Documentation

# s2t

Convert S-parameters to T-parameters

## Syntax

```t_params = s2t(s_params) ```

## Description

`t_params = s2t(s_params)` converts the scattering parameters `s_params` into the chain scattering parameters `t_params`. The `s_params` input is a complex 2-by-2-by-M array, representing M 2-port S-parameters. `t_params` is a complex 2-by-2-by-M array, representing M 2-port T-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

collapse all

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 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 ```

## References

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

## See Also

#### Four Steps to Building Smarter RF Systems with MATLAB

Download white paper