Visar resultat 1 - 5 av 87 avhandlingar innehållade ordet sis.
Sammanfattning : In most radio astronomy instrumentation, cryogenic low noise amplifiers (LNA) are used as intermediate frequency (IF) amplifiers. The system noise temperature is among the most important parameters of a receiver and requires state of the art components. LÄS MER
Sammanfattning : Demand on ultimately sensitive heterodyne receivers for, e.g., radio astronomy and environmental science instrumentation, has driven large research activities on novel materials and devices for extending the frequency range into the THz domain. LÄS MER
Sammanfattning : This thesis deals with several distinct subjects such as thin film deposition, design, fabrication and characterization of components for low-noise THz electronics.High energy-gap superconducting materials are of specific importance for low-noise THz mixer applications. LÄS MER
Sammanfattning : 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. LÄS MER
Sammanfattning : .... LÄS MER