Academic literature on the topic 'Radio over Fiber, Microwave Photonics'

Light has found applications in data transmission, such as optical fibers and waveguides and in optoelectronics. It consists of a series of electromagnetic waves, with particle behavior. Photonics involves the proper use of light as a tool for the benefit of humans. It is derived from the root word “photon”, which connotes the tiniest entity of light analogous to an electron in electricity. Photonics have a broad range of scientific and technological applications that are practically limitless and include medical diagnostics, organic synthesis, communications, as well as fusion energy. This will enhance the quality of life in many areas such as communications and information technology, advanced manufacturing, defense, health, medicine, and energy. The signal transmission methods used in wireless photonic systems are digital baseband and RoF (Radio-over-Fiber) optical communication. Microwave photonics is considered to be one of the emerging research fields. The mid infrared (mid-IR) spectroscopy offers a principal means for biological structure analysis as well as nonintrusive measurements. There is a lower loss in the propagations involving waveguides. Waveguides have simple structures and are cost-efficient in comparison with optical fibers. These are important components due to their compactness, low profile, and many advantages over conventional metallic waveguides. Among the waveguides, optofluidic waveguides have been found to provide a very powerful foundation for building optofluidic sensors. These can be used to fabricate the biosensors based on fluorescence. In an optical fiber, the evanescent field excitation is employed to sense the environmental refractive index changes. Optical fibers as waveguides can be used as sensors to measure strain, temperature, pressure, displacements, vibrations, and other quantities by modifying a fiber. For some application areas, however, fiber-optic sensors are increasingly recognized as a technology with very interesting possibilities. In this review, we present the most common and recent applications of the optical fiber-based sensors. These kinds of sensors can be fabricated by a modification of the waveguide structures to enhance the evanescent field; therefore, direct interactions of the measurand with electromagnetic waves can be performed. In this research, the most recent applications of photonics components are studied and discussed.

In future cellular radio networks Radio over Fiber (RoF) is a very attractive technology to deliver microwave and millimeter-wave signals containing broad band multimedia services to numerous base stations of the network. The radio signals are placed on an optical carrier and distributed by means of an optical fiber network to the base stations (BS). In the BS the optical signals heterodyne in a photodiode to produce the radio signals which are then sent via a wireless link to the mobile units (MU). The optical fiber network provides high frequency, wideband, low loss and a means of signal distribution immune to electromagnetic interference. In this thesis, different methods of electrooptical upconversion were investigated. The generation of an optical double-sideband with suppressed carrier (DSB-SC) signal is a straightforward method due to the fact that only one optical modulator driven at half the millimeter-wave frequency is required. One or both sidebands were ASK-modulated with baseband data rates of up to 10 Gbps. Optical single sideband modulation proves to be dispersion resilient as error free transmission was demonstrated after 53 km of single mode fiber transmission for data rates up to 10 Gbps. Wireless links up to 7 m were also demonstrated, proving the feasibility of this approach for broadband wireless inhouse access systems
Für zukünftige zellulare Funknetze ist „Radio over Fiber (RoF)“ eine sehr attraktive Technologie, um breitbandige Multimedia-Dienste mit Mikro- und Millimeterwellen zu übertragen. Die Funksignale werden dabei auf eine optische Trägerwelle aufmoduliert und mittels eines optischen Fasernetzes zu den Basisstationen (BS) verteilt. In den BS erfolgt die Überlagung der optischen Signale durch eine Fotodiode, um die Funksignale zu erzeugen. Diese werden dann über eine drahtlose Verbindung zu den beweglichen Multimedia-Endgeräten geschickt. Vorteile des optischen Fasernetzes sind Breitbandigkeit, geringe Dämpfung und eine gegenüber elektromagnetischen Störungen immune Signalverteilung. In dieser Arbeit werden verschiedene Methoden der elektrooptischen Aufwärtskonversion erforscht und die wichtigsten Eigenschaften dieser untersucht. Die Erzeugung eines optischen Zweiseitenbandsignales mit unterdrücktem Träger (DSB-SC) ist eine einfache Methode, da nur ein optischer Modulator, betrieben mit der halben elektrischen Trägerfrequenz, benötigt wird. Eine oder beide Seitenbänder konnten mit Bitraten bis zu 10 Gbps amplitudenmoduliert werden. Optische Einseitenbandmodulation ist extrem tolerant bezüglich der chromatischen Dispersion der Faser, wie die fehlerfreie Übertragung nach 53 km Glasfaser beweist. Drahtlose Links bis zu 7 m wurden realisiert und zeigen die Möglichkeit dieser Verfahren für breitbandige drahtlose Inhouse-Zugangssysteme

