×

Automatic threshold squelch

  • US 4,411,021 A
  • Filed: 07/27/1981
  • Issued: 10/18/1983
  • Est. Priority Date: 07/27/1981
  • Status: Expired due to Term
First Claim
Patent Images

1. An automatic threshold squelch circuit, for radio receiver having a demodulator responsive to noise signals from the receiver demodulator for generating a mute signal when no transmission is being received by the receiver, said squelch circuit comprising:

  • noise detector means for producing a unidirectional signal level as a function of the noise signal from the demodulator;

    memory means, coupled to the noise detector means, for sampling and storing the unidirectional signal level when no transmissions are being received by the receiver;

    comparator means, coupled to the detector means and the memory means, for comparing the unidirectional signal level from the noise detector means to the stored signal level, and generating an unmute signal when the uni-directional signal level is less than the store signal level.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×