment, de nouvelles architectures de réception radio dites " échantillonnées " sont apparues (TexasInstruments, STMicroelectronics, UCLA). Dans ce cas, l'échantillonnage est fait directement sur le signal RF et la majorité du traitement de signal se fait en temps-discret par des capacités commutées. L'évolution de la technologie CMOS et la miniaturisation des transistors rendent la conception analogique de plus en plus difficile (capacités parasites, bruit, linéarité, etc.). De nouveaux effets parasites apparaissent comme la fuite de grille qui inquiète désormais les technologues et les concepteurs de circuits. D'un autre côté, des contraintes de dynamique surgissent avec la diminution des tensions d'alimentation et le bruit des circuits numériques de plus en plus denses augmente considérablement. Le but de ce travail de thèse est de répondre à la question de la portabilité de la solution échantillonnée, en étudiant l'impact des différents effets parasites cités précédemment sur les performances radio de la solution. Ainsi, les critères de portabilité qui sont considérés sont la reconfigurabilité, l'immunité aux effets parasites, l'adaptation à la baisse des tensions d'alimentation, la surface, la consommation et la facilité de conception. Ce travail de thèse a été basé sur des études théoriques et sur des simulations d'une solution échantillonnée de réception radio. Afin d'affronter réellement les problématiques de portabilité, un portage d'une chaîne de réception échantillonnée Wi-Fi/WiMAX de CMOS 65nm à 45nm a été réalisé. Les résultats de mesures obtenus sur ce circuit donnent une grande confiance vis-à-vis des performances radio de la solution échantillonnée et constituent un premier élément de réponse concret à la question de portabilité étudiée.
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Kraemer, Michael. "Design of a low-power 60 GHz transceiver front-end and behavioral modeling and implementation of its key building blocks in 65 nm CMOS." Phd thesis, INSA de Toulouse, 2010. http://tel.archives-ouvertes.fr/tel-00554674.
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Worldwide regulations for short range communication devices allow the unlicensed use of several Gigahertz of bandwidth in the frequency band around 60 GHz. This 60GHz band is ideally suited for applications like very high data rate, energy-autonomous wireless sensor networks or Gbit/s multimedia links with low power constraints. Not long ago, radio interfaces that operate in the millimeter-wave frequency range could only be realized using expensive compound semiconductor technologies. Today, the latest sub-micron CMOS technologies can be used to design 60GHz radio frequency integrated circuits (RFICs) at very low cost in mass production. This thesis is part of an effort to realize a low power System in Package (SiP) including both the radio interface (with baseband and RF circuitry) and an antenna array to directly transmit and receive a 60GHz signal. The first part of this thesis deals with the design of the low power RF transceiver front-end for the radio interface. The key building blocks of this RF front-end (amplifiers, mixers and a voltage controlled oscillator (VCO)) are designed, realized and measured using the 65nm CMOS technology of ST Microelectronics. Full custom active and passive devices are developed and characterized for the use within these building blocks. An important step towards the full integration of the RF transceiver front-end is the assembly of these building blocks to form a basic receiver chip. Circuits with small chip size and low power consumption compared to the state of the art have been accomplished. The second part of this thesis concerns the development of behavioral models for the designed building blocks. These system level models are necessary to simulate the behavior of the entire SiP, which becomes too complex when using detailed circuit level models. In particular, a novel technique to model the transient, steady state and phase noise behavior of the VCO in the hardware description language VHDL-AMS is proposed and implemente d. The model uses a state space description to describe the dynamic behavior of the VCO. Its nonlinearity is approximated by artificial neural networks. A drastic reduction of simulation time with respect to the circuit level model has been achieved, while at the same time maintaining a very high level of accuracy.
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Perumana, Bevin George. "Low-power CMOS front-ends for wireless personal area networks." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/26712.
Full textAbstract:
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: Laskar, Joy; Committee Member: Chakraborty, Sudipto; Committee Member: Chang, Jae Joon; Committee Member: Divan, Deepakraj; Committee Member: Kornegay, Kevin; Committee Member: Tentzeris, Emmanouil. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Costa, Arthur Liraneto Torres. "Inductorless balun low-noise amplifier (LNA) for RF wideband application to IEEE 802.22." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/106442.