Avec la croissance forte de ces dernières années des objets connectés les technologies de communication optique et radio voient davantage d’opportunités de s’associer et se combiner dans des technologies bas-couts Photoniques-Microondes (MWP). Les réseaux domestiques en sont un exemple. La bande millimétrique notamment, de 57GHz à 67GHz, est utilisé pour contenir les exigences des communications sans fils très haut-débit, néanmoins, la couverture de ces systèmes wireless est limitée en intérieur (indoor) essentiellement à une seule pièce, à la fois du fait de l’atténuation forte de l’atmosphère dans cette bande de fréquence, mais aussi de fait de l’absorption et de la réflexion des murs. Ainsi il nécessaire de déployer une infrastructure pour diffuser l’information au travers d’un système d’antennes distribuées. Les technologiques optiques et photoniques-microondes sont une des solutions envisagées. Les technologies MWP se sont également étendues et couvrent une gamme très large d’applications incluant les communications mobiles 5G, les analyses biomédicales, les communications courtes-distances (datacom), le traitement de signal par voie optique et les interconnexions dans les véhicules et aéronefs. Beaucoup de ces applications requièrent de la rapidité, de la bande-passante et une grande dynamique à la fois, en même temps de demander des dispositifs compacts, légers et à faible consommation. Le cout d’implémentation est de plus un critère essentiel à leur déploiement, en particulier dans l’environnement domestique ainsi que dans d’autres applications variées des technologies MWP.Ce travail de thèse vise ainsi le développement de composants photonique-microondes (MPW) intégrés en technologie BiCMOS ou Bipolaire SiGe/Si, à très bas coût, incluant les phototransistors bipolaires à hétérojonctions (HPT) SiGe/Si, les Diodes Electro-Luminescentes (LED) Si et SiGe, ainsi que l’intégration combinées des composants optoélectroniques et microondes, pour l’ensemble des applications impliquant des courtes longueurs d’ondes (de 750nm à 950nm typiquement).Ces travaux se concentrent ainsi sur les points suivants :La meilleure compréhension de phototransistors SiGe/Si latéraux et verticaux conçus dans une technologie HBT SiGe 80GHz de Telefunken GmbH. Nous traçons des conclusions sur les performances optimales du phototransistor. Les effets de photodétection du substrat et de la dispersion spatiale des flux de porteurs sont analysés expérimentalement. Cette étude aide à développer des règles de dessin pour améliorer les performances fréquentielles du phototransistor HPT pour les applications visées.Dans l’objectif de développer de futures interconnexions intra- et inter- puces, nous concevons des lignes de transmissions faibles-pertes et des guides d’ondes optiques polymères sur Silicium faible résistivité. Il s’agit d’une étape afin d’envisager des plateformes Silicium dans lesquelles les HPT SiGe pourront potentiellement être intégrés de manière performante à très bas coût avec d’autres structures telles que des lasers à émission par la surface (VCSEL), afin de construire un transpondeur optique complet sur une interface Silicium. Le polymère est utilisé comme une interface diélectrique entre les lignes de transmission et le substrat, pour les interconnexions électriques, et pour définir le gain du guide d’onde optique dans les interconnexions optiques.La conception, la fabrication et la caractérisation du premier lien photonique-microonde sur puce Silicium sont menées en se basant sur la même technologie HBT SiGe 80GHz de Telefunken dans la gamme de longueur d’onde 0,65µm-0,85µm. Ce lien optique complétement intégré combine des LEDS Silicium en régime d’avalanche (Si Av LED), des guides d’ondes optiques Nitrure et Silice ainsi qu’un phototransistor SiGe. Un tel dispositif pourrait permettre d’accueillir à l’avenir des communications sur-puce, de systèmes micro-fluidiques et des applications d’analyse biochimiques
