Design of an enhanced bandwidth PIFA with modified shorting strip

In this paper, a novel compact internal wide-band planar inverted F-antenna (PIFA) is presented. The proposed antenna consists of a main patch with stubs and folded plate and occupies a total volume of 36 times 16 times 6 mm³. The dual bands characteristic can be achieved by changing the length of a main patch. A wide impedance bandwidth characteristic was obtained by optimizing the length of folded patch, stubs and shorting strip. The measured impedance bandwidth, determined by 6 dB return loss, of the operating bands reach 10.85% at 922.5 MHz and 58% at 2115 MHz, respectively. The maximum gains at the frequencies of 915, 1576, 1785, 2170, 2400 and 2630 MHz were 1.0, 2.7, 5.43, 4.65 and 1.52, 2.95 dBi, respectively. The overall shapes of the radiation patterns are suitable for mobile communication application.