System Overview
R&S
®
ZVT
60
Getting Started 1300.0045.62 ─ 10
3.2.4.2
Conversion of Complex into Real Quantities
The results in the "Trace – Measure" menu can be divided into two groups:
●
"S-Parameters", "Ratios", "Wave Quantities", "Impedances", "Admittances", "Z-
Parameters", and "Y-Parameters" are complex.
●
"Stability Factors" and "DC Input" values (voltages, PAE) are real.
The following table shows how the response values in the different Cartesian diagrams
are calculated from the complex measurement values z = x + jy (where x, y, z are func-
tions of the sweep variable). The formulas also hold for real results, which are treated
as complex values with zero imaginary part (y = 0).
Trace Format
Description
Formula
dB Mag
Magnitude of z in dB
|z| = sqrt ( x2 + y2 )
dB Mag(z) = 20 * log|z| dB
Lin Mag
Magnitude of z, unconverted
|z| = sqrt ( x2 + y2 )
Phase
Phase of z
φ (z) = arctan (y/x)
Real
Real part of z
Re(z) = x
Imag
Imaginary part of z
Im(z) = y
SWR
(Voltage) Standing Wave Ratio
SWR = (1 + |z|) / (1 – |z|)
Delay
Group delay, neg. derivative of the
phase response
– d φ (z) / dΩ (Ω = 2
π
* f)
An extended range of formats and conversion formulas is available for markers. To
convert any point on a trace, create a marker and select the appropriate marker format.
Marker and trace formats can be selected independently.
Screen Elements