With the recent explosive growth of connected objects, for example in Home Area Networks, the wireless and optical communication technologies see more opportunity to merge with low cost MicroWave Photonic (MWP) technologies. Millimeter frequency band from 57GHz to 67GHz is used to accommodate the very high speed wireless data communication requirements. However, the coverage distance of these wireless systems is limited to few meters (10m). The propagation is then limiting to a single room mostly, due to both the high propagation attenuation of signals in this frequency range and to the wall absorption and reflections. Therefore, an infrastructure is needed to lead the signal to the distributed antennas configuration through MWP technology. Moreover, MWP technology has recently extended to address a considerable number of novel applications including 5G mobile communication, biomedical analysis, Datacom, optical signal processing and for interconnection in vehicles and airplanes. Many of these application areas also demand high speed, bandwidth and dynamic range at the same time they require devices that are small, light and low power consuming. Furthermore, implementation cost is a key consideration for the deployment of such MWP systems in home environment and various integrated MWP application.This PhD deals with very cheap, Bipolar or BiCMOS integrated SiGe/Si MWP devices such as SiGe HPTs, Si LEDs and SiGe LEDs, and focused on the combined integration of mm wave and optoelectronic devices for various applications involving short wavelength links (750nm to 950nm).This research focused on the study of the following points:The better understanding of vertical and lateral illuminated SiGe phototransistors designed in a 80 GHz Telefunken GmbH SiGe HBT technology. We draw conclusions on the optimal performances of the phototransistor. The light sensitive Si substrate and two-dimensional carrier flow effects on SiGe phototransistor performance are investigated. This study helps to derive design rules to improve frequency behavior of the HPT for the targeted applications.For future intra /inter chip hybrid interconnections, we design polymer based low loss microwave transmission lines and optical waveguides on low resistive silicon substrate. It is a step to envisage further Silicon based platforms where SiGe HPT could be integrated at ultra-low cost and high performances with other structures such high-speed VCSEL to build up a complete optical transceiver on a Silicon optical interposer. The polymer is used as dielectric interface between the line and the substrate for electrical interconnections and to design the core and cladding of the optical waveguide.The design, fabrication and characterization of the first on-chip microwave photonic links at mid infrared wavelength (0.65-0.85μm) based on 80 GHz Telefunken GmbH SiGe HBT technological processes. The full optical link combines Silicon Avalanche based Light Emitting Devices (Si Av LEDs), silicon nitride based waveguides and SiGe HPT. Such device could permit hosting microfluidic systems, on chip data communication and bio-chemical analysis applications

碩士
國立臺北科技大學
光電工程系研究所
100
In recent years, microwave photonics has attracted much research attention, due to its combining the advantages of both wireless communications and photonics, such as the mobility of wireless communications, large bandwidth, low loss, lightweight, and immunity to electromagnetic interference. Recently, microwave photonics has been explored more intensively at the subsystem and application levels. In this dissertation, we study application of microwave photonic filter using semiconductor laser in radio-over-fiber and test it in different data rates. Then single-frequency or dual-frequency was filtered in this system. In the future, these investigations will be usefully in microwave photonics.

碩士
國立中央大學
電機工程研究所
99
In this thesis, an integrated photonic transmitter front-end is demonstrated. In essence, the front-end circuit consists of an RF-choke, a W-band bandpass filter, an uni-planar slotline-to-waveguide transition, and a W-band horn antenna. The front-end is built with a near-ballistic uni-traveling-carrier photodiode (NBUTC-PD), which exhibits an extremely broadband bandwidth as well as an ultra-wide optical-to-electrical response. It is shown that the NBUTC-PD with proper integrated front-end circuits can find applications in the Radio-over-Fiber (RoF) system for ultra-high-speed wireless data transmission. 　This thesis also presents equivalent circuits to further simplify the system design procedures. The equivalent circuit of the entire system leads to reasonably accurate W-band optical-to-electrical response and intermediate frequency (IF) modulated bandwidth. For experimental demonstration, the proposed front-end is integrated with NBUTC-PD through flip-chip bonding for realization of a W-band integrated photonic transmitter. Since the wide optical-to-electrical bandwidth (35 GHz) as well as broad IF modulated bandwidth (25 GHz), the proposed photonic transmitter is of a high data rate up to 20 Gbit/s and expected to find applications in the broadband wireless-over-fiber system.

