Magnetic field sensor using acoustically driven ferromagnetic resonance

An acoustically driven ferromagnetic resonance (ADFMR) device, comprising:

• a piezoelectric element comprised of piezoelectric material;
• a first electrode and a second electrode arranged in a vertical stack with the piezoelectric element between the first and second electrodes to activate the piezoelectric element to generate an acoustic wave;
• a magnet comprised of a magnetostrictive material in the vertical stack with the first electrode and the second electrode and the piezoelectric material;
• a radio frequency voltage source electrically connected to the first electrode and the second electrode to cause the piezoelectric material to generate an acoustic wave at or near a ferromagnetic resonance of the magnetostrictive material;
• and
• a readout circuit connected to the first electrode and the second electrode to detect a change in the acoustic wave by detecting one of an output voltage amplitude, a change in impedance or a reflection of the acoustic wave in the magnet to measure an unknown magnetic field in which the ADFMR device resides and as experienced at the magnetostrictive material.