Contents
Digital Filters: An Introduction
Objectives:
Digital filters are used for two main purposes below. A big advantage for digital filters over analog ones is that digital filters can satisfy criteria for filters far better than analog ones. This slecture hopes to share characteristics important to digital filter use and design in addition to how concepts learned in ECE 438 apply to actual filter design.
1. Separation of signals that have been combined
2. Restoration of signals that have been distorted in some way
Basic Characteristics
When designing filters, it is important to understand where the desired/important information is contained in the signal of interest. In a time-domain important signal, desired information is contained in the amplitude changes when an event occurs, for example, intensity of sunlight on a forest floor over time. Meanwhile in the frequency-domain, one is primarily concerned with the relationship between main points in the signal and, consequently, one looks for periodic change in the signal of interest.