Dissertations / Theses on the topic 'Half-wave and full-wave rectifier'

This master’s thesis deals with half-wave and full-wave rectifiers and instrumentation amplifier design in CMOS technology, suitable for biomedical signal processing. Properties of optional solutions are analyzed and appropriate circuits are designed. Their functionality is verified with simulation. Designed circuits are then used to form a circuit converting differential input voltage into rectified output current.

In recent years, both a significant increase in electrical demand and a large influx of intermittent renewable energy sources have put a considerable stress on the nation’s electrical grid. Conventional power flow control techniques such as capacitor banks and tap-changing transformers are incapable of adequately handling the rapid fluctuations in power supply and demand that today’s grid experiences. Flexible AC Transmission System (FACTS) controllers are a practical way to compensate for such rapid power fluctuations. One type of shunt FACTS controller is the Static Synchronous Compensator (STATCOM), which uses fully controllable switches to source or sink reactive power to a point on the grid, thus reducing voltage fluctuations due to load changes. The purpose of this thesis is to model and simulate the operation of two Distribution STATCOMs (D-STATCOMs) operating on the same point on the grid. These D-STATCOMs also utilize parallel full-wave rectifiers that directly connect the ac grid to the dc capacitor of the D-STATCOMs. Parameters such as power loss, reaction time, stability, and THD are measured for several test scenarios. Results from this thesis show that two D-STATCOMs operating on the same point can be stable and effective under a wide range of conditions. This thesis also concludes that the inclusion of parallel rectifiers with the D-STATCOMs results in no performance improvement of the D-STATCOMs.

In this thesis
analysis, design and implementation of a DC-DC converter with active clamp forward topology is presented. The main objective of this thesis is generating a rectified sinusoidal voltage at the output of the converter. This is accomplished by changing the reference signal of the converter. The converter output is applied to an inverter circuit in order to obtain sinusoidal waveform. The zero crossing points of the converter is detected and the inverter drive signals are generated in order to obtain sinusoidal waveform from the output of the converter. Next, the operation of the DC-DC converter and sinusoidal output inverter coupled performance is investigated with resistive and inductive loads to find out how the proposed topology performs. The design is implemented with an experimental set-up and steady state and dynamic performance of the designed power supply is tested. Finally an evaluation of how better performance can be obtained from this kind of arrangement to obtain a sinusoidal output inverted is thoroughly discussed

Wave power is an energy source which could make a decisive difference in thetransition towards a more sustainable energy sector. The growth of wave powerproduction has however not been as rapid as the growth in other renewableenergy fields, such as wind power and solar power. Some technical obstaclesremain before a major breakthrough for wave power can be expected. Oneobstacle so far has been the low voltages and the resulting high power lossesin many wave power plants. A new type of wave power generator, which hasbeen invented by Anders Hagnestål at KTH in Stockholm, aims to solve theseproblems. This master’s thesis deals with the power electronic converter systemfor Anders Hagnestål’s generator. It describes the planning and constructionprocess for a single-phase AC/DC converter, which will eventually be a partof the larger converter system for the generator. A control system based onhysteresis current control is planned and assembled. The finished single-phaseconverter shows agreeable results working as an inverter, generating a distinctlysinusoidal AC voltage. However, some additional construction and calibrationin the digital control system remain, before the converter can be used in thepower conversion for a wave power plant.
Vågkraft är en energikälla som skulle kunna göra en avgörande skillnad i omställningenmot en hållbar energisektor. Tillväxten för vågkraft har dock intevarit lika snabb som tillväxten för andra förnybara energislag, såsom vindkraftoch solkraft. Vissa tekniska hinder kvarstår innan ett stort genombrott för vågkraftkan bli möjligt. Ett hinder fram tills nu har varit de låga spänningarna ochde resulterande höga effektförlusterna i många vågkraftverk. En ny typ av vågkraftsgenerator,som har tagits fram av Anders Hagnestål vid KTH i Stockholm,avser att lösa dessa problem. I det här examensarbetet behandlas det effektelektroniskaomvandlingssystemet för Anders Hagneståls generator. Det beskriverplanerings- och konstruktionsprocessen för en enfasig AC/DC-omvandlare, somså småningom skall bli en del av det större omvandlingssystemet för generatorn.Ett kontrollsystem för omvandlaren, baserat på hystereskontroll för strömmen,planeras och sätts ihop. Den färdiga enfasomvandlaren visar goda resultat underdrift som växelriktare. Dock kvarstår visst konstruktionsarbete och viss kalibreringav det digitala kontrollsystemet innan omvandlaren kan användas för sinuppgift i effektomvandlingen hos vågkraftverket.

