R&S 1311.6010K22, Руководство пользователя

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Concepts and features
R&S
®
ZNB/ZNBT
130 User Manual 1173.9163.02 ─ 62
) Re(
) Re(
1
0
0
1
1 0
0
i
i
i
i
i i
i
ii
Z
Z
Z
Z
Z Z
Z
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:













 
 
 






i
i
i i i i
i i i i
i i
i
i
b
a
Z Z Z Z
Z Z Z Z
Z Z
b
a
0
0
1 0 1 0
1 0 1 0
1 0
1
1
) Re( ) Re( 2
1
The renormalized S-matrix S1 is calculated as:
 
 
A S E S A S
1
0 0
1
1


    
with the unit matrix E and two additional matrices with the elements
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.
Measurement results