| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable disturbing wave attenuation in consideration of a situation where a desired wave and a disturbing wave, whose frequencies are close to each other, are received.SOLUTION: A distributor 7 unequally distributes a radio wave received by an antenna 2, outputs a slightly attenuated signal to a first route 5, and outputs a significantly attenuated signal to a second route 6. The signal inputted into the second route is amplified by a first amplifier 9 and is converted by a phase inverter 10 into a signal whose phase is delayed by 180°. The signal, whose phase is delayed by 180°, is synthesized by a synthesizer 11 with the signal inputted into the first route 5. When a desired wave is small and a disturbing wave is large, the desired wave is buried in a noise floor due to a branch loss of the distributor 7 and only the disturbing wave is delayed in phase by 180° in the second route 6, so only the disturbing wave is attenuated at the time of the synthesizing. The signal after the synthesizing is amplified by a second amplifier 12 and is inputted into a reception circuit 4.</p> |
