Improved Single Layer LC Sensor Tag

LC sensor tags are used in many wireless capacitive and inductive sensing applications. They typically consist of a discrete planar spiral inductor and a discrete capacitive sensor, such as an interdigitated electrode capacitive sensor. This sensor tag architecture usually requires either two conductive layers, two discrete substrates, or a coplanar implementation. However, by adding interdigitated teeth between adjacent spiral inductor turns, the inductor's self-capacitance can be augmented and used as the capacitive sensor, allowing the implementation to only require one conductive layer. This was demonstrated in a printed circuit board wireless LC sensor tag implementation with a 26.4% increase in detection sensitivity compared to only using the inductor's self-capacitance as the sensor.