User`s guide

RIGOL Chapter 2 Front Panel Operations

2-22 DSG3000 User’s Guide

Frequency Modulation (FM)

During frequency modulation (FM), the modulating signal changes the frequency of

the RF carrier waveform.

To Enable FM

Press FM/øM  FM/

M to select “FM” and press Switch to select “On” or “Off”.

 On: enable the FM function. The backlight of FM/øM goes on and the FM label

is displayed in the function status area in the user interface.

 Off: disable the FM function and this is the default state.

NOTE: The frequency modulation and phase modulation cannot be enabled at the

same time.

To Select the Modulation Source

Press FM/øM  Source to select “Int”, “Ext” or “Int & Ext” modulation source.

1. Internal Source

After selecting “Int”, the internal modulation source is turned on. At this point,

the instrument provides the modulating signal and you can set the modulation

frequency and modulation waveform of the modulating signal.

2. External Source

After selecting “Ext”, Rate and Waveform are grayed out and disabled. The RF

signal generator receives the external modulating signal input from the [EXT

MOD INPUT] connector (as shown in the figure below) at the front panel. This

modulating signal can be any waveform.

NOTE: The input amplitude of external modulating signal reaches +/-3V.

3. Internal & External

After selecting “Int & Ext”, both internal and external modulating sources are

selected at the same time and you can perform dual-tone FM signal modulation.