Extremely electrically small antennas based on multiferroic materials

A multiferroic radio frequency antenna apparatus, comprising:

• a piezoelectric substrate;
• at least one pair of electrodes, coupled to said piezoelectric substrate, and configured for converting between an electrical signal at the electrodes to mechanical waves in the piezoelectric substrate, or from mechanical waves in the piezoelectric substrate to electrical signals at the electrodes;
• and
• a plurality of magnetoelastic and/or magnetostrictive resonators, coupled to said piezoelectric substrate, and configured for converting between mechanical waves in the piezoelectric substrate to electromagnetic waves from the magnetoelastic and/or magnetostrictive resonators, or from electromagnetic waves received by the magnetoelastic and/or magnetostrictive resonators into mechanical waves in the piezoelectric substrate;
• wherein said piezoelectric substrate interfaces between said at least one pair electrodes and said plurality of magnetoelastic and/or magnetostrictive resonators to transmit electromagnetic signals by converting radio frequency electrical signals applied at said electrodes into electromagnetic waves from the magnetoelastic and/or magnetostrictive resonators, and to receive electromagnetic signals by converting electromagnetic waves received at said magnetoelastic and/or magnetostrictive into radio frequency electrical signals at said electrodes.

A multiferroic radio frequency antenna apparatus, comprising:

• a piezoelectric substrate;
• a plurality of magnetoelastic and/or magnetostrictive resonators coupled to said piezoelectric substrate;
• at least one pair of electrodes, having a first electrode coupled to a first surface plane of said piezoelectric substrate, and a second electrode coupled to a second surface plane of said piezoelectric substrate;
• wherein in receive mode said plurality of magnetoelastic and/or magnetostrictive resonators create mechanical waves in response to being excited into magnetic oscillation by receiving electromagnetic radiation, and these mechanical waves coupled to the piezoelectric substrate cause it to generate an electrical output signal at said electrodes;
• and
• wherein in transmit mode an electrical signal coupled through said electrodes to the piezoelectric substrate induces mechanical waves directed to said plurality of magnetoelastic and/or magnetostrictive resonators which are excited into magnetic oscillation to output electromagnetic waves.