| 摘要 |
<p>PURPOSE:To decrease the loss of a transmission signal and a reception signal by selecting a band pass filter having a large gradient in the attenuation in the FDMA system and applying the transmission and reception at a separate time, and selecting a band pass filter having a small loss and a small gradient in the attenuation in the TDMA system. CONSTITUTION:Band pas filters 41, 51 with many number of stages are employed for the use of the FDMA system to increase the gradient in the attenuation near the border of transmission and reception frequencies and band pass filters 42, 52 with less number of stages are employed for the use of the TDMA system to decrease the loss. A signal is sent/received in a time slot assigned to a transmitter-receiver in the TDMA system, the signal is sent through an incoming line by a transmission reception antenna via the band pass filter 42 and a transmission reception changeover switch 64 and the signal is received through an outgoing line by the transmission reception changeover switch 64 and the band pass filter 52 and inputted to a demodulator 23.</p> |
