Patent ID: 7397300

Claim:
An FSK demodulator system with tunable spectral shaping comprising: a pair of quadri-correlators responsive to first and second quadrature signals, one of said pair deriving first and second signals representative of the frequency deviation of said quadrature signals at even integer multiples of said frequency deviation and for resolving the modulated FSK data represented by said quadrature signals and the other of said pair deriving first and second signals representative of the frequency deviation of said quadrature signals at odd integer multiples of said deviation frequency and for resolving the modulated FSK data represented by said quadrature signals; and a delay control circuit for setting a delay to each of said pair of quadri-correlators to control said first and second signals representative of the frequency deviation of said quadrature signals derived by each of said pair of quadri-correlators and generate a tuned spectral response at both even and odd integer multiples of said frequency deviation.