To provide an on-vehicle transmitting and receiving apparatus capable of canceling a transmission signal from a transmitting and receiving antenna when the transmission signal is routed to a reception signal received by a receiving antenna.
The on-vehicle transmitting and receiving apparatus having a transmitting antenna and the receiving antenna includes: a multiplexing circuit connected to a signal line for transmission connected to the transmitting antenna and a signal line for reception connected to the receiving antenna; a first coupler disposed between the transmitting antenna and the multiplexing circuit; a second coupler disposed between the receiving antenna and the multiplexing circuit; and a transmission line connecting the first coupler and the second coupler to each other. The first coupler transmits a first signal as the transmission signal to the second coupler through the transmission line, and the reception signal that the receiving antenna receives includes a second signal comprising the transmission signal routed from the transmitting antenna to the receiving antenna to be received. The second coupler multiplexes a first signal which has the same amplitude with the second signal and has a phase difference of 180 with the second signal with the reception signal to cancel the second signal of the reception signal.
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SUMITOMO WIRING SYSTEMS
SUMITOMO ELECTRIC INDUSTRIES