Time domain optimization of UWB antenna by means of genetic algorithm

Antennas generally are a source of distortion for time domain pulses in ultra wideband (UWB) systems due to the variation of their transfer functions with frequency. It is well known that the pulse distortion in transmission and reception by typical antennas can be very strongly dependent on the angle of radiation or reception. In this paper, a promising UWB antenna-discone antenna is chosen for initial study and a novel optimization method for the design of antennas for UWB wireless communication systems is presented. The optimization is based on the time domain characteristics of the antenna. The correlation factors obtained for several angles were used as the optimization goals in the optimization procedure. The optimization of the antenna is performed by genetic algorithm (GA) search concepts. Based on GA, the optimization method of united impedance matching and waveform fidelity is presented. The electromagnetic analysis of the antenna is done by means of a time method using the commercially available CST Microwave Studio software. Numerical analysis indicates that the pulse fidelity could be obviously improved after optimization design.