Agilent Technologies X Series Manual page 544

Sweep/Control
Initial S/W Revision
Best Dynamic Range
This selection tells the analyzer to choose between swept and FFT analysis with the primary goal of
optimizing dynamic range. If the dynamic range is very close between swept and FFT, then it chooses
the faster one. This auto selection also depends on RBW Type.
In determining the Swept or FFT setting, the auto rules use the following approach:
• If the RBW Filter Type is Gaussian use the RBW for the Normal Filter BW and if that RBW > 210
Hz, use swept; for RBW <= 210 Hz, use FFT
• If the RBW Filter Type is Flat Top, use the same algorithm but use 420 Hz instead of 210 Hz for the
transition point between Swept and FFT
• If any of the CISPR detectors is chosen for any active trace, always use Swept.
Key Path
Example
Couplings
Readback
Initial S/W Revision
Best Speed
This selection tells the analyzer to choose between FFT or swept analysis based on the fastest analyzer
speed.
Key Path
Example
Couplings
Readback
Initial S/W Revision
FFT Width
This menu displays and controls the width of the FFT's performed while in FFT mode. The "FFT
width" is the range of frequencies being looked at by the FFT, sometimes referred to as the "chunk
width" -- it is not the resolution bandwidth used when performing the FFT.
It is important to understand that this function does not directly set the FFT width, it sets the limit on the
FFT Width. The actual FFT width used is determined by several other factors including the Span you
have set. Usually the instrument picks the optimal FFT Width based on the current setup; but on occasion
you may wish to limit the FFT Width to be narrower than that which the instrument would have set.
544
Prior to A.02.00
Sweep/Control, Sweep Setup, Sweep Type Rules
SWE:TYPE:AUTO:RUL DRAN sets the auto rules to dynamic range.
Directly selecting this setting sets AUTO to OFF.
Dynamic Range
Prior to A.02.00
Sweep/Control, Sweep Setup, Sweep Type Rules
SWE:TYPE:AUTO:RUL SPE sets the rules for the auto mode to speed
Directly selecting this setting sets AUTO to OFF.
Speed.
Prior to A.02.00