An Impedance Match-Based Method for Parity-Time Symmetric Systems With High-Precision Sensing Capability

The fusion of the parity-time (PT) concept and inductor-capacitor (LC) resonant sensing system has led to the development of advanced wireless sensor systems with very high sensitivity. This study investigates the impact of disruption on the impedance characteristics of PT-based sensor systems by asymmetric perturbations. We explore the phenomenon where the system’s input impedance intersects with the source impedance at the precise phase of PT symmetry, facilitating a more harmonious parameter adjustment process. Consequently, we propose an impedance match-based parameter regulation strategy for PT systems. This methodology offers a superior alignment with the needs of parameter tuning within the exact phase of PT symmetry, which contrasts with a conventional approach that relies on tracking fluctuations of the minimum values of the ${S}_{{11}}$ spectrum. After parameter adjustment, the Q value and resolution are greatly improved, and the sensor precision is improved. Precision distance sensing experiments affirm that the technique has much-enhanced Q value and resolution compared to the existing method, the sensitivity of the metal distance sensor reaches 50 kHz/mm. This advancement underscores the potential for broader application and increased reliability in PT-symmetric sensing technologies.