DIGITAL RADIO FREQUENCY RECEIVER/TRANSMITTER OF TIME DIVISION DUPLEX TYPE

摘要

PURPOSE: A time division digital RF(Radio Frequency) transmitting and receiving apparatus is provided to simply and inexpensively manufacture a circuit by embodying transmitting and receiving time division using a coupler without a switch or a switching circuit. CONSTITUTION: A transmitting and receiving coupler(20) has the first coupling element(CP1) for connecting an output terminal of a power amplifier(13) to an antenna(ATN), the second coupling element(CP2) for connecting its one side to the first coupling element(CP1) and a low noise amplifier at a uniform interval, and an impedance matching resistor(R) for connecting the other terminal of the second coupling element(CP2) to the ground. The first and second coupling elements(CP1,CP2) of the transmitting and receiving coupler(20) are composed as inductors having a response characteristic as to a use frequency.