Search for dissertations about: "hot-electron bolometer"

Showing result 1 - 5 of 16 swedish dissertations containing the words hot-electron bolometer.

2. 1. 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

4. 2. 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

5. 3. Thermoelectric- and hot-electron effects in graphene devices

   Author : Grigory Skoblin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Parylene; bolometer; CVD; encapsulation; graphene; thermoelectric effects;

   Abstract : A technology of encapsulation of graphene in Parylene was introducedas an alternative to encapsulating graphene in hBN. Edge contacts to theencapsulated graphene in this case showed resistivity down to 14 Ohm um,which is the lowest reported value so far. READ MORE

6. 4. NbN Hot Electron Bolometric Mixers for a Quasi--Optical THz Receiver

   Author : Matthias Kroug; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; bolometric mixer; superconducting NbN; heterodyne detection; hot electron effect; quasi-optical;

   Abstract : Experimental work on the development of a quasi-optical heterodyne receiver for the THz frequency range is reported. The mixing device is a superconducting hot electron bolometer (HEB) made from ultrathin, d = 3 - 5 nm, niobium nitride (NbN) films. READ MORE

7. 5. Antenna Integrated Superconducting Mixers

   Author : Hans Ekström; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; tapered slotline antenna; mixer; double dipole antenna; superconducting; hot electron; receiver; Niobium; bolometer; trilayer junction; edge junction; Niobium Nitride; SIS;

   Abstract : This thesis investigates the prospects of some different superconducting mixers integrated with planar antennas for the millimeter and submillimeter regime. Two kinds of Superconductor/Insulator/Superconductor (SIS) tunnel junctions for use in mixers have been fabricated; Nb/PbBi edge junctions and Nb trilayer junctions. READ MORE