An Empirical Equation for Predicting Fractional Bandwidth of Pifa Antenna

A parametric study is performed on a planar inverted-F antenna (PIFA) that operates on the low frequency band; 900 MHz. The study is dedicated to the effect of parameters on bandwidth (BW) and resonant frequency, covering most of the parameters that constitute the design of the antenna; patch dimensions, ground dimensions and substrate height. Based on the results, an empirical equation is developed to predict the fractional bandwidth (FBW) of the antenna. The equation relates the FBW to the parameters that have an effect on BW and no or insignificant effect on the resonant frequency. In comparison, values obtained from simulation and values calculated using the equation are very close (around 1% difference in values obtained).