Abstract: A method and an apparatus for providing non-contact measurement of waveforms proximate to a surface of a sample. In one embodiment, the described apparatus includes a composite probe waveform generator configured to provide a composite probe waveform having a plurality of overlapping component probe waveforms. Each of the overlapping component probe waveforms have a repetition rate substantially equal to the repetition rate of the sample waveform to be measured from the sample. The apparatus includes a cantilever with a signal path to carry the composite probe waveform to a position above the sample surface where the sample waveform is to be measured. In one embodiment, each of the component probe waveforms of the composite probe waveform is modulated at a frequency near a mechanical resonance frequency of the cantilever.

Abstract: A method and an apparatus for providing non-contact measurement of waveforms proximate to a surface of a sample. In one version, the describe apparatus includes a probe waveform generator that generates probe waveforms with the same repetition rate as a sample waveform to the measured from the sample. The apparatus includes a cantilever with a signal path to carry the probe waveform to a position above the sample surface where the sample waveform is to be measured. The apparatus of the present invention also includes a gate to periodically route the probe waveforms to the cantilever tip. The gate is controlled by a periodic gating signal with a period substantially longer than the signal period of the sample waveform. In one version, the gate is switched at a repetition rate substantially equal to a mechanical resonant repetition rate of the cantilever. Capacitive coupling between the cantilever and the signal line of the sample results in a periodic motion of the cantilever at the gating repetition rate.