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Digital phase detector

  • US 3,956,623 A
  • Filed: 10/21/1974
  • Issued: 05/11/1976
  • Est. Priority Date: 10/21/1974
  • Status: Expired due to Term
First Claim
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1. A digital phase detector which periodically detects the phase angle θ

  • k of a carrier signal in which data are encoded as discrete phase changes, said detector comprising;

    means responsive to said carrier signal for separating said carrier signal into its in-phase and quadrature-phase signal components Ro cos θ

    (t) and Ro sin θ

    (t);

    means for converting said signal components Ro cos θ

    (t) and Ro sin θ

    (t) at predetermined modulation intervals, into encoded binary signals Ro cos θ

    hd k and Ro sin θ

    k ;

    means responsive to said binary signals for forming said phase angle θ

    k that is proportional to the encoded data, said forming means comprising;

    dividing means responsive to said binary signals Ro cos θ

    k and Ro sin θ

    k for digitally forming the quotient Ψ

    of said binary signals, such that |Ψ

    |≦

    1;

    data look-up means for digitally forming a reference angle signal Φ

    such that Φ

    = tan -1 Ψ

    ; and

    logic means for modifying the reference signal Φ

    to be the phase angle θ

    k, said modification being determined by said binary signals Ro cos θ

    k and Ro sin θ

    k.

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