Shorting Strap Tunable Stacked Patch PIFA

Abstract

An oppositely shorted dual-band stacked patch planar inverted-F antenna (PIFA) is developed. RF switches are integrated to the shorting straps of the stacked patches to make a tunable PIFA. The L band switch yields 0.45-dB insertion loss and 10-dB isolation bandwidth (BW) of 108% at 1.8 GHz. The tunable PIFA yields 10% frequency tunability BW at 745 MHz when the number of upper radiating patch's shorting straps changes and 20% BW at 1137 MHz when the number of lower radiating patch's shorting straps changes. Independent lower and upper frequency tunings are achieved through this technique.