Digital Storage Oscilloscope

Abstract

An oscilloscope is an electronic device used to display or analyze the waveform of electronic signals. An oscilloscope can be used to display a waveform representing change of a first variable as a function of a second variable. An oscilloscope draws a graph of instantaneous signal voltage as a function of time. Several types and forms of oscilloscopes have been developed over the years. An early form of oscilloscope, known as a cathode-ray oscilloscope, created a focused electron beam that would move in patterns across the face of a cathode ray tube (CRT) to produce a graph.

Today's oscilloscopes typically use a computer processor to generate the graph and display the graph on a liquid crystal or other type of display. The oscilloscope is useful because it enables the visualization of the time varying character of signals, using a vertical axis representing level and horizontal axis representing time. Oscilloscopes have been used for years for a number of purposes, including monitoring waveforms of various data, among other purposes. They have become an essential for research, development, and manufacturing of electronic devices.

An analog oscilloscope displays an analog signal in real time as a function of amplitude versus time. The display of the analog signal starts when a trigger signal is generated in response to a trigger event, such as the zero crossing of the analog signal. Analog oscilloscopes have long been the most utilized instruments for viewing waveforms. Analog oscilloscopes provide a continuous time-based display of the instantaneous amplitude values of electrical phenomena, and are thus able to accurately display the waveforms of complex signals, such as high-frequency carrier signals having low-frequency envelopes.

Analog oscilloscopes however have a significant disadvantage in that they are unable to store signal waveforms. Higher frequency signals may be monitored since any speed limitations are placed, not by the speed of the analog-to-digital converter, but by the bandwidth of the oscilloscopes' electronics. Further, analog oscilloscopes can monitor the signal continuously or almost continuously. With the progress of digital technology, digital oscilloscopes have been developed allowing them to store signal waveforms.