Concepts and features
R&S
®
ZNA
129
User Manual 1178.6462.02 ─ 20
U
0
I
1
I
2
U
1
U
2
U
0
Z
0j
Z
ij
Z
0i
The calculation formula of a converted parallel transmission impedance Z
ij
depends on
the waveguide circuit theory according to which
Table 4-6: Calculation of Converted Parallel Transmission Impedances
Traveling Waves
Power Waves
4.3.3.2
Z-parameters
The Z-parameters describe the impedances of a DUT with open output ports (impe-
dance = 0). The analyzer provides the full set of Z-parameters including the transfer
impedances (i.e. the complete nxn Z-matrix for an n port DUT).
This means that Z-parameters can be used as an alternative to S-parameters (or Y-
parameters) to characterize a linear n-port network completely.
2-port Z-parameters
In analogy to S-parameters, Z-parameters are expressed as Z
ij
, where i denotes the
measured and j the stimulated port.
The Z-parameters for a two-port are based on a circuit model that can be expressed
with two linear equations:
2
22
1
21
2
2
12
1
11
1
I
Z
I
Z
V
I
Z
I
Z
V
Meaning of Z-parameters
Measurement results
