A resonator structure of an electric apparatus, wherein the resonator structure is configured to interact with a radio frequency signal. The resonator structure includes a dielectric resonator element configured to resonate as a response to the radio frequency signal for transmitting and/or receiving electromagnetic energy wirelessly, and a conductive grounding structure magnetically coupled with the dielectric resonator element and configured to resonate with the dielectric resonator element. The conductive grounding structure includes at least a portion of the casing of the electric apparatus.