GB1377818A - Relay stations for use in a telecommunication transmission system - Google Patents

Abstract

1377818 Relay systems SIEMENS AG 23 June 1972 [4 Aug 1971] 29476/72 Heading H4L In a satellite relay station where the I.F. band derived from the received R.F. signal 1 is split into separate adjacent sub-bands a to m, Fig. 1, for separate amplification 14, each amplified I.F. signal is separately combined 15 with a respective output t1s to t12s of a common carrier oscillator 30, 34, 35, and fed to a respective amplifier 16, the outputs of all of which are combined 23 and transmitted 25, 29. The I.F. and mixer channel 14, 15, 16 is duplicated 22 for reliability, and each I.F. sub-band channel 18, 19, 20, 21, 22 incorporates this redundancy. Channels a-f are odd channels, and g-m are even channels, and feed respective outputs 23, 25 and 27, 29. The duplicate mixers (15) also receive the same carrier frequency t1s<SP>1</SP> to t12s<SP>1</SP>, all these carriers t1s to t12s<SP>1</SP> being derived from a single oscillator 30 by means of frequency dividers 31 ( x 12) and 35 ( x 16), travelling wave amplifiers 39, 41, 49, 50, and hybrid junctions 40 42, 51, 52; redundancy 36, 45, 46 is again provided. The oscillator 30 also provides the receiver superhet carrier frequency t1e (t1e<SP>1</SP>, t2e, t2e<SP>1</SP>) by means of divider 33 and couplers 37, 38, 47, 48. Receiver redundancy 7, 11 is also included. The transmitter carrier amplifiers 39, 41, 49, 50 may also be used to amplify the receiver carrier output of the oscillator (Fig. 2, not shown), filters (55, 56, 58, 59) being used to combine and separate the two carriers before and after the amplifier (57). Circuits (Figs. 3, 4, not shown), are disclosed for providing a beacon signal for satellite tracking at the transmitted carrier frequency and they include means for phase modulating the beacon signal with telemetry information (at 74, 76).