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

Abstract

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.

Perturbed Sierpinski carpet resonator and its usage in compact dual and triple band bandpass filters

“…In Ref. a compact wideband BPF covering 3.14 to 6.89 GHz was presented using modified Minkowski island fractal haped planar patch resonator. A fractal space filling curve shaped open loop resonator was employed in to combine the benefitsof different sized open loop resonator in order to obtain two pass bands at 2.45 and 5.74 GHz, respectively.…”

Compact dual‐band bandpass filters based on a novel defected ground spiral resonator

“…In and , dual‐band BPFs were designed through adopting one dual‐mode resonator cell. Dual‐mode resonators with two degenerate modes are usually in the forms of a square patch , a circular disk , or a circular ring . However, they have the disadvantages in the resonator size, for example, S patch ≈ ( λ g /2) 2 , S disk ≈ (1.84 λ g / π ) 2 , S ring ≈ ( λ g / π ) 2 , where λ g is the guided wavelength of the resonant frequency, S patch , S disk , and S ring are the areas of the resonators.…”