abcd2s

Convert ABCD-parameters to S-parameters

Syntax

s_params = abcd2s(abcd_params,z0)

Description

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, representing M 2N-port S-parameters.

Examples

Convert ABCD-Parameters to S-Parameters

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

abcd_params — N-port- S-Parameters

array of complex numbers

The abcd_params input is a complex 2N-by-2N-by-M array, representing M 2N-port ABCD-parameters.

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

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

z0 — Reference impedance

50 (default) | positive real scalar | vector

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

s_params — 2N-port hybrid S-Parameters

array of complex numbers

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

Alternatives

You can also use network parameter objects to perform network parameter conversions. For more information, see RF Network Parameter Objects.

References

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