Search for dissertations about: "S-parameters Measurements"

Showing result 1 - 5 of 15 swedish dissertations containing the words S-parameters Measurements.

2. 1. Design and development of a microwave multifrequency polarimetric scatterometer for biosphere remote sensing

   Author : Anders Stjernman; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polarimetry; scatterometer; microwave remote sensing; calibration; network analyzer based; S-parameters; scattering matrix;

   Abstract : Microwave radar and radiometer techniques are used to gather crucial information about the earth and its atmosphere. The ERS-1, JERS-1, RadarSAT and NASA’s Mission to Planet Earth projects are designed to study the changing global environment. In all these endeavors, the key instrument is the radar or scatterometer. READ MORE

4. 2. Improved components for 2SB THz receivers with enhanced sideband rejection performance

   Author : Hawal Marouf Rashid; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thin-film Circuits; S-parameters Measurements; Sideband Separating Receivers; Superconducting Circuits; Millimetre Wave Mixers; Directional Coupler; Terahertz Technology; Waveguide Directional Coupler;

   Abstract : The thesis presents work done in improving the sideband rejection ratio for 2SB cryogenic radio astronomy receivers in general, but more specifically, for the future Onsala 20 m 3-mm receiver system and the ALMA Band 5. In order to attain better than 15 dB sideband rejection ratio over the entire bandwidth (approximately 26% RF fractional bandwidth and one octave the IF bandwidth), it is necessary to improve both RF and IF hybrid assembly to optimum performance, i. READ MORE

5. 3. Design of High Linearity MMIC Power Amplifiers for Space Applications

   Author : Oliver Silva Barrera; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pHEMT; GaAs; reliability; Power amplifier; non-linear modeling; Junction temperature; C-Band; Infrared measurements;

   Abstract : The high linearity performance in satellite transmitters is receiving increasing attention due to the demands of higher data rates in satellite communication links. During the last decade, digital communication links in satellite system have been replacing the previous analog links increasing the channel efficiency by allocating multiple carriers in the transponder bandwidth. READ MORE

6. 4. Antenna Evaluation for Vehicular Applications in Multipath Environment

   Author : Edith Condo Neira; Erik G. Ström; Kristian Karlsson; Claes Beckman; RISE; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicular antenna evaluation; V2V measurements; LTE.; multipath environment; IEEE 802.11p; V2V simulations;

   Abstract : Antennas are essential components in any wireless communication system. To evaluate them is challenging, especially when new technologies are emerging.Future intelligent transport systems, where vehicular communications play an important role will cover important aspects such as traffic safety and traffic efficiency. READ MORE

7. 5. Characterisation of terahertz integrated membrane circuits

   Author : Johanna Hanning; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; waveguide width error; calibration; THz; membrane circuit; TRL; measurement uncertainty; single-flange 2-port; 220–325 GHz; cable flex; WR-03; VNA; S-parameter;

   Abstract : In this thesis a novel measurement setup and thru-reflect-line (TRL) calibration kit for vector network analyser (VNA) measurements at 220 GHz to 325 GHz (WR-03) is presented. Measurements on passive membrane circuit devices under test (DUTs) show improvement in the S-parameters compared to a waveguide integrated membrane circuit setup in previous work, especially in reducing the ripples and increasing repeatability of the measurements. READ MORE