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Title: A quasi-optical astronomical receiver
Author: Lesurf, James Christopher George
ISNI:       0000 0001 3608 4312
Awarding Body: Queen Mary University of London
Current Institution: Queen Mary, University of London
Date of Award: 1981
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This thesis describes the work undertaken in producing the passive radio-frequency section of a heterodyne receiver for use on the United Kingdom Infra-Red Telescope at signal frequencies in the 200-300 GHz range. This is a Quasi-Optical system, comprised of a Martin-Puplet polarising interferometer employed as a diplexer and the lenses and feed horns by which the diplexer was coupled to the telescope, local oscillator, and mixer. The Gaussian beam-mode approach was employed to develop a theoretical basis for understanding the operation of such a system upon coherent paraxial beams. Quasi-Optical systems were then designed and their performance predicted by the application of this extension of Gaussian optics. Two such systems were constructed and their performance determined by laboratory measurements to be as predicted. One of these systems was then installed on the telescope where it was shown to function as designed. As part of the calibration and test routine on the telescope a number of astronomical measurements were made, including a determination of the apparent temperatures of the planets Jupiter and Saturn by a method different to that employed for results previously published. The Quasi-Optical receiver was successfully calibrated and commissioned as a common-user instrument. As such it will continue to be used in a variety of astronomical research programs undertaken by various groups.
Supervisor: Not available Sponsor: Science Research Council
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Physics ; heterodyne receiver ; Quasi-Optical systems ; Gaussian optics.