“…Most of these designs either suffer with low attenuation (<20 dB) range in the stop-band or have larger size. In addition, for better roll-off rate as well as compactness, an elliptical-function response is used in many LPFs which are based on several structures, such as stepped-impedance hairpin resonator [8], tapered resonator [12], slit-loaded tapered compact microstrip resonator cell [13], symmetrically loaded radial-shape patches and meandered transmission line [14], triangular patch resonators and radial patch resonators [15], symmetrically loaded triangular and high-low impedance resonators [16], P-shaped resonators [17], novel asymmetric structures for resonator and suppressor [18], wide stop-band using tri-section stepped impedance resonator [19] etc.…”