Microwave Linear Displacement and Position Sensor based on Transversal Signal Interference

A new linear-displacement and position microwave sensor with high-frequency sensitivity is introduced in this paper. It takes advantage of the spectral two-notch frequencies or transmission zeros produced by the signal interference of microwave bi-path transversal signal interference (TSI) structure, the value of which varies with the displacement to be measured. The sensor designs on microstrip technology, in which a slider made up of an open-ended stub is loaded to the TSI stator as a movable contact slider. As the slider shifts its position, the transmission line contact point with the stator is modified, essentially altering one path of the TSI stator and, as a result, the inter-transmission-zero separation. Furthermore, a proof-of-concept microstrip-based prototype is designed at 2 GHz with a 16 mm displacement range and an averaged sensitivity of 52.5 MHz/mm to validate the proposed approach.