Patent ID: 7457599

Claim:
A frequency transceiver for transmitting an RF (radio frequency) signal oscillated from an RF oscillator to an exterior to convert an external RF signal into an IF (intermediate frequency) signal, the frequency transceiver comprising: a local oscillator for oscillating a VHF (very high frequency) signal proportional to a VHF oscillation control voltage inputted; a first IF processor for mixing an external RF signal with the VHF signal oscillated by the local oscillator to convert the external RF signal into a first IF signal proportional to the VHF signal; a second IF processor for mixing the RF signal oscillated by the RF oscillator with the VHF signal oscillated by the local oscillator to convert the RF signal into a second IF signal proportional to the VHF signal, and converting the second IF signal into an output voltage; a control signal generator for generating a control signal which controls VHF signal oscillation of the local oscillator according to the output voltage of the second IF processor, the control signal generator comprising: a reference voltage generating unit for generating a reference voltage used to control the first IF signal and the second IF signal; a driving control signal generating unit for comparing the output voltage with the reference voltage and generating a driving control signal; a voltage sample holder for delaying the output voltage; and a counting control signal generating unit for comparing the delayed output voltage with the reference voltage and generating a counting control signal; and a VHF oscillation controller for outputting the VHF oscillation control voltage to the local oscillator according to the driving control signal and the counting control signal.