# abcd2s

Convert ABCD-parameters to S-parameters

## Description

example

s_params = abcd2s(abcd_params,z0) converts the ABCD-parameters abcd_params into the scattering parameters s_params. z0 is the reference impedance; its default is 50 ohms.

s_params is a complex 2N-by-2N-by-M array, where M representing number of frequency points of a 2N-port S-parameters.

## Examples

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Define a matrix of ABCD-parameters.

A =      0.999884396265344 +  0.000129274757618717i;
B =      0.314079483671772 +      2.51935878310427i;
C = -6.56176712108866e-007 + 6.67455405306704e-006i;
D =      0.999806365547959 +  0.000247230611054075i;
abcd_params = [A,B; C,D]
abcd_params = 2×2 complex

0.9999 + 0.0001i   0.3141 + 2.5194i
-0.0000 + 0.0000i   0.9998 + 0.0002i

Convert these ABCD parameters to S-parameters.

s_params = abcd2s(abcd_params)
s_params = 2×2 complex

0.0038 + 0.0248i   0.9961 - 0.0250i
0.9964 - 0.0254i   0.0037 + 0.0249i

## Input Arguments

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The abcd_params input is a complex 2N-by-2N-by-M array, where M representing number of frequency points of a 2N-port ABCD-parameters.

The function assumes that the ABCD-parameter matrices have distinct A, B, C, and D submatrices:

$\left[\begin{array}{cc}\left[A\right]& \left[B\right]\\ \left[C\right]& \left[D\right]\end{array}\right]$

Reference impedance of N-port S-Parameters, specified as positive real scalar in ohms.

Note

z0 must be a positive real scalar or vector. If z0 is a vector, then the vector must be equal to the number of network parameter data points or frequency vector.

## Output Arguments

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2N-port S-parameters, returned as a 2N-by-2N-by-M array of complex numbers, where M representing number of frequency points of a 2N-port S-Parameters.

## References

[1] Pozar, David M. Microwave Engineering. 3rd ed, J. Wiley, 2005.

## Version History

Introduced before R2006a