416 Keysight EXG and MXG X-Series Signal Generators User’s GuideMultitone and Two-Tone Waveforms (Option 430)Using Two–Tone Modulation5. 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.7. Turn on waveform averaging.8. Create a marker and place it on the peak of one of the two tones.9. Create a delta marker and place it on the peak of the adjacent intermodulation product, whichshould be spaced 10 MHz from the marked tone.10.Measure the power difference between the tone and its distortion product.You should now see a display that is similar to the one shown in Figure 17-3 on page 416. Youroptimized two–tone signal can now be used to measure the IMD products generated by a device–under–test.Note that carrier feedthrough changes with time and temperature. Therefore, you will need toperiodically readjust your I and Q offsets to keep your signal optimized.Figure 17-3Changing the Alignment of a Two–Tone WaveformThis procedure describes how to align a two–tone waveform left or right, relative to the centercarrier frequency. Because the frequency of one of the tones is the same as the carrier frequency,this alignment typically hides any carrier feedthrough. However, image frequency interferencecaused by left or right alignment may cause minor distortion of the two–tone signal. This procedurebuilds upon the previous procedure.1. On the signal generator, press Mode > Two Tone > Alignment Left Cent Right to Left.2. Press Apply Settings to regenerate the waveform.Main MarkerDelta MarkerMinimizedCarrierFeedthroughFor details on eachkey, use key help asdescribed onpage 40.
