Keysight Technologies N5511A, User Manual

Page: 261 / 369

N5511A Phase Noise Test System User’s Guide 261
AM Noise Measurement Fundamentals
Calibration and Measurement General Guidelines
User entry of phase detector constant
Advantages
— Easy method of calibrating the measurement system.
— Will measure DUT without modulation capability.
— Requires only an RF power meter to measure drive levels into the AM
detector.
— Fastest method of calibration. If the same power levels are always at the AM
detector, as in the case of leveled outputs, the AM detector sensitivity will
always be essentially the same.
— Very quick method of estimating the equivalent phase detector constant.
Disadvantages
— It is the least accurate of the calibration methods.
— It does not take into account the amount of power at harmonics of the
signal.
1. Using information shown in Figure 11-4 and Figure 11-5 , Connect the
circuit and tighten all connections.
Figure 11-4 Phase detector constant AM noise setup
2. Measure the power which will be applied to the AM detector (see Figure
11-5 ).
Figure 11-5 AM noise calibration setup
3. Locate the drive level on the AM sensitivity graph ( Figure 11-6 ), and enter
the data.