Tektronix AWG 2021 - Manual (Page 13)

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Figure 13. The TDS 744A shows the intermodu-
lation performance with expanders disabled and
enabled. There is no distortion with the expander
disabled. The first order intermodulation products
are about 35 dB below the fundamental tones
with expanders enabled.
Figure 13 shows the demodu-
lated output from an FM
receiver with the expander
disabled and enabled. The top
two traces show the unexpanded two-tone signal and its spectrum
as calculated by the TDS 744A
FFT function. The lower two
traces show the same signals
with the expander enabled. The intermodulation products are
now significant, with the first
order products about 35 dB
below the fundamental tones.
Demodulated output, unexpanded
Demodulated output, expanded
Unexpanded spectrum
Expanded spectrum