| 摘要 |
1,221,177. Radio signalling. INTERNATIONAL STANDARD ELECTRIC CORP. 25 June, 1969 [28 June, 1968], No. 32096/69. Heading H4L. In a radio repeater or transponder, the incoming signal is supplied via a filter 2 to a. three-stage tunnel diode amplifier 3 which due to the tunnel diode characteristic also acts as a limiter. The output of amplifier 3 is supplied to a mixer 4 and the output of a crystal oscillator 5 is supplied via a transistor frequency multiplier 7, a varactor frequency multiplier 8, a filter 9 and a hybrid coupler 10 to the mixer. A tunnel diode 11 amplifies and limits the output of the mixer 4 for retransmission via a travelling wave tube amplifier 13. The hybrid coupler 10 also supplies a further varactor frequency multiplier 15 providing a tracking signal which is combined with the main signal at 12. When the repeater is carried by a satellite, this tracking signal is used by the co-operating ground station to follow the motion of the satellite. |
