Frequency demodulator for recovering SECAM chrominance signal and method thereof

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.