3 mm waves band radiometric sensor for array receiver

Abstract

In 3 mm wavelengths band the small-sized radiometric sensor has been developed as a base element for design of multichannel receiving array. The heterodyne circuit with input mixer has been chosen for sensor design. The sensor includes the mixer operating in a double-sideband (DSB) mode, intermediate frequency amplifier (IFA), square-law detector and low frequency amplifier (LFA). The conical horn is used at sensor's input as a feed of the main antenna. The mixer circuit uses beam-lead antiparallel-pair Schottky diodes of capacitance 30 fF and resistance 6 Ohm. IFA after mixer contains three amplifying stages in which the gain factor is 55 dB in 0.1-2.5 GHz frequency band. This construction is convenient for design of an array in form of two rows of receiver sensors, which are arranged in a focal plane of quasioptical antenna. Thus the sensor can find application for design of the passive imaging systems in a short-wave part of a millimeter waves band.