High Selectivity Filter Employing Stepped Impedance Resonators,series Capacitors and Defected Ground Structures for Ultra Wide Band Applications

Abstract

The paper presents a compact planar Ultra Wide Band filter employing folded stepped impedance resonators with series capacitors and dumb bell shaped defected ground structures. An interdigital quarter wavelength coupled line is used for achieving the band pass characteristics. The transmission zeros are produced by stepped impedance resonators. The filter has steep roll off rate and good attenuation in its lower and upper stop bands, contributed by the series capacitor and defected ground structures respectively.