| 摘要 |
<P>PROBLEM TO BE SOLVED: To cancel a transmission signal and reception band noise on the transmission side simultaneously because a tunable filter of a tunable-enabled DPX module has a frequency characteristic, and reduce the power consumption of an amplifier amplifying a signal attenuated by the coupler and synthesizer disposed in a canceler being loosely coupled. <P>SOLUTION: Cancelers 8 and 9 include: filters 82, 92, 86 and 96 having a frequency characteristic similar to that of tunable filters 31 and 32; and functions 85, 95, 84 and 94 for compensating for amplitude, phase and delay. Using the two systems of the cancelers, a leakage component of a transmission signal and that of a reception band thermal noise are respectively canceled. Further, for reducing the power consumption of an amplifier, couplers 88 and 98 are loosely coupled, while synthesizers 81 and 91 are tightly coupled. For minimizing an influence of the tight coupling on the reception system, a common mode input-amplifier is adopted for the synthesizer. <P>COPYRIGHT: (C)2012,JPO&INPIT |
