Multi Mode (Reflection and Transmission) Operated Dielectric Resonator based Displacement Sensor

A multi-mode operated microwave resonator based displacement sensor is presented. To enable this, a cylindrical dielectric resonator (DR) coupled microstrip line structure is established. The parameters like |S11| in reflection mode and |S21| in transmission mode are sensitive to DR displacements w.r.to transmission lines. The HFSS is carried out for numerical analysis and the fabricated sensor prototype is realized with VNA measurement. The sensor exhibits sensitivity of 6.2 dB/mm in the range of 0-4 mm in reflection mode and 1 dB/mm over 0-18 mm range in transmission mode. Both the HFSS and VNA responses are in good agreement with each other for this multi-mode operation. This reveals the selection of mode freedom to the choice of operation.