User`s guide

12-10 Agilent Technologies E5500 Phase Noise Measurement System
AM Noise Measurement Fundamentals
Method 1: User Entry of Phase Detector Constant
Method 1, Example 2 Advantages
• Easy method of calibrating the measurement system.
• Will measure DUT without modulation capability.
• Requires little additional equipment: only a voltmeter or an oscilloscope.
• 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.
• Measures the AM detector gain in the actual measurement
configuration. Super-quick method of estimating the equivalent phase
detector constant.
Disadvantages
• Has only moderate accuracy compared to the other calibration methods.
Procedure
1. Connect circuit as shown in Figure 12-9, and tighten all connections. If
the Agilent/HP 70420A Option 001 or Agilent/HP 70427A is available,
use one of the connection diagrams described in “AM Noise
Measurement Block Diagrams” on page 12-3.
2. Measure the power which will be applied to the AM detector. It must be
between0and+23dBm.
Figure 12-9 User Entry of Phase Detector Constant AM Noise Measurement Setup
Method 1, Example 2
3. Measure the monitor output voltage on the AM detector with an
oscilloscope or voltmeter. Locate the diode detector’s dc voltage along
the bottom of the AM sensitivity graph (Figure 12-8 on page 12-9).
Moving up to the diagonal calibration line and over, the equivalent
phase detector constant can then be read from the left side of the graph.
The measured data will be plotted as single-sideband AM noise in
dBc/Hz.