ELEC 241 Lab

Introduction

In the last 2 Labs we looked at various kinds of signals: DC, sinusoidal, square waves, speech, etc. But to build our optical communication system, we will have to do more than look. We need to be able to manipulate signals so that we can impress the desired information onto a "carrier" signal to transmit it and then extract the information from the received signal. Another term for this signal manipulation is signal processing.

Basically, signal processing is simply doing math on signals: adding or multiplying them together, scaling them to make them smaller or larger, filtering them to make them "smoother" or to separate a desired signal from an undesired one. In this Lab and the next we will begin investigating basic signal processing operations including attenuation, amplification, and filtering.

Another theme of the first two labs was the study of components. With this lab we will begin studying circuits, or combinations of components. The simplest circuit (well, maybe the second simplest) is the voltage divider: just two resistors (or more generally two impedances) in series. Yet this simple configuration is the heart of some of the most important circuits in all of EE. Combined with the notion of Thévenin equivalence, it describes the behavior of subsystems when they are interconnected. It is the basis for attenuators, filters, amplifiers, logic gates, many types of transducers, and a host of other functions that make up electronic systems.

In this lab we will look at a number of basic circuits (all derived from the voltage divider) and see how we might use them in processing (and originating) signals.