| 摘要 |
PURPOSE:To prevent the momentary interruption and line interruption by constituting that the impedance viewing one antenna is matched via the switch from the circulator and the impedance viewing another antenna is unmatched. CONSTITUTION:When the switch circuit SW is OFF, only the signal received at the antenna ANT2 is fed from the transmission and reception common unit to the circulator, and it is the branch unit consisting of the cirulators CRa1, CRa2 and the band pass filters BPFa1, 2 through the reflection at SW, and fed to the receivers RX1, RX2 by being branched evry channels CH1, CH2. When SW is ON, the impedance viewing from the circulator to ANT1 is matched and the reception signal of ANT2 is not almost delivered to the circulators CRa1, 2. Then, the reception signal of ANT1 is fed to the units RX1, 2. Accordingly, in response to the reception state, the selection system can be realized by controlling the switch circuit SW. |
