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Visar resultat 1 - 5 av 28 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Heterostructure barrier varactors

   Författare :Lars Dillner; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency multiplier; power source; III-V semiconductor; heterostructure barrier varactor HBV ; submillimeter wave; varactor diode; millimeter wave;

   Sammanfattning : .... LÄS MER

3. 2. SiC Varactors for Dynamic Load Modulation of Microwave Power Amplifiers

   Författare :Christer Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear characterization; varactors; active load-pull; power; microwave; amplifier; dynamic load modulation; SiC; energy efficiency;

   Sammanfattning : The rapid consumer adoption of mobile services is leading to an exponential growth in wireless data traffic. In order to accommodate more concurrent high data-rate users, the required complexity of transmitting radio base station (RBS) power amplifiers (PAs) is increasing. LÄS MER

4. 3. High Efficiency Microwave Amplifiers and SiC Varactors Optimized for Dynamic Load Modulation

   Författare :Christer Andersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear measurements; power amplifiers; load modulation; GaN; SiC; varactors; HEMT; wide bandgap technology; energy efficiency;

   Sammanfattning : The increasing use of mobile networks as the main source of internet connectivity is creating challenges in the infrastructure. Customer demand is a moving target and continuous hardware developments are necessary to supply higher data rates in an environmentally sustainable and cost effective way. LÄS MER

5. 4. High Temperature Superconducting and Tunable Ferroelectric Microwave Devices

   Författare :Erik F. Carlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; varactors; tunable microwave circuits; conformal mapping; cryogenic probe station; ferroelectrics; high temperature superconductors; microwave circuits; narrow-band filters; phase-shifter;

   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

7. 5. Millimetre wave waveguide enclosed grid frequency multipliers and imaging

   Författare :Robin Dahlbäck; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Millimeter wave; THz imaging; THz sources; Grid; Heterostructure Barrier Var- actors HBVs ; Varactors; Array; FMCW; 2D-grid; Quasi-optical.; Frequency multipliers; Radars; sub-millimetre waves; Schottky diodes;

   Sammanfattning : The utilisation of the THz spectrum ( 0.3-10 THz ) is hampered by fundamental difficulties in generating power at these frequencies. LÄS MER