Sökning: "antennas"

Visar resultat 1 - 5 av 356 avhandlingar innehållade ordet antennas.

1. 1. Integrated Antennas : Monolithic and Hybrid Approaches

   Författare :Erik Öjefors; Anders Rydberg; Sayan Mukherjee; Duixian Liu; Uppsala universitet; []
   Nyckelord :Electronics; antenna travelling wave arrays; antenna phased arrays; phase shifters; micromachining; silicon; monolithic microwave integrated circuits; dipole antennas; loop antennas; slot antennas; Elektronik;

   Sammanfattning : This thesis considers integration of antennas and active electronics manufactured on the same substrate. The main topic is on-chip antennas for commercial silicon processes, but hybrid integration using printed circuit board technology is also addressed. LÄS MER

3. 2. Wideband Active and Passive Antenna Solutions for Handheld Terminals

   Författare :Peter Lindberg; Anders Rydberg; Anders Pers; Nicholas Buris; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; active antennas; impedance matching; dipole antennas; baluns; slot antennas; microstrip antennas; mobile antennas; multifrequency antennas; antenna proximity factors; receiving antennas; ferrite devices; Teknisk fysik;

   Sammanfattning : This thesis presents solutions and studies related to the design of wideband antennas for wireless handheld terminal applications. A method of electrically shortening the terminal chassis length to obtain resonance at high frequencies has been proposed and evaluated, thereby increasing the antennas impedance bandwidth. LÄS MER

4. 3. Decoupling and Evaluation of Multiple Antenna Systems in Compact MIMO Terminals

   Författare :Hui Li; Sailing He; Cyril Luxey; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; mutual coupling; compact antennas; frequency reconfigurable antennas; pattern reconfigurable antennas; meta-material antennas; mobile antennas; fractal antennas; collocated antennas; antenna measurement.;

   Sammanfattning : Research on multiple antenna systems has been a hot topic in recent years due to the demands for higher transmission rate and more reliable link in rich scattering environment in wireless communications. Using multiple antennas at both the transmitter side and the receiver side increases the channel capacity without additional frequency spectrum and transmitted power. LÄS MER

5. 4. Printable Green RFID Antennas for Embedded Sensors

   Författare :Yasar Amin; Hannu Tenhunen; Lirong Zheng; Qiang Chen; Leena Ukkonen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RFID; Antennas; Inkjet printing; Wideband Antennas; Narrow-band Antennas;

   Sammanfattning : In the recent years, radio-frequency identification (RFID) technology has been widely integrated into modern society applications, ranging from barcode successor to retail supply chain, remote monitoring, detection and healthcare, for instance. In general, an RFID tag or transponder is composed of an antenna and an application-specific integrated circuit chip. LÄS MER

7. 5. Predictor Antennas : Enabling channel prediction for fast-moving vehicles in wireless broadband systems

   Författare :Joachim Björsell; Mikael Sternad; Anders Ahlén; Fredrik Tufvesson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Predictor antenna; Channel prediction; Long-range prediction; Massive MIMO; Spline interpolation; Channel aging; Outdated CSI; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

   Sammanfattning : Many advanced transmission techniques utilize channel state information (CSI) at the transmitter (CSIT) to improve throughput, spectral efficiency, power efficiency, and other performance metrics. Estimating CSI accurately is important to fully benefit from many of these techniques. LÄS MER