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).

Pitch Generators and Audio Generators

A pitch generator is a type of signal generator optimized for use in audio and acoustics applications. Pitch generators typically include sine waves over the audio frequency range (20 Hz–20 kHz). Sophisticated pitch generators will also include sweep generators (a function which varies the output frequency over a range, in order to make frequency-domain measurements), multipitch generators (which output several pitches simultaneously, and are used to check for intermodulation distortion and other non-linear effects), and tone bursts (used to measure response to transients). Pitch 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 pitch 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.

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.