UWB Antennas and Their Applications

The UWB antennas are proposed for applications of communication systems, various kinds of antenna test ranges, and high resolution microwave imaging. The narrower instantaneous bandwidth of UWB antennas will degrade the performance of the above applications. By using different characteristic of geometries, structures and sizes, good impedance bandwidth and instantaneous bandwidth can be achieved for these UWB antennas. In this paper, the design of various kinds of UWB antennas with wider instantaneous bandwidth will be discussed. Results of simulation and measurement of these UWB antennas will be presented. The application of these antennas is used as the feed to replace the traditional narrowband feeds for the antenna test ranges (far field range, near field range, and compact range). The test results of double ridge horn antenna measured by the antenna test ranges with either various kinds of narrowband feeds or a single UWB antenna are quite agreed.