Investigation of new dual‐mode triangular‐patch bandpass filters using spur‐lines

Without any perturbations on the surface of the patch resonator or orthogonal feed lines, new microstrip dual‐mode triangular‐patch bandpass filters are presented in this article. The degenerate modes are excited by the use of the spur‐lines for input/output microstrip lines. Also, the influence of design parameters on the frequency characteristics of the proposed dual‐mode filters is discussed. In addition, a modified dual‐mode filter using double‐spur‐lines is introduced and simulated. Measurement verifies the validity of the introduced design method. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2100–2103, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21880