In future cellular radio networks Radio over Fiber (RoF) is a very attractive technology to deliver microwave and millimeter-wave signals containing broad band multimedia services to numerous base stations of the network. The radio signals are placed on an optical carrier and distributed by means of an optical fiber network to the base stations (BS). In the BS the optical signals heterodyne in a photodiode to produce the radio signals which are then sent via a wireless link to the mobile units (MU). The optical fiber network provides high frequency, wideband, low loss and a means of signal distribution immune to electromagnetic interference. In this thesis, different methods of electrooptical upconversion were investigated. The generation of an optical double-sideband with suppressed carrier (DSB-SC) signal is a straightforward method due to the fact that only one optical modulator driven at half the millimeter-wave frequency is required. One or both sidebands were ASK-modulated with baseband data rates of up to 10 Gbps. Optical single sideband modulation proves to be dispersion resilient as error free transmission was demonstrated after 53 km of single mode fiber transmission for data rates up to 10 Gbps. Wireless links up to 7 m were also demonstrated, proving the feasibility of this approach for broadband wireless inhouse access systems.
Für zukünftige zellulare Funknetze ist „Radio over Fiber (RoF)“ eine sehr attraktive Technologie, um breitbandige Multimedia-Dienste mit Mikro- und Millimeterwellen zu übertragen. Die Funksignale werden dabei auf eine optische Trägerwelle aufmoduliert und mittels eines optischen Fasernetzes zu den Basisstationen (BS) verteilt. In den BS erfolgt die Überlagung der optischen Signale durch eine Fotodiode, um die Funksignale zu erzeugen. Diese werden dann über eine drahtlose Verbindung zu den beweglichen Multimedia-Endgeräten geschickt. Vorteile des optischen Fasernetzes sind Breitbandigkeit, geringe Dämpfung und eine gegenüber elektromagnetischen Störungen immune Signalverteilung. In dieser Arbeit werden verschiedene Methoden der elektrooptischen Aufwärtskonversion erforscht und die wichtigsten Eigenschaften dieser untersucht. Die Erzeugung eines optischen Zweiseitenbandsignales mit unterdrücktem Träger (DSB-SC) ist eine einfache Methode, da nur ein optischer Modulator, betrieben mit der halben elektrischen Trägerfrequenz, benötigt wird. Eine oder beide Seitenbänder konnten mit Bitraten bis zu 10 Gbps amplitudenmoduliert werden. Optische Einseitenbandmodulation ist extrem tolerant bezüglich der chromatischen Dispersion der Faser, wie die fehlerfreie Übertragung nach 53 km Glasfaser beweist. Drahtlose Links bis zu 7 m wurden realisiert und zeigen die Möglichkeit dieser Verfahren für breitbandige drahtlose Inhouse-Zugangssysteme.

Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia
Actualmente, as comunicações sem fios (wireless) estão a entrar numa nova fase, as redes de 5ª geração (5G), onde se espera o aumento de serviços que necessitam de grande largura de banda, nomeadamente, serviços interactivos e multimédia. Para suportar estas exigências, uma vertente da investigação em comunicações wireless estuda a operação na gama das microondas/ondas milimétricas para assim evitar o congestionamento espectral nas baixas frequências. Esta estratégia implica uma redução do tamanho da célula e, consequentemente, um aumento do número de células necessárias para cobrir uma determinada área. Tais redes exigem um número elevado de Estações de Base (BSs-Base Stations) para fazer a cobertura de uma área de serviço; assim, uma BS de baixo custo é a chave de sucesso no mercado. Esta exigência levou ao desenvolvimento de uma arquitectura de um sistema onde funções tais como o encaminhamento (routing)/processamento são tratadas numa Unidade Central (CU-Central Unit), mais do que na BS, tornando as BSs em unidade rádio remotas simples (RRHs-Remote Radio Head). A arquitectura de rede centralizada permite a equipamento sensível de ser localizado num ambiente mais seguro, para além de permitir a partilha dos componentes mais dispendiosos pelas várias RRHs. Uma estratégia atractiva para ligar uma CU com as RRHs é através de uma rede de fibra óptica, pois a fibra óptica tem baixas perdas e tem uma grande largura de banda. No entanto, os sinais de rádio são severamente distorcidos por estas ligações. A distorção, introduzida pelo sistema de transmissão ótico, será um fator limitante, uma vez que a potência dos sinais tem de ser reduzida para que os componentes operem na zona linear, diminuindo, assim, o alcance das ligações.O espectro disponível torna-se uma limitação do aumento da taxa de transmissão, uma vez que a largura de banda não será suficiente para as redes de próxima geração. Uma banda que se encontra em estudo para responder a este desafio é a banda não licenciada nos 60 GHz, apesar das suas elevadas atenuações limitarem significativamente o alcance das ligações.Nesta dissertação é implementado um modelo de simulação de um sistema rádio sobre fibra. As distorções sofridas pelos sinais rádio são identificadas, analisadas e compensadas com um bloco de pré-distorção digital baseado em polinómios de memória. A conversão eletro-ótica do sinal rádio multiplexado por divisão em frequências ortogonais (OFDM – Orthogonal Frequency Division Multiplexing) através do modulador Mach-Zehnder é destacada, uma vez que é a principal causa da distorção do sistema ótico.Ao longo desta dissertação, os componentes e a arquitetura da rede são discutidos; modelos para o modulador Mach-Zehnder, fotodetector e fibra são apresentados. O ponto de polarização DC do Mach-Zehnder é estudado, assim como a sua influência no desempenho do sistema; o número de símbolos e o débito binário são otimizados e o impacto do comprimento da fibra e a largura espetral do laser são também discutidos.
