MINIATURIZED RECONFIGURABLE BAND-PASS FILTER WITH ELECTRONICALLY CONTROLLABLE FOR WiMAX/WLAN APPLICATIONS

A novel reconfigurable band-pass filter for worldwide interoperability for microwave access (WiMAX)/wireless local area network (WLAN) applications is presented. By using an H-shaped strip with a pair of C-shaped slots in the band-pass filter two new resonances can be achieved. The proposed band-pass filter has three different switchable states: 2.25-10.72 GHz in WLAN mode, 3.34-3.71 GHz in WiMAX mode, and 1.65-1.89 GHz in narrowband mode. The band-pass filter which uses a switchable slotted structure for reconfigurability has a simple structure and smallest size in comparison to band-pass filters reported in literature (Kikkert, TENCON 2005 IEEE region 10, 2005, Fan et al., Prog Electromagn Res 75 (2007), 285-293, Wang et al., Prog Electromagn Res 77 (2007), 67-73, Ojaroudi et al., Advanced electromagnetics symposium, 2012, Zhao et al., Prog Electromagn Res B 3 (2008), 131-141). Also the proposed filter has a major advantage in providing tighter capacitive coupling to the line in comparison to known radiating strip. To generate DC isolation in the RF path, we use a pair of gap distances in the microstrip loop. Simulated and experimental results obtained for this band-pass filter show that the proposed band-pass filter has a good return and insertion loss within the WiMAX/WLAN frequency range. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:509-512, 2014