Procedure - Agilent Technologies X Series Manual

Displayed Average Noise Level (DANL)

Procedure

Procedure
1. Configure the equipment as shown in
2. Press ,
Mode Spectrum Analyzer
3. Set up the signal analyzer by pressing:
,
FREQ Channel Center Freq
Input/Output, RF Input
,
SPAN X Scale Span
, –70,
AMPTD Y Scale
, Attenuation,
AMPTD Y Scale
, , 1,
BW Res BW kHz
, , 100,
BW Video BW
Meas Setup, Average/Hold, Number
Trace/Detector, Trace Average
Single
4. Press
Restart, then wait for Average/Hold to display 20/20
5. Press
View/Display, Display,
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.
NOTE Ignore the residual response if one appears when taking the measurement.
8. Enter the value of the display line as the Measured Average Noise Level at 10 MHz column in
Table 2-1.
9. 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:
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.
10. Enter the normalized value of the displayed average noise level in
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 2-1 Value],
Center Freq
16
Figure 2-1.
, on the analyzer.
Mode Preset
, 10,
MHz
, , select
RF Coupling DC
, 10,
kHz
dBm
, 0,
Atten dB
Hz
, 20,
Enter
then press
Display Line
GHz
.
, .
On
Table 2-1.
Table 2-1. Press: ,
FREQ Channel
Chapter 2