434 research outputs found

    S-band hybrid amplifiers based on hydrogenated diamond FETs

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    The first realizations of S-band hybrid amplifiers based on hydrogenated-diamond (H-diamond) FETs are reported. As test vehicles of the adopted H-diamond technology at microwave frequencies, two designs are proposed: one, oriented to low-noise amplification, the other, oriented to high-power operation. The two amplifying stages are so devised as to be cascaded into a two-stage amplifier. The activities performed, from the technological steps to characterization, modelling, design and realization are illustrated. Measured performance demonstrates, for the low-noise stage, a noise figure between 7 and 8 dB in the 2–2.5 GHz bandwidth, associated with a transducer gain between 5 and 8 dB. The OIP3 at 2 GHz is 21 dBm. As to the power-oriented stage, its transducer gain is 5–6 dB in the 2–2.5 GHz bandwidth. The 1-dB output compression point at 2 GHz is 20 dBm whereas the OIP3 is 33 dBm. Cascading the measured S-parameters of the two stages yields a transducer gain of 15 ± 1.2 dB in the 2–3 GHz bandwidth

    RF power generation

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    This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.Comment: 35 pages, contribution to the CAS - CERN Accelerator School: Specialised Course on RF for Accelerators; 8 - 17 Jun 2010, Ebeltoft, Denmar

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

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    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

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    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

    High-Capacity Communications from Martian Distances

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    High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power

    Parallel Doherty RF Power Amplifier For WiMAX Applications

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    abstract: This work covers the design and implementation of a Parallel Doherty RF Power Amplifier in a GaN HEMT process for medium power macro-cell (16W) base station applications. This work improves the key parameters of a Doherty Power Amplifier including the peak and back-off efficiency, operational instantaneous bandwidth and output power by proposing a Parallel Doherty amplifier architecture. As there is a progression in the wireless communication systems from the first generation to the future 5G systems, there is ever increasing demand for higher data rates which means signals with higher peak-to-average power ratios (PAPR). The present modulation schemes require PAPRs close to 8-10dB. So, there is an urgent need to develop energy efficient power amplifiers that can transmit these high data rate signals. The Doherty Power Amplifier (DPA) is the most common PA architecture in the cellular infrastructure, as it achieves reasonably high back-off power levels with good efficiency. This work advances the DPA architecture by proposing a Parallel Doherty Power Amplifier to broaden the PAs instantaneous bandwidth, designed with frequency range of operation for 2.45 – 2.70 GHz to support WiMAX applications and future broadband signals.Dissertation/ThesisMasters Thesis Electrical Engineering 201

    Advanced 3-V semiconductor technology assessment

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    Components required for extensions of currently planned space communications systems are discussed for large antennas, crosslink systems, single sideband systems, Aerostat systems, and digital signal processing. Systems using advanced modulation concepts and new concepts in communications satellites are included. The current status and trends in materials technology are examined with emphasis on bulk growth of semi-insulating GaAs and InP, epitaxial growth, and ion implantation. Microwave solid state discrete active devices, multigigabit rate GaAs digital integrated circuits, microwave integrated circuits, and the exploratory development of GaInAs devices, heterojunction devices, and quasi-ballistic devices is considered. Competing technologies such as RF power generation, filter structures, and microwave circuit fabrication are discussed. The fundamental limits of semiconductor devices and problems in implementation are explored
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