Frequency Modulation Receiver and Frequency Modulation Receiving Method
AssigneeMStar Semiconductor, Inc.
InventorsYu-Che SU, Kuan-Chou LEE, Tai-Lai TUNG
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Abstract
A frequency modulation receiver includes a frequency modulation demodulation circuit that generates a first signal, and a phase locked loop (PLL) circuit coupled to the frequency modulation demodulation circuit to receive the first signal. The PLL circuit includes: a voltage-controlled oscillator (VCO), generating an oscillation output signal according to a filtered output signal; a phase detector, coupled to the VCO, generating a phase signal according to the oscillation output signal and the first signal; and a proportional-integral-derivative (PID) filter, coupled to the VCO and the phase detector, receiving the phase signal and generating the filtered output signal to the VCO.
Claims7
A frequency modulation receiver, comprising:
- a frequency modulation demodulation circuit, generating a first signal;
- and
- a first phase locked loop (PLL) circuit, coupled to the frequency modulation demodulation circuit to receive the first signal, the PLL circuit comprising:
- a voltage-controlled oscillator (VCO), generating an oscillation output signal according to a filtered output signal;
- a phase detector, coupled to the VCO, comprising a phase extractor for generating a phase signal according to the oscillation output signal and the first signal;
- and
- a proportional-integral-derivative (PID) filter, coupled to the VCO and the phase detector, receiving the phase signal and generating the filtered output signal to the VCO, the PID filter comprising:
- a proportion circuit, multiplying the phase signal by a proportion coefficient to generate a proportion result;
- an integration circuit, performing an integration calculation on the phase signal, and multiplying the integration calculation result by an integration coefficient to generate an integration result;
- a differentiation circuit, performing a differentiation calculation on the phase signal, and multiplying the differentiation calculation result by a differentiation coefficient to generate a differentiation result;
- and
- a summation circuit, generating the filtered output signal according to the proportion result, the integration result and the differentiation result.
A frequency modulation receiving method, applied to a frequency modulation receiver to track a frequency or a phase of a single-tone signal of a first signal, the frequency modulation receiver comprising a frequency modulation demodulation circuit and a phase locked loop (PLL) circuit, the PLL circuit comprising a voltage-controlled oscillator (VCO) and a phase detector, the frequency modulation receiving method comprising:
- generating the first signal by the frequency modulation demodulation circuit;
- generating a phase signal according to the first signal and the oscillation output signal that the VCO generates by the phase detector;
- multiplying the phase signal by a proportion coefficient to generate a proportion result;
- performing an integration calculation on the phase signal, and multiplying the integration calculation result by an integration coefficient to generate an integration result;
- performing a differentiation calculation on the phase signal, and multiplying the differentiation calculation result by a differentiation coefficient to generate a differentiation result;
- generating the filtered output signal according to the proportion result, the integration result and the differentiation result;
- and
- generating the oscillation output signal according to the filtered output signal by the VCO;
- wherein, the PLL circuit approximates the frequency or the phase of the single-tone signal according to the oscillation output signal.
Dependencies are inferred from the claim text.