User`s guide

Agilent X-Series Signal Generators User’s Guide 371
Multitone and Two–Tone Waveforms (Option 430)
Using Two–Tone Modulation
4. Press Mode > More > Two–Tone > Freq Separation > 10 > MHz.
5. Press Two Tone Off On to On.
6. Turn on the RF output.
The two–tone signal is now available at the signal generator RF OUTPUT connector. Figure 14- 1 on
page 371 shows what the signal generator display should look like after all steps have been
completed. Notice that the T-TONE, I/Q, annunciators are displayed; the RF ON, MOD ON are on; and
the parameter settings for the signal are shown in the status area of the signal generator display.
Figure 14-1
Viewing a Two–Tone Waveform
This procedure describes how to configure the spectrum analyzer to view a two–tone waveform and
its IMD products. Actual key presses will vary, depending on the model of spectrum analyzer you are
using.
1. Preset the spectrum analyzer.
2. Set the carrier frequency to 6 GHz.
3. Set the frequency span to 60 MHz.
4. Set the amplitude for a 10 dB scale with a –10 dBm reference.
5. Adjust the resolution bandwidth to sufficiently reduce the noise floor to expose the IMD products.
A 9.1 kHz setting was used in our example.
6. Turn on the peak detector.
7. Set the attenuation to 4 dB, so you’re not overdriving the input mixer on the spectrum analyzer.
You should now see a two–tone waveform with a 6 GHz center carrier frequency that is similar to
the one shown in Figure 14- 2 on page 372. You will also see IMD products at 10 MHz intervals above
and below the generated tones, and a carrier feedthrough spike at the center frequency with carrier
feedthrough distortion products at 10 MHz intervals above and below the center carrier frequency.
Mode > Two–Tone
For details on
each key, use
key help as
described on
page 44.