Wave energy converter (WEC) harnesses energy from the ocean to produce electrical power. The electrical power produced by the WEC is fluctuating and is not maximized as well, due to the varying ocean conditions. As a consequence, without any intermediate power conversion stage, the output power from the WEC can not be fed into the grid. To feed WEC output power into the grid, a two-stage power conversion topology is used, where the WEC output power is first converted into DCpower through rectification, and then a DC-AC converter (inverter) is used to supply AC power into the grid. The main motive of this research is to extract maximum electrical power from the WEC by active rectification and smoothing the power fluctuation of the wave energy converter through a hybrid energy storage system consisting of battery and flywheel. This research also illustrates active and reactive power injection to the grid according to load demand through a voltage source inverter.

Direct drive wave energy conversion systems have been identified as a potentially major contributor to the world’s energy demands, forecasting shares of up to 25 % of the energy mix. Anders Hagnestål conducts research at the Royal Institute of Technology where a novel linear transverse flux permanent magnet generator is developed. This concept machine is particularly well-suited for the pertaining operating conditions in marine environments, producing large forces at low speeds with outstandingly low resistive losses. However, it exhibits severe magnetic saturation and draws unsymmetrical phase currents at nominal operation. In addition, it possesses a low power factor. All in all, this places stern requirements on the power electronic system and control algorithms. The aim of this thesis has been to design a functioning power conditioning system that connects the machine to the electric grid. For this purpose, a three-phase two-level voltage source converter is proposed to be back-to-back connected with two-level single-phase voltage source converters (active rectifiers) interfacing each and every machine phase. It is shown that the intermediate DC link can be maintained at a constant voltage with restricted ripple while feeding power at unity power factor to the grid by appropriately sizing the DC capacitor and adopting a feedback linearization control scheme. The phase currents can be controlled effectively by means of a cascaded gain-scheduled PID controller. By including a low-pass filter the iron losses in the machine may be suppressed even at lower switching frequencies. A constrained cost optimization indicates that the converter consequently can reach 99.1 % efficiency. Finally, with this thesis as a background, it is suggested that the thermal stresses on the selected semiconductor modules and the iron losses of the machine are evaluated to further improve the design. If higher efficiency of the active rectifiers is strived for, more complex converter topologies could be considered.
Direktdrivna vågenergiomvandlingssystem har utpekats som en potentiellt starkt bidragande resurs för att tillgodose världens efterfrågan på energi med andelar på uppemot 25 % av energimixen förutspådda. Anders Hagnestål bedriver forskning och utveckling av en ny typ av linjär permanentmagnetiserad transversalflödesmaskin vid Kungliga Tekniska Högskolan. Konceptmaskinen är särskilt väl lämpad för de rådande marina förhållandena genom att kunna producera stora krafter vid låga hastigheter med utomordentligt låga resistiva förluster. Maskinen går emellertid i kraftig magnetisk mättnad och drar asymmetriska strömmar vid nominell drift. Dessutom är effektfaktorn låg i jämförelse med standardmaskiner. Alltsomallt inför detta hårda krav på det effektelektroniska systemet och kontrollalgoritmerna. Målet med detta examensarbete har varit att designa ett funktionellt effektkonditioneringssystem som sammanfogar maskinen med det angränsande elektriska nätet. För att åstadkomma detta föreslås att en tvånivås-trefasomriktare kopplas rygg-mot-rygg till tvånivås-enfasomvandlare (aktiva likriktare) som i sin tur är kopplade till varje maskinfas. Med den här konfigurationen visas det att spänningen på den mellanliggande DC-länken kan hållas konstant med begränsat rippel, alltmedan effekt tillförs nätet vid effektfaktor ett genom att dimensionera DC-kondensatorn på rätt sätt och använda en kontrollag baserad på exakt linjärisering. Maskinens fasströmmar kan kontrolleras effektivt med hjälp av en kaskadkopplad PID-regulator med schemalagda förstärkningsfaktorer. Genom att inkludera ett lågpassfilter förväntas det att järnförlusterna i maskinen kan begränsas även vid lägre switchfrekvenser. Genom att lösa ett kostnadsoptimeringsproblem visas det att den resulterande aktiva likriktaren kan uppnå en verkningsgrad på 99.1 %. Slutligen, med det här examensarbetet som grund, föreslås det att den termiska stressen på de valda halvledarkomponentsmodulerna och järnförlusterna i maskinen utvärderas för att ytterligare förbättra designen. Om högre verkningsgrad eftersträvas hos de aktiva likriktarna kan mer komplicerade omvandlartopologier övervägas.

