Abstract:All-pass phase shifters using ferroelectric varactors are designed, fabricated, and measured. The design equations for the allpass phase shifter are presented. The fabrication process of the ferroelectric varactors is described. Measurement results of singlestage all-pass phase shifters show that phase shift greater than 85゚ can be achieved under 10-V bias. At the frequency where maximum phase shift occurs, the insertion loss is less than 2 dB and the return loss is greater than 12 dB. Simulations based on the… Show more
“…True-time delay lines (TTDL) and phase shifters are widely used in RF and microwave applications, especially in phased-array antennas and radars [1,2,3,4,5,6,7,8]. A simple transmission line could work as a fixed time delay line.…”
True time delay lines and phase shifters are widely used in RF timed/phased array systems. Conventional delay lines and phase shifters often associate with reflection type circuits or distributed (periodically loaded) transmission lines. In this paper, we propose a new type of distributed circuit which composed of uniform transmission lines built on integrated Schottky active layer. A bi-functional chip is designed based on the new distributed structure. An Archimedean spiral topology is adopted to reduce the chip area. Theoretical analysis of the design method and circuit parameters is performed and a miniaturized prototype is implemented with p-HEMT technology to validate the design theory. Measurement results shows that this chip could work as either an areaefficient true-time delay line or a low-voltage phase shifter over the bandwidth 11-15 GHz. As an area-efficient true-time delay line, this chip provides 82.1 ps delay time per square millimeter when the biasing voltage fixed at −1.4 V. As a low-voltage phase shifter, this chip provides 26.43°p hase shift per volt when the biasing voltage sweeps form 0 V to −1.4 V.
“…True-time delay lines (TTDL) and phase shifters are widely used in RF and microwave applications, especially in phased-array antennas and radars [1,2,3,4,5,6,7,8]. A simple transmission line could work as a fixed time delay line.…”
True time delay lines and phase shifters are widely used in RF timed/phased array systems. Conventional delay lines and phase shifters often associate with reflection type circuits or distributed (periodically loaded) transmission lines. In this paper, we propose a new type of distributed circuit which composed of uniform transmission lines built on integrated Schottky active layer. A bi-functional chip is designed based on the new distributed structure. An Archimedean spiral topology is adopted to reduce the chip area. Theoretical analysis of the design method and circuit parameters is performed and a miniaturized prototype is implemented with p-HEMT technology to validate the design theory. Measurement results shows that this chip could work as either an areaefficient true-time delay line or a low-voltage phase shifter over the bandwidth 11-15 GHz. As an area-efficient true-time delay line, this chip provides 82.1 ps delay time per square millimeter when the biasing voltage fixed at −1.4 V. As a low-voltage phase shifter, this chip provides 26.43°p hase shift per volt when the biasing voltage sweeps form 0 V to −1.4 V.
“…They can be implemented in switched line, loaded line, hybrid coupled line, and high-pass low-pass phase shifters. Continuous or discrete steps in phase change are expected to happen in analog or digital electronically controlled phase shifters respectively [105][106][107][108].…”
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.
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