Wide stopband single layer <scp>quasi?elliptic ultra?wideband</scp> bandpass filter

This paper presents the design of a microstrip ultra-wideband (UWB) bandpass filter that exhibits desirable characteristics low-loss, high selectivity, wide stopband and out-of-band rejection at room temperature. These are normally achieved with temperature superconductor filters require cryogenic cooling. The proposed was realized by exciting multiple resonant modes in unique Z-shaped resonator. admittance configuration can be tuned prior to fabrication adjust its center frequency about 11.5% without affecting profile response however this have an impact loss. allows adjustment upper lower transmission zeros defining 20.5% 11.4%, respectively, degrading overall response. low-loss quasi-elliptic function UWB fabricated on commercially available dielectric substrate using standard PCB technology performance verified. insertion-loss 0.68 dB return-loss better than 17 dB.