Time Domain Resonance Frequency Measurement of Inductively Coupled Resonant Sensors Using the Matrix Pencil Method

Inductively coupled resonant (ICR) sensors can be used to determine environmental parameters. Hereby a measur- and alters the sensor resonance frequency via an inductance, capacitance and/or resistance change. Due to their simple buildup these sensors are a promising approach for lowest cost, printed environmental parameter monitoring solutions. Commonly used are frequency domain techniques to determine sensor resonance frequencies, and time domain based signal analysis techniques, which evaluate the decaying sensor response, are only rarely employed. Within this work the Matrix Pencil Method is compared to several other time domain approaches. In numerical experiments carried out with a developed Matlab based test framework, a modified Matrix Pencil Method implementation did show a very good performance with regard to the relative frequency estimation error and algorithm robustness. The results were verified with applied laboratory measurements. When comparing the Matrix Pencil Method based wireless time domain resonance frequency measurement approach to wireless and wired frequency domain approaches, the differences of determined resonance frequencies of ICR sensor sample resonators are below 1%.