Patent ID: 7542731

Claim:
An apparatus for transmitting/receiving a radio frequency signal, comprising: a receiving means for converting a radio frequency signal received by an antenna into an intermediate signal based on an intermediate frequency (IF) band local signal; a transmitting means for converting an intermediate signal into a radio frequency signal based on a radio frequency (RF) band local signal; and a local signal generating means for generating the IF band local signal and the RF band local signal, wherein said local signal generating means includes: a phase locked loop (PLL) for both the receiving means and the transmitting means for selecting a channel to reduce interference with the radio frequency signal; a voltage control oscillator for generating a first local signal based on the channel selected by the PLL; a multiplier for multiplying the frequency of the first local signal by a predetermined number to generate a multiplied signal; an amplifier for amplifying the multiplied signal to generate the RF band local signal; a divider for dividing the frequency of the first local signal by a predetermined number to generate a divided signal; and a phase shifter for shifting a phase of the divided signal to generate the IF band local signal.