US Patent 11567147 Phononic comb enhanced gradiometers

A differential gradiometer comprising a substrate with at least a pair of resonators disposed thereon, wherein each of the at least a pair of resonators is sensitive to environmental factors which produces differential strains between the resonators, a first one of said pair of resonators being connected with a circuit for forming a first oscillator, the second one of said pair of resonators being connected with another circuit for forming a non-linear oscillator, an output of the first oscillator being applied to the non-linear oscillator for generating a comb of frequencies, wherein an addition oscillator is locked to the nth tooth of the comb thereby increasing the sensitivity of the gradiometer by a factor of n.