One-Port and High-Sensitivity Angular Displacement Sensor Based on a Microwave Quarter-Wavelength Resonator

This work presents a high-sensitivity angular displacement sensor using microstrip technology. The sensor configuration includes a stator that incorporates a quarter-wavelength angular segment, which is short-circuited through a via hole. The rotor is designed as a transmission line, precisely aligning with the stator’s angular segment to ensure optimal interaction. This paper provides a comprehensive description of the design methodology and presents the equivalent electrical circuit. Additionally, detailed simulation and measurement results are included. To ensure accuracy, the sensor underwent multiple measurements, which were statistically analyzed. The sensor achieves a dynamic range of 160°, exhibiting excellent linearity across this range and a high sensitivity of 4.7 MHz/°. It also demonstrates a resolution of 2° and maintains precision for each indicated angle, with an average standard deviation of 2.243 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> GHz. Due to its single-port design, this sensor is particularly well-suited for seamless integration as a sensor node within Wireless Sensor Networks (WSN).