A Reconfigurable PIFA Using a Pin Diode

Abstract

A frequency reconfigurable PIFA using PIN diodes for WiMAX application has been demonstrated by simulation and measurement. The frequency reconfigurability was controlled by adjusting the bias of the PIN diodes. By adjusting the coupling element and substrate, the size of the proposed antenna can be reduced by about 50% compared to a conventional PIFA. The PIFA consists of three rectangular radiating elements, two PIN diodes, and control circuits. One diode is placed between two main radiating elements on the top, and the other diode is placed between a coupled radiating element and the ground. Depending on diodes on and off, the antenna operates over 2.3 to 2.4 GHz, 2.5 to 2.7 GHz, and 3.3 to 3.8 GHz for worldwide mobile-WiMAX bands. To optimize an antenna structure, a parametric analysis is performed as sweeping length and width of radiators. All the simulated and measured results were in good agreement. The radiation patterns are good performance of M-WiMAX operation. The proposed frequency reconfigurable PIFA, therefore, can be used for Fourth-Generation applications, such as the WiMAX communication system.