A signal generator is an electronic device that generates electrical signals with set properties of amplitude, frequency, and wave shape. These signals are used as a stimulus for testing and evaluating electronic devices and systems. Signal generators can be used to test electronic devices and instruments in a variety of applications, and there are several different types of signal generators available, including:

• Function generators: These are used to generate simple repetitive waveforms of varying magnitudes and frequencies.
• RF and microwave signal generators: These are used to generate radio frequency (RF) and microwave signals with analog and digital modulation schemes.
• Arbitrary waveform generators: These are used to generate complex waveforms with precise control over the shape, frequency, and amplitude of the waveform.
• Digital pattern generators: These are used as stimulus sources for digital integrated circuits and embedded systems for functional validation and testing.
• Frequency generators: These are used to generate signals with a specific frequency.

Signal generators can be standalone instruments or incorporated into more complex automatic test systems. They can be controlled by a microprocessor or a personal computer. Signal generators are essential for engineers, as they allow for precise and customizable signals to test and evaluate electronic systems.