Design and Analysis of Ultra-wide Band Bandpass Filter Using Spiral Stub-Loaded Triple-Mode Resonator with a Notched Band

An ultra-wide band band-pass filter using novel spiral stub-loaded triple-mode resonator (SSL-TMR) is presented. New spiral stub loaded resonator is analyzed with odd and even modes analysis for this class of BPF, achieving higher band wide and size reduction. In order to have a good response characterized, two (SSL-TMRs) and two quarter wavelength digital coupled lines are used. This new design filter produces triple modes, one odd mode and two even modes in the desired band and two transmission zeroes(TZs) out of band, providing sharp cut off, low insertion-loss and good return-loss characteristics. The measured results are in good agreement with the electromagnetic simulation.