Investigating the Performance of Planar Inverted-F Antenna (PIFA) in Dual Resonant Mode

Abstract

In this research work, we propose a low-profile PIFA to operate under the dual resonant frequencies of f0,1/2 and f2,1/2 to show their improvement in gain and bandwidth. Initially, our study focuses on removing all the even-order modes by placing the shorting wall at one end of the patch. Then, a couple of shorting (connecting) pins are fixed at the nodal lines of the radiating element to examine the variant of their resonant frequencies in odd-order modes. This results in increasing the lower resonant frequency of f0,1/2 while maintaining the higher resonant mode of f2,1/2. In addition to that, the patch width is tuned effectively to reallocate the resonant modes more closely to one another. Finally, a small rectangular slot is created on the radiating element to minimize the corresponding inductance formed by the feeding probe and a couple of shorting pins. The results show that f0,1/2 and f2,1/2 are moved close to each other by placing a couple of perfect electric (shorting) pins under the patch element and adjusting the radiating patch width, respectively. It alters the lower and higher resonant frequency from 2.48 to 3.49 GHz and 4.81 to 4.49 GHz, and also it reduces the frequency ratio from 1.93% to 1.28%. The proposed patch antenna is modeled and simulated using high-frequency structure simulator (HFSS), and the results show that PIFA has a bandwidth of 76.8 MHz with a peak gain of 6.46 dB.