SAWOA: Self-Adaptive Whale Optimization Algorithm for Notch Filter Design in UWB Antenna Applications

In this letter, a new Self-Adaptive Whale Optimization Algorithm (SA WOA)is introduced and applied to the design of a printed antenna with ultra wide band (UWB)characteristics. This algorithm is implemented on a basic structure of an octagonal printed antenna which includes a search process based on finding an optimal solution for the effective length of a H-Shaped Notch filter located in the patch. The filter position in conjunction with the effective length determines the frequency ranges that will be rej ected and can be adjusted over the entire operational range of the antenna. In this case, it is proposed to rej ect the frequency bands for IEEE 802.11a and WLAN-HIPERLAN / 2 from 5.1 to 5.9 GHz by applying SA WOA, obtaining an effective filter length of approximately 18.6454 mm and positioned around 12.5269 mm from the power line to ensure an optimum rejection with a center frequency of 5.5 GHz. The dimensions for the optimized printed UWn B octagonal antenna are 30 mm 35 mm, with a bandwidth of3.1 to 12 GHz and a return loss less than-10 dB throughout the UWB frequency range except in the optimized rejection range. The proposed SA WOA algorithm uses a correlation-based cost function between the fitness agent and a previously defined response pattern, resulting in a shorter computational time to achieve best parameters providing a high structure precision as well as high performance level.