Radar wear sensing for tire applications

A tire structure comprising:

• a first annular bead and a second annular bead, a body ply extending between the first annular bead and the second annular bead, a circumferential belt disposed radially above the body ply and extending axially across a portion of the body ply, a circumferential undertread disposed radially above the circumferential belt and extending axially across a portion of the body ply, a first sidewall extending between the first annular bead and a first shoulder, the first shoulder being associated with the circumferential undertread, a second sidewall extending between the second annular bead and a second shoulder, the second shoulder being associated with the circumferential undertread, and an electronic device disposed radially between the circumferential belt and a bottom tread surface such that wear does not disable or damage the electronic device, wherein the electronic device includes:
• an emitter configured to emit pulsed electromagnetic waves having a frequency between 30 and 300 GHz and a bandwidth between 15 and 35 ps;
• a receptor configured to receive reflected electromagnetic waves;
• a processor that compares at least one property difference between an emitted and reflected wave;
• and
• a transmitter configured to transmit data to an interrogator, wherein the electronic device observes wear over the life of the tire, at sub-millimeter resolution.