Frequency modulation receiver and receiving method thereof
AssigneeRichWave Technology Corp.
InventorHuei-Chiang Shiu
Life of this patent
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Abstract
A frequency modulation receiver is provided. The frequency modulation receiver includes an automatic frequency controller and a signal detector. The automatic frequency controller receives a demodulated frequency modulation signal demodulated from a radio frequency signal and outputs a control voltage to control an oscillation frequency of a local oscillator. The signal detector coupled to the automatic frequency controller receives the control voltage and determines whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range.
Claims18
A frequency modulation receiver, comprising:
- an automatic frequency controller, receiving a demodulated frequency modulation signal demodulated from a radio frequency signal and outputting a control voltage to control an oscillation frequency of a local oscillator according to the demodulated frequency modulation signal;
- and
- a signal detector coupled to the automatic frequency controller, receiving the control voltage and determining whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range.
A frequency modulation signal receiving method, comprising:
- receiving a demodulated frequency modulation signal demodulated from a radio frequency signal, and outputting a control voltage to control an oscillation frequency of a local oscillator according to the demodulated frequency modulation signal;
- and
- determining whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range.
A frequency modulation receiver, comprising:
- an antenna, receiving a radio frequency signal;
- a radio frequency amplifier, amplifying the radio frequency signal;
- a mixer, receiving the amplified radio frequency signal and a local oscillation signal, and down converting the amplified radio frequency signal to an intermediate frequency to output an intermediate frequency signal according to the local oscillation signal;
- a frequency modulation demodulator coupled to the mixer, receiving the intermediate frequency signal and demodulating the intermediate frequency signal to output a demodulated frequency modulation signal;
- an automatic frequency controller coupled to the frequency modulation demodulator, receiving the demodulated frequency modulation signal and outputting a control voltage according to the demodulated frequency modulation signal;
- a signal detector coupled to the automatic frequency controller, receiving the control voltage and determining whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range;
- and
- a local oscillator, outputting the local oscillation signal according to the control voltage.
A frequency modulation signal receiving method, comparing:
- receiving a radio frequency signal;
- amplifying the radio frequency signal;
- down converting the amplified radio frequency signal to an intermediate frequency to output an intermediate frequency signal according to a local oscillation signal;
- demodulating the intermediate frequency signal and outputting a demodulated frequency modulation signal;
- outputting a control voltage to control an oscillation frequency of a local oscillator according to the demodulated frequency modulation signal;
- and
- determining whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range.
Dependencies are inferred from the claim text.