Compact High-Index Resonator Supercavity System with a Complementary Backplane Feed Element

We study the excitation of extended supercavity (SC) modes in a microwave microstrip-high-index resonator (m-HIR) system. The extended set of SC points in the spectral response of the m-HIR system is achieved after adding a complementary feed element to the backplane that generates a scaled negative image of the original feed current. The optimal design of the complementary feed element for operation at the extended SC regimes enables a desired high-Q resonance while cutting the required volume of the high-index resonator in half.