Rohde & Schwarz ZVL series - Conversion of Complex into Real Quantities

R&S
®
ZVL System Overview
Basic Concepts
Quick Start Guide 1303.6538.62-01 81
3.1.7.2 Conversion of Complex into Real Quantities
The results to be selected in the Trace – Meas menu can be divided into two groups:
E S-Parameters, Impedances, and Admittances are complex.
E Stability Factors 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
functions 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 ( x
2
+ y
2
)
dB Mag(z) = 20 * log|z| dB
Lin Mag Magnitude of z, unconverted |z| = sqrt ( x
2
+ y
2
)
Phase Phase of z  (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|)
Group Delay Group delay, neg. derivative of
the phase response
– d  (z) / d ( = 2 * f)