Six-port precision directional coupler

A design for a six-port, high phase and amplitude balance, stripline coupler is presented. Both the predicted and the measured performance of a hardware prototype show phase and amplitude balance better than 0.2 dB and 0.9 at the design frequency of 2.46 GHz when fabricated on an FR-4 substrate

Design considerations for a monolithic, GaAs, dual-mode, QPSK/QASK, high-throughput rate transceiver

A monolithic, GaAs, dual mode, quadrature amplitude shift keying and quadrature phase shift keying transceiver with one and two billion bits per second data rate is being considered to achieve a low power, small and ultra high speed communication system for satellite as well as terrestrial purposes. Recent GaAs integrated circuit achievements are surveyed and their constituent device types are evaluated. Design considerations, on an elemental level, of the entire modem are further included for monolithic realization with practical fabrication techniques. Numerous device types, with practical monolithic compatability, are used in the design of functional blocks with sufficient performances for realization of the transceiver

Development of a solid state amplifier for the 3rd harmonic cavity for ALBA synchrotron light source

In Synchrotron Light Source facilities with high energy and low emittance electron beams different techniques for improving the quality of the synchrotron light for the users are applied. With this aim ALBA, the Spanish 3rd generation Synchrotron Light Source, is developing a 3rd Harmonic radiofrequency (RF) system as a system additional to the main RF system of the storage ring. This system will consist of four normal conducting active cavities at 1.5 GHz that will provide the required 1.1 MV accelerating voltage to the electron beam and will be fed by four 20 kW power transmitters. This power will be generated by modular Solid State Power Amplifiers (SSPAs) in a continuous wave mode at 1.5 GHz. On the basis of preliminary studies it has been decided that the architecture of each 20 kW power transmitter is a tree diagram made up of primary 1 kW SSPA modules connected in parallel in a combination array. The present PhD thesis is devoted to the design, building and evaluation of a prototype of the 1 kW SSPA module formed four 250 W primary power amplifier modules. Accordingly, all subsystems, namely input and output matching networks of the 250 W primary module, and a four-way power splitter, a four-way power combiner and a novel directivity compensated directional coupler for the non-invasive power monitoring of the 1 kW power amplifier were also designed and their prototypes were tested. A final evaluation of the combined 1 kW SSPA prototype module was successfully carried out and has shown good performance.En las instalaciones de tipo Fuentes de luz de sincrotrón de haz de electrones de alta energía y baja emitancia se aplican diferentes técnicas de mejora de la calidad de la luz de sincrotrón. Con este objetivo, el ALBA, la fuente española de luz de sincrotrón de la tercera generación, está desarrollando un sistema de radiofrecuencia (RF) de la 3ª Harmónica como un sistema adicional al sistema de RF principal del anillo de almacenamiento. Este sistema consistirá de cuatro cavidades activas de conductividad normal de frecuencia 1,5 GHz que suministrarán un voltaje acelerador de 1.1 MV necesario para el haz de electrones y que serán alimentadas por cuatro transmisores de potencia de 20 kW. Esta potencia será generada en modo de onda continua a frecuencia 1.5 GHz por amplificadores de potencia de estado sólido (APES) de estructura modular. A partir de unos estudios preliminares se ha decidido que la arquitectura de cada transmisor de potencia de 20 kW es de tipo diagrama de árbol que consiste de APES primarios de potencia 1 kW conectados en paralelo formando una matriz de combinación. El tema de la presente tesis es el diseño, la construcción y la caracterización de un prototipo del módulo de APES de potencia 1 kW formado por cuatro amplificadores primarios de 250 W de potencia. También, todos subsistemas, concretamente los circuitos de adaptación de entrada y de salida del módulo primario de 250 kW, así como un divisor de cuatro salidas, un combinador de cuatro entradas y un acoplador direccional con una nova solución de compensación de directividad para una monitorización no invasiva han sido diseñados y sus prototipos han sido testeados. La evaluación final de funcionamiento del APES de 1 kW de potencia ha sido realizada con éxito y ha demostrado su buen rendimiento.Postprint (published version

Development of a solid state amplifier for the 3rd harmonic cavity for ALBA synchrotron light source

