Resonator switching techniques for notched ultra-wideband antenna in wireless applications

This study presents the design of switching techniques for dual-notched ultra-wideband antenna. The dual band-notched frequencies are achieved by using switched defected microstrip structure band stop filter inserted in the microstrip feed line and a switched meandered slot etched in the radiation patch. The switching reconfiguration is accomplished by combining the two ideal switches to introduce a notch filter response to prevent the interference to the primary users operating in the middle and upper WiMAX wireless local area network bands. The proposed structure has four modes by controlling the two switches on and off. The proposed antenna has good matched impedance from 2.5 to 12 GHz with two notched bands from 3.3 to 3.8 GHz (middle WiMAX applications) and from 5.1 to 5.9 GHz (upper WiMAX applications). The antenna is fabricated and tested. Good agreement is achieved between the simulated and measured results.