HP 85422E, Руководство пользователя

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Making 3rd Order Measurements
Two-tone , third order intermodulation distortion is a common problem
in many electronic systems . When two signals are present in a system,
they can mix with any generated second harmonics and create third
order intermodulation distortion products . Third order product
frequency and amplitude dierences can be easily measured using the
one-button 3rd Ord Meas function.
Figure 7-12. Setup for Making 3rd Order Measurements
1. Connect two sources to the receiver through an amplier with
the appropriate frequency range . Refer to Figure 7-12. Set one
source to 300 MHz and 80 dBV (027 dBm) and the other source to
301 MHz and 80 dBV (027 dBm).
CA UTION
Y ou may need to vary the source powers and/or frequencies ,
depending on the available test amplier . Use sucient input
attenuation or suciently small signals to prevent damage to the
input of the receiver .
2. Set the receiver to a known state by pressing:
4 PRESET 5
4 INPUT 5
4 FREQUENCY 5
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
CENTER FREQ : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 300 4 MHz 5
4 SP AN 5 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 5 4 MHz 5
3. A djust the receiver so at least one of the fundamental signals and a
third-order product is displayed.
7-18 Making Other Measurements