Wireless communications are currently entering a new stage, 5th generation networks (5G), where an increase of services requiring high bandwidth is expected; namely, interactive services and multimedia. To support such demands, investigation in wireless communications has a strand studying operation at microwaves/millimeter waves to avoid spectral congestion in lower frequencies. This strategy implies a reduction in size of the cells, consequently leading to higher numbers of cells needed to provide coverage to a certain area. Such networks require a high number of Base Stations (BSs); thus, low cost BSs are the key to success in the market. This demand led to the development of an architecture of a system where functions such as routing/processing are dealt with at the Central Unit (CU), making BSs simple Remote Radio Heads (RRHs). This centralized network architecture allows sensible equipment to be localized at a safer environment while allowing resource sharing of the high cost components between RRHS. This strategy is attractive to connect a CU to RRHs trough optical fiber, since optical fiber has low losses and high bandwidth. However, radio signals are highly distorted by these connections. The distortion, introduced by the optical transmission system, will be a limiting factor, since the power of the signals must be reduced so the components operate at a linear zone, thus decreasing the range of the connections.Available spectrum becomes a restraint in the increase of transmission rate, since the bandwidth will not be sufficient for next generation networks. The unlicensed 60 GHz band is being studied to meet this challenges, despite its high attenuation significantly limiting the range of the connections.In this dissertation, a simulation model of a Radio over Fiber system is implemented. The distortions suffered by radio signals are identified, analyzed and compensated with a digital predistortion block based on memory polynomials. Electro-optic conversion of the Orthogonal Frequency Division Multiplexing (OFDM) radio signal is highlighted, since it is the main cause of distortion in the optical system.Throughout this work, the components and architecture of the network are presented and discussed; the models for the Mach-Zehnder, optical fiber, photodetector and predistorter are shown. The impact on the performance of the bias point of the MZM is analyzed, the number of symbols and bit rate are optimized and the impact of the fiber’s length and laser’s linewidth are discussed.
FCT

Besides colorless ONUs, we investigate potentially low cost, high speed vertical-cavity-surface-emitting lasers (VCSELs) for use in future access networks. VCSELs are attractive because they may meet the stringent size, power dissipation and cost constraints of access network components. We carry out experiments to demonstrate that up to 20 Gb/s direct modulation of long wavelength VCSEL is possible and evaluate their performance as high-speed transceivers.
In order to reduce the complexity and costs of ONU transceiver, we propose a scheme based on a nonreciprocal optical modulator and a linear loop mirror for receiving downstream and sending upstream data We show that the nonreciprocity of traveling wave electrodes can selectively impress signal modulation onto the reflected upstream signals only. Monolithic integrated transceivers may thus remodulate downstream signals for upstream data transmission without needing integrated optical circulators. The proposed ONU is thus compatible with monolithic integration.
In this thesis, we describe our research on photonic devices and subsystems for future access networks. Since optical network units (ONUs) are the most cost-sensitive parts, we first investigate the use of advanced modulation format in colorless ONU structure. We implement a scheme which uses dark return-to-zero (DRZ) for downstream transmission and remodulation of it using a differential-phase-shift-keying (DPSK) for upstream both at 10 Gb/s. We also experimentally demonstrate silicon microring based optical frequency discriminators for use in demodulating DPSK and differential-quadrature-phase-shift-keying (DQPSK) signals. We show that the scheme is robust to variations in bit-rates in contrast with conventional Mach-Zehnder delay interferometer scheme.
