s2t

Convert S-parameters to T-parameters

Syntax

t_params = s2t(s_params)

Description

t_params = s2t(s_params) converts the scattering parameters to the chain scattering parameters.

This function uses the following definition for T-parameters:

$$\left[\begin{array}{c}{a}_1\\ b_1\end{array}\right]=\left[\begin{array}{cc}{T}_{11}& T_{12}\\ T_{21}& T_{22}\end{array}\right]\left[\begin{array}{c}{b}_2\\ a_2\end{array}\right],$$

where:

• a₁ is the incident wave at the first port.

• b₁ is the reflected wave at the first port.

• a₂ is the incident wave at the second port.

• b₂ is the reflected wave at the second port.

Examples

Convert S-Parameters to T-Parameters

Define a matrix of S-parameters.

s11 = 0.61*exp(j*165/180*pi);
s21 = 3.72*exp(j*59/180*pi);
s12 = 0.05*exp(j*42/180*pi);
s22 = 0.45*exp(j*(-48/180)*pi);
s_params = [s11 s12; s21 s22];

Convert S-parameters to T-parameters.

t_params = s2t(s_params)

t_params = 2×2 complex

   0.1385 - 0.2304i   0.0354 + 0.1157i
  -0.0452 + 0.1576i  -0.0019 - 0.0291i

Input Arguments

s_params — 2N-port S-parameters

2N-by-2N-by-M array of complex numbers

2N-port S-parameters, specified as a 2N-by-2N-by-M array for the complex numbers (since R2023a), where M represents the number of frequency points of 2N-port S-parameters.

Output Arguments

t_params — 2N-port T-parameters

2N-by-2N-by-M array of complex numbers

2N-port T-Parameters, returned as a 2N-by-2N-by-M array of complex numbers (since R2023a), where M represents the number for the frequency points of 2N-port T-parameters.

References

[1] Gonzalez, Guillermo. Microwave Transistor Amplifiers: Analysis and Design. 2nd edition. Prentice-Hall, 1997, p. 25.

[2] D. A. Frickey. "Conversions between S, Z, Y, H, ABCD, and T parameters which are valid for complex source and load impedances". IEEE Transactions on Microwave Theory and Techniques, vol. 42, no. 2, pp. 205-211. Feb. 1994, doi: 10.1109/22.275248.

Version History

Introduced before R2006a

R2023a: s2t function now accepts a 2N-by-2N-by-M array

Starting R2023a, you can specify the s_params argument as a 2N-by-2N-by-M array of complex numbers. In earlier releases, the function supported only a 2-by-2-by-M array of complex numbers in the s_params argument.