4-9.
SINGLE SIDEBAND PHASE NOISE (Cont’d)
7. Adjust the HP 3585A marker to the peak of the IF.
8. On the HP 3585A, press COUNTER.
9. Adjust the frequency of the LO for an HP 3585A COUNTER reading of 1 MHz ±0.9Hz. This
removes any frequency offsets between the DUT and LO.
10. Adjust the output power of the DUT for 0 dBm at the peak of the IF. Select a REFERENCE LEVEL
of 0 dBm on the HP 3585A.
SYSTEM CALIBRATION
30 Hz Offset Calibration
(not applicable to units equipped with Option 007, Relaxed Phase Noise specifications)
11. On the HP 3585A, press FREQUENCY SPAN, 2S0 Hz, RES BW, 3 Hz. Allow one sweep to occur.
Ensure power at peak if IF is still 0 dBin.
12. Reduce LO frequency by 30 Hz (IF
=
1.00003 MHz ±0.9Hz).
13. Allow one sweep of the HP 3585A to occur. Adjust the HP 3585A marker to the peak of the IF.
Record the marker power level (Cal Data) into Table 4-19.
Table 4-19.
Phase Noise Calibration Data
Step
Offset (Hz)
Cal Data (dB)
13
30
CD =
14
100
CD
16
1K
CD =
19
10K
CD
21
lOOK
CD =
22
0
IFDC =
100
Hz Offset Calibration
14. Reduce the LO frequency by 70 Hz (IF
=
1.0001 MHz ±0.9Hz) Repeat step 13.
1 kHz Offset Calibration
15. On the HP 3585A, press FREQUENCY SPAN, 2S00 Hz, RES BW, 30 Hz.
16. Reduce LO frequency by 900 Hz (IF
=
1.001 MHz ±0.9Hz). Repeat step 13.
10 kHz Offset Calibration
17. Connect 1 MHz Notch Filter as shown in Figure 4-9. Select 1 MOhin input impedance on the HP
3585A.
18.
On the
HP
3585A,
press FREQUENCY SPAN, 2S kHz, RES BW, 100 Hz.
19. Reduce LO frequency by 9 kHz (IF
=
1.01 MHz ±0.9
Hz). Repeat step 13.
4-48
Performance Tests
HP 8340B/41B
