Compact Heptaband Reconfigurable Loop Antenna for Mobile Handset

In this letter, an internal folded reconfigurable loop antenna for mobile handset applications is designed, built, and tested. Two operating states with different frequencies are obtained by switching the shorting pins of the loop. The bandwidth of the proposed antenna has been increased by adopting a matching bridge. In a compact volume of 60×5×5 mm
³
, the proposed antenna operates in heptaband, including GSM850, GSM900, GPS, DCS, PCS, UMTS, and WLAN, with the return loss lower than 6 dB. The efficiency and gain with the p-i-n diodes with their bias circuit are also measured and analyzed.