A device for detecting and selectively reflecting an incident microwave signal or millimeter-wave signal is disclosed. The device includes a plurality of antennae disposed in an array; and a diode disposed at each input of each antenna, each diode having an input adapted to selectively receive a reverse bias signal, or a zero bias signal, or a forward bias signal. The device also includes a switching device connected to each input, and configured to selectively apply the forward bias signal, or the reverse bias signal or the zero bias signal to each of the diodes. In forward bias, each of the plurality of antennae reflects the incident microwave signal or millimeter wave signal; and in zero bias or reverse bias each of the plurality of antennae detects the incident microwave signal or millimeter wave signal.