Sökning: "bandwidth conversion"

Visar resultat 1 - 5 av 59 avhandlingar innehållade orden bandwidth conversion.

1. 1. Study of MgB2 HEB mixers at THz frequencies

   Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; noise temperature; mixers; bandwidth; THz detectors; superconductors; bolometers; conversion gain; MgB2;

   Sammanfattning : The terahertz (THz) range is very attractive for astronomical observations. Spectroscopy and photometry of remote space objects in the THz range 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. LÄS MER

3. 2. MgB2 hot-electron bolometer mixers for sub-mm wave astronomy

   Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. On Performance of Digital Radio Receiver in Non-Gaussian Interference

   Författare :Kia Wiklundh; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bandwidth conversion; performance estimation; APD; interference; minimum shift keying; man-made noise; Gaussian approximation; measurement; emission requirements; non-Gaussian interference; micro-wave oven; MSK; amplitude probability distribution; emission;

   Sammanfattning : Interference from electrical equipment can degrade a co-located digital radio receiver severely. To avoid this performance degradation it is necessary to have estimation methods to predict the influence from an interference environment on a radio receiver in advance. LÄS MER

5. 4. A new approach for considering the interference impact on digital radio systems from complex interference environments

   Författare :Kia Wiklundh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; minimum shift keying; class A; amplitude probability distribution; bandwidth conversion; Gaussian approximation; emission; non-Gaussian interference; performance estimation; man-made noise; measurement; emission requirements; micro-wave oven; MSK; coding gain; APD; interference;

   Sammanfattning : Interference from electrical equipment can severely degrade aco-located digital radio receiver. To avoid such performance degradation, it isnecessary to have estimation methods to predict the influence of an interferenceenvironment on a radio receiver. LÄS MER

7. 5. Photonic Techniques for Real-Time Analog-to-Digital Conversion

   Författare :Johan Stigwall; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tunable THz generation; photonic time-stretch; photonic sampling; Photonic analog-to-digital conversion; optical signal processin; photonic binary encoding; microwave photonics; photonic thresholding;

   Sammanfattning : All-electronic analog-to-digital conversion (ADC) technology is limited by the timing accuracy and inherent speed of semiconductor materials. Photonic techniques, however, can potentially enable real-time ADC at a considerably wider bandwidth, higher sample rate and/or resolution, thanks to the availability of extremely accurate optical clocks and the immense bandwidth of optical systems. LÄS MER