N9030B PXA Signal Analyzer Service Guide 579
Functional Tests
Displayed Average Noise Level (DANL)
6. Rotate the knob and set the display line at the average amplitude of the
displayed noise floor by visual inspection.
7. Confirm that the measurement is performed on the analyzer noise floor
and not on a residual response within the displayed 10 kHz span.
8. Enter the value of the display line as the Measured Average Noise Level at
10 MHz column in Table 18-2.
9. Normalize the measured value to a 1 Hz BW by adding –30 dB to the
measured value.
10.Enter the normalized value of the displayed average noise level in. Table
18-2
11.The value of the normalized displayed average noise should be less than
the specification value.
12.Change the analyzer center frequency to the next value listed in Table
18-2. Press: FREQ Channel, Center Freq, [Table 2-1 Value], GHz
13.Repeat step 4 through step 12 to fill in the remainder of Table 18-2 for
your analyzer frequency range.
Ignore the residual response if one appears when taking the measurement.
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:
Normalized Noise = 10 Log (BW 2/BW 1) where BW 2 is the 1 kHz
BW we measure and BW 1 is 1 Hz BW to which we want to
normalize.
Therefore, 10 Log (1000) = 30 dB, so the noise floor will be 30 dB
lower in a 1 Hz BW.
Table 18-2 Displayed Average Noise Level (DANL) Results
Center Frequency
Measured Average Noise Level (dBm) Normalized Average Noise Level/(1 Hz
BW) (dBm)
Test Limits
(dBm)
10 MHz –153
2 GHz –151
6 GHz –148
13 GHz –147
20 GHz –141
26.5 GHz –135
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