Miniaturized Cavity Resonator Supporting Both Electromagnetic Resonances and Magneto-Inductive Resonances

We present a miniaturized cavity resonator by embedding double split-ring resonators (DSRRs) in a conventional substrate integrated waveguide (SIW) cavity. Apart from the electromagnetic wave in the cavity, an induced current wave referred to as a magneto-inductive wave is also supported by the periodic array of DSRRs due to the mutual coupling. As a result, the proposed cavity resonator supports both electromagnetic resonances and magneto-inductive resonances, and the lowest resonant frequency of each kind of resonance is lower than that of the conventional cavity. This can help to reduce the size of cavity resonators. The measured results agree well with the simulated results.