Vibration control is a large branch in control research, because all moving systems may induce desired or undesired vibration. Due to the limitation of passive system's adaptability and changing excitation input, vibration control brings the solution to change system dynamic with desired behavior to fulfill control targets. According to preference, vibration control can be separated into two categories: vibration reduction and vibration amplification. Lots of research papers only examine one aspect in vibration control. The thesis investigates the control development for both control targets with two different control applications: vehicle suspension and ocean wave energy converter. It develops control methods for both systems with simplified modeling setup, then followed by the application of a novel mechanical motion rectifier (MMR) gearbox that uses mechanical one-way clutches in both systems. The flow is from the control for common system to the control design for a specifically designed system. In the thesis, active (model predictive control: MPC), semi-active (Skyhook, skyhook-power driven damper: SH-PDD, hybrid model predictive control: HMPC), and passive control (Latching Control) methods are developed for different applications or control performance comparison on single system. The thesis also studies about new type of system with switching mechanism, in which other papers do not talk too much and possible control research direction to deal with such complicated system in vibration control. The state-space modeling for both systems are provided in the thesis with detailed model of the MMR gearbox. From the simulation, it can be shown that in the vehicle suspension application, the controlled MMR gearbox can be effective in improving vehicle ride comfort by 29.2% compared to that of the traditional hydraulic suspension. In the ocean wave energy converter, the controlled MMR WEC with simple latching control can improve the power generation by 57% compared to the passive MMR WEC. Besides, the passive MMR WEC also shows its advantage on the passive direct drive WEC in power generation improvement. From the control development flow for the MMR system, the limitation of the MMR gearbox is also identified, which introduces the future work in developing active-MMR gearbox by using an electromagnetic clutch. Some possible control development directions on the active-MMR is also mentioned at the end of the thesis to provide reference for future works.
Master of Science
Vibration happens in our daily life in almost all cases. It is a regular or irregular back and forth motion of particles. For example, when we start a vehicle, the engine will do circular motion to drive the wheel, which causes vibration and we feel wave pulses on our body when we sit in the car. However, this kind of vibration is undesirable, since it makes us uncomfortable. The car manufacture designs cushion seats to absorb vibration. This is a way to use hardware to control vibration. However, this is not enough. When vehicle goes through bumps, we do have suspension to absorb vibration transferred from road to our body. The car still experiences a big shock that makes us feel dizzy. On the opposite direction, in some cases when vibration becomes the motion source for energy harvesting, we would like to enhance it. Hardware can be helpful, since by tuning some parameters of an energy harvesting device, it can match with the vibration source to maximize vibration. However, it is still not enough due to low adaptability of a fixed parameter system. To overcome the limitation of hardware, researches begin to think about the way to control vibration, which is the method to change system behavior by using real-time adjustable hardware. By introducing vibration control, the theory behind that started to be investigated. This thesis investigates the vibration control theory application in both cases: vibration reduction and vibration enhancement, which are mentioned above due to opposite application preferences. There are two major applications of vibration control: vehicle suspension control and ocean wave energy converter (WEC) control. The thesis starts from the control development for both fields with general modeling criteria, then followed by control development with specific hardware design-mechanical motion rectifier (MMR) gearbox-applied on both systems. The MMR gearbox is the researcher designed hardware that targets on vibration adjustment with hardware capability, which is similar as the cushion seats mentioned at the beginning of the abstract. However, the MMR cannot have capability to furtherly optimize system vibration, which introduces the necessity of control development based on the existing hardware. In the suspension control application, the control strategy introduced successfully improve the vehicle ride comfort by 29.2%, which means the vehicle body acceleration has been reduced furtherly to let passenger feel less vibration. In the WEC application, the power absorbed from wave has been improved by 57% by applying suitable control strategy. The performance of improvement on vibration control has proved the effect on further vibration optimization beyond hardware limitation.

