HP 70427A User Manual page 153

NOTE
Table 5-3
Tunable Source Operation
Phase Noise Measurement With PLL
To determine HP 3048A PLL bandwidth see the HP 3048A Reference
Manual
Loop suppression cannot be calculated accurately if the HP 3048A PLL
bandwidth approaches the bandwidth of the narrowest HP 70428A Option
002 PLL bandwidth in use. The narrowest HP 70428A Option 002 PLL
bandwidth should be at least 5 times greater than the HP 3048A system
bandwidth.
Note that increasing the HP 70428A Option 002's 100 MHz PLL bandwidth
or 600 MHz PLL bandwidth will degrade phase noise at some offsets.
Enter the bandwidth as follows:
1. Press the softkey.
Ref Chain
2. Press the
100 MHz PLL BW
3. Press the appropriate bandwidth softkey.
Step 7 - Define the measurement
Follow the instructions in the HP 3048A manual together with the
information below.
Specify Measurement Type and Frequency Range
•
Measurement Type: Phase Noise Using a Phase Lock Loop
Enter Source and Interface Parameters
•
Carrier Frequency: DUT's output frequency.
•
Detector/Discr. Input Frequency: DUT's output frequency.
•
VCO Tuning Constant: See table below.
•
Center Voltage of VCO Tuning Curve: 0V
•
Voltage Tuning Range of VCO: See table below.
•
VCO Tune-port Input Resistance: 1 M
•
Phase Detector: Internal Phase Detector - 1.2 GHz to 18 GHz
VCO Tuning Constant and Range vs. HP 70428A Tuning Sensitivity
5-6 HP 70427A/HP 70428A User's Guide
or the softkey.
600 MHz PLL BW
Ω