rfplot

Plot S-parameter data

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Syntax

rfplot(s_obj)

rfplot(s_obj,i,j)

rfplot(s_obj,[i₁:i_n],[j₁:j_n])

rfplot(s_obj,{[i₁ j₁];...;[i_n j_n]})

rfplot(___,LineSpec)

rfplot(___,plotflag)

rfplot(s_obj,'diag')

rfplot(s_obj,part)

rfplot(s_obj,part,k)

rfplot(ax,___)

hline = rfplot(___)

[hline,haxes] = rfplot(filter,frequencies)

Description

rfplot(s_obj) plots the magnitude in decibels versus frequency of all S-parameters (S₁₁, S₁₂ ... S_NN) on the current axes.

example

rfplot(s_obj,i,j) plots the magnitude of S_{i
j} in decibels on the current axis.

rfplot(s_obj,[i₁:i_n],[j₁:j_n]) plots the magnitude of multiple S-parameters in decibels on the current axis.

example

rfplot(s_obj,{[i₁ j₁];...;[i_n j_n]}) plots the magnitude of specific S-parameters in decibels on the current axis.

example

rfplot(___,LineSpec) plots S-parameters using the line parameters specified in LineSpec.

rfplot(___,plotflag)plots S-parameters according to the type specified in plotflag.

rfplot(s_obj,'diag') plots the magnitude of S_{i
i} reflection coefficients or the diagonal elements of the S-parameter matrix 'diag' on the current axis.

example

rfplot(s_obj,part) plots the upper or lower triangular portion of the S-parameters matrix on the current axis.

rfplot(s_obj,part,k) plots the elements on, above, or below the kth diagonal of the S-parameters matrix. For more information, see the tril and triu functions.

example

rfplot(ax,___) plots the S-parameters on the axes specified in ax instead of the current axes. Specify ax as the first input argument followed by any of the input argument combinations in the previous syntaxes. Return the current axes using the gca function.

hline = rfplot(___) plots the S-parameters and returns a column vector of line handles in hline.

example

[hline,haxes] = rfplot(filter,frequencies) plots the magnitude response of the S-parameters of the RF filter.

Examples

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Plot S-Parameter Data

Open Live Script

Use the sparameters function to create a set S-parameters.

hs = sparameters('default.s2p');

Plot all the S-parameters.

rfplot(hs)

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude (dB) contains 4 objects of type line. These objects represent dB(S_{11}), dB(S_{21}), dB(S_{12}), dB(S_{22}).$

Plot S21.

rfplot(hs,2,1)

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude (dB) contains an object of type line. This object represents dB(S_{21}).$

Plot the angle of S21 in degrees.

rfplot(hs,2,1,'angle')

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Angle (degrees) contains an object of type line. This object represents angle(S_{21}).$

Plot the real part of S21.

rfplot(hs,2,1,'real')

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Re(S-parameters) contains an object of type line. This object represents real(S_{21}).$

Plot S-Parameters in Specified Range

Open Live Script

Create an S-parameter object from a three-port Touchstone file.

sobj = sparameters('default.s3p');

Plot S12, S13, S22, S23, S32, and S33.

rfplot(sobj,[1:3],[2:3],'abs')

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude contains 6 objects of type line. These objects represent abs(S_{12}), abs(S_{13}), abs(S_{22}), abs(S_{23}), abs(S_{32}), abs(S_{33}).$

Plot Specific S-Parameters

Open Live Script

Create an S-parameter object from a three-port Touchstone file.

sobj = sparameters('default.s3p');

Plot S12, S33, S11, and S22.

rfplot(sobj,{[1 2]; [3 3]; [1 1]; [2 2]},'abs')

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude contains 4 objects of type line. These objects represent abs(S_{12}), abs(S_{33}), abs(S_{11}), abs(S_{22}).$

Plot Reflection and Transmission Coefficients

Open Live Script

Create an S-parameter object from a three-port Touchstone file.

sobj = sparameters('default.s3p');

Plot the reflection coefficients of the S-parameters.

rfplot(sobj,'diag','abs')

$Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude contains 3 objects of type line. These objects represent abs(S_{11}), abs(S_{22}), abs(S_{33}).$

Plot the transmission coefficients of the S-parameters.

rfplot(sobj,'triu',1,'abs')
hold on
rfplot(sobj,'tril',-1,'abs')

Input Arguments

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`s_obj` — S-parameters
network parameter object

S-parameters, specified as RF Toolbox™ network parameter object. To create this type of object, use the sparameters function.

