Group-Delay-Based Angular-Displacement Microwave Sensor Using Transversal Signal-Interference Principle

The design of a microwave angular-displacement sensor is discussed in this study and is based on the demonstrated group-delay variation. Transversal signal interference (TSI), which was previously utilized to develop sharp-rejection microwave filters with transmission zeros (TZs) through constructive/destructive signal-interaction phenomena, serves as the foundation for the RF sensor. By altering the frequency separation between the two newly formed notched bands or TZs below/above its main passband, this RF sensor utilizes the spectral phase-slope variation of its transfer function for the first time. A microstrip prototype of the devised group-delay-based angular-displacement TSI sensor is manufactured and evaluated for experimental validity. The sensor demonstrates a sensitivity of 0.1841 ns/degrees at the operating frequency of 1 GHz and a dynamic range of 70 degrees as the main performance metrics.