Improved performance of ebgs on a co-planar transmission line using tapered distribution

Conventional electromagnetic crystals or electromagnetic bandgaps (EBGs) with uniform distribution show spurious ripples in the pass band and poor stop-band responses. This paper presents a detailed theoretical investigation of the performance of EBGs on a uniplanar transmission line using tapered distribution. The nonuniform size of the EBGs is used to improve the ripple height, 20-dB rejection band, and selectivity of the filter over the pass-band and stop-band regions. The calculated S parameters exhibit significant improvement in ripple height and rejection bandwidth, as compared with the conventional EBG-assisted coplanar transmission line. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 128-131, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.2022