A transceiver assembly is configured to detect an object. The transceiver assembly includes a first transmit antenna array configured to transmit a first signal at a first frequency, a second transmit antenna array configured to transmit a second signal at a second frequency that differs from the first frequency, and a receive antenna array configured to receive a third signal at a third frequency that is a difference between the first frequency and the second frequency. The transceiver assembly detects the object in response to reception of the third signal by the receive antenna array.