According to the invention, a transmitter antenna selector switch 109 or a receiver antenna selector switch 111 is respectively connected between the first antenna 101a and the second antenna 101b and the transmitter 103 or the receiver 105. Transmission signals output from the transmitter 103 are supplied to either the first antenna 101a or the second antenna 101b in transmission, while reception signals are received from either the first antenna 101a or the second antenna 101b via the receiver antenna selector switch 111 in reception. |