Mobile, field-testing and airborne applications benefit from lighter, battery-operated platforms. RF signal generators are available as benchtop instruments, rackmount instruments, embeddable modules and in card-level formats. But when testing receiver sensitivity, a low signal level is required to see how the receiver behaves under low signal-to-noise conditions. For example, if a signal has to travel through a very long cable out to an antenna, a high output signal may be needed to overcome the losses through the cable and still have sufficient power at the antenna. A wide range of output power is desirable, since different applications require different amounts of signal power. Depending on the manufacturer and model, output powers can range from -135 to +30 dBm. A common feature is an attenuator vary the signal’s output power. This could include AM, FM, ΦM (phase modulation) and pulse modulation. Many models offer various types of analog modulation, either as standard equipment or as an optional capability to the base unit. RF signal generators produce continuous wave radio frequency signals of defined, adjustable, amplitude and frequency. There was a sharp distinction in purpose and design of radio-frequency and audio-frequency signal generators. RF and microwave signal generators can be classified further as analog or vector signal generators.Īnalog signal generators based on a sine-wave oscillator were common before the inception of digital electronics, and are still used. Some models go as high as 70 GHz with a direct coaxial output, and up to hundreds of GHz when used with external waveguide source modules. RF signal generators typically range from a few kHz to 6 GHz, while microwave signal generators cover a much wider frequency range, from less than 1 MHz to at least 20 GHz. RF and microwave signal generators normally have similar features and capabilities, but are differentiated by frequency range. RF (radio frequency) and microwave signal generators are used for testing components, receivers and test systems in a wide variety of applications including cellular communications, WiFi, WiMAX, GPS, audio and video broadcasting, satellite communications, radar and electronic warfare. An AWG is used in higher-end design and test applications.
An AWG is generally more expensive than a function generator and often has less bandwidth. Unlike a function generator that produces a small set of specific waveforms, an AWG allows the user to specify a source waveform in a variety of different ways. Main article: Arbitrary waveform generatorĪn arbitrary waveform generator (AWG or ARB) is a sophisticated signal generator that generates arbitrary waveforms within published limits of frequency range, accuracy, and output level. Signal generators may be free-standing self-contained instruments, or may be incorporated into more complex automatic test systems. Modern general-purpose signal generators will have a microprocessor control and may also permit control from a personal computer. More general-purpose signal generators allow control of all the characteristics of a signal. In general, no device is suitable for all possible applications.Ī signal generator may be as simple as an oscillator with calibrated frequency and amplitude. These types include function generators, RF and microwave signal generators, pitch generators, arbitrary waveform generators, digital pattern generators, and frequency generators.
There are many different types of signal generators with different purposes and applications and at varying levels of expense. These generated signals are used as a stimulus for electronic measurements, typically used in designing, testing, troubleshooting, and repairing electronic or electroacoustic devices, though it often has artistic uses as well. For an electronic musical instrument, see Sound module.Ī signal generator is one of a class of electronic devices that generates electronic signals with set properties of amplitude, frequency, and wave shape.