Interface electronics for an RF resonance-based displacement sensor

We propose, design, and test an electronic interface for a new standalone, affordable and compact displacement transducer based on resonant cavities. The operation of the interface establishes a self-resonance in the cavities and detects the resonance frequency (which is directly related to the position to be measured) by analyzing the attenuation produced by a low pass filter. The results obtained in a first prototype of the interface built with discrete elements show that the obtainable positioning accuracy using this cost-effective solution is about 5 micrometers.