Millimeter wave resonator apparatuses and methods

A method of operating a tunable millimeter wave resonator, comprising:

• applying a voltage across first and second sides of a resonating member consisting essentially of a rare-earth nickelate;
• generating a first resonance frequency of at least 30 GHz with the resonating member by said applying a voltage;
• varying the voltage applied across the first and second sides of the resonating member;
• and
• varying the first resonance frequency of the resonating member to a second resonance frequency of at least 30 GHz by said varying the voltage, wherein the second resonance frequency is different from the first resonance frequency;
• wherein:
• a first electrode is connected to the first side of the resonating member and a second electrode is connected to the second side of the resonating member;
• and
• said applying a voltage includes
• electrically communicating a voltage between the first electrode and the second electrode, and
• said electrically communicating uses a capacitive coupling for electrically communicating with the first electrode and an inductive coupling for electrically communicating with the second electrode.

A millimeter wave resonator, comprising:

• a substrate defining a first side and a second side;
• a resonating member consisting essentially of a rare-earth nickelate and defining a first side and a second side, wherein the first side of the resonating member is coplanar with the first side of the substrate, and wherein the second side of the resonating member is coplanar with the second side of the substrate;
• a first electrically conductive material mounted to the first side of the substrate and the first side of the resonating member;
• and
• a second electrically conductive material mounted to the second side of the substrate and the second side of the resonating member;
• wherein a resonant frequency of the resonating member is changed when an electrical potential between the first electrically conductive material and the second electrically conductive material changed.