Design of LC-type passive wireless multi-parameter sensor

This paper presents an innovative design of miniature LC-type passive wireless multi-parameter sensor. The sensor consists of multiple planar inductors on a single substrate and variable capacitors forming resonant LC tanks with separated resonant frequencies. The multiple parameters of interest could be remotely measured by tracking the changes in the peak frequencies of the impedance phase at an external readout coil which is magnetically coupled to the sensor. In order to make sure that the discernible peaks can be observed, the partly-overlapped planar embedded inductors in a multi-layer organic substrate are used and respectively in parallel connected with MEMS variable capacitors. The sensor in this stacking configuration achieves multi-parameter telemetry without any significant increase in size compared to the previous single parameter counterpart. EM simulation and tentative experiments both have been carried out, and the results validate the proposed design.