A Planar Printed Nona-Band Loop-Monopole Reconfigurable Antenna for Mobile Handsets

In this letter, a planar loop-monopole reconfigurable antenna is proposed for mobile handsets with a relative compact dimension of 60 × 10 × 0.8 mm
³
. A novel coverage strategy is proposed to utilize the loop mode for the low and the high bands (LTE700, GSM850, GSM900; LTE2300, WLAN, LTE2500) and the strip monopole mode for the medium band (DCS, PCS, UMTS). As a result, a nona-band coverage for 2G/3G/4G bands is achieved within limited space. Only one p-i-n diode is used with a simple bias circuit to avoid high insertion loss. With the proposed compact structure, the antenna is suitable for wideband smartphone applications. A prototype of the proposed antenna is fabricated and measured to verify the design strategy. The measured results match well with simulation with acceptable radiation efficiency in the covered bands. Especially, the efficiency in the low band is higher than 70%.