Patent ID: 8224260

Claim:
An RF signal transmission/reception apparatus comprising: an antenna for transmitting a signal of a radio frequency (RF) band and receiving the signal of the RF band; a frequency synthesizer for outputting an oscillation signal of a certain frequency; a bi-directional mixer for converting a reception signal of the RF band received through the antenna into a first signal in any one of a baseband and an IF band by using the oscillation signal outputted from the frequency synthesizer and mixing the oscillation signal with the reception signal, and for outputting the converted first signal; a first signal selector for selecting the first signal outputted from the bi-directional mixer, and selecting a fourth signal that is sent to the bi-directional mixer to be converted and then transmitted by the antenna as the signal of the RF band; a modem for receiving and demodulating a third signal processed from the first signal, and modulating and outputting a second signal in any one of the baseband and the IF band that is different from the first signal frequency band; a second signal selector for selecting the second signal outputted from the modem to be processed into the fourth signal, and selecting the third signal processed from the first signal to be sent to the modem; and a signal transmitter/receiver unit for receiving and processing the second signal selected by the second signal selector from the modem into the fourth signal and outputting the fourth signal to the bi-directional mixer, and receiving and processing the first signal selected by the first signal selector into the third signal and outputting the third signal to the modem, wherein the bi-directional mixer converts the reception signal received by the antenna into the first signal and, at the same time, converts the fourth signal into the signal of the RF band to be transmitted by the antenna, and wherein the signal transmitter/receiver unit comprises: a low-noise amplifier for low-noise amplifying the first signal selected by the first signal selector; a filter for filtering an output signal from the low-noise amplifier; and a variable gain amplifier for variably amplifying an output signal from the filter and outputting the amplified signal to the second signal selector as the third signal.