GB871735A - Microwave distribution networks - Google Patents

Abstract

871,735. Radio-frequency input and output couplings for aerials; combined radio receiving and transmitting systems. SPERRY RAND CORPORATION. March 9, 1956 [March 14, 1955], No. 7549/56. Classes 40(5) and 40(7) Apparatus for distributing micro-wave power for an -antenna array comprises a primary micro-wave transmission line section; one or more secondary micro-wave transmission line sections which is, or each of which is, connected to a radiating means; a directional coupler coupling the, or each, secondary line section to the primary line section and adapted to transfer a predetermined portion of the energy in the primary line to the coupled secondary line; and one or more receiver transmission line sections which is, or each of which is, coupled to a secondary line section, to receive energy received in the secondary line section from its radiating means. In a stacked beam radar system it is required that the powers introduced into each beam are such as to produce a uniform return from a constant altitude target independent of its range. In the arrangement shown in Fig. 3 this is achieved if the powers radiated by the forms 5, 6, 7 and 8 into a common reflector are in the ratios 1:0À5: 0À25:0À125. The transmitter 11 feeds the form 5 directly through a waveguide 13; the remaining forms are coupled to the transmitter through waveguides 22, 23, 24 and directional couplers 14, 15, 16 which tap off the desired amount of power from waveguide 13. Receiver 30 is coupled to form 5 by a waveguide 31 and TR switch 41, an ATR switch 51 being provided on the waveguide 13. Receivers 33, 34, 35 are coupled to their respective horns through waveguides and TR switches 43, 44, 45. Since these switches are situated on the wrong side of the directional couplers 14-16, only a small amount of transmitter power passes to them so that they may be of a low power type; in fact the power may be insufficient to operate TR switch 45 so that it may be omitted, or the directional coupler may be designed to pass sufficient power to trigger a TR switch, or a reflective post may be provided in the secondary arm of the coupler to reflect sufficient power towards the TR switch to fire it. In a modification, Fig. 4 (not shown), the system is extended to feed seven horns from one transmitter and to couple the seven horns each to its own receiver. U.S.A. Specification 2,602,859 is referred to.