Toward long-term stability of SAW sensor interface electronics with minimized heat generation and baseline fluctuation

Three different interface architectures were developed to convert changes in surface acoustic wave (SAW) velocity, generated by a two-port SAW delay line with a UV-C sensing material, into measurable frequency shifts for real-time monitoring and analysis. The system includes an oscillator, multiplexer (MUX), mixer, low-pass filter (LPF), comparator, field-programmable gate array (FPGA), and a PC-based visualization unit. The three architectures were evaluated based on signal stability, noise performance, baseline drift, and frequency detection accuracy. All designs demonstrated low noise, minimal heat generation, and stable long-term operation with negligible baseline fluctuations. Depending on the specific sensor application, the most appropriate architecture can be selected and integrated into the system. Each architecture provides a compact and reliable solution for high-resolution SAW sensor signal processing and monitoring. Additionally, a visualization algorithm was implemented to display real-time data and provide warning alerts using color-coded indicators around the display window.