| 摘要 |
First and second transmission paths P1 and P2 are disposed between a first port #1 connected to an antenna ANT and a second port #2 connected to a transceiving circuit 10. The first transmission path P1 includes receiving filters Rx1, Rx2, and Rx2', an amplification circuit LNA, and 90 DEG hybrid circuits 12 and 14. The second transmission path P2 includes a transmitting filter Tx1. A received signal amplified by the amplification circuit LNA is transmitted to the port #2 via the 90 DEG hybrid circuits 12 and 14, but is not transmitted to the second transmission path P2. A transmission signal is transmitted from the port #2 to the second transmission path P2. This prevents oscillation of the received signal due to positive feedback. A transceiving filter device that prevents degradation in the insertion loss, noise figure, and group delay characteristics in the transmission frequency band or the receiving frequency band and that prevents oscillation, and a communication apparatus using the transceiving filter device are provided. <IMAGE>
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