What is the function of a radar duplexer?

• A. It amplifies received signals to improve range.
• B. It stores radar data for later processing.
• C. It allows the same antenna to transmit and receive by isolating the transmitter from the receiver.
• D. It converts frequency bands for display.

Answer: (C)

Duplexers let a radar use a single antenna for both transmitting and receiving by providing isolation between the transmitter and the receiver. During the transmit phase, the duplexer routes the strong RF pulse to the antenna while preventing that energy from entering the receiver path. After the pulse, it switches so the receiver is connected to the antenna and can sense the returning echoes, while keeping any residual transmitter energy from corrupting the received signal. This isolation protects the sensitive receiver and helps keep the received data clean. It doesn’t amplify, store, or frequency-convert signals—the duplexer’s job is switching and isolation to allow one antenna to handle both transmit and receive.