Planar Inverted-F Antenna for Portable Devices: An Empirical Study of the Resonant Frequency and Fractional Bandwidth

A comprehensive parametric study is performed on planar inverted-F antenna (PIFA) to investigate the effect of antenna parameters on resonant frequency and fractional bandwidth. Empirical formulas for predicting the fractional bandwidth and resonant frequency of PIFA incorporating most of the antenna parameters are numerically obtained. Comparison is provided between the proposed expressions and the existing counterparts. We believe that these results are useful in the design of PIFA.