A system for sensing proximity using EHF signals may include a communication circuit configured to transmit via a transducer an EM signal at an EHF frequency, and a proximity sensing circuit configured to sense a nearby transducer field-modifying object by detecting characteristics of a signal within the communication circuit. A system for determining distance using EHF signals may include a detecting circuit coupled to a transmitting communication circuit and a receiving communication circuit, both communication circuits being mounted on a first surface. The transmitting communication circuit may transmit a signal toward a second surface, and the receiving communication circuit may receive a signal relayed from the second surface. The detecting circuit may determine distance between the first surface and a second surface based on propagation characteristics of the signals.