R&S ZNL Series User Manual

VNA concepts and features
R&S
®
ZNL/ZNLE
223User Manual 1178.5966.02 ─ 20
This means that Y-parameters can be used as an alternative to S-parameters (or Z-
parameters) to characterize a linear n-port network completely.
2-port Y-parameters
In analogy to S-parameters, Y-parameters are expressed as Y
<out>< in>
, where <out>
and <in> denote the output and input port numbers of the DUT. In analogy to Z-param-
eters, the Y-parameters for a two-port are based on a circuit model that can be
expressed with two linear equations:
2221212
2121111
VYVYI
VYVYI


Meaning of Y-parameters
The four 2-port Y-parameters can be interpreted as follows:
●
Y
11
is the input admittance, defined as the ratio of the current I
1
to the voltage V
1
,
measured at port 1 (forward measurement with output terminated in a short circuit,
V
2
= 0).
●
Y
21
is the forward transfer admittance, defined as the ratio of the current I
2
to the
voltage V
1
(forward measurement with output terminated in a short circuit, V
2
= 0).
●
Y
12
is the reverse transfer admittance, defined as the ratio of the current I
1
to the
voltage V
2
(reverse measurement with input terminated in a short circuit, V
1
= 0).
●
Y
22
is the output admittance, defined as the ratio of the current I
2
to the voltage V
2
,
measured at port 2 (reverse measurement with input terminated in a short circuit,
V
1
= 0).
Y-parameters can be easily extended to describe circuits with more than two ports or
several modes of propagation.
9.3.5 Wave quantities and ratios
The elements of the S-, Z- and Y-matrices represent fixed ratios of complex wave
amplitudes. As long as the assumption of linearity holds, the S-, Z- and Y-parameters
are independent of the source power.
The network analyzer provides two additional sets of measurement parameters which
have an unambiguous meaning even if the DUT is measured outside its linear range:
●
Wave quantities provide the power of any of the transmitted or received waves.
●
Ratios provide the complex ratio of any combination of transmitted or received
wave quantities.
Measurement results

R&S ZNL Series Specifications

General

Brand	R&S
Model	ZNL Series
Category	Measuring Instruments
Language	English