Wireless Real-Time Capacitance Readout Based on Perturbed Nonlinear Parity-Time Symmetry

TL;DR

This paper introduces a real-time, wireless capacitance measurement system using perturbed nonlinear parity-time symmetry, eliminating the need for a vector network analyzer and enabling high sensitivity sensing in various applications.

Contribution

The work presents a novel PT-symmetry-based wireless readout system that operates in different modes and demonstrates high sensitivity at the exceptional point.

Findings

Successfully measured sensor capacitance changes wirelessly.

Demonstrated high sensitivity at the PT symmetry exceptional point.

Validated the system's potential for medical and harsh environment applications.

Abstract

In this article, we report a vector-network-analyzer-free and real-time LC wireless capacitance readout system based on perturbed nonlinear parity-time (PT) symmetry. The system is composed of two inductively coupled reader-sensor parallel RLC resonators with gain and loss respectively. By searching for the real mode that requires the minimum saturation gain, the steady-state frequency evolution as a function of the sensor capacitance perturbation is analytically deduced. The proposed system can work in different modes by setting different perturbation point. In particular, at the exceptional point of PT symmetry, the system exhibits high sensitivity. Experimental demonstrations revealed the viability of the proposed readout mechanism by measuring the steady-state frequency of the reader resonator in response to the change of trimmer capacitor on the sensor side. Our findings could impact many emerging applications such as implantable medical device for health monitoring, parameter detection in harsh environment and sealed food packages, etc.