gammams

Calculate source reflection coefficient of two-port network

Syntax

coefficient = gammams(s_params)

coefficient = gammams(hs)

Description

coefficient = gammams(s_params) calculates the source reflection coefficient of a two-port network required for simultaneous conjugate match.

coefficient = gammams(hs) calculates the source reflection coefficient of the two-port network represented by the S-parameter object hs.

Examples

Source Reflection Coefficient Calculation

Calculate the source reflection coefficient using network data from a file.

ckt = read(rfckt.amplifier,'default.s2p');
s_params = ckt.NetworkData.Data;
coefficient = gammams(s_params)

coefficient = 191×1 complex

  -0.7247 + 0.4813i
  -0.7324 + 0.4723i
  -0.7401 + 0.4632i
  -0.7478 + 0.4541i
  -0.7554 + 0.4449i
  -0.7630 + 0.4357i
  -0.7704 + 0.4264i
  -0.7778 + 0.4170i
  -0.7850 + 0.4075i
  -0.7921 + 0.3980i
      ⋮

Source Reflection Coefficient Calculation of S-Parameters Object

Define a S-parameters object specified from a file.

hs = sparameters('default.s2p');

Calculate the source reflection coefficient using gammams function.

coefficient = gammams(hs)

coefficient = 191×1 complex

  -0.7247 + 0.4813i
  -0.7324 + 0.4723i
  -0.7401 + 0.4632i
  -0.7478 + 0.4541i
  -0.7554 + 0.4449i
  -0.7630 + 0.4357i
  -0.7704 + 0.4264i
  -0.7778 + 0.4170i
  -0.7850 + 0.4075i
  -0.7921 + 0.3980i
      ⋮

Input Arguments

s_params — Two-port S-parameters

complex 2-by-2-by-M array

Two-port S-parameters, specified as a complex 2-by-2-by-M array. M is the number of two-port S-parameters.

Data Types: double

hs — Two-port network

S-parameter object

Two-port network, specified as an S-parameter object.

Data Types: function_handle

Output Arguments

coefficient — Source reflection coefficient

M element complex vector

Source reflection coefficient, returned as a M element complex vector.

Algorithms

The function calculates coefficient using the equation

$${\Gamma }_{MS}=\frac{B_1\pm \sqrt{B_1{}^2-4\left|C_1{}^2\right|}}{2C_1}$$

where

$$\begin{array}{c}{B}_1=1+\left|S_{11}{}^2\right|-\left|S_{22}{}^2\right|-\left|{\Delta }^2\right|\\ C_1=S_{11}-\Delta \cdot S_{22}^{*}\\ \Delta =S_{11}{S}_{22}-S_{12}{S}_{21}\end{array}$$

Version History

Introduced before R2006a