A frequency reconfigurable antenna for multiband mobile handset applications

A frequency-reconfigurable antenna is presented for multiband (GSM850/900/GLONASS1616/DCS1800/PCS 1900/UMTS/LTE2300/2500/WLAN) mobile handset applications. It mainly consists of radiating elements with two PIN diodes. By switching the ON/OFF states of the PIN diodes, the proposed structure can operate in three states: OFF-ON, ON-OFF, and ON-ON. When PIN diodes are in the OFF-ON states, the proposed antenna can cover the GSM850/900, PCS1900, and UMTS2100 bands by operating in Invented-F antenna (IFA) mode. When PIN diodes are in the ON-OFF states, the antenna can cover the LTE2300/2500 and WLAN2400 bands in monopole mode. Moreover, when PIN diodes are switched to the ON-ON states, the designed antenna works in loop mode and its resonant frequencies include the GLONASS1616, DCS1800/1900, and LTE2500 bands. With the reconfigurable technique, the proposed antenna achieves a compact size of 15 x 28.5 mm(2) with high efficiency from 34% to 84.86% in the total frequency range.