GB723008A - Improvements in or relating to radar systems - Google Patents

Abstract

723,008. Pulse radar. DECCA RECORD CO., Ltd. Aug. 5, 1952 [Dec. 17, 1951], No. 29540/51. Drawings to Specification. Class 40(7). In a pulse radar operating simultaneously or selectively at two or more harmonic radio frequencies the output from the pulsed transmitter oscillator is applied to a harmonic generator. As illustrated in Fig. 1 (not shown), the direct output from a pulsed magnetron oscillator and the fourth harmonic produced by a coaxial-line diode and filter are applied simultaneously to separate directional aerials or selectively by means of a waveguide switch to a common aerial or to separate aerials. At the receiver, Fig. 2 (not shown), the high- and lowfrequency signals received by separate aerials are reduced to a common IF by means of separate local oscillators having a common AFC, the outputs from the two mixers being selectively applied to a single IF channel; in a modification, Fig. 3 (not shown), the highfrequency local oscillator comprises a lowerfrequency oscillator and harmonic generator. Alternatively separate IF channels may be employed, Fig. 4 (not shown), the output from a single local oscillator being applied drectly and via a harmonic generator to the two mixers and the outputs from the two channels being applied either to separate displays or to a common display.