Improvement in the linearity of fast digital oscilloscopes used in averaging mode

Accurate measurement of signals with very fast variations between values separated by several orders of magnitude is difficult. When signals are periodical, a fast digital oscilloscope may be used in averaging mode, but the measurement accuracy is mainly limited by analog-to-digital conversion (ADC) nonlinearity. In this paper, several methods for improving the conversion linearity are proposed. These methods are theoretically justified and experimentally validated. Several of these methods may be used simultaneously by an 8-bit digital oscilloscope to provide, in averaging mode, the linearity of an 11- or 12-bit ADC