| 摘要 |
PURPOSE:To attain phase detection only in a transmission/reception module by stopping the operation of a high power amplifier section of a transmission system at phase detection, operating only the pre-stage of a tranmission system amplifier section and inputting a transmission signal from the said pre-stage to a reception system so as to obtain high isolation in an input route of other signal. CONSTITUTION:In detecting a phase fluctuation between input and output of a reception system amplifier 9, a switch 7 is kept open and a switching device 31 of a power line is turned off. In this case, several tens of dB (nearly 60dB) of isolation is obtained at the input/output of a high power amplifier 3 of the transmission system normally, then a signal level leaked through the amplifier 3, a circulator 5, an antenna 6 and the switch 7 changes as shown in alternate long and two short dashes lines (c) in figure, the signal is inputted with a level shown in broken lines (d) and alternate long and short dash lines a1 in figure through a coupler inserted to an output of a preamplifier 2 and a route 21 to the amplifier 9 and the phase at the input/output of the said amplifier 9 is detected without saturating the amplifier 9. |
