Patent ID: 9726518
Date: 2017-08-08
CPC Classifications: B60L,G01D,G01N,G01V,H01F,H02J,H04B,Y02E,Y02T,Y04S

Claim:
1. An apparatus for detecting a presence of an object, the apparatus comprising: a plurality of resonant sense circuits, each having a resonant frequency, each resonant sense circuit comprising an electrically conductive structure and a coupling circuit configured to determine resonance and an amount of coupling, the electrically conductive structure comprising a loop positioned within a multidimensional loop array; a multiplexer coupled to the plurality of resonant sense circuits; at least one capacitor coupled between the plurality of resonant sense circuits and the multiplexer; and a detection circuit coupled to the multiplexer, the detection circuit configured to detect the presence of the object in response to detecting a difference between a measured characteristic that depends on a frequency at which a resonant sense circuit of the plurality of resonant sense circuits is resonating and a corresponding characteristic that depends on the resonant frequency of the resonant sense circuit.