Parametric Acoustic-based Passive Transponders for Ultra-sensitive Temperature and Temperature-Threshold Sensing

In this work, we report a new class of passive acoustic-based transponders (PATs), enabling both continuous and threshold temperature sensing, in a reduced form-factor. These PATs rely, for the first time, on the dynamical features exhibited by high-Q X-cut Lithium Niobate (LiNbO
3
) acoustic resonators, connected to the output of solid-state parametric frequency dividers (PFDs). The unique dynamics of the PFD boost the temperature sensitivity of the acoustic resonator by orders of magnitude. A threshold input power of ~ −15 dBm triggers a sub-harmonic oscillation in the PFD which is proportional to the temperature variations. This unique feature makes any temperature data accessible, in real-time, needlessly of expensive transponder architectures.