This work discusses about nowadays problematic of the electronic comutation motors.This work also describes the opportunity of electronic control of these motors. The result of this work is realization of electronic control circuit from discreet components. There also are mentioned is proposal of electronic control board from SMD components. This control board include temperature control with ventilator switching , commutation logic, PWM speed control. In the last part of this paper are results of evaluation measurements of EC motor.

碩士
中原大學
電子工程研究所
93
The thesis is to discuss with the design of precision full-wave and half-wave rectifiers using OTAs（ Operation Transconductance Amplifiers ）. This paper will introduce the characteristic of the active OTA current-mode analog integrated circuit, and discuss the marking of OTA’s circuit structure. The OTA is designed by N-MOSFET and P-MOSFET of TSMC 0.35μm CMOS technology. Then, the output of the OTA is connected to the rectifier, thus forming rectified current waveform at the output of the rectifier. Then, through the output resistor RL, the current waveform is transformed into voltage waveform. In this paper, the design of positive and negative half-wave rectifier uses one OTA, and the design of positive and negative full-wave rectifier uses two OTAs. In the design of the full-wave rectifier, BOTA ( Bidirectional Operational Transconductance Amplifier ) can also be used to represent the equivalent circuit of such rectifier. The diodes used by the full-wave and half-wave rectifier also belongs to TSMC 0.35μm CMOS technology. Throughout the experiment, the H-spice is used to simulate the output waveform to confirm the waveform theory.

碩士
國立臺灣科技大學
電機工程系
102
Asymmetrical half-bridge converter (AHB) features ZVS operating under wide line and load ranges so that it is suitable for high frequency and high input voltage power conversion applications. An alternative half-wave rectifier is introduced instead and an asymmetrical half-bridge converter with half-wave rectifier (AHB-HWR) is proposed in this thesis. However, the AHB has pulsating input current waveform, that associated to the EMI problem. There are several ripple reduction converters have been proposed in the literatures. The built-in input filter is obtained by using current ripple cancellation mechanism. To employ this mechanism, therefore, an input current ripple reduction asymmetrical half-bridge converter with half-wave rectifier (RRAHB-HWR) is proposed. Furthermore, two proposed converters with same specifications 300V-400V input and 24V/10A output are analyzed implemented and tested to demonstrate their feasibilities.

碩士
中原大學
電子工程研究所
99
This paper presents an OPA-based precision full-wave rectifier without loading effect. The circuit consists of two operational amplifiers, two diodes and few passive elements. This circuit uses few elements, and is capable of giving amplified output and has high input impedance and low output impedance. The mentioned circuit has the resistance-matching problem. We can solve this problem by applying the precision resistors. HSPICE simulation and the experiment results are in good agreement with the theoretical analysis.