In Synchrotron Light Source facilities with high energy and low emittance electron beams different techniques for improving the quality of the synchrotron light for the users are applied. With this aim ALBA, the Spanish 3rd generation Synchrotron Light Source, is developing a 3rd Harmonic radiofrequency (RF) system as a system additional to the main RF system of the storage ring. This system will consist of four normal conducting active cavities at 1.5 GHz that will provide the required 1.1 MV accelerating voltage to the electron beam and will be fed by four 20 kW power transmitters. This power will be generated by modular Solid State Power Amplifiers (SSPAs) in a continuous wave mode at 1.5 GHz. On the basis of preliminary studies it has been decided that the architecture of each 20 kW power transmitter is a tree diagram made up of primary 1 kW SSPA modules connected in parallel in a combination array. The present PhD thesis is devoted to the design, building and evaluation of a prototype of the 1 kW SSPA module formed four 250 W primary power amplifier modules. Accordingly, all subsystems, namely input and output matching networks of the 250 W primary module, and a four-way power splitter, a four-way power combiner and a novel directivity compensated directional coupler for the non-invasive power monitoring of the 1 kW power amplifier were also designed and their prototypes were tested. A final evaluation of the combined 1 kW SSPA prototype module was successfully carried out and has shown good performance.En las instalaciones de tipo Fuentes de luz de sincrotrón de haz de electrones de alta energía y baja emitancia se aplican diferentes técnicas de mejora de la calidad de la luz de sincrotrón. Con este objetivo, el ALBA, la fuente española de luz de sincrotrón de la tercera generación, está desarrollando un sistema de radiofrecuencia (RF) de la 3ª Harmónica como un sistema adicional al sistema de RF principal del anillo de almacenamiento. Este sistema consistirá de cuatro cavidades activas de conductividad normal de frecuencia 1,5 GHz que suministrarán un voltaje acelerador de 1.1 MV necesario para el haz de electrones y que serán alimentadas por cuatro transmisores de potencia de 20 kW. Esta potencia será generada en modo de onda continua a frecuencia 1.5 GHz por amplificadores de potencia de estado sólido (APES) de estructura modular. A partir de unos estudios preliminares se ha decidido que la arquitectura de cada transmisor de potencia de 20 kW es de tipo diagrama de árbol que consiste de APES primarios de potencia 1 kW conectados en paralelo formando una matriz de combinación. El tema de la presente tesis es el diseño, la construcción y la caracterización de un prototipo del módulo de APES de potencia 1 kW formado por cuatro amplificadores primarios de 250 W de potencia. También, todos subsistemas, concretamente los circuitos de adaptación de entrada y de salida del módulo primario de 250 kW, así como un divisor de cuatro salidas, un combinador de cuatro entradas y un acoplador direccional con una nova solución de compensación de directividad para una monitorización no invasiva han sido diseñados y sus prototipos han sido testeados. La evaluación final de funcionamiento del APES de 1 kW de potencia ha sido realizada con éxito y ha demostrado su buen rendimiento

Design and analysis of wideband passive microwave devices using planar structures

A selected volume of work consisting of 84 published journal papers is presented to demonstrate the contributions made by the author in the last seven years of his work at the University of Queensland in the area of Microwave Engineering. The over-arching theme in the author’s works included in this volume is the engineering of novel passive microwave devices that are key components in the building of any microwave system. The author’s contribution covers innovative designs, design methods and analyses for the following key devices and associated systems: Wideband antennas and associated systems Band-notched and multiband antennas Directional couplers and associated systems Power dividers and associated systems Microwave filters Phase shifters Much of the motivation for the work arose from the desire to contribute to the engineering o

Étude et réalisation de matrices à commutation de faisceaux en technologie guide d'ondes intégré au substrat

