R&S ZNA67 - Page 106

Concepts and features
R&S
®
ZNA
106User Manual 1178.6462.02 ─ 20
Multiple peak search
Multiple peak search allows you to find multiple local minima/maxima at once. Markers
1 to 10 are assigned to the peaks detected from the start frequency towards the stop
frequency. Multiple peak search uses its own search and tracking settings; search and
tracking settings for standard marker search are ignored.
Bandfilter search
In a bandfilter search, the R&S ZNA locates trace segments with a bandpass or band-
stop shape and determines characteristic filter parameters.
Bandpass and bandstop regions can be described with the same parameter set:
●
A bandpass region contains a local maximum around which the magnitude of the
trace falls off by more than a specified value.
●
A bandstop region contains a local minimum around which the magnitude of the
trace increases by more than a specified value.
The analyzer locates bandpass and bandstop regions and determines their position
("Center" frequency) and shape ("Bandwidth", "Lower Edge" and "Upper Edge", quality
factor. For a meaningful definition of the bandwidth factor, the trace format must be "dB
Mag".
The info field contains the following search results:
●
"Bandwidth" is the n-dB bandwidth of the bandpass/bandstop region, where n is a
selectable bandwidth factor. The bandwidth is equal to the difference between the
lower and the upper band edge frequency.
●
"Center" is calculated as the geometric or arithmetic mean of the lower band edge
frequency f
LBE
and the upper band edge frequency f
UBE
:
f
Center
= sqrt (f
LBE
* f
UBE
) (geometric mean) or
f
Center
= 1/2 (f
LBE
+ f
UBE
) (arithmetic mean)
The arithmetic mean is always higher than the geometric mean. The values are
close if the bandwidth is small compared to the geometric mean of the band edges.
●
"Lower Edge" is the closest frequency below the maximum (or minimum), where
the trace value is equal to the maximum (minimum) value minus (plus) n dB.
●
"Upper Edge" is the closest frequency above the maximum (or minimum), where
the trace value is equal to the maximum (minimum) value minus (plus) n dB.
●
The "Quality Factor (3 dB)" is the ratio between the "Center" frequency and the 3-
dB "Bandwidth"; it does not depend on the selected bandwidth factor.
●
The "Quality Factor (BW)" is the ratio between the "Center" frequency and the
"Bandwidth" displayed above. This result is available only if the selected bandwidth
factor is different from 3 dB.
Screen elements