Internet traffic has undergone tremendous growth in the past decades and has already penetrated into the daily lives of the general population. Demand for new high bandwidth services is beginning to drive the deployment of optical fiber-based access networks to solve the so-called last mile bottleneck around the world. Passive optical networks (PON) are attractive because there are no active components in the transmission line, thus reducing operational and deployment costs. Time-division-multiplexing (TDM) used in currently deployed PON, in which the bandwidth is shared among the users by time domain multiplexing, does not fully utilize the bandwidth potential of optical fibers and will not be able to satisfy the bandwidth demand in access networks in the near future. Among the advanced multiplexing techniques, wavelength-division-multiplexing (WDM) PON is a good candidate technology for providing sustained bit-rates beyond 10 Gb/s in access networks. However, reduction of costs in WDM PON remains a key challenge for their practical deployment.
Wired and wireless hybrid optical access networks are also investigated. Radio-over-fiber is one low-cost approach to deliver broadband wireless services, in which radio signals at the carrier frequency are delivered over optical networks from a central office to remote antenna base stations. Generation of high frequency carrier and radio frequency fading are the main research challenges. We propose and demonstrate frequency upconversion based on frequency doubling and quadrupling. Novel wired and wireless hybrid subsystems that mitigate millimeter-wave signal distortion are also demonstrated.
Xu, Lin.
Adviser: H. K. Tsang.
Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: .
Thesis (Ph.D.)--Chinese University of Hong Kong, 2010.
Includes bibliographical references.
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.

Photonics and Optical techniques have advanced recently by a great extend to play an important role in Microwave and Radar applications. Antenna array of modern active phased array radars consist of multiple low power transmit and receive mod- ules. This demands distribution of the various Local Oscillator(LO) signals for up conversion of transmit signals and down conversion of receive signals during various modes of operation of a radar system. Additionally, these receivers require control and clock signals which are digital and low frequency analog, for the synchronization between receive modules. This is normally achieved through RF cables with complex distribution networks which add significantly higher additional weight to the arrays. During radar operations, radio frequency (RF) transmit signal needs to be distributed through the same modules which will in turn get distributed to all antenna elements of the array using RF cables. This makes the system bulky and these large number of cables are prone to Electromagnetic Interference (EMI) and need additional shielding. Therefore it is very desirable to distribute a combination of these RF, analog and digital signals using a distribution network that is less complex, light in weight and immune to EMI. Advancements in Optical and Microwave photonics area have enabled carrying of higher datarate signals on a single fiber due to its higher bandwidth capability including RF signals. This is achieved by employing Wavelength Division Multi- plexing (WDM) that combine high speed channels at different wavelengths. This work proposes, characterizes and evaluates an optical Wavelength Division Multiplexed(WDM) distribution network that will overcome the above mentioned problems in a phased array radar application. The work carries out a feasibility analysis supported with experimental measurements of various physical parameters like am- plitude, delay, frequency and phase variation for various radar waveforms over WDM links. Different configurations of optical distribution network are analyzed for multipoint distribution of both digital and RF signals. These network configurations are modeled and evaluated against various parameters that include power level, loss, cost and component count. A configuration which optimizes these parameters based on the application requirements is investigated. Considerable attention is paid to choose a configuration which does not provide excess loss, which is economically viable, compact and can be realized with minimum component count. After analysing the link configuration, multiplexing density of the WDM link is considered. In this work, since the number of signals to be distributed in radar systems are small, a coarse WDM(CWDM) scheme is considered for evaluation. A comparative study is also performed between coarse and dense WDM (DWDM) links for selection of a suitable multiplexing scheme. These configurations are modeled and evaluated with power budgeting. Even though CWDM scheme does not permit the utilisation of the available bandwidth to the fullest extent, these links have the advantage of having less hardware complexity and easiness of implementation. As the application requires signal distribution to thousands of transmit-receive modules, amplifiers are necessary to compensate for the reduction of signal level due to the high splitting ratio. Introduction of commonly available optical amplifiers like Erbium Doped Fiber Amplifier (EDFA), affect the CWDM channel output powers adversely due to their non-flat gain spectrum. Unlike DWDM systems, the channel separation of CWDM systems are much larger causing significantly high channel gain differences at the EDFA output. So an analysis is carried out for the selection of a suitable wavelength for CWDM channels to minimize the EDFA output power variation. If