Search for dissertations about: "optical mixers"

Found 3 swedish dissertations containing the words optical mixers.

  1. 1. Photonic terahertz-wave generation, radiation and quasioptical integration

    Author : Biddut Kumar Banik; [2007]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

    Abstract : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. READ MORE

  2. 2. Characterisation and Modelling of Graphene FETs for Terahertz Mixers and Detectors

    Author : MICHAEL ANDERSSON; [2016]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; graphene; millimetre and submillimetre waves; power detectors; nonlinear device modelling; microwave amplifiers; nanofabrication; integrated circuits; noise modelling; Field-effect transistors FETs ; terahertz detectors; Volterra; subharmonic resistive mixers;

    Abstract : Graphene is a two-dimensional sheet of carbon atoms with numerous envisaged applications owing to its exciting properties. In particular, ultrahigh-speed graphene field effect transistors (GFETs) are possible due to the unprecedented carrier velocities in ideal graphene. READ MORE

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

    Author : Hawal Marouf Rashid; [2013]
    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