ECE PhD Student Wins Best Student Paper Award at EFTF-IFCS 2021
Hussein M. E. Hussein, PhD’24, electrical engineering, was awarded the 2021 Joint Conference of European Frequency and Time Forum & the IEEE International Frequency Control Symposium (EFTF-IFCS) Best Student Paper Award for Paper “Parametric Acoustic-Based Passive Transponders for Ultra-Sensitive Temperature and Temperature-Threshold Sensing.”
Abstract: 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 LiNbO3 acoustic resonators, connected to the output of solid-state parametric frequency dividers (PFDs). In particular, depending on the ambient temperature (T), which sets the actual resonance frequency (fres) of the resonator, when an interrogating radio-frequency (RF) signature, with frequency close to 2fres, reaches the input of a PAT, its PFD can trigger a sub-harmonic oscillation, at fres, through a bifurcation mechanism. Based on the varactor DC-bias (VDC), such bifurcation can be either super-critical or sub-critical, where the super-critical enables a smooth but steep dependence of the PFD output power (Pout) vs. T, while the sub-critical introduces a sudden increase of Pout in presence of small temperature rises. The generated Pout can be radiated back to the interrogating node, which can receive the information through a different channel from the one used to transmit the signature. This unique feature makes any temperature data accessible, in real-time, needlessly of expensive transponder architectures.