a capacitive encoder includes a signal - balanced shield electrode configuration that does not require electrical ground connection or active sensing and control in order to maintain the shield electrode at a sufficiently constant voltage during capacitive position measurements . the shield electrode configuration is positioned in a capacitive coupling gap between transmitter electrodes and receiver electrodes during operation . the shield electrode configuration is patterned in a manner that complements the layout of the transmitter electrodes , such that the shield electrode configuration inherently floats at a nominally constant electrical potential when coupled to the signals present on the transmitter electrodes . the resulting capacitive encoder is thus more economical to build , convenient to install , and reliable during operation than capacitive encoders which use an electrical connection , compensation drive circuitry , or grounding in order to control the potential of a shield member that operates at a potential that is not inherently constant .