Sökning: "microwave devices"
Visar resultat 1 - 5 av 145 avhandlingar innehållade orden microwave devices.
1. Silicon Carbide Microwave Devices
Sammanfattning : This work deals with silicon carbide (SiC) microwave devices. It treats two devices; the Schottky diode and the metal semiconductor field effect transistor (MESFET). Different MESFET materials, fabrication processes, theoretical models for physical simulation, and device models are presented. LÄS MER
2. Microwave power device characterization
Sammanfattning : The first part of the thesis covers work done on device characterizationmethods. A statistical method for estimating small-signal model parametersin FET-models was proposed. A maximum likelihood estimator wasderived and the new method was compared to a standard direct extractiontechnique. LÄS MER
3. High Temperature Superconducting and Tunable Ferroelectric Microwave Devices
Sammanfattning : This thesis addresses some applications of High Temperature Superconductors (HTS) and ferroelectric materials in tunable microwave devices and circuits. The work is divided into three main areas: i) modeling of multilayered structures including ferroelectric layers, ii) realization and characterization of tunable coplanar waveguides (CPW), capacitors and resonators based on ferroelectrics, and iii) an investigation of microstrip HTS K-band filters. LÄS MER
4. Nonlinear Characterization of Wideband Microwave Devices and Dispersive Effects in GaN HEMTs
Sammanfattning : Measurements play a key role in the development of microwave hardware as they allow engineers to test and verify the RF performance on a system, circuit, and component level. Since modern cellular standards employ complex modulation formats with wider signal bandwidths to cope with the growing demand of higher datarates, nonlinear characterization using wideband stimuli is becoming increasingly important. LÄS MER
5. Determining and Optimizing the Current and Magnetic Field Dependence of Spin-Torque and Spin Hall Nano-Oscillators : Toward Next-Generation Nanoelectronic Devices and Systems
Sammanfattning : Spin-torque and spin Hall nano-oscillators are nanoscale devices (about 100 nm) capable of producing tunable broadband high-frequency microwave signals ranging from 0.1 GHz to over 65 GHz that several research groups trying to reach up to 200 - 300 GHz. LÄS MER