HP 70427A User Manual page 146

Table 4-2
NOTE
HP 70428A's default bandwidths. The following table shows reference chain
configuration and default bandwidths for each tuning sensitivity.
HP 700428A Reference Chain Parameters
Tune Osc.
PLL
Sens Tuned
0.05 10 MHz 100
ppm/V MHz
1.0 100 MHz 600
ppm/V MHz
20 ppm/V 600 MHz none
Loop suppression cannot be calculated accurately if the HP 3048A PLL
bandwidth approaches the bandwidth of the narrowest HP 70428A PLL
bandwidth. The narrowest HP 70428A PLL bandwidth should be at least 5
times greater than the HP 3048A system bandwidth.
Increasing the HP 70428A'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 6 - 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
Phase Noise Measurement With PLL
Default PLL
BW
126 Hz
10 kHz
n/a
or the softkey.
600 MHz PLL BW
HP 70427A/HP 70428A User's Guide 4-5
Source Operation