All-Inductive Cross-Coupled Over-Moded Dual-Mode Filters

A new configuration of all-inductive dual-mode filters with pseudo-elliptic response is presented in this paper. The new configuration employs over-moded TE 302/203 cavities whose modes are coupled and cross-coupled through a multi-aperture inductive iris for the realization of quadruplet topologies. The oversized nature of the cavities and the all-inductive “planar” configuration make these filters especially suitable for high frequency and narrowband applications. The proposed configuration is validated by the experimental results of a Ka-band two-cavity filter (0.27% nominal fractional bandwidth at 36.650 GHz) with 2 symmetric transmission zeros.