There is provided a frequency transceiver for automatically controlling a TX/RX IF signal in a radar or a communication system, which transmits/receives an RF signal. The frequency transceiver includes a local oscillator for oscillating a VHF proportional to a VHF oscillation control voltage, a first IF processor for mixing an external RF signal with the VHF signal oscillated by the local oscillator and converting the RF signal into an 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, converting the RF signal into an IF signal proportional to the VHF signal, and converting the converted IF signal into a voltage, a control signal generator for generating a control signal to control the VHF signal oscillation of the local oscillator according to an output voltage of the second IF processor, and a VHF oscillation controller for outputting the VHF oscillation control voltage to the local oscillator according to the control signal generated from the control signal generator.