APPARATUS FOR ATTENUATING INTERFERENCE FREQUENCY RECEIVING SIGNAL OF DUAL BAND RADIO COMMUNICATION SYSTEM

摘要

PURPOSE: An apparatus for attenuating the interference frequency receiving signal of the dual band radio communication system is provided to output selectively a first band signal or a second band signal by attenuating the interference frequency receiving signal by a control signal in a dual band radio receiving apparatus. CONSTITUTION: A duplex(103) inputs a signal from an antenna(101) and passes a first band signal or a second band signal. A resonator is composed of a first coil(203), a first capacitor(204), a second capacitor(206) and a ground terminal(210). The control voltage signal to receive selectively the first band signal and a second band is inputted to the anode terminal of a diode(205) via a resistance(209) and a coil(208). A low noise amplifier(105) amplifies the signal inputted, and outputs it to a band pass filter equipped in a dual band receiving apparatus.