| 摘要 |
PROBLEM TO BE SOLVED: To improve isolation between a transmission side circuit and a reception side circuit.SOLUTION: A transmission/reception circuit connected among an antenna 10 for transmitting a high-frequency transmission signal and receiving a high-frequency reception signal, a first conversion unit 30 for converting a modulation signal into the high-frequency transmission signal, and a second conversion unit 60 for converting the high-frequency reception signal into a demodulation signal comprises: a first filter 21 for letting the high-frequency reception signal received via the antenna 10 get through; a second filter 22 for letting the high-frequency transmission signal transmitted via the antenna 10 get through; a third filter 23 provided between the first filter 21 and the first conversion unit 30 for letting a signal included in a first frequency band corresponding to the high-frequency reception signal get through; and a fourth filter 24 provided between the second filter 22 and the second conversion unit 60 for letting a signal included in a second frequency band corresponding to the high-frequency transmission signal get through.SELECTED DRAWING: Figure 1 |