RÉSUMÉ Les applications radar pour les voitures demandent des composants de hautes performances mais avec faible coût de revient. Cette thèse présente la conception des réseaux d’alimentation d’antennes en ondes millimétriques utilisant la technologie du guide d’ondes intégré aux substrats (GIS), pour satisfaire les exigences du coût et du faible encombrement dans ces applications de radar. Dans un système radar, l’antenne défini la largeur du secteur couvert, la portée, la discrimination angulaire et le filtrage du bruit généré par d’autre sources. Généralement les antennes intelligentes remplissent ce cahier des charges. La direction dans laquelle le réseau ayant la réponse maximale serait la direction du pointage de faisceau. Pour un choix de faisceau dans une direction désirée, un ajustement de phase doit être accompli. Les matrices à commutation donnent des distributions de phase aux sorties différentes pour chaque port d’entrée. Le guide d’ondes intégré aux substrats (GIS) offre une technologie intéressante pour les réseaux d’alimentation d’antennes en termes de faible pertes par radiation, ce qui assure un très faible niveau d’interférences et d’effets parasitiques entre les circuits de GIS. Nous proposons dans ce travail plusieurs matrices de formation de faisceaux basées sur la technologie GIS. La thèse est présentée sous forme d’articles. Ce travail montre les étapes entreprises afin de mener à terme la conception, la fabrication, les mesures et l’évaluation de plusieurs topologies de la matrice de Butler. Nous verrons donc dans un premier temps les composants nécessaires au bon fonctionnement d’un tel système soit: les coupleurs 3 dB, les déphaseurs et les croisements. Le choix de la configuration sera justifié pour chacun de ces éléments. L’usage de simulateur (Ansoft HFSS) basé sur la méthode des éléments finis (une méthode à ondes complètes) sera nécessaire dans ce travail. Ce logiciel donne des résultats assez proches des essais expérimentaux. Trois matrices de Butler sont développées, la première à 77 GHz sans croisement, une deuxième est une structure à deux couches à 24 GHz et la troisième est une matrice complètement planaire avec un coupler 0 dB à 12.5 GHz.---------- ABSTRACT Automotive radar applications require components with high performance but low cost. This thesis presents the design of millimeter wave antennas feeding networks using the substrate integrated waveguide (SIW) technology, to satisfy the requirement of low cost and compactness in these radar applications.In a radar system the antenna define the width of covered area, the range, the angular discrimination and the filter noise generated by other sources. Generally smart antennas must be used to satisfy the specifications. The beam pointing can be achieved only by adjusting the phase of signals from different elements. For a choice of beam in a desired direction, a phase adjustment must be done. Switching matrices are used to provide phase distribution at output ports that is different for each input port. The substrates integrated waveguide (SIW) is a promising technology for the antenna feed networks in terms of low radiation and transmission losses with reduced interferences among SIW circuit elements. We propose in this work several beamforming matrices based on SIW technology. This thesis is presented in paper form. First of all, this work shows the steps taken to finalize the design, fabricate, measurement and evaluation of several Butler matrix topologies. We will see at first that the building components necessary for the proper functioning of such a network: the 3 dB couplers, phase shifters and crossovers. The choice of a configuration will be justified for each of these elements. An electromagnetic simulator (Ansoft HFSS) based on the finite element method (full-wave method) is used in this work. This software package would be able to yield results close to experimental counterparts. Three Butler matrices are developed, the first at 77GHz without crossover, the second is related to a two layer structure at 24 GHz and the third is completely made planar with a cross-over at 12.5 GHz. The Nolen matrix compared to Butler matrix has the advantages of being free from crossovers in the structure. The loads placed on unused ports in the Blass matrix do not appear in the Nolen matrix which increases efficiency. We propose two architectures, the first one is related to perpendicular configuration in Ku band while the second platform presents a parallel topology which shows a good performance over a broad band around 77 GHz

On the development of novel multi-layer passive components and the implementation of compact wideband two-layer 4x4 Butler matrix in SIW technology

