Analysis of a Symmetrical Planar Structure Formed by Stepped Penta-Mode Resonator for Designing Filters with Multi-band Response

Stepped impedance resonators with multiple mode response consist one of the most efficient methods to achieve the desired resonant frequencies and insertion loss of several filters, by selecting the appropriated impedance ratio. They can be used, either in multi-band or wideband applications. In this paper, a novel penta-mode resonator which is composed of five cascade SIRs (PMSIR) is suggested and theoretically analyzed. The even–odd mode technique is applied to derive the formulas of the first five resonant frequencies. The analytical approach was verified numerically through simulation in microstrip technology with Advance Design System (ADS) for several cases and a very good accuracy of the predicted resonant is distinguished.