3 Spectrum Analyzer Mode
3.3 Channel Power Measurement
Preselector and Bandwidth Conflict
When the Frequency Extender Preselector is applied and the signal bandwidth is
greater than 2.5 [GHz], then a settings alert message will show to warn the user that
the signal may be distorted due to the limitation of the Frequency Extender
Preselector bandwidth.
An example of the settings alert message is shown below.
Settings Alert message in the Status Bar at the bottom of the display.
Settings Alert message in the error queue
.
Software Preselection
Provided in some instruments, either to compensate for issues with provided
hardware preselection or to provide the preselection function when there is no
hardware preselector.
N9041B
Software Preselection compensates for the frequency range limit of the microwave
preselector. Since the microwave preselector only goes up to 50GHz, software
preselection must be used to suppress and separate images above 50GHz. The
specific algorithm used for software preselection is specified by the SW Preselection
Type selection – Normal or Advanced.
In N9041B, Software Preselection only applies for frequencies above 50GHz,
therefore it is only used for RF Input 2. Even if turned on, it is not used for other
inputs, and never for frequencies below 50GHz. This is why the label of this control
contains the parenthetical note “(>~50GHz)”.
Note that in N9041B, in Swept SA measurement, Software Preselection works even
if the measurement is using an FFT Sweep Type. In measurements other than Swept
SA, Software Preselection is not used if the measurement is using an FFT sweep
type.
Spectrum Analyzer Mode User's &Programmer's Reference 603