An integrated spiral antenna system for UWB

As wireless communication applications require more and more bandwidth, the demand for wideband antennas increases as well. For instance, the ultra wideband radio (UWB) utilizes the frequency band of 3.1-10.6 GHz. The spiral antenna has a higher spectral efficiency than other planar antennas like the patch antenna. Theoretically, any type of antennas can be combined into different kind of arrays, in order to improve performance beyond that from one single antenna. The electrically coupled parallelism is one solution to extend bandwidth. By combining two spiral antennas with different radius of the radiation zone, the standing wave ratio (SWR) can be kept low for a large bandwidth, resulting in an improved spiral antenna performance for UWB. Furthermore, a study of how spiral dimensions impact on gain and SWR was conducted and presented.