| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitting/receiving device that can be miniaturized while reducing loss at a transmission/reception switch in the transmitting/receiving device using an antenna for both of transmission and reception. SOLUTION: The transmitting/receiving device has the antenna used for both of transmission and reception, a low-noise amplifier, a receiver, a high-output amplifier, a transmitter, and a 90°hybrid distribution synthesizer with four terminals. A phase-shift circuit composed of a phase shifter and a controlled phase shifter is arranged between the antenna and the 90°hybrid distribution synthesizer. The phase-shift amount of the controlled phase shifter is switched in a receiving mode and in a transmitting mode, respectively. A received signal composed of a signal component inputted to the antenna and having a different phase of 180°is inputted to the receiver by adding it in the same phase via the low-noise amplifier in the receiving mode. A signal from the transmitter is outputted from the antenna as a transmitting signal composed of two signal components respectively having a different phase difference of 180°via the high-output amplifier in the transmitting mode. COPYRIGHT: (C)2007,JPO&INPIT
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