1. An ultra-wideband (UWB) directional sampler, comprising: an electronic coupler having a first port operating in real time, a second port operating in real time and coupled to the first port, a third port coupled to the first port and isolated from the second port and providing an equivalent time representation of a signal at the first port, and a fourth port coupled to the second port and providing an equivalent time representation of a signal at the second port; a sampling gate pulse generator for sampling signals at the first and second ports.