TRIPLE BAND TRANSMISSION/RECEPTION MULTIPLEX VCO FOR TDMA TYPE WIRELESS TERMINAL, CAPABLE OF GENERATING OSCILLATION SIGNALS OF THREE TRANSMISSION/RECEPTION FREQUENCY BANDS BY USING ONLY ONE ANTENNA

摘要

PURPOSE: A triple band transmission/reception multiplex VCO for TDMA type wireless terminal is provided to output signals to different output terminals by varying signal gains according to transmission/reception signals. CONSTITUTION: A transmission/reception selector(29) is used for generating a transmission band selection signal or a reception band selection signal according to a first selection control signal. A first VCO(21) is used for oscillating frequencies within oscillation signal range corresponding to a first type TDMA transmission signal and second and third TDMA type reception signals, and generating oscillation frequencies corresponding to a first TDMA type transmission band or second and third TDMA type reception bands according to a tuning voltage. A second VCO(23) is used for generating oscillation frequencies to perform the second and third TDMA type transmission process and the first type reception process. First and second power controllers(22,24) are used for controlling output power of the first VCO and the second VCO according to the transmission band selection signal or the reception band selection signal. First and second buffers(25,26) are commonly connected to an output part of the first VCO to output oscillation signals to first and second output terminals. Third and fourth buffers(27,28) are commonly connected to an output part of the second VCO to output oscillation signals to third and fourth output terminals.