Sökning: "Directional Coupler"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Directional Coupler.

1. 1. 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

3. 2. Design, Simulation and Characterization of Some Planar Lightwave Circuits

   Författare :Yaocheng Shi; Anand Srinivasan; Sailing He; Daniel Erni; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; planar lightwave circuit; waveguide; coupler; multimode interference; photonic crystal waveguide; de multiplexer; triplexer; polarization beam splitter; dry etching; carrier life time.; Photonics; Fotonik;

   Sammanfattning : Optical devices based on planar lightwave circuit (PLC) technology have the advantages of small size, high reliability, possibility for large scale production, and potential integration with electronics. These devices are widely employed in optical telecommunications, sensing, data storage, imaging, and signal processing. LÄS MER

4. 3. On signal processing and electromagnetic modelling : applications in antennas and transmission lines

   Författare :Jonas Lundbäck; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector sensors; Statistical signal processing; Antennas; Directional Coupler; Tranmission lines; Partial discharge;

   Sammanfattning : This doctoral thesis is comprised of five parts. The first three parts concern signal processing and electromagnetic modelling of multiport antennas. The last two parts concern signal processing and transmission line theory applied to wave splitting on transmission lines. LÄS MER

5. 4. Novel RF MEMS Devices Enabled by Three-Dimensional Micromachining

   Författare :Umer Shah; Joachim Oberhammer; Raafat Mansour; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microelectromechanical systems; MEMS; Radio frequency microelectromechanical systems; RF MEMS; Micromachined transmission line; Micromachining; Tuneable capacitor; Switched capacitor; Coupled-line coupler; Tuneable directional coupler; Intermodulation distortion; MEMS varactor; Two-tone IIP3 measurement; Passive components and circuits; Reliability; Magnetic materials; NiFe multilayer composite; Permeability; Permittivity; Micromachined inductors;

   Sammanfattning : This thesis presents novel radio frequency microelectromechanical (RF MEMS) circuits based on the three-dimensional (3-D) micromachined coplanar transmission lines whose geometry is re-configured by integrated microelectromechanical actuators. Two types of novel RF MEMS devices are proposed. LÄS MER

7. 5. Design, fabrication and characterization of plasmonic components based on silicon nanowire platform

   Författare :Fei Lou; Lech Wosinski; Lars Thylén; Sebastian Lourdudoss; Anatoly Zayats; KTH; []
   Nyckelord :Planar integrated circuit; silicon photonics; plasmonics; subwavelength; directional coupler; polarization beam splitter; disk resonator; ring resonator; finite-difference time-domain; photonic crystal; electro-optic polymer; Purcell factor.;

   Sammanfattning : Optical interconnects based on CMOS compatible photonic integrated circuits are regarded as a promising technique to tackle the issues traditional electronics faces, such as limited bandwidth, latency, vast energy consumption and so on. In recent years, plasmonic integrated components have gained great attentions due to the properties of nano-scale confinement, which may potentially bridge the size mismatch between photonic and electronic circuits. LÄS MER