The Research On Optimization For Time-domain Behavior Of UWB Antenna Based On EPD

Ultra-wide-band (UWB) technology is a wireless communication technology with time-domain short pulses, which is becoming a mighty competitor in currently high-speed wireless data access technology. As a core component of UWB system, the antenna's time-domain performance such as pulse fidelity can impact the whole system directly.UWB pulses in frequency-domain can cover a very wide bandwidth, it requires that the UWB antenna design include the ultra-wide-band performance of the impedance matching, stable gain radiation. At the same time, it should have the ability of radiating and receiving time-domain short pulses, and have a stability phase center to ensure there is no distortion. Therefore, when design UWB antenna we concern its characteristic in frequency-domain, as well as in time-domain.This paper made a careful study against the subject of "time-domain characteristic research and optimization of UWB antenna", Firstly, the paper described the research background, developments and the newest research results about UWB antenna, listed the classification of UWB antenna, Secondly, introduced the general frequency and time domain parameters of UWB antenna. Then presented a set of energy position descriptors (EPD) used for judging the time-domain behavior of UWB antenna, which is. On the basic of it, the paper proposed a scheme to optimize the time-domain features of UWB antenna based on parameter scanning (PS). The scheme used EPD as the time-domain index of UWB antenna and realized automatic simulation and structure updating by running CST and MATLAB concurrently. Then by improving the scheme, the paper proposed a new scheme based on genetic algorithm (GA). It reconstructed structures of antenna by GA and after that the antenna show structure diversity. Then two UWB antennas were optimized by using these two schemes. One is the scheme based on PS, which choose correlation coefficient as the index and used parameter scanning to optimize vivaldi UWB antenna. Simulated and measured results showed that the optimized antenna had good pulse fidelity in the direction of most radiation, at the same time, it met the broadband requirements of UWB system and suitable for UWB system with higher pulses fidelity requirements. The other one is the scheme based on GA, which choose MECG as the index and used genetic algorithm to reconstruct the structure of plane rectangle occasional UWB antenna. Simulated and measured results showed that it had good ability of radiation and fidelity in all directions and it was small enough for UWB system.