R&S 1332.4500K22, Руководство пользователя

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Concepts and features
R&S
®
ZNA
127 User Manual 1178.6462.02 ─ 20
i i
i i
ii
Z Z
Z Z
0 1
0 1


 
ii ii
ii
ii
ii
A
  
 
 

1
1
1
4.3.3 Impedance parameters
An impedance is the complex ratio between a voltage and a current. The analyzer pro-
vides two independent sets of impedance parameters:
●
Converted impedances (each impedance parameter is obtained from a single S-
parameter)
●
Z-parameters (complete description of an n-port DUT)
4.3.3.1 Converted impedances
The converted impedance parameters Z
ij
(1 ≤i,j ≤n) describe the input impedances of
an n-port DUT with fully matched outputs. The analyzer converts a single measured S-
parameter S
ij
to determine the corresponding converted impedance, under the
assumption that each of the other ports is terminated with its respective reference
impedance Z
0k
(matched-circuit parameters). As a result, converted impedances can-
not completely describe general n-port DUTs.
The extension of the impedances to more ports and mixed mode measurements is
analogous to S-parameters. Z
dd44
is the differential mode input impedance at port 4 of a
DUT that is terminated at its other ports with the reference impedance Z
0
.
The Converted admittances are defined as the inverse of the converted impedances.
Reflection impedance
The converted impedance Z
ii
(1 ≤ i ≤n) describes the input impedance at port i of the
DUT.
U
0
I
1
U
1
Z
0i
Z
ii
Measurement results