Antenna for the application in UWB-monopulse-radar technique

Angular resolution and range resolution are two very important characteristics of a radar system. A very high range resolution requires an enormous bandwidth, which is available with Ultra-Wide-Band (UWB) technology. The frequency range extends from 3.1 GHz to 10.6 GHz in many applications, which complies with the frequency mask defined by the FCC for licence free operation. With such defined frequency range, the theoretical range resolution is approx. 2 cm. However in the radar systems not only the range but also angular resolution is of big interest. Possible solutions to increase the angular resolution include imaging algorithms and highly directive antennas. The application of imaging algorithms generally requires a movement of the antennas along a known track. On the other hand, highly directive antennas have a large aperture. Another way to increase the angular resolution without the aforementioned drawbacks is the monopulse radar principle [1]. The application of this technology in the UWB frequency range requires a directional UWB-180°-hybrid-coupler or UWB monopulse antennas. This paper presents an UWB antenna with integrated feeding network for UWB-monopulse radar.