Equivalence of Open-Loop and Closed-Loop Operation of SAW Resonators and Delay Lines

Abstract

Surface acoustic wave (SAW) sensors in the form of two-port resonators or delay lines are widely used in various fields of application. Readout of such sensors is achieved by electronic systems operating either in an open-loop or in a closed-loop configuration. The mode of operation of the sensor system is usually chosen based on requirements like e.g. bandwidth, dynamic range, linearity, costs, and immunity against environmental influences. Because the limit of detection (LOD) at the output of a sensor system is often one of the most important figures of merit, both readout structures, i.e. open-loop and closed-loop systems, are analyzed in terms of the minimum achievable LOD. Based on a comprehensive phase noise analysis of these structures for both, resonant sensors and delay line sensors, expressions for the various limits of detection are derived. Under generally valid conditions equivalence of open-loop and closed-loop operation is shown for both types of sensors. These results are not only valid for SAW devices but are also applicable to all kinds of phase sensitive sensors.

References in corpus (3)

• On the measurement of frequency and of its sample variance with high-resolution counters
• On the relation between uncertainties of weighted frequency averages and the various types of Allan deviations
• A generalization of the Leeson effect

Cited by in corpus (4)

• Noise Analysis of Open-Loop and Closed-Loop SAW Magnetic Field Sensor Systems
• Probing quantum phases in ultra-high-mobility two-dimensional electron systems using surface acoustic waves
• A high-performance surface acoustic wave sensing technique
• Phase Sensitivity and Phase Noise of Cantilever-Type Magnetoelastic Sensors Based on the $\Delta$E Effect