<P> A typical function generator can provide frequencies up to 20 MHz . RF generators for higher frequencies are not function generators in the strict sense since they typically produce pure or modulated sine signals only . </P> <P> Function generators, like most signal generators, may also contain an attenuator, various means of modulating the output waveform, and often the ability to automatically and repetitively "sweep" the frequency of the output waveform (by means of a voltage - controlled oscillator) between two operator - determined limits . This capability makes it very easy to evaluate the frequency response of a given electronic circuit . </P> <P> Some function generators can also generate white or pink noise . </P> <P> More advanced function generators are called arbitrary waveform generators (AWG). They use direct digital synthesis (DDS) techniques to generate any waveform that can be described by a table of amplitudes . </P>

What is the purpose of the dc offset in the function generator