SACPDE: Self-Adaptive Control Parameters in Differential Evolution Algorithm for Notch Filter Design in UWB Antenna Applications

In this letter, a Differential Evolution Algorithm with Self-Adaptive Control Parameters (SACPDE)is introduced and applied to Notch filter designs in Ultra Wide Band (UWB)antennas. The proposed SACPDE algorithm uses a correlation-based cost function which compare the response of each search individual with a previously defined response pattern to determine the fitness agent, resulting in a shorter computational time to reach the overall optimal solution. The algorithm was implemented on a heptagonal printed antenna using a Notch filter located in the feed line. The proposed algorithm determines the optimal position and effective length of the filter to reject the industrial, scientific and medical (ISM)radio band located from 5.15 to 5.35 and 5.725 to 5.825 GHz in the reflection coefficient response of the antenna and minimally affecting the Non-ISM frequency bands. SACPDE got a U-Shaped Notch filter with effective filter length of 18.8088 mm and positioned approximately 7.9674 mm from the feed line to ensure an optimal rejection of-2.43 dB at 5.5 GHz. The optimized dimensions for this printed UWB heptagonal antenna are 30 mm 35 mm with an impedance bandwidth of <-10 dB from 3.1 to 12 GHz, except for the rejected ISM band.