Multibeam antennas have become a key element in nowadays wireless communication systems where increased channel capacity, improved transmission quality with minimum interference and multipath phenomena are severe design constraints. These antennas are classified in two main categories namely adaptive smart antennas and switched-beam antennas. Switched-beam antennas consist of an elementary antenna array connected to a Multiple Beam Forming Network (M-BFN). Among the different M-BFNs, the Butler matrix has received particular attention as it is theoretically lossless and employs the minimum number of components to generate a given set of orthogonal beams (provided that the number of beams is a power of 2). However, the Butler matrix has a main design problem which is the presence of path crossings that has been previously addressed in different research works. Substrate Integrated Waveguide (SIW) features interesting characteristics for the design of microwave and millimetre-wave integrated circuits. SIW based components combine the advantages of the rectangular waveguide, such as the high Q factor (low insertion loss) and high power capability while being compatible with low-cost PCB and LTCC technologies. Owing to its attractive features, the use of SIW technology appears as a good candidate for the implementation of BFNs. The resulting structure is therefore suitable for both waveguide-like and planar structures. In this thesis, different novel passive components (couplers and phase shifters) have been developed exploring the multi-layer SIW technology towards the implementation of a two-layer compact 4×4 Butler matrix offering wideband performances for both transmission magnitudes and phases with good isolation and input reflection characteristics. Different techniques for the implementation of wideband fixed phase shifters in SIW technology are presented. First, a novel waveguide-based CRLH structure is proposed. The structure is based on a single-layer waveguide with shunt inductive windows (irises) and series transverse capacitive slots, suitable for SIW implementations for compact phase shifters. The structure suffers relatively large insertion loss which remains however within the typical range of non-lumped elements based CRLH implementations. Second, the well-known equal length, unequal width SIW phase shifters is discussed. These phase shifters are very adapted for SIW implementations as they fully exploit the flexibility of the SIW technology in different path shapes while offering wideband phase characteristics. To satisfy good return loss characteristics with this type of phase shifters, the length has to be compromised with respect to the progressive width variations associated with the required phase shift values. A twolayer, wideband low-loss SIW transition is then proposed. The transition is analyzed using its equivalent circuit model bringing a deeper understanding of its transmission characteristics for both amplitude and phase providing therefore the basic guidelines for electromagnetic optimization. Based on its equivalent circuit model, the transition can be optimized within the well equal-length SIW phase shifters in order to compensate its additional phase shift within the frequency band of interest. This twolayer wideband phase shifter scheme has been adopted in the final developed matrix architecture.This transition is then exploited to develop a three-layer, multiply-folded waveguide structure as a good candidate for compensated-length, variable width, low-loss, compact wideband phase shifters in SIW technology. Novel two-layer SIW couplers are also addressed. For BFNs applications, an original structure for a two-layer 90° broadband coupler is developed. The proposed coupler consists of two parallel waveguides coupled together by means of two parallel inclined-offset resonant slots in their common broad wall. A complete parametric study of the coupler is carried out including the effect of the slot length, inclination angle and offset on both the coupling level and the transmission phase. The first advantage of the proposed coupler is providing a wide coupling dynamic range by varying the slot parameters allowing the design of wideband SIW Butler matrix in two-layer topology. In addition, previously published SIW couplers suffer from direct correlation between the transmission phase and the coupling level, while the coupler, hereby proposed, allows controlling the transmission phase without significantly affecting the coupling level, making it a good candidate for BFNs employing different couplers, such as, the Nolen matrix. A novel dual-band hybrid ring coupler is also developed in multi-layer Ridged SIW (RSIW) technology. This coupler has been jointly developed with Tarek Djerafi in a collaboration scenario with Prof. Ke Wu from the Ecole Polytechnique de Montréal. The coupler has an original structure based on two concentric rings in RSIW topology with the outer ring periodically loaded with radial, stub-loaded transverse slots. A design procedure is presented based on the Transverse Resonance Method (TRM) of the ridged waveguide together with the simple design rules of the hybrid ring coupler. A C/K dual band coupler with bandwidths of 8.5% and 14.6% centered at 7.2 GHz and 20.5 GHz, respectively, is presented. The coupler provides independent dual band operation with low-dispersive wideband operation. Finally, for the Butler matrix design, the two-layer SIW implementation is explored through a two-fold enhancement approach for both the matrix electrical and physical characteristics. On the one hand, the two-layer topology allows an inherent solution for the crossing problem allowing therefore more flexibility for phase compensation over a wide frequency band. This is achieved by proper geometrical optimization of the surface on each layer and exploiting the SIW technology in the realization of variable width waveguides sections with the corresponding SIW bends. On the other hand, the two-layer SIW technology is exploited for an optimized space saving design by implementing common SIW lateral walls for the matrix adjacent components seeking maximum size reduction. The two corresponding 4×4 Butler matrix prototypes are optimized, fabricated and measured. Measured results are in good agreement with the simulated ones. Isolation characteristics better than -15 dB with input reflection levels lower than -12 dB are experimentally validated over 24% frequency bandwidth centered at 12.5 GHz. Measured transmission magnitudes and phases exhibit good dispersive characteristics of 1dB, around an average value of -6.8 dB, and 10° with respect to the theoretical phase values, respectively, over the entire frequency band