GB1107416A - Improvements in radar systems - Google Patents

Abstract

1,107,416. Radar. CSF-COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. 14 June, 1965 [17 June, 1964], No. 25125/65. Heading H4D. In a monopulse radar with two channels, each having a primary element which cooperates with a common reflector so that two narrow beam radiation polar diagrams are produced (Fig. 1, not shown), in which the signals A and B received in the channels are made available as outputs representing respectively the sum and the difference of the said signals, circuitry is provided to derive from those outputs a further output representing the product of the said signals. As described, the outputs (A+B) and (A - B) are taken through I.F. amplifiers 1, 2, Fig. 3, to an adder 3 and to a subtractor 4, the outputs of which, representing, respectively, 2A and 2B are taken to a phase-multiplying detector 5, from which a product representing A.B is taken to a final stage 6. In an alternative, the sum and difference outputs are taken through amplifiers (10), (11), Fig. 4 (not shown), to square-law detectors (21), (22), whose outputs are taken to a subtracter (23), from which a product output is obtained. It is stated that when echoes of pulses are received from a plurality of moving targets, unwanted product values of signals from different targets may be eliminated by providing integrating devices in the final stage 6, Fig. 3, to take advantage of phase differences between signals (which may be due to the Doppler effect). Such a device may make use of a suitable fluorescent display screen of a cathode-ray tube.