| 摘要 |
PROBLEM TO BE SOLVED: To provide a demodulating/modulating device wherein a demodulating/ modulating switching circuit is improved to demodulate a reception signal with high efficiency and to modulate the reception signal with high efficiency. SOLUTION: This device is equipped with a strip line circuit network 1 connected to a transmission and reception antenna 7, a demodulating/modulating switching circuit 2 having first and second diodes 11 and 12 which are connected to the output of the strip line circuit network 1, and a bias voltage supply circuit 4 for selectively supplying a bias voltage to the first and the second diodes 11 and 12. The demodulating/modulating switching circuit 2 has the first diode 11 connected between its input and output terminals and has the second diode 12 connected between the input terminal and a reference potential point. The bias voltage supply circuit 4 turns on the first and the second diodes 11 and 12 in turn in accordance with a modulation signal or supplies a bias voltage for turning on only the first diode 11 and, when the demodulating/ modulating switching circuit 2 performs demodulating/modulating operation, the circuit supplies a voltage for turning off the first and the second diodes 11 and 12. |
