| 摘要 |
The modulating and demodulating device comprises a microstrip line network (1) connected to a transmitting/receiving antenna (7), the modulator-demodulator having first and second diodes (11,12) connected to an output of the microstrip line network, and a bias voltage supplying circuit (4) for supplying a bias voltage selectively to the first and second diodes. In the modulator-demodulator, the first diode is connected between the input and output terminals, and the second diode is connected between the input terminal and a reference potential point. When the modulator-demodulator executes a modulating operation, the bias voltage supplying circuit supplies a bias voltage to turn on both the first and second diodes or a bias voltage to turn on only the first diode in accordance with a modulation signal. When the modulator-demodulator executes a demodulating operation, the bias voltage supplying circuit supplies a bias voltage to turn off both the first and second diodes. <IMAGE> |
