Patent ID: 7564929

Claim:
An apparatus for the coherent demodulation of a Binary Phase Shift Keying BPSK signal having a frequency f, comprising: means for recovering a carrier signal (C) having a frequency 2f from said BPSK signal, means for injecting said carrier signal having a frequency 2f in an injection locking oscillator (ILO), which has a natural resonant frequency f r which is substantially equal to f, said injection locking oscillator providing differential output signals (O p , O n ) having a phase difference of π rad, which the original carrier with a phase shift of (θ e −k)/2, where θ e = arc ⁢ ⁢ sin ⁡ ( f r - f α ⁢ ⁢ A i ⁢ f ) where α and k are parameters that depend on the type of predominant non-linearity in the injection locking oscillator (ILO), and A i is the amplitude of the recovered carrier signal at a frequency of 2f, and means for combining the differential output signals (O p , O n ) with copies of the incoming BPSK signal in order to generate a demodulated signal (DEMOD).