The application of quasi-optical techniques to millimetre wave radar

Abstract

The application of Quasi Optical techniques has been of great benefit to the field of instrumentation for frequencies between 750Hz and several hundred OHz. The application of Quasi Optical techniques to millimetre wave radar, described in this thesis, has produced an FMCW Doppler radar capable of operation at 940Hz and 1400Hz. Total polarization agility and a capability to operate over a very wide bandwidth is demonstrated. Quasi Optical circuits are proposed as solutions for many of the system requirements, and these are fully analyzed. Significant benefits of these techniques are demonstrated, and future improvements are suggested. A new design tool, in the form of a program, for Quasi Optical circuit analysis is presented and is used for the analysis of all the optical circuits in this thesis. The program has speeded up the design process for optical circuits. A new type of feedhorn is described and characterized. Its performance compares well with existing feedhorns, and it provides a low cost alternative to existing antenna requirements.