Audio Generator Functions 4
U8903A User’s Guide 77
SMPTE IMD waveform
There are three predefined SMPTE IMD dual sine waveforms
comprising SMPTE IMD 1:1, 4:1, and 10:1. They conform to
the SMPTE standard RP120- 1983 for testing intermodulation
distortion. The SMPTE IMD waveforms consist of a lower
and an upper frequency sine waveform, at default values of
60 Hz and 7 kHz respectively. They are differentiated by the
amplitude ratio between the lower and upper frequencies.
The following figure shows the SMPTE IMD waveform menu.
Figure 4-9 SMPTE IMD waveform menu
The SMPTE IMD waveform may be configured with the
following parameters.
• Upper Frequency
• Lower Frequency
• Amplitude
• DC Offset
Amplitude refers to the amplitude of the composite signal.