`i` — Row index
scalar | vector | cell array

Row index of the data to plot, specified as a scalar, vector, or cell array.

Type of Plot How to Specify Indices

Single parameter

Type of Plot	How to Specify Indices
Single parameter	Specify `i` and `j`as scalars. `rfplot(s_obj,[1,2])`
Set of parameters	Specify `i` and `j` as vectors. `rfplot(s_obj,[1:3],[2:3])` `rfplot(s_obj,[1,2],[2,3])`
Specific parameters	Specify a cell array of `i` and `j` scalars. `rfplot(s_obj, {[1 2];[2 3]})`

Specify i and jas scalars.

rfplot(s_obj,[1,2])

Set of parameters

Specify i and j as vectors.

rfplot(s_obj,[1:3],[2:3])

rfplot(s_obj,[1,2],[2,3])

Specific parameters

Specify a cell array of i and j scalars.

rfplot(s_obj, {[1 2];[2 3]})

`j` — Column index
scalar | vector | cell array

Column index of the data to plot, specified as a scalar, vector, or cell array.

Type of Plot How to Specify Indices

Single parameter

Type of Plot	How to Specify Indices
Single parameter	Specify `i` and `j`as scalars. `rfplot(s_obj,[1,2])`
Set of parameters	Specify `i` and `j` as vectors. `rfplot(s_obj,[1:3],[2:3])` `rfplot(s_obj,[1,2],[2,3])`
Specific parameters	Specify a cell array of `i` and `j` scalars. `rfplot(s_obj, {[1 2];[2 3]})`

Specify i and jas scalars.

rfplot(s_obj,[1,2])

Set of parameters

Specify i and j as vectors.

rfplot(s_obj,[1:3],[2:3])

rfplot(s_obj,[1,2],[2,3])

Specific parameters

Specify a cell array of i and j scalars.

rfplot(s_obj, {[1 2];[2 3]})

`LineSpec` — Line style, marker, and color
character vector | string

Line style, marker, and color, specified as a character vector or a string containing symbols. The symbols can appear in any order. You do not need to specify all three characteristics (line style, marker, and color). For example, if you omit the line style and specify the marker, then the plot shows only the marker and no line.

Example: '--or'creates a dashed line in red with circular markers

Line Style	Description	Resulting Line
`'-'`	Solid line
`'--'`	Dashed line
`':'`	Dotted line
`'-.'`	Dash-dotted line

Marker	Description	Resulting Marker
`'o'`	Circle
`'+'`	Plus sign
`'*'`	Asterisk
`'.'`	Point
`'x'`	Cross
`'_'`	Horizontal line
`'\|'`	Vertical line
`'s'`	Square
`'d'`	Diamond
`'^'`	Upward-pointing triangle
`'v'`	Downward-pointing triangle
`'>'`	Right-pointing triangle
`'<'`	Left-pointing triangle
`'p'`	Pentagram
`'h'`	Hexagram

Color Name	Short Name	RGB Triplet
`'red'`	`'r'`	`[1 0 0]`
`'green'`	`'g'`	`[0 1 0]`
`'blue'`	`'b'`	`[0 0 1]`
`'cyan'`	`'c'`	`[0 1 1]`
`'magenta'`	`'m'`	`[1 0 1]`
`'yellow'`	`'y'`	`[1 1 0]`
`'black'`	`'k'`	`[0 0 0]`
`'white'`	`'w'`	`[1 1 1]`

`plotflag` — Plot types
`'db'` (default) | `'real'` | `'imag'` | `'abs'` | `'angle'`

Plot types, specified as either 'db', 'real', 'imag', 'abs', or 'angle'.

Example: 'angle'

`filter` — RF filter
`rffilter` object | `lcladder` object

RF filter, specified as an rffilter object or an lcladder object.

`frequencies` — Frequencies to plot magnitude response
vector

Frequencies to plot magnitude response, specified as a vector.

`part` — Portion of S-parameters matrix
`'triu'` | `'tril'`

Portion of the S-parameters matrix, specified as 'triu' or 'tril'. Specify triu to plot the Upper Triangular portion of the matrix and tril to plot the Lower Triangular portion.

`k` — Diagonals to include
`0` (default) | scalar

Diagonals to include, specified as a scalar.

k = 0 specifies the main diagonal.
k > 0 specifies a diagonal above the main diagonal.
k < 0 specifies a diagonal below the main diagonal.

Matrix with the main diagonal labeled