Sökning: "radio astronomy instrumentation"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden radio astronomy instrumentation.
Sammanfattning : The thesis presents work done in developing instrumentation for mm- and submm-wave radio astronomy. The work described is in several fields. The greater part of the thesis is concerned with sensitive heterodyne receivers and in particular the cryogenically cooled mixers. In paper A the SEST telescope and its observing system are described. LÄS MER
Sammanfattning : .... LÄS MER
Sammanfattning : This thesis is focused on the field of instrumentation for radio-astronomy and atmospheric science, and specifically deals with problems such as optical design and its verification, horn antennas and receiver optics’ components, different aspects of measurement systems in order to characterize low-noise THz receivers, and its calibration techniques.Ultra low-noise Terahertz receivers, used in radio-astronomy, are typically coupled to the telescope system through relay optics that provides guiding of the signal to the receiver frontend with minimal loss. LÄS MER
Sammanfattning : This thesis presents work done in developing instrumentation for mm-wave radio astronomy. The main subject of the thesis is a sideband separating (2SB) receiver for 85-115 GHz based on a quadrature scheme with two identical SIS mixer junctions pumped by a LO applied with 90° phase difference. LÄS MER
Sammanfattning : This PhD thesis presents the work that was done developing radioastronomy instrumentation. The first part of this work deals with 2-stage low-noise cryogenic amplifiers using commercial GaAs HEMT transistors for frequency bnads: 3.4-4.6 GHz, 4-8 GHz and 8-9 GHz. LÄS MER