For measurements on electronic devices, mainly analog ones, signals often have to be generated which serve as input signals for the DUT. This signal generation can be performed by function generators.
A function generator or waveform generator is an electronic device that generates signals in various waveforms, frequencies and amplitudes. The basic waveforms of function generators are the sine, the square, and the triangle. From these basic waveforms, other waveforms such as the pulse and sawtooth can be derived.
Technically, the heart of a function generator is a square wave generator. By integrating the output voltage, a triangular signal is generated, and from this, by slowly limiting the amplitude using shaping, the sinusoidal signal is generated.
The frequency range of function generators can be set in steps or continuously and extends from ultra-low frequencies in the microhertz range (µ Hz) up to the two- digit megahertz range( MHz). Similarly, the output voltage can be adjusted in steps or continuously, typically from a few millivolts (mV) to two-digit volts (V). In addition, function generators can produce single oscillations and bursts and can be triggered and swept.
Of course, there is a wide range of function generators, which differ in some important parameters. There are the signal shapes to mention. In addition to the basic waveforms mentioned, some function generators can also generate white noise, others also work as a DC voltage source, and still others fulfill the functions of a modulator or sweeper.
Important criteria are the setting and accuracy offrequency and voltage, duty cycle, rise time, overshoot, signal symmetry and roof slope of the square wave signal, duty cycle and linearity of the triangular signal and THD of the sinusoidal signal. For tunable function generators, the amplitude response over the tunable frequency range must also be mentioned. Since some function generators use direct digital synthesis( DDS), they achieve accuracy values of `10^-6` and higher.
In addition to the function generators mentioned above, there are also those that can generate an arbitrary waveform. These function generators are called arbitrary waveform gener ators or Arb function generators for short.