UNI-T UTG1000 Series User Manual page 33

1) Internal Source
When modulation source is internal, modulation wave can be: sine wave, square wave, rising ramp wave, falling
ramp wave, arbitrary wave and noise. After enabling FM function, the default of modulation wave is sine wave. If
need to change, press Carrier Wave →Parameter→Type in turn.
Square wave: duty cycle is 50%

Lead Ramp Wave: symmetry degree is 100%

Tail Ramp Wave: symmetry degree is 0%

Arbitrary Wave: Arbitrary wave length limit is 1kpts

Noise: White Gauss noise

2) External Source
When modulation source is external, carrier waveform will be modulated by an external waveform. FM frequency
deviation is controlled by ±5V signal level of external modulation input terminal on front panel. In positive signal
level, FM output frequency is more than carrier wave frequency, while in negative signal level, FM output frequency
is less than carrier wave frequency. Low external signal level has small deviation. For example, if the frequency
offset is set to 1kHz and the external modulation signal is +5V, FM output frequency will be the current carrier
frequency plus 1kHz. When the external modulation signal is -5V, FM output frequency will be the current carrier
frequency minus 1kHz.
Modulation Shape Frequency Setting
When modulation source is internal, frequency of modulation shape can be modulated. After enabling FM function,
the default of modulation shape frequency is 100Hz. If need to change, press Carrier Wave Parameter→
Modulation Frequency in turn, and the modulation frequency range is 2mHz to 50kHz. When modulation source is
external, parameter list will hide the modulation shape option and modulation frequency option, and carrier
waveform will be modulated by an external waveform. The range of modulation signal input from external is 0Hz to
20Hz.
Frequency Deviation Setting
UTG1000A Series 31