A Practical Approach to Robust Design of a RFID triple-band PIFA structure

This paper presents a practical methodology of obtaining a robust optimal solution for a multi U-slot PIFA (Planar Inverted F-Antenna) structure with triple bands of 433 MHz, 912 MHz and 2.45 GHz. Using evolutionary strategy, a global optimum is first sought out in terms of the dimensions of the slots and shorting strip. Then, starting with the optimized values, Taguchi quality method is carried out in order to obtain a robust design of the antenna against the changes of uncontrollable factors such as material property and feed position. To prove the validity of the proposed method, the performance of the antenna is predicted by general-purpose electromagnetic software and also compared to experimental results.