Signal Generator Vs. Function Generator

Signal generator and function generator, both devices are used in testing, designing, and troubleshooting circuits by producing desired test signals. The two instruments may sound similar but there are some key differences that differentiate them from each other.

So, through this page, we will have a close look at what each of these instruments has to provide and what makes them unique.

What is A Signal Generator?

A signal generator is a type of electronic device that produces analog or digital electronic signals. The output of a signal generator can be calibrated and modified based on user parameters such as frequency, impedance, waveform, modulation, and output voltage.

Types of Signal Generators

  • RF Signal Generators: These are the signal generators for testing circuits for RF communications, such as wireless and cellular communications, radar, electronic warfare, etc. Users can change the amplitude, frequency, and modulation of the signal.
  • Audio Signal Generators: It is, as the name implies, a signal generator, an electronic test tool that produces a precisely calibrated signal at frequencies ranging from audio to microwave.

What is A Function Generator?

The function generator is the voltage source that produces sine, triangle, or square waves. It is a convenient and realistic method of delivering stimulus signals to a circuit. The waveform can be adjusted, as well as its frequency, amplitude, duty cycle, and DC offset. The frequency range is wide enough to generate conventional alternating current (AC) as well as audio and high frequency signals.

Types of Function Generators

  • Arbitrary Function Generators: Arbitrary Function Generators (AFGs) are identical to function generators, but with one significant difference: the onboard memory allocated to a user-defined waveform. This allows you to design a waveform, store it in the AFG’s onboard memory, and then generate the waveform via direct digital synthesis.

Top 3 Differences Between Signal Generator And Function Generator

Simple waveforms can be generated via a signal generator (usually just a sine wave). You can allow different types of modulation (AM, FM, phase modulation, digital standards).

Many models of modern signal generators can generate sophisticated digital signals such as those used by cell phones, Wi-Fi, Bluetooth, satellite communications, and more. Signal generators can cover a wide range of frequencies, from fractions of a Hertz to gigahertz.

In addition to generating the waveforms listed above, a function generator can also generate custom waveforms which, in some situations, can be developed by software and inserted into the generator. Some models include high-speed digital-to-analog converters that can simulate a variety of waveforms. They can overlay DC values ​​at the output. Filters are typically used at the output to remove unwanted harmonics. At higher levels, your frequency range is often limited (tens of MHz, maybe hundreds of MHz).

Signal GeneratorFunction Generator
Produce Sine waves onlyProduce Sine, Square, Triangular, Saw tooth
Frequency Stability is limited, can deviate from mean frequency over timeProvides High-Frequency Stability
Does not allow Phase-Locking with other sourcesPhase locking is allowed


Both Signal and function generators are pretty similar and are often classified under the same category, yet they differ as we have seen the differences that set them apart. As far as the recommendation goes, a function generator would be our top choice since it allows users to create different types of signals and offers a lot of different features.

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