The instrument used to generate various test signals is called signal generator or signal source for short. It can be widely used as a variety of simulation signal or excitation signal in the test of various machines, systems, components and components. For example, a signal source is used to generate a modulation signal that is fed to a receiver to test its performance. When we demonstrate like oscilloscope to the customer, we often take some signal sources, such as the arbitrary waveform generator ArbStudio of like to generate some special signals, which is convenient to demonstrate various functions of the oscilloscope. There are many kinds of signal sources, such as sinusoidal signal generator, function generator, arbitrary waveform generator and so on. Sinusoidal signal is very important for frequency domain analysis of linear systems, which makes sinusoidal signal generator widely used. Users' requirements for such signal sources are usually wide frequency range, high frequency accuracy and stability, high spectrum purity and low phase noise. For example, sinusoidal signal generator needed in the test of communication system is generally required to extend the frequency to the radio frequency segment and have various modulation functions. The principle of sinusoidal signal generator is usually phase lock technology and frequency synthesis technology.
A function generator is a source of signals that can generate such things as sine waves, square waves, and triangular waves. A traditional function generator USES a constant current source to charge and discharge the capacitor. The voltage at both ends of the capacitor is the triangular wave. If triangular waves are sent to a comparator, square waves are produced. Triangle wave through waveform shaping circuit can also generate sine wave.By varying the current and capacitance, the signal frequency can be adjusted. This kind of signal source can generally output low frequency, low frequency accuracy and stability. With the development of digital technology, the realization of function generator gradually evolves from analog to digital. For example, DDS technology will be introduced later to generate signals, which also makes the function generator gradually merged into any waveform generator. Sinusoidal signal generator and function generator can only produce regular signals. And produce irregular signals need with the aid of Arbitrary Waveform Generator (AWG, Arbitrary Waveform Generator). The basic design idea of AWG is to intercept the signal waveform needed to reproduce for a period of uniform sampling and store it in memory. The waveform data in memory is read out in order, converted by DAC, and then filtered to obtain the desired waveform. AWG and digital storage oscilloscope can be considered as a reciprocal process in principle. Digital storage oscilloscope digitizes the analog waveform through ADC, and AWG converts the digitized waveform data into the analog waveform through DAC. Both devices are subject to Nyquist's law and can measure/output at no more than half the sampling rate of an ADC/DAC. Both devices are subject to Nyquist's law and can measure/output at no more than half the sampling rate of an ADC/DAC. A waveform can be collected using a rico oscilloscope and saved as a file. Import the waveform file into any waveform generator ArbStudio of like, and the simulated waveform can be restored. In practical applications, the waveform data used in AWG are not all truly sampled, and are usually generated by software.