Troubleshooting Harmonic Spurious By Fundamental Frequency; To Verify Harmonic Performance At The Rf Output - Agilent Technologies N5161A Service Manual

Troubleshooting
Troubleshooting Harmonic Spurious

Troubleshooting Harmonic Spurious by Fundamental Frequency

All mixing products and by-products are generated on the A3 RF assembly. Harmonic spurious problems will most likely be associated with
the A3 RF assembly.
• Spurious harmonic levels beyond the published specifications of the N5181A/82A require the replacement of the A3 RF assembly.

To Verify Harmonic Performance at the RF Output

1. Signal Generator Settings
a. Set the frequency of the signal generator to the harmonic frequency being measured. For example, when planning to measure the
second harmonic of a 1 GHz signal, set the frequency of the signal generator to 2 GHz.
b. Set the power level of the signal generator to +4 dBm (+7.5 dBm for Option UNB).
2. Spectrum Analyzer Settings
a. Connect a spectrum analyzer to the RF Output connector of the signal generator.
b. Set the frequency of the spectrum analyzer to the harmonic frequency being measured.
To continue with our example, set the frequency of the spectrum analyzer to 2 GHz.
c. On the spectrum analyzer, press the
The marker should indicate approximately 0 dBm.
3. Signal Generator Settings
a. Set the signal generator to the fundamental frequency of the harmonic being measured.
In this example, because the measured harmonic was at 2 GHz, the signal generator should be set to 1 GHz.
4. Spectrum Analyzer Settings
a. On the spectrum analyzer, read the power level (and record it for future reference, in case further troubleshooting is necessary). The
marker should indicate a power level in dBc; this is the power level of the harmonic being measured.
b. Compare the power level of the marker against the specified harmonic performance level for your signal generator.
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and
Peak Search Marker Delta
Agilent N5161A/62A/81A/82A/83A MXG Signal Generators Service Guide
keys.