Miniaturization microstrip rectangular-ring bandpass filter using high permittivity substrate

A selective band-pass filter with a microstrip rectangular-ring resonator is proposed for wireless LANs such as the IEEE 802.11 systems (2.45 or 5.25 GHz). The miniaturized band-pass filter is implemented using a high-permittivity dielectric substrate. The full-wave simulator IE3D is used to design the single rectangular-ring resonator. The responses of the implemented filters using FR4 (er = 4.7, tanδ = 0.016) and Sm(Co1/2, Ti1/2)O3 (er = 25.5, tanδ = 0.00013) dielectric substrates are designed at dual-band frequencies of 2.45 and 5.25 GHz. Compact size and good agreement between the simulation and implementation results are obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 540–543, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21402