Search for dissertations about: "HEMT"

Showing result 1 - 5 of 75 swedish dissertations containing the word HEMT.

2. 1. Integrated VCOs in Gallium Arsenide HEMT technologies with a novel varactor structure

   Author : Mattias Ferndahl; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; design; Oscillator; HEMT; pHEMT; MMIC; VCO; varactor; GaAs; mHEMT;

   Abstract : This thesis presents results on metamorphic and pseudomorpic GaAs HEMT based Voltage Controlled Oscillators and a novel high-Q varactor structure, used in the VCOs, together with a straightforward extraction procedure for the varactors.Theory and fundamentals around LC-oscillators with oscillator criteria, phase noise and different topologies are given as background together with VCO phase noise measurement methods and an overview on device flicker noise; its physical origin and measurement. READ MORE

4. 2. Development of Cryogenic Low Noise 4-8 GHz HEMT Amplifier and its Advanced Characterization

   Author : Erik Sundin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shot-noise; low noise amplifier; cryogenic amplifier; sis; noise measurement; HEMT;

   Abstract : In most radio astronomy instrumentation, cryogenic low noise amplifiers (LNA) are used as intermediate frequency (IF) amplifiers. The system noise temperature is among the most important parameters of a receiver and requires state of the art components. READ MORE

5. 3. Low-Power HEMT LNAs for Quantum Computing

   Author : Yin Zeng; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low-noise amplifier; qubit; Cryogenic; InP HEMT.; quantum computing; low-power;

   Abstract : The rapid development of quantum computing technology predicts much more qubits to handle in the detection, readout, and amplification of qubits than in today's system. Due to the limited cooling capability of the dilution refrigerator, the current low-noise amplifiers (LNAs) are in need of ten to hundred times reduced dc power consumption yet with lowest noise temperature at qubit readout frequencies, typcially 4-12 GHz. READ MORE

6. 4. InP HEMT Technology and Applications

   Author : Anders Mellberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Indium phosphide InP ; cryogenic LNA; high electron mobility transistor HEMT ; metal-insulator-metal capacitor; MODFET; thin film resistor; semiconductor device fabrication; MMIC;

   Abstract : Indium phosphide high electron mobility transistors (InGaAs/InAlAs/InP HEMTs) exhibit the highest cut-off frequencies and the lowest microwave noise figures of all transistor technologies. Both InP HEMT technology and associated circuit demonstrators are therefore interesting to explore further. READ MORE

7. 5. Optimum GaN HEMT Oscillator Design Targeting Low Phase Noise

   Author : Mikael Hörberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low frequency noise; resonator coupling; cavity resonator; GaN HEMT; MMIC; reflection oscillator; phase noise;

   Abstract : The thesis considers design of low phase noise oscillators, given the boundary condition of the used technology. Important conditions are the power handling of the active device, device noise floor, the quality factor of the resonator, bias settings, and low frequency noise. READ MORE