碩士
國立臺灣科技大學
電機工程系
102
An asymmetric push-pull converter with half-wave rectifier is proposed for wide input range applications. The proposed converter not only has zero-voltage switching operation on the MOSFETs, but also has zero-current switching on the rectifier diodes. Moreover, it has larger voltage gain and the rectifier diodes have no voltage spike. These characteristics make it suitable for high frequency, high efficiency, and wide input voltage power conversion applications. In addition to the descriptions of the operation principle, theoretical analysis and design considerations, one-stage and two-stage converters with 24~132-V input and 14.5 V/145 W output specifications are implemented and tested.

碩士
明志科技大學
機電工程研究所
100
LED is well expected for lighting thanks to the energy-saving and environmental pollution-free of the LED light source. The commercial LED light sources are drived by driver composed of constant current IC, electrolytic capacitor and resistance as well as the AC/DC transformer. The cost of the driver is about 15 to 20 % of a whole LED light source. Moreover, the electrolytic capacitors used within the driver would shorten the life of LED lighting source. In this study, a full-wave bridge rectifier composed by LEDs is developed for directly driving the LED light source without electrolytic capacitor. Four schemes of the LED light bulb sources are derived and then tested for its electrical and optical properties. The comparison of the developed LED bulb light sources and the commercial ones are taken finally. The pulse waveform of the DC is formed by the LED composed bridge full-wave rectifier. The theoretical voltage ripple and ripple factor of this bridge full-wave rectifier can be derived. The bridge full-wave rectifier is built by the 24 pieces of LED and then connected to the parallel strings. Each string has 30 pieces of LED. Results show that the luminous flux of each LED within the bridge full-wave rectifier is 3.6 (lm), while the one in the 30 pieces of LED is 4.9 (lm). The scattering structure of the plastic cover may reduce the luminous flux of 17%. Besides, the efficiency and luminous flux of the cool white LED bulbs light source with the scattering plastic cover are 82 (lm/W) and 328 (lm), respectively. A 7W bulb light source composed by 5630 LEDs is driven under constant current situation by LM 317 IC. The constant current is obtained successfully by varying of the input AC voltage. This study shows well in development of the non-isolated driver without electrolytic capacitor for LED bulbs light source. The contribution of this study is therefore concrete.

碩士
崑山科技大學
電機工程研究所
101
Most electronic circuits and devices need the supply of direct current source. However, generally, the energy transmitted by electric power companies to users is alternating current（as far as Taiwan region is concerned, that is AC 110V/ 60Hz）. So, according to circuit demand, most users have to get suitable voltage supply through the step-down and boost of transformer.Through the transition of transformer, actually, alternating current has to pass two steps of rectifier and filter, then users can get direct current source. The thesis mainly uses analog circuit to finish the analysis of Power Factor and Total Harmonic Distortion of single-phase full-wave rectifier, using the advantages of full-wave rectifier, such as small ripple and less quantity of elements, to make AC/DC conversion. In addition, the thesis also analyzes the impact of different capacitance values on power factor and current harmonics. Finally, experiment results are used to verify the feasibility of system and theory suggested by the thesis. In the course of verification, comparison ismade between experiment data and IEEE/Std 519-1992 harmonic standards.

博士
國立臺灣科技大學
電子工程系
88
This dissertation presents analysis, design, and implementation of two novel rectifier and inverter for the uninterruptible power system (UPS). A full-wave boost rectifier (FWBR) realized by zero-current-switching pulse-width-modulation (ZCS-PWM) control to achieve unity power factor is presented as the front end use in UPS. Two resonant cells are configured in the presented FWBR to perform ZCS in the power switches and to pre-regulate the input current to follow up the input voltage. Only one diode and one power switch losses are included in the proposed FWBR during the rectification. Four transition states for describing the behavior of the ZCS-PWM FWBR in one switching period are described. A small-signal model is built for the system analysis by PWM-switch modeling method and state-space average technique, and an average-current-mode control is employed to formulate the input current waveform with low harmonics. The control strategy and design consideration are programmed to realize a 1000W ZCS-PWM FWBR, which provides high power efficiency of 95% and high power factor over 0.99. A DC/AC inverter without cycloconversion configured by a half-bridge series-resonant inversion (HB-SRI) is presented as the main system of the UPS. The inverter is operated in the mode of parallel-loaded series-resonance with a LC resonant tank. Two auxiliary switches are in parallel across the resonant capacitor so as to adaptively configure the load driving loop for impedance drives. The synthesized sinusoidal voltage is composed of equal-amplitude quasi-sinusoidal pulses (QSPs) and its corresponding current is with adaptively phase-shifting to the impedance load. The presented HB-SRI is driven by frequency modulation with constant-on time control. System modeling and mathematical analysis are clearly conducted. A typical design example of 500W HB-SRI inverter is examined. Simulation and experimental results are so close to each other. The power efficiency is over 90% for the output power above 200W and the total harmonic distortion (THD) for various impedance loads is within 5%.

