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RF gain enhancement for cellular telephone

  • US 5,898,908 A
  • Filed: 10/09/1996
  • Issued: 04/27/1999
  • Est. Priority Date: 10/09/1996
  • Status: Expired due to Term
First Claim
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1. A portable radio telephone with enhanced gain control comprising:

  • a) an RF transmitter adapted to provide an RF signal;

    b) internal amplifier circuitry having variable gain for providing variable power amplification of the RF signal to produce an output RF signal;

    c) an internal antenna coupled to said internal amplifier circuitry and adapted to transmit the output RF signal;

    d) an interface adapted to couple said telephone to an external antenna to transmit the output RF signal from the external antenna when said interface is coupled to said external antenna;

    e) means for generating a first signal representative of the presence of an external power source, a second signal representative of a request for hands-free operation of said telephone, and a third signal representative of the presence of an external microphone and speaker; and

    f) logic circuitry coupled to said internal amplifier circuitry for controlling the variable gain of said internal amplifier circuitry, said logic circuit being operative to increase the gain of said internal amplifier circuitry from a first gain level to a second gain level within the same power class rating only when said first, second and third signals are simultaneously present.

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