Very high sample rate digital filters using the δ operator

The paper reports upon the theoretical and practical issues concerned with achieving digital filters in which the sample rate is very much higher than the dominant frequency, illustrated by means of a general-purpose second-order digital filter section which can readily be configured for lowpass, highpass, bandpass or bandreject operation over a range of frequencies. The δ operator approach is used throughout, although a brief comparison is included to show what the implications would be using the z operator. The paper shows how full performance can be achieved even with four orders of magnitude between the filter frequency and sampling frequency, including practical results from implementation using a DSP device.