Design of dual‐mode pentagon patch resonator filter using asymmetrical λ/4 interdigital coupled lines

In this letter, an improved coupling mechanism using asymmetrical λ/4 interdigital coupled lines is introduced and applied to design dual-mode pentagon patch resonator filter. This perturbation method is easy to realize without occupying extra space while the patch resonator structure remains intact. Coupling characteristics and transmission characteristics of this new filter are discussed, and the design methodology is verified by measurements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51:2817–2819, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24783