R&S ZNB Series User Manual page 130

®
R&S ZNB/ZNBT
P
2. Power waves
In the model of Kurokawa ("Power Waves and the Scattering Matrix"), the wave
quantities a and b are transformed as follows:

 

The renormalized S-matrix S1 is calculated as:
S
with the unit matrix E and two additional matrices with the elements

A
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
an n-port DUT with fully matched outputs. The analyzer converts a single measured S-
parameter S
assumption that each of the other ports is terminated with its respective reference
impedance Z
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
DUT that is terminated at its other ports with the reference impedance Z
The
User Manual 1173.9163.02 ─ 62
Z Z

0 i 1 i
ii

Z Z Z
0 i 1 i 0 i

a
1
1 i  

b
2 Re( Z ) Re(

1 i
0 i
 

    
1
A S E
1 0

Z Z

1 i 0 i
ii

Z Z
1 i 0 i
 
1
   
ii 1
ii ii
 
1
ii
to determine the corresponding converted impedance, under the
ij
(matched-circuit parameters). As a result, converted impedances can-
0k
Converted admittances
Re( Z )
0 i
Re( Z )
1 i


Z Z Z


0 i 1 i 0


Z ) Z Z Z

1 i 0 i 1 i 0


 1
S A
0
ii
(1 ≤i,j ≤n) describe the input impedances of
ij
is the differential mode input impedance at port 4 of a
dd44
are defined as the inverse of the converted impedances.
Concepts and features
Measurement results

  
a
Z
  
  0 i  
i 1 i

b
Z
 

0 i
i 1 i
0
.
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