Inter-digital coupled dual-mode patch resonator with crossed-island configuration for tri-band filter design

摘要

The miniaturized dual-mode tri-band band-pass filters (BPF) using crossed-island patch resonator is proposed in this article. The BPF is mainly formed by a square patch resonator in which a crossed-island configuration is embedded in the patch. The patch size reduction with 74.4% is achieved. By the perturbation and the alternative inter-digital coupling, the tri-band responses are obtained. The proposed filter covers the required bandwidths for WLAN band (2.26–3.11 GHz and 5.02–6.0 GHz) and X-band (7.58–8.41 GHz) applications. Five transmission zeros are placed between three pass-bands and resulted in a good isolation. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:457–463, 2014.