Sökning: "IF amplifier"

Visar resultat 16 - 20 av 37 avhandlingar innehållade orden IF amplifier.

1. 16. Reconfigurable and Wideband Receiver Components for System-on-Chip Millimetre-Wave Radiometer Front-Ends

   Författare :Shakila Bint Reyaz; Robert Malmqvist; Anders Rydberg; Luca Roselli; Uppsala universitet; []
   Nyckelord :Reconfigurable; Wideband; Receivers; Millimetre-Wave; Radiometers; System-on-Chip; Passive Imaging.; Engineering Science with specialization in Microwave Technology; Teknisk fysik med inriktning mot mikrovågsteknik;

   Sammanfattning : This thesis presents solutions and studies related to the design of reconfigurable and wideband receiver circuits for system-on-chip (SoC) radiometer front-ends within the millimetre-wave (mm-wave) range. Whereas many of today’s mm-wave front-ends are bulky and costly due to having discrete RF components, single-chip receiver modules could potentially result in a wider use for emerging applications such as wireless communication, short range radar and passive imaging security sensors if realised with adequate performances and at a lower cost. LÄS MER

3. 17. Optical Amplifiers and their Applications in Nonlinear Fiber-Optic Communication Systems

   Författare :Kent Bertilsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The work presented in this dissertation deals with the characterization and modeling of optical amplifiers as well as their applications in nonlinear transmission systems with the main motivation to enhance system capacity. In the first part of the dissertation the work is focused on two different types of amplifiers: the semiconductor laser amplifier (SLA) and the erbium-doped fiber amplifier (EDFA). LÄS MER

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

   Författare :Hawal Marouf Rashid; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

5. 19. High speed CMOS optical receiver

   Författare :Håkan Bengtson; Linköpings universitet; []
   Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : Optical communication develops very fast and is today the main method for long distance wired communication. However cost is still high. Looking back to the evolution of optical transmission systems, one main objective of system development has become more and more important; minimize cost per gigabytes per second per kilometre, Gb/s/km. LÄS MER

7. 20. Effects of acute metabolic interventions on hemodynamics, endothelial function and forearm glucose uptake

   Författare :Andreas Fugmann; Uppsala universitet; []
   Nyckelord :Medical sciences; Insulin; glucose; lipids; bloodflow; endothelium; MEDICIN OCH VÅRD; MEDICINE; MEDICIN; Medicine; medicin;

   Sammanfattning : Hyperinsulinemia is known to augment endothelium-dependent.vasodilation (EDV). If physiological levels of insulin lead to peripheral, vasodilation and if this vasodilation is an independent determinant of skeletal muscle glucose uptake is however under debate. LÄS MER