Agilent Technologies E1441A Amplitude Modulating Waveform Shape, Amplitude Modulation Depth

You cannot use the noise function or dc volts as the AM carrier waveform.

Use the following command to select the shape of the output function:

FUNCtion:SHAPe SINusoidSQUareTRIangleRAMPUSERDC

You can also use the APPLy command to select the function, frequency, amplitude, and offset with a single command. Because the APPLy command also changes duty cycle, modulation type, trigger source, and trigger slope, you must place the APPLy command first in any sequence of configuration commands.

AM Carrier Frequency Carrier frequency: 100 ∝Hz to 15 MHz (100 kHz for triangle and ramp). The default is 1 kHz.

For arbitrary waveforms, the maximum carrier frequency depends on the number of points specified in the waveform. The five built-in arbitrary waveforms can be output at a maximum of 5 MHz.

Use the following command to set the carrier frequency:

FREQuency <frequency>MINimumMAXimum

Amplitude Modulating Waveform Shape

The function generator will accept an internal modulating signal, an external modulating signal, or both.

Modulating waveform shape (internal source): Sine, Square, Triangle, Ramp, Noise, or Arbitrary waveform. The default is Sine.

You can use the noise function as the modulating waveform. However, you cannot use the noise function or dc volts as the carrier waveform.

Use the following command to set the modulating waveform shape:

AM:INTernal:FUNCtion SINSQUTRIRAMPNOISUSER

Amplitude Modulating Waveform Frequency

The function generator will accept an internal modulating signal, an external modulating signal, or both.

Modulating frequency (internal source): 10 mHz to 20 kHz. The default is 100 Hz.

The sync signal for AM is referenced to the modulating signal (not the carrier). A momentary TTL “high” pulse (> 200 ns) is output at each zero-crossing point of the modulating signal. The signal is output from the front-panel SYNC terminal.

Use the following command to set the modulating waveform frequency:

AM:INTernal:FREQuency <frequency>MINimumMAXimum

Amplitude Modulation Depth

The modulation depth is expressed as a percentage and represents the extent of the amplitude variation. At 0% modulation, the output amplitude is half of the selected value. At 100% modulation, the output amplitude equals the selected value.

Chapter 2 Agilent E1441A Application Information 29