Search for dissertations about: "THz mixer"

Showing result 1 - 5 of 20 swedish dissertations containing the words THz mixer.

2. 1. Millimeter and Sub-Millimeter Wave Integrated Active Frequency Down-Converters

   Author : Yu Yan; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 145 GHz; self-oscillating mixer; mixer; conversion gain; millimeter wave; radar; mHEMT; noise figure; monolithic; sub-millimeter wave; InP; THz; resistive mixer; Gilbert mixer; DHBT; SiGe; 340 GHz; 220 GHz; FMCW; transconductance mixer; BiCMOS; transceiver; harmonic; GaAs;

   Abstract : In recent years, the increasing amount of data transmission, the need for automotiveradars, and standoff imaging for security applications are the main factors that accelerateresearch in the millimeter and sub-millimeter wave frequency ranges. The semiconductorindustries have continuously developed their processes, which have opened upopportunities for manufacturing monolithically integrated circuits up to a few hundredGHz, based on transistor technologies. READ MORE

4. 2. NbN and NbTiN Hot Electron Bolometer THz Mixers

   Author : Pourya Khosropanah; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; receiver noise; hot electron bolometer; superconducting detector; spiral antenna; NbTiN; submillimeter mixer; THz mixer; HEB; FTS; NbN; quasioptical receiver; heterodyne receiver; double slot antenna; twin slot antenna; Fourier Transform Spectrometer;

   Abstract : The thesis reports the development of Hot Electron Bolometer (HEB) mixers for radio astronomy heterodyne receivers in THz frequency range. Part of this work is the fabrication of HEB devices, which are based on NbN or NbTiN superconducting thin films (≤5 nm). They are integrated with wideband spiral or double-slot planar antennas. READ MORE

5. 3. Integration of Planar Antennas with MMIC Active Frontends for THz Imaging Applications

   Author : Yogesh Karandikar; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sub-Harmonic Resistive Mixer; Planar Antennas; Gaussian Coupling; MMIC; Gilbert Cell Mixer; THz;

   Abstract : In recent years, there has been constant growth in using THz frequencies or mm, sub- mm wavelengths for various applications such as: Astronomy, Atmospheric studies, security, bio-medical imaging. All these applications are now seen more feasible due to rapid enhancements of semi-conductor processing technologies. READ MORE

6. 4. MgB2 hot-electron bolometer mixers for sub-mm wave astronomy

   Author : Evgenii Novoselov; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hot-electron bolometer; gain bandwidth; noise bandwidth; thin film; electron-phonon interaction; noise temperature; THz detector; conversion gain; mixer; magnesium diboride; superconductor;

   Abstract : Spectroscopy and photometry in the terahertz (THz) range of remote space objects allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. Due to high spectral resolution, THz heterodyne receivers al- low for studying dynamical properties of space objects manifested in doppler-shifted emission lines. READ MORE

7. 5. Superconducting THz mixers based on MgB2 film

   Author : Stella Bevilacqua; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bolometers; IF bandwidth.; superconductors; MgB2; THz Detectors; mixers;

   Abstract : Superconducting NbN hot electron bolometer (HEB) mixers are widely used in terahertz radio astronomy. Such mixers have superior performance compared to SIS and Schottky diode mixers at frequency above 1THz. However, their drawback is a limited IF bandwidth. READ MORE