A novel high-performance smart capacitive angular-position sensorwith a full circle measurement range is presented. It is mainly composedof three parts: the capacitive sensing element, a signal processor and amicrocontroller. A modified algorithm is used to calculate the positionfrom the capacitor's values. With this algorithm the effect of the mainundesired influences is eliminated or strongly reduced and themeasurement range of the sensor is extended to 360° . The structureof the sensing element is optimised to reduce the influence of theelectric-field bending effect and the nonflatness of electrodes. Thesignal processor has multi-capacitance input and one period-modulatedoutput and includes a very linear capacitance/period converter. Themicrocontroller acquires output data of the processor, calculates thepositions and optionally communicates with the outside world. Theresolution of the smart capacitive angular-position sensor is 0.58arcsec and the nonlinearity is less than ±90 arcsec (13.8 bits)over 0-360° range for a measurement time of 100 ms
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