A Bridge-Balancing Circuit for Balanced Measurement of Resonant Sensors

Abstract

We present a simple and low-cost signal-balancing circuit for application to electronic readout of resonant sensors. The circuit described is broadband and amenable to integration with a wide variety of balanced measurement schemes. We verify the operational performance of our circuit with a vector network analyzer, demonstrating achievable antiphase signal cancellation on the order of 100 dB under direct summing. We then present a number of illustrative application examples, demonstrating how our circuit can compensate for nonidealities in a number of test and measurement configurations. In the interest of making the field of microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) resonant sensors more accessible to researchers, we are releasing all design documents, lowering the barrier to entry to researchers wishing to integrate resonant sensors into their research programs.