Novel dual‐band bandstop filter with controllable stopband frequencies

Abstract

AbstractThis article presents a novel dual‐band bandstop filter (BSF) with controllable stopband frequencies and sharp skirt selectivity.The proposed filter consists of a main transmission line and stub‐loaded resonators coupled to the main line. The stub‐loaded resonator has the advantage that the even‐mode resonant frequencies can be flexibly controlled by changing the stub length without affecting the odd‐mode resonant frequencies. Using this configuration, the stopband frequencies can be easily tuned to desired values. Based on the proposed idea, a third‐order dual‐band BSF is implemented operating at 2.4 and 3.5 GHz. Comparisons of experimental and simulated results are presented and good performance is observed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1203–1206, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26786