Signal generator

A signal generator, also known variously as a test signal generator, function generator, tone generator, arbitrary waveform generator, digital pattern generator or frequency generator is an electronic device that generates repeating or non-repeating electronic signals (in either the analog or digital domains). They are generally used in designing, testing, troubleshooting, and repairing electronic or electroacoustic devices; though they often have artistic uses as well.

There are many different types of signal generators, with different purposes and applications (and at varying levels of expense); in general, no device is suitable for all possible applications.

Traditionally, signal generators have been embedded hardware units, but since the age of multimedia-PCs, flexible, programmable software tone generators have also been available.

General purpose signal generators

Function generators

A function generator is a device which produces simple repetitive waveforms. Such devices contain an electronic oscillator, a circuit that is capable of creating a repetitive waveform. (Modern devices may use digital signal processing to synthesize waveforms, followed by a digital to analog converter, or DAC, to produce an analog output). The most common waveform is a sine wave, but sawtooth, step (pulse), square, and triangular waveform oscillators are commonly available as are arbitrary waveform generators (AWGs). If the oscillator operates above the audio frequency range (>20 kHz), the generator will often include some sort of modulation function such as amplitude modulation (AM), frequency modulation (FM), or phase modulation (PM) as well as a second oscillator that provides an audio frequency modulation waveform.

function generators are typically used in simple electronics repair and design; where they are used to stimulate a circuit under test. A device such as an oscilloscope is then used to measure the circuit's output. Function generators vary in the number of outputs they feature, frequency range, frequency accuracy and stability, and several other parameters.

Arbitrary waveform generators

Arbitrary waveform generators, or AWGs, are sophisticated signal generators which allow the user to generate arbitrary waveforms, within published limits of frequency range, accuracy, and output level. Unlike function generators, which are limited to a simple set of waveforms; an AWG allows the user to specify a source waveform in a variety of different ways. AWGs are generally more expensive than function generators, and are often more highly limited in available bandwidth; as a result, they are generally limited to higher-end design and test applications.

Special purpose signal generators

In addition to the above general-purpose devices, there are several classes of signal generators designed for specific applications.

Tone generators and audio generators

A tone generator is a type of signal generator optimized for use in audio and acoustics applications. Tone generators typically include sine waves over the audio frequency range (20 Hz–20 kHz). Sophisticated tone generators will also include sweep generators (a function which varies the output frequency over a range, in order to make frequency-domain measurements), multitone generators (which output several tones simultaneously, and are used to check for intermodulation distortion and other non-linear effects), and tone bursts (used to measure response to transients). Tone generators are typically used in conjunction with sound level meters, when measuring the acoustics of a room or a sound reproduction system, and/or with oscilloscopes or specialized audio analyzers.

Many tone generators operate in the digital domain, producing output in various digital audio formats such as AES-3, or SPDIF. Such generators may include special signals to stimulate various digital effects and problems, such as clipping, jitter, bit errors; they also often provide ways to manipulate the metadata associated with digital audio formats.

The term synthesizer is used for a device that generates audio signals for music, or that uses slightly more intricate methods.

Video signal generators

A video signal generator is a device which outputs predetermined video and/or television waveforms, and other signals used to stimulate faults in, or aid in parametric measurements of, television and video systems. There are several different types of video signal generators in widespread use. Regardless of the specific type, the output of a video generator will generally contain synchronization signals appropriate for television, including horizontal and vertical sync pulses (in analog) or sync words (in digital). Generators of "composite" video signals (such as NTSC and PAL) will also include a colorburst signal as part of the output. Video signal generators are available for a wide variety of applications, and for a wide variety of digital formats; many of these also include audio generation capability (as the audio track is an important part of any video or television program or motion picture).

External links

* [http://rf-microwave.blogspot.com Signal Generators]
* [http://www.signalforge.com/home/sf1/smartlist_11/Application_Notes.html Applications for signal generators]
* [http://www.radio-electronics.com/info/t_and_m/generators/rf-signal-generator-specs-specifications.php Understanding signal generator specifications]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • signal generator — ▪ electronics       electronic test instrument that delivers an accurately calibrated signal at frequencies from the audio to the microwave ranges. It is valuable in the development and testing of electronic hardware. The signal generator… …   Universalium

  • signal generator — signalų generatorius statusas T sritis automatika atitikmenys: angl. signal generator vok. Meßsender, m; Signalgenerator, m rus. генератор сигналов, m; сигнал генератор, m pranc. générateur de signaux, m …   Automatikos terminų žodynas

  • signal generator — signalų generatorius statusas T sritis Standartizacija ir metrologija apibrėžtis Generatorius, kuriantis įvairių parametrų signalus. atitikmenys: angl. signal generator vok. Signalgenerator, m; Signaloszillator, m rus. генератор сигналов, m;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • signal generator — signalų generatorius statusas T sritis fizika atitikmenys: angl. signal generator vok. Signalgenerator, m; Signaloszillator, m rus. генератор сигналов, m; сигнальный генератор, m pranc. générateur des signaux, m …   Fizikos terminų žodynas

  • Signal generator — A&V A test oscillator that can be adjusted to provide a test signal at some desired frequency, voltage, modulation, and waveform …   Audio and video glossary

  • signal generator — F/A/V test equipment instrument that produces calibrated electronic signals intended for the testing or alignment of electronic circuits or systems …   Audio and video glossary

  • signal generator — /ˈsɪgnəl dʒɛnəreɪtə/ (say signuhl jenuhraytuh) noun a device which generates artificial signals to test electronic equipment …   Australian English dictionary

  • signal generator for measuring purposes — matuojamasis signalų generatorius statusas T sritis Standartizacija ir metrologija apibrėžtis Elektrinių signalų šaltinis, kurio charakteristikos (signalo pavidalas, dažnis, įtampa ir kt.) gali kisti fiksuotai arba būti reguliuojamos pasirinktoje …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • Video signal generator — A video signal generator is a type of signal generator which outputs predetermined video and/or television waveforms, and other signals used to stimulate faults in, or aid in parametric measurements of, television and video systems. There are… …   Wikipedia

  • stair-step signal generator — laiptuotojo signalo generatorius statusas T sritis radioelektronika atitikmenys: angl. staircase signal generator; stair step signal generator vok. Stufensignalgenerator, m rus. генератор ступенчатого сигнала, m pranc. générateur de signal en… …   Radioelektronikos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.