the gain difference is still significant, separate techniques needs to be implemented to flatten the output power at the antenna end. A CWDM configuration using C-band and L-band EDFAs is proposed and is supported with a feasibility analysis. As a part of evaluation of these links for radar applications, a mathematical model of the WDM link is developed by considering both the RF and digital sig- nals. A generic CWDM system consisting of transmitters, receivers, amplifiers, multiplexers/ demultiplexers and detectors are considered for the modeling. For RF signal transmission, the transmitters with external modulators are considered. Mod- eling is done based on a bottom-top approach where individual component models are initially modeled as a function of input current/power and later cascaded to obtain the link model. These models are then extended to obtain the wavelength dependent model ( spectral response) of the hybrid signal distribution link Further mathematical analysis of the developed link model revealed its variable separable nature in terms of the input power and wavelength. This led to significant reduction in the link equation complexity and development of some approximation techniques to easily represent the link behavior. The reduced form of the link spectral model was very essential as the initially developed wavelength model had a lot of parametric dependency on the component models. This mathematical reduction process led to simplification of the spectral model into a product of two independent functions, the input current and wavelength. It is also noticed that the total link power within specific wavelength range can be obtained by the integrating these functions over a specific link input power. After the mathematical modelling, an experimental prototype physical link is set up and characterized using various radar signals like continuous wave (CW) RF, pulsed RF, non linear frequency modulated signal (NLFM) etc. Additionally a proof of concept Radio-Over-Fiber (RoF) link is established to prove the superior transmission of microwave signal through an optical link. The analysis is supported with measurements on amplitude, delay, frequency and phase variations. The NLFM waveforms transmissions are further analysed using a matched _ltering process to confirm the side lobe requirement. Further a prototype WDM link is built to study the performance when digitally modulated channels are also multiplexed into the link. The link is again validated for signal levels, delay, frequency and phase parameters. Since amplitude and delay are deterministic, it is proposed that these parameter variations can be compensated by using suitable components either in the electrical or the optical domain. Radar systems use low frequency digital signals of different duty-cycles for synchronization and control across various transmit-receive modules. In the proposed link, these digital signals also modulate a WDM channel and hence the link is called a hybrid system. As the proposed link has EDFA to compensate for the splitting losses, there are chances of transient effects at the EDFA output for these low bitrate channels. Owing to the long carrier lifetime, low bitrate digital channels are prone to EDFA transient effects under specific signal and pump power conditions. Additionally, the synchronization signals used in radar application vary the duty-cycle over time, which is found to introduce variations in transient output. This practical challenge is further studied and the thesis for the first time, includes an analysis of EDFA transient e_ects for variable duty-cycle pulsed signals. The analysis is carried out for various parameters like bitrate, input power, pump power and duty-cycle. Investigations on EDFA transients on variable duty-cycle signals help in proposing a viable method to predict the lower duty-cycle transients from higher duty-cycle transients. The predicted transients were again validated against simulated transients and experimental results. As these transient effects are not desirable for radar signals, we propose a novel transient suppression techniques in optical and electrical domain which are validated with simulation and experimental measures. One suppression technique tries to avoid transient effect by keeping the optical input to EDFA always constant by feeding an inverted version of the original pulse into the EDFA along with the actual pulse. It is observed that as the wavelength of the inverted pulse is closer to the original input pulse, the transient effect settles faster. These EDFA transients are evaluated with WDM link configurations, where both high and low bitrate signals are co-propagated. Another challenging aspect of the link operation is the non-at gain spectrum of EDFA. i.e., EDFA provides unequal power level for various signals at WDM link output. This is especially true in the case of local oscillator signals, where it is preferable to have the same amplitude signals before feeding it to the mixer stages. But in the radar applications, this will require additional hardware circuits to equalize the signal level within a phased array antenna. This work also proposes some of the power equalization methods that can be used along with the WDM links. This part of the work is also supported with simulation model and experimental results. The analytical and experimental study of this thesis aids the evaluation process of a suitable optical Wavelength Division Multiplexed(WDM) distribution network that can be used for the distribution of both RF and digital signals. The optical WDM links being superior with its light weight, less loss and EMI/ EMC immunity provides a better solution to future class of radars.