Coherent side lobe canceller circuit for received parasitic signals - includes digital circuitry for calculating weighting coefficients to be applied to mixer combining signals from main and secondary aerials

摘要

The circuit includes a mixer circuit (60) which effects a linearly weighted combination of the three channels from the main aerial (1) and auxiliary aerials (2,3) in the receiving system. Analogue-digital convertors are connected to the receiving channels (11,21,31), and a digital circuit (40) calculates the weighting coefficients for each channel. The outputs of the calculating circuit are applied to digital-analogue convertors to provide analogue signals used to control the weighting (601, 602) within the mixer circuit. The mixer circuit is an analogue circuit operating with hyperfrequency signals. ADVANTAGE - Circuit reduces power of parasitic signals received by secondary lobes of aerial.