R&S
®
ZVL
System Overview
Basic Concepts
Quick Start Guide 1303.6538.62-01
87
Circles of equal
conductance
Arcs of equal
susceptance
Open-circuited
load (Y = 0)
Short-circuited
load (Y = infinity)
Matching
admittance (Y = Y
0
)
Examples for special points in the inverted Smith chart:
E
The magnitude of the reflection coefficient of a short circuit (Y = infinity, U = 0) is
one, its phase is –180
0
.
E
The magnitude of the reflection coefficient of an open circuit (Y = 0, I = 0) is one, its
phase is zero.
3.1.7.6 Measured Quantities and Display Formats
The analyzer allows any combination of a display format and a measured quantity. The
following rules can help to avoid inappropriate formats and find the format that is
ideally suited to the measurement task.
E
All formats are suitable for the analysis of reflection coefficients S
ii
. The formats
SWR, Smith
and
Inverted Smith
lose their original meaning (standing wave ratio,
normalized impedance or admittance) if they are used for transmission
S-
parameters
.
E
The complex
Impedances,
and
Admittances
are generally displayed in one of the
Cartesian diagrams with linear vertical axis scale or in a polar diagram.
E
The real
Stability Factors
are generally displayed in a linear Cartesian diagram
(Lin
Mag
or
Real).
In complex formats, real numbers represent complex numbers with
zero imaginary part.
The following table gives an overview of recommended display formats.
Complex
dimensionless
quantities:
S-parameters
Complex quantities with
dimensions:
impedances, admittances
Real quantities:
Stability Factors
Lin Mag
(default for impedances,
admittances)
(default)
dB Mag
(default)
–
Phase
–
Real
Imag
–
Unwrapped Phase
–
Smith
(reflection coefficients S
ii
)
–
–
Polar
–
–
