A Study of the Digital N-path Band-Pass Filter with Special Purpose Applications.

摘要

The N-path technique provides an alternate approach to the digital band-pass problem and an alternate approach to several special purpose digital filter problems. The N-path, particularly in the narrow band-pass area, is shown to have distinct advantages over filters realized by the standard low-pass to band-pass transformation. The main advantages are reduced computational requirements, lower coefficient quantization sensitivities and characteristics that make the filter amenable to certain special purpose filter problems. The N-path digital band-pass filter has properties that make the technique amenable to certain special purpose filter problems. The total dependency of the center frequency on the sampling frequency may be used for phase lock loop applications. The analogy of the N-path to an impulse correlator may be used to detect and display periodic signals of complex shapes. The high processing gain provided by impulse correlation makes it possible to extract periodic signals of complex shape cleanly from noise contamination while retaining the wave shape.