A Frequency Reconfigurable Multi-mode Printed Antenna

A multi-frequency reconfigurable antenna is proposed. The designed antenna can be electronically tuned to achieve the tuning operation in the 2.4 GHz band defined by the IEEE 802.11b standard and the ultra-wideband (UWB) low frequency. An L-shaped branch and a polygon patch are used as the main radiators of the antenna. Two varactor diodes are mounted on the slots and one PIN diode is mounted on the L-shaped branch to vary the effective electrical length of the antenna. The simulation and measurement results match well. With high frequency reconfiguration stability under guaranteed miniaturization, good impedance matching (S11 > −10 dB) is obtained in several operating bands, and the overall impedance bandwidth covers 2.34–2.58 GHz and 3.11–5.14 GHz. It provides solutions for operation within WiMax, WLAN, and 5G-sub6 GHz.