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Repeater

  • US 6,888,881 B1
  • Filed: 06/20/2000
  • Issued: 05/03/2005
  • Est. Priority Date: 06/20/2000
  • Status: Expired due to Fees
First Claim
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1. A relay device, in which a radio wave of a parent station is received and amplified and a transmission radio wave having the same frequency as that of the radio wave of the parent station is transmitted, comprising:

  • a main reception antenna for receiving both the radio wave of the parent station and a go-around radio wave of a relay station;

    a subsidiary reception antenna for receiving the go-around radio wave of the relay station;

    a changeable attenuator for changing an amplitude of a signal of the go-around radio wave received by the subsidiary reception antenna;

    a phase shifter for changing a phase of the signal of the go-around radio wave received by the subsidiary reception antenna;

    a composite signal producer for producing a composite signal from a signal of the radio wave of the parent station received by the main reception antenna, the signal of the go-around radio wave of the relay station and the signal of which the amplitude is changed by the changeable attenuator and the phase is changed by the phase shifter;

    a directivity coupler for extracting a composite voltage of the composite signal output from the composite signal producer;

    an electric power detector for obtaining a composite electric power from the composite voltage extracted by the directivity coupler; and

    a microcomputer for controlling both a change of the amplitude performed by the changeable attenuator and a change of the phase performed by the phase shifter so as to minimize an average value of the composite electric power obtained by the electric power detector.

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