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Set modulation depth
Modulation depth is the degree of amplitude change, expressed in percentage. The range of AM depth is 0%~120%,
100% by default. When modulation depth is 0%, a constant amplitude is output (half of carrier amplitude). When
modulation depth is 100%, the output amplitude varies with the modulation waveform. When modulation depth is more
than 100%, the instrument will not output a peak-to-
peak voltage (terminating at 50Ω) more than ±5V. You can change it
with multi-functional control and direction key on AM interface or by pressing Depth. In case of external modulation source,
the output amplitude of instrument is also controlled by ±5V signal level on external analog modulation input terminal
(Modulation In connector) on the back panel. For example, if modulation depth in parameter list is set to be 100%, AM
output amplitude is the maximum when external modulation signal is +5V and the minimum when external modulation
signal is -5V.
Comprehensive example
First set the instrument to run in amplitude modulation (AM) mode, and then set an internal sine wave of 200Hz as
modulation signal and a square wave with frequency of 10kHz, amplitude of 200mVpp and duty ratio of 45% as carrier
signal. Finally set modulation depth to be 80%.
The specific steps are as follows:
1)
Use AM function
Press MOD to use the function, and select AM function (press soft key “Type” to select).
Figure 4- 4 Select AM function
2)
Set modulation signal parameters
Set with the multi-functional control and direction key after using AM function. You can also press soft keys of function on
the above interface for using AM function.
