Patent ID: 8107013

Claim:
A frequency demodulator for recovering a chrominance signal, the frequency demodulator comprising: a phase differentiator generating a phase difference component between neighboring samples from an input signal; and a phase estimator calculating a phase difference between the neighboring samples by using an arctangent approximation, based on the generated phase difference component, wherein the frequency demodulator generates a frequency-demodulated chrominance signal and the phase difference corresponds to the chrominance signal, wherein the phase differentiator comprises: a first delay line generating a first delayed sample by delaying a real number portion sample of the input signal; a first multiplier generating a first multiplication result by multiplying the real number portion sample and the first delayed sample; a second delay line generating a second delayed sample by delaying an imaginary number portion sample of the input signal; a second multiplier generating a second multiplication result by multiplying the imaginary number portion sample and the second delayed sample; a summator generating a real number portion of the phase difference component by summing the first multiplication result and the second multiplication result; a third multiplier generating a third multiplication result by multiplying the first delayed sample and the imaginary number portion sample; a fourth multiplier generating a fourth multiplication result by multiplying the second delayed sample and the real number portion sample; and a subtracter generating an imaginary number portion of the phase difference component by calculating a difference between the third multiplication result and the fourth multiplication result.