108 Chapter 3
PSA Functional Tests
Displayed Average Noise Level (DANL)
PSA Functional Tests
4. Press Display, then press the Display Line key.
5. Rotate the RPG knob and set the display line at the average amplitude of the displayed
noise floor by visual inspection.
6. Confirm that the measurement will be performed on the spectrum analysis noise floor
and not on a residual response within the displayed 10 kHz span.
NOTE Ignore the residual response if one appears when taking the measurement.
7. Enter the value of the display line as the Measured Average Noise Level at 5 MHz
column in Table3-3.
8. Normalize the measured value to a 1 Hz BW by adding −30 dB to the measured value.
NOTE The −30 dB value is added because the formula used to calculate the value of
the noise power in a 1 Hz BW when measured with a 1 kHz BW is:
Noise = 10 Log (BW 2/BW 1) where BW 2 is the 1 kHz BW we measure and
BW 1 is 1 Hz BW we want to normalize to.
Therefore, 10 Log (1000) = 30 dB, so the noise floor will be 30 dB lower in a
1 Hz BW.
9. Enter the normalized value of the displayed average noise level in Table3-3.
10.The value of the normalized displayed average noise should be less than the
specification value.
11.Change the analyzer center frequency to the next value listed in Table3-3
12.Repeat steps 4 through 10 to fill in the remainder of Table 3-3 for your analyzer
frequency range.
Table3-3 Displayed Average Noise Level (DANL) Results
Center
Frequency Measured Average Noise
Level (dBm) Normalized Average Noise
Level/(1 Hz BW) (dBm) Test Limit s
(dBm)
5 MHz –140
2 GHz –149
6 GHz –147
13 GHz –145
20 GHz –142
26.5 GHz –136
40 GHz –124
50 GHz –126