Full textAbstract:
Um novo circuito amplificador de 50 MHz - 1 GHz com alta linearidade para o padrão IEEE 802.22 “wireless regional area” (WRAN) é apresentado. Ele foi implementado sem nenhum indutor e oferece uma saída diferencial para ser utilizada como balun. Técnicas de cancelamento de ruído e aumento de linearidade foram usadas para melhorar a performace do amplificador de modo que eles pudessem ser otimizados separadamente. A linearidade foi melhorada utilizando transistores conectados como diodo. O amplificador foi implementado em um processo CMOS 130 nm, em uma área compacta de 136 m x 71 m. As simulações são apresentadas para esquemáticos pós-leiaute para duas classes diferentes de projeto: um visando a melhor linearidade e o outro a melhor Figura de Ruído (FR). Quando otimizado para melhor linearidade, os resultados de simulação atingem um ganho de tensão > 23.7 dB (ganho de potência > 19.1 dB), uma figura de ruído < 3.6 dB na banda inteira (com 2.4 dB min), um ponto de intersecção de terceira ordem (IIP3) > 3.3 dBm (7.6 dBm max) e um coeficiente de reflexão de entrada S11 < -16 dB. Quando otimizado para melhor figura de ruído, ele atinge um ganho de tensão > 24.7 dB (ganho de potência > 19.8 dB), uma FR < 2 dB na banda inteira, um IIP3 > -0.3 dBm e um S11 < -11 dB. Resultados de simulação Monte Carlo confirmam baixa sensibilidade à variabilidade de processo. Além disso, uma baixa sensibilidade com a temperatura na faixa de -55 até 125 C foi observada para Ganho, FR e S11. Consumo de potência é 17.6 mA sob fonte de alimentação de 1.2 V.A new 50 MHz - 1 GHz low-noise amplifier circuit with high linearity for IEEE 802.22 wireless regional area network (WRAN) is presented. It was implemented without any inductor and offers a differential output for balun use. Noise cancelling and linearity boosting techniques were used to improve the amplifier performance in a way they can be separately optimized. Linearity was improved using diode-connected transistors. The amplifier was implemented in a 130 nm CMOS process in a compact 136 m x 71 m area. Simulations are presented for post-layout schematics for two classes of design: one for best linearity, another for best noise figure (NF). When optimized for best linearity, simulation results achieve a voltage gain > 23.7 dB (power gain > 19.1 dB), a NF < 3.6 dB over the entire band (with 2.4 dB min figure), an input third-order intercept point (IIP3) > 3.3 dBm (7.6 dBm max.) and an input power reflection coefficient S11 < -16 dB. When optimized for best NF, it achieves a voltage gain > 24.7 dB (power gain > 19.8 dB), a NF < 2 dB over the entire band, an IIP3 > -0.3 dBm and an S11 < -11 dB. Monte Carlo simulation results confirm low sensitivity to process variations. Also a low sensitivity to temperature within the range -55 to 125 C was observed for Gain, NF and S11. Power consumption is 17.6 mA under a 1.2 V supply.
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Mailand, Marko. "Systemanalyse und Entwicklung Six-Port basierter Funkempfängerarchitekturen unter Berücksichtigung analoger Störeffekte." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1199900991755-90088.
Full textAbstract:
Due to the increasing demand of broadband capability and reconfigurability for mobile applications, there is an enormous interest to develop appropriate analog receiver front-ends. In this respect, one promising candidate group is the Six-Port-based direct conversion receiver. The presented work focuses on the investigation of Six-Port-based mobile receiver front-ends with their specific systematical signal processing. Thereby, issues of spurious interfering signals which are generated within the down conversion process of such receivers are of special interest. Based on a comprehensive description of the analog signal processing within additive frequency conversion, a reason could be identified why existing Six-Port receivers have not found any practical application in mobile communication yet – the dynamic DC-offset. With this insight compensation techniques were developed to overcome the negative influences of the dynamic DC-offset. Furthermore, this work presents novel Six-Port-based receiver architectures which, on the one hand, keep the advantages of additive mixing systems like: low power consumption, broadband capability and simplicity of implementation especially for mm-wave transmissions. On the other hand, these novel architectures comprise compensation techniques such that systematically generated spurious signals are inherently compensated in the analog part of the receiver. Moreover, the influence of impairments of phase and amplitude within the IQ-branches of a receiver was investigated. The resulting, unwanted IQ-imbalance was shown to be a mixing method (multiplicative or additive) independent spurious effect. It is suggested to compensate for IQ-imbalance in the digital part of the receiver system. This can be realized with the use of adaptive algorithms. The comparison with conventional analog receiver architectures (especially homodyne receivers) with respect to the reception of today’s and future digitally modulated transmission signals indicate the proposed Six-Port-based receiver architectures to be suitable candidates to fulfill the difficult tasks of modern mobile communication.
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Cordova, Vivas David Javier. "Design of CMOS active downconversion mixers for gigahertz multi-band and multiple-standard operation." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/117761.
