TRANSMITTING DEVICE OF A WIRELESS COMMUNICATION TERMINAL FOR A DUAL BAND, PARTICULARLY FOR MORE EFFICIENTLY REMOVING NOISE BY USING TWO DIPLEXERS

摘要

PURPOSE: A transmitting device in a wireless communication terminal for a dual band is provided to more efficiently remove noises of a cellular frequency band signal and a PCS(Personal Communication Service) frequency band signal outputted from a signal generator by using two diplexers instead of two SAW(Surface Acoustic Wave) filters. CONSTITUTION: A signal generating unit(21) generates a signal of a PCS frequency band and a signal of a cellular frequency band according to a communication frequency band. The first diplexer(22) removes noise from the signals of the PCS frequency band and the cellular frequency band generated from the signal generating unit(21). The second diplexer(23) divides the signals outputted from the first diplexer(22) according to each frequency band. Amplifying units(24,25) amplify the signal of the cellular frequency band and the signal of the PCS frequency band divided by the second diplexer(23). A coupler(26) isolates the signal of the cellular frequency band with the signal of the PCS frequency band to prevent interference between the signals. The first duplexer(27) and the second duplexer(28) separate a transmitting signal and a receiving signal from the signal of the cellular frequency band and the signal of the PCS frequency band. The third diplexer(29) divides the signals of the cellular frequency band and the signal of the PCS frequency band, and transmits an output signal corresponding to each frequency band through an antenna.