Keysight E8357D/67D & E8663D PSG User’s Guide 265
Two–Tone Waveform Generator
Creating, Viewing, and Modifying Two–Tone Waveforms
Figure 10-3
To Minimize Carrier Feedthrough
This procedure describes how to minimize carrier feedthrough and measure
the difference in power between the tones and their intermodulation distortion
products. Carrier feedthrough only occurs with center–aligned two–tone
waveforms.
This procedure builds upon the previous procedure.
1.
On the spectrum analyzer, set the resolution bandwidth for a sweep rate
of about
100 to 200 ms. This will allow you to dynamically view the carrier
feedthrough spike as you make adjustments.
2.
On the signal generator, press
I/Q
>
I/Q Adjustments
>
I/Q Adjustments
Off On
to On.
3.
Press
I Offset
and turn the rotary knob while observing the carrier
feedthrough with the spectrum analyzer. Changing the I offset in the
proper direction will reduce the feedthrough level. Adjust the level as low
as possible.
4.
Press
Q Offset
and turn the rotary knob to further reduce the carrier
feedthrough level.
5.
Repeat steps 3 and 4 until you have reached the lowest possible carrier
feedthrough level.
6.
On the spectrum analyzer, return the resolution bandwidth to its previous
setting.
Carrier
Feedthrough
Intermodulation
Distortion
Two–Tone
Channels
Carrier Feedthrough
Distortion