Full textAbstract:
Os requisitos de linearidade e ruído em aplicações multi-banda e multi-protocolo fazem que o projeto de misturadores RF seja uma tarefa muito desafiadora. Nesta dissertação dois misturadores com base na topologia célula de Gilbert são propostas. Linearidade e ruído foram as principais figuras de mérito consideradas para o misturadores propostos. Para aumento linearidade, foi utilizada uma técnica de cancelamento de harmônicas pós-distorção (PDHC). E, para redução de ruído, foi utilizado um circuito de redução dinâmica de corrente combinada com um filtro LC sintonizado na frequência do LO e cancelamento de ruído térmico. A análise por séries Volterra do estágio transcondutância do misturador proposto é reportada para mostrar a eficácia da técnica de cancelamento de harmônicos com pósdistorção. O circuito de linearização adicionado não aumenta o tamanho do misturador, nem degrada ganho de conversão, figura de ruído, ou consumo de potência. Simulações elétricas foram realizadas em nível de pós-layout para a primeira topologia e nível esquemático para a segunda topologia, usando processo CMOS de 0.13 mm da IBM. As melhorias em IIP2 e IIP3 são apresentadas em comparação com o misturador do tipo célula de Gilbert convencional. Para a primeira topologia, foi obtido um ganho de conversão de 10.2 dB com uma NF de 12 dB para o misturador projetado funcionando a 2 GHz, com uma frequência intermediária de 500 kHz. E um IIP2 e IIP3 de 55 dBm e 10.9 dBm, respectivamente, consumindo apenas 5.3 mW de uma fonte de 1.2 V. Para a segunda topologia, foram obtidos um ganho de conversão de [13.8 ~11] dB, um coeficiente de reflexão na entrada (S11) de [-18 ~-9.5] dB e um NF de [8.5 ~11] dB no intervalo de 1 a 6 GHz. Para as especificações de linearidade, um valor médio de IIP3 de 0 dBm foi alcançado para toda a faixa de frequência, consumindo 19.3 mW a partir de uma fonte de 1.2 V. Especificações adequadas para operação multi-banda e multi-protocolo.The linearity and noise requirements in multi-band multi-standard applications make the design of RF CMOS mixers a very challenging task. In this dissertation two downconversion mixers based on the Gilbert-cell topology are proposed. Linearity and noise were the principal figures of merit for the proposed mixers. For linearity improvement, post distortion harmonic cancellation (PDHC) was employed. And, for noise reduction, dynamic current injection combined with an LC filter tuned at the LO frequency and thermal-noise cancellation were used. A Volterra series analysis of the transconductance stage is reported to show the effectiveness of the post-distortion harmonic cancellation technique. The added linearization circuitry does not increase the size of the mixer, nor does it degrade conversion gain, noise figure, or power consumption. Electrical simulations were performed on extracted layout level from the first topology and schematic level from the second topology. Using an IBM 0.13 mm CMOS process improvements on IIP3 and IIP2 in comparison to the conventional Gilbert-cell mixer are demonstrated. For the first topology, we achieved a conversion gain of 10.2 dB with a NF of 12 dB for the designed mixer working at 2 GHz, with a low-IF of 500 kHz and an IIP2 and IIP3 of 55 dBm and 10.9 dBm, respectively, while consuming only 5.3 mW from a 1.2 V supply. For the second topology, we achieved a conversion gain range of [13.8 ~11] dB, an input reflection coefficient (S11) of [-18 ~-9.5] dB and a NF of [8.5 ~11] dB in the frequency range of 1 to 6 GHz. For the linearity specs, an IIP3 of 0 dBm was achieved for the whole frequency range, while consuming 19.3 mW from a 1.2 V supply, making the second topology well suited for multi-band and multi-standard operation.
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Mailand, Marko. "Systemanalyse und Entwicklung Six-Port basierter Funkempfängerarchitekturen unter Berücksichtigung analoger Störeffekte." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A24036.
Full textAbstract:
Due to the increasing demand of broadband capability and reconfigurability for mobile applications, there is an enormous interest to develop appropriate analog receiver front-ends. In this respect, one promising candidate group is the Six-Port-based direct conversion receiver. The presented work focuses on the investigation of Six-Port-based mobile receiver front-ends with their specific systematical signal processing. Thereby, issues of spurious interfering signals which are generated within the down conversion process of such receivers are of special interest. Based on a comprehensive description of the analog signal processing within additive frequency conversion, a reason could be identified why existing Six-Port receivers have not found any practical application in mobile communication yet – the dynamic DC-offset. With this insight compensation techniques were developed to overcome the negative influences of the dynamic DC-offset. Furthermore, this work presents novel Six-Port-based receiver architectures which, on the one hand, keep the advantages of additive mixing systems like: low power consumption, broadband capability and simplicity of implementation especially for mm-wave transmissions. On the other hand, these novel architectures comprise compensation techniques such that systematically generated spurious signals are inherently compensated in the analog part of the receiver. Moreover, the influence of impairments of phase and amplitude within the IQ-branches of a receiver was investigated. The resulting, unwanted IQ-imbalance was shown to be a mixing method (multiplicative or additive) independent spurious effect. It is suggested to compensate for IQ-imbalance in the digital part of the receiver system. This can be realized with the use of adaptive algorithms. The comparison with conventional analog receiver architectures (especially homodyne receivers) with respect to the reception of today’s and future digitally modulated transmission signals indicate the proposed Six-Port-based receiver architectures to be suitable candidates to fulfill the difficult tasks of modern mobile communication.