SIGLENT
SSA3000X User Manual 44
2.3.3.2 Noise Marker
Execute the Noise marker function for the selected marker and read the noise power spectral
density.
If the current marker is “Off” in the Marker menu, pressing Noise Marker will first set it to
Normal type automatically; then measure the average noise level at the marked point and
normalize this value to 1 Hz bandwidth. During this process, certain compensation is always
made on the basis of the detection and trace types. The measurement will be more precise if
RMS Avg or Sample detection type is used.
This function can be used for measuring the C/N ratio.
2.3.3.3 N dB BW
Enable the N dB BW measurement or set the value of N dB. The N dB BW denotes the frequency
difference between two points that are located on both sides of the current marker and with N dB
fall (N<0) or rise (N>0) in amplitude as shown in the figure on the next page.
Figure 2-9 N dB BW
When the measurement starts, the analyzer will search for the two points which are located at both
sides of the current point with N dB fall or rise in amplitude and display the frequency difference
between the two points in the active function area. "----" would be displayed if the search fails.
Table 2-28 N dB Noise