Frequency Reconfigurable Antenna for Wireless Communications Using GaAs FET Switch

A compact frequency reconfigurable antenna which could be easily switched between a narrowband state and a dual-band state is presented in this letter. The narrowband covers the WLAN (2.4-2.48 GHz) and WiMAX (2.5-2.69 GHz), while the dual-band supports the PCS (1.85-1.99 GHz) and WiMAX (3.4-3.69 GHz). The reconfigurability is achieved by using a single GaAs field effect transistor switch to change the length of the current flow path. The switch can be directly driven by digital signal, and no bias network is needed. The simulated results are in agreement well with the measured results. The proposed antenna is well suited to be integrated within the wireless handheld devices.