碩士
國立中山大學
電機工程學系研究所
104
This thesis proposes a novel bi-directional full-wave rectifier with higher step-up and step-down voltage ratio which can be used in renewable energy generation systems. The low-voltage side of this circuit is full-bridge topology, combined with transformer, and the high-voltage side is composed of two full-wave rectifier circuits to construct a four times voltage multiplier rectifier. In the boost mode, the power switches of low-voltage side are driving by phase-shift control to reduce the stresses on the power switches. Meanwhile, the Time Division Multiplex (TDM) control strategy is used to transfer energy from the output rectifier diodes to the output capacitors at different time intervals. TDM control strategy can reduce voltage stress of the output capacitors and rectifier diodes. The voltages of output capacitors can almost achieve equalizing voltage. The four times output voltage can then be realized due to the superposition of the output capacitor voltages. In buck mode, the different capacitors based on TDM control strategy can release energy to load in different time intervals. All capacitor voltages in the buck mode are also almost same. A novel bi-directional full-bridge full-wave rectifier with higher step-up and step-down voltage ratio is implemented in this thesis. The specifications for the boost and buck modes are 24V DC input, 200V DC output, and rated power 100W and 200V DC input, 24V DC output, and rated power 100W, respectively. Experimental results show that the bi-directional functionality of the proposed circuit can be achieved. Besides, the conversion efficiency for both boost and buck modes is above 86%. Experimental and simulated results also indicate that the voltage stresses of output capacitors and rectifier diodes in the proposed four times voltage multiplier rectifier is less than the conventional half-wave or full-wave rectifiers. Therefore, the proposed bi-directional circuit has great potential to be used in the converters of renewable energy generation systems requiring higher step-up and step-down voltage ratio.

A new generation of electronic devices has emerged requiring micro-watt-level power supply to operate. Thanks to micro-power processors and sensors, micro-power sources have become an attractive option for industry and research. This work is interested in micro-power sources that harvest vibrational energy by deploying electrostatic, electromagnetic, and piezoelectric transduction techniques. The output power of vibrational energy harvesters is in AC form, whereas electronic loads require known DC power supply to operate. Thus, there is a need for AC-DC conversion between harvesters and electronic loads to get DC power out of AC. Traditional full-wave bridge rectifiers and center-tapped transformer rectifiers are not feasible in micro-watt-level harvesters. Low output power undermines the power efficiency of those traditional rectifiers. Thus, novel, low power, high efficiency conversion circuits are required instead of traditional rectifiers. This goal is particularly challenging when it comes to electromagnetic energy harvesters since their output voltage is much lower than that of electrostatic and piezoelectric harvesters. In this work, we studied four different full-wave rectifiers; a silicon diode bridge rectifier, a Schottky diode bridge rectifier, a passive MOSFET rectifier, an an active MOSFET rectifier. Out of simulation results, we found the voltage and power efficiency of each rectifier. We found that MOSFET-type rectifiers are better than diode type rectifiers in terms of voltage and power efficiency. Both full-wave MOSFET rectifiers have about 99% voltage and power efficiency. There is only a small difference in power and voltage efficiency between the two MOSFET rectifier types below 600mV input voltage amplitude. Since active MOSFET rectifier has extra components and need of external DC supply to power its active devices, we concluded it was not good option for small scale harvester systems. We implemented the passive MOSFET rectifier, tested its performance in rectifying the output of an electromagnetic harvester, and analyzed its effects on the harvester performance. When we connected the MOSFET rectifier to the harvester it doubled the optimum load resistance from 24 Ohm to 48 Ohm. We also studied the rectifier effect on harvester's natural frequency, and it does not change much the natural frequency which means our rectifier acts like resistance, and we also calculated the power efficiency based on harvester test and we have maximum 74% power efficiency.

