A proximity fuze (proximity fuse) comprising an ultra wideband (UWB) radar transmitter, a UWB radar receiver, an antenna, a timing system, and a signal processor. One embodiment includes an antenna with an annular conical radiation pattern. In another embodiment, a trigger delay is produced that is related to target detection range. In a further embodiment, multiple range shells are utilized to further discriminate target characteristics including velocity. A method is disclosed that utilizes target range, velocity, signal amplitude, and radar signal phase to identify the target and trigger the detonation. A proximity fuze system having a long storage life is disclosed comprising a proximity fuze element powered by a turbine generator and internal gas source.