Measurements of an Antenna and Pulse Generator for an Ultra-Wideband Radar System

UWB systems show significant promise for use in communications, localization and radar. As part of a project focusing on UWB radar, both a pulse generator and an antenna have been designed, prototyped and measured. The antenna is an open horn, designed with a smoothly varying profile to provide a wideband transition from the feeding waveguide to free space. Late-time ringing is supressed by the use of an EM-absorbent material within the waveguide. It is well matched in the desired 3–5 GHz band and has a reasonable gain and directivity. The generator, constructed from off-the-shelf components, emits a monocycle with a spectrum of 0.1–4.5 GHz and with a central flank rise time on the order of 150 ps. Measurements show that the pulse is significantly widened when transmitted with the prototype antenna but that it remains sharp enough for radar applications.status: publishe