What’s the difference between RF Signal Generators and Function Generators?

Signal Generators and Function Generators basically do the same thing, they produce signals over a frequency range. The main differences are the frequencies they produce. Function generators generally produce signals up to 200-300 MHz. RF Signal Generators is a general term used to describe RF signals from the MHz range to many GHz.

I need a square wave at a higher frequency than my function generator can produce. Can I use an RF Signal Generator?

No. RF Signal Generators only produce RF CW waves that are sinusoidal. Depending on your application, you may need to use a high-end arbitrary waveform generator. See our collection of Keysight high speed arbs here.

What are the classes and types of Keysight RF Signal Generators?

There are two general types of Keysight RF Signal Generators, analog signal generators and vector signal generators. Analog signal generators have the same frequency coverage as vector signal generators but lack digital modulation. Digital modulation forms the basis of communication for modern systems over the airwaves. Vector signal generators can produce digital modulation for 5G, digital TV, SATCOM and many more.

How do I choose the right Keysight RF Signal Generator?

Here are the main performance features when selecting an RF generator:

1. Modulation types – Analog modulation is available in both analog and vector RF signal generators, but digital modulation is available only in vector signal generators. Make further choices after first determining which type you need.
2. Frequency range – The Keysight series of RF generators cover different frequency ranges. This is because covering mm Wave frequencies is more expensive than covering frequency ranges for radio communications or 5G. Refer to the table of Keysight RF Signal Generators later in this document.
3. Hardware options. These options may not be automatically included with signal generator models. They are largely application dependent and need to be specified for every job. Here is a list of common hardware options:
   • Attenuators – Many applications require signals to be very small or have a low output level. This is a common requirement for receiver testing and other applications where low output levels are needed.
   • Precision frequency reference. – This option increases the stability and repeatability of the base system oscillator of the generator. This increases the overall frequency accuracy of the generator as a system.
   • Additional output power – Additional amplifiers can be added to many signal generators to increase output power. This option for high power is often used for amplifier and module testing but is not required for all applications.
   • Analog modulation - Analog modulation includes AM, FM, and phase modulation. Often these are available as one option. Pulse modulation is often considered to be an analog modulation. Pulse modulation is generally a separate option.
   • Phase Noise – A RF signal generator’s phase noise contribution will influence the entire system it’s used for. Many Keysight RF generators have enhanced phase noise options that are ordered separately.

Keysight RF Vector Signal Generators

(a) The UXG is an analog generator with a vector component, the N5194A.

Keysight RF Analog Signal Generators

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