New Flat Bow Slot Antenna

Rapid development in communication systems has led to the prosperity of antennas, among which ultra-wideband antenna is promising and valuable for applications and have been the international research frontiers. There are not any differences in the radiation theories between the ultra-wide band antenna and the ordinary narrow band one, but the former is developed based on the latter. The main content of the subject on the ultra-wide band antenna is to explore the novel theories, techniques, and methods to research them in very broad band. This dissertation mainly researches the bowtie-slot antennas. Finally, the antenna has a good bandwidth by improving the figure of this antenna. Many technologies of them are discussed in theory, simulation and experiment.The first three chapters of this thesis are attached on the research background, kinds of ultra-wideband antennas, several parameters to describe the performance of ultra-wideband antennas, factors to influence the bandwidth of antennas, methods to improve bandwidth and their main analytical methods.The fourth chapter of this thesis is attached on the development of bowtie antennas. It describes the ordinary bowtie antenna and types of developing bowtie antennas, and methods of increasing bandwidth.The fifth chapter is main portion of this thesis. In this chapter, a bowtie-slot antenna fed by CPW is advanced. The bandwidth of this antenna is greatly improved by increasing two sector patches and adding round corners to the square slot. By these methods, we gain a 10dB return loss bandwidth from 25% to 80%, from 9.5GHz to 22.4GHz. We analyse a few parameters of this antenna and their influences to bandwidth of antenna. We test performances of a processing bowtie slot antenna and the measured data agrees well the simulated ones.The innovation of this thesis:1) It improves the figure of the ordinary bowtie-slot antenna by adding two small sectors, which is a great enhancement to improve bandwidth from 25% to 56%.2) It improves the figure of the ordinary bowtie-slot antenna again by adding round corners to the square slot. It controls the influence of return loss by adjusting radius of round corners. The bandwidth of antenna reaches to 80% eventually.It is concluded from the results of this thesis that, increasing patches and adding round corners are feasible methods.