碩士
國立交通大學
電機學院電信學程
107
This thesis studies the design of half-wave and full-wave rectennas for 900MHz~2.4GHz wireless power transfer. The overall system consists of: (1) PIFA antenna, (2) RF energy-to-DC power supply circuit consisted of balanced and unbalanced converter, matching network, half-wave and full-wave rectifier circuit and RF Schottky diode, and (3) DC-TO-DC charge-pump boost circuit. Experimental results show that the overall system developed can reach a dc output of 8.48V (without antenna) at 2.45GHz. With a load resistance of 470Ω and an injected power of 12dBm, the peak conversion efficiency is 88.24% with antenna and 85.75% without antenna. The 900MHz dc voltage output can reach up to 8.41V (without antenna). With a load resistance is 470Ω and an injected power of 12dBm, the peak conversion efficiency is 89% with antenna and 79.32% without antenna.

碩士
國立臺北科技大學
電腦與通訊研究所
100
In this thesis, circularly polarized(CP) half&full wave double voltage rectenna for the applications of wireless power transmission has been studied. This study includes: 1. Design of a circularly polarized wide-slot antenna which can reduce the multi-path fading efficiently and solve the depolarization effect of random polarization in free space and complicate environment. 2. Design of the balun and matching network by using the chip components. Through the balun to make unbalanced signals transfer into balanced signals, then the positive or negative signals could totally performed on back-end circuit. It can not only achieve the impedance matching between the receiver antenna and voltage-doubler rectifier, but also suppress the higher order harmonics efficiently. 3. Design of the voltage-doubler rectifying circuit. A RF schottky barrier diode suitable for the current specification and the requirement for design of the voltage-doubler rectifying circuit is selected as a rectifying device of the circuit to increase the output DC voltage and RF-to-DC conversion efficiency. The proposed design of circular polarized slot antenna, balun, matching network and the half/full wave double voltage rectifier which exhibit bandwidth and axial ratio bandwidth are following the specification of IEEE 802.11b (2.4~2.485 GHz). The result of the antenna gain is about 2.2~3.2 dBi. With the present design, a maximum voltage of 8.15 V and a conversion efficiency of 81 % colud be attainable.

碩士
國立交通大學
電子工程學系 電子研究所
103
Radio-Frequency identification (RFID) system is a well-developed technique and is everywhere is our daily life, such as campus IC cards, access cards, electronic toll collection, etc. Efforts have been made mainly on a RFID tag IC design since the size of a tag directly determines the variety of RFID applications. Current RFID tag has large physical size due to the off-chip antenna, which limits the RFID applications because a tag cannot be mounted on objects smaller than itself. In this thesis, a downlink/uplink operating frequency of 60/24 GHz is used in order to reduce the antenna size. Since the proposed tag is passive, it requires a rectifier which converts RF power collected from surroundings to dc output supply voltage. A design of a robust rectifier becomes the most important task needed to be accomplished because as the frequency moves higher, the sensitivity of a RFID tag decreases due to the inevitable parasitic capacitance which impact the rectifier’s performance significantly. To overcome the parasitic effects, this thesis proposes an In-Phase Gate-Boosting Rectifier (IGR) which is a new circuit technique. The implemented IC achieves a state-of-the-art -7 dBm sensitivity with a peak power conversion efficiency of 20.65% at 7 dBm input power in the millimeter-wave rectifier circuit design domain.