A novel post-processing technique for high resolution digital storage oscilloscope (DSO) based on cascade average

High resolution digital storage oscilloscope (DSO) plays a significant role for electric equipment to keep systems safety, reliability, and availability. In the architecture of such an instrument, a key process is post-processing unit, which is optimizing the effective number of bit (ENOB) for some specific requirement. Tradition digital average method is popular for it is easy to implement. However, this technique has the problem of bad performance in transition band with Gibbs effect. In this work, we propose a new average method as high resolution strategy which cascades a number of stages of two-lap rectangle filter. Closed-form equations of resolution improvement and band limitation of this method have been explicitly derived. This method improves the bandwidth and is better than tradition average method in band performance. Experimental results based on baseline test and waveform test show that lower noise and better SNR using the proposed method.