Automatic system for measuring millimeter wave intensity distribution based on a glow discharge detector

Abstract

An automatic system is described for the measurement of intensity distribution of millimeter electromagnetic waves propagating inside a hollow conducting pipe, whose diameter is larger than the free space wavelength. A miniature glow discharge tube served as the millimeter wave detector. This tube offers many advantages over solid state detectors in applications for systems of the kind described here. A mechanical apparatus moved the detector along a spiral trajectory, which is suitable for round pipes. The position of the detector was traced by an optical chopper. A microcomputer was applied for controlling the movements of the mechanical apparatus collecting the data from the detector and storing it for further analysis. Pictures of the millimeter wave intensity were obtained on a small printer controlled by the microcomputer.