Hover-sensitive touchpad

A touch detector, comprising:

• touch surface;
• plurality of antennae comprising plurality of row antennae and plurality of column antennae, the plurality of antennae being positioned beneath the touch surface;
• each of the plurality antennae being spaced apart from each other of the plurality of antennae such that no portion of any one of the plurality of antennae touches any portion of any other of the plurality of antennae;
• the plurality of row antennae being organized into N logical rows such that each of the plurality of row antennae is associated with one of the N logical rows, each of plurality of row antennae within each of the N logical rows being conductively coupled together by a row trace;
• the plurality of column antennae being organized into M logical columns such that each of the plurality of column antennae is associated with one of the M logical columns, each of the plurality of column antennae within each of M logical columns being conductively coupled together by a column trace;
• N signal emitters, where N is at least two, each of the N signal emitters being conductively coupled to one of the N row traces, the N signal emitters being adapted to simultaneously output N frequency-orthogonal signals, each of the N frequency-orthogonal signals being frequency orthogonal to each of the other N frequency-orthogonal signals;
• M signal receivers, where M is at least two, each of the M signal receivers conductively coupled to one of the M column traces, each of the M signal receivers being adapted to capture a frame of signals present on the coupled column trace;
• signal processor adapted to:
• (i) determine a measurement for each of the frequency-orthogonal signals from each frame, each measurement corresponding to an amount of each of the frequency-orthogonal signals present on the column trace during a time the corresponding frame was received;
• and
• (ii) produce a heat map of touch events proximate to the surface, wherein at least one of the touch events is hover, the heat map being based at least in part on the measurements.