A novel miniature dual‐band bandpass filter based on the first and second resonances for 2.4/5.2 GHz WLAN application

Abstract

ABSTRACTIn this article, a dual‐band narrow bandpass filter using U‐shaped stepped‐impedance resonator (SIR) for 2.4/5.2 GHz wireless local area network (WLAN) application is proposed. The filter is composed of a simple U‐shaped SIR and novel feedlines with two open stubs. Furthermore, this article relatively used the first and second resonances to achieve the dual‐band performance. To validate the design and analysis, a prototype filter has been fabricated with two passbands are centered at 2.4 and 5.2 GHz with the fractional bandwidth of 4.9 and 3.5%, respectively. Its excellent selectivity is suitable for WLAN application. The measurement performances show good agreements with the simulated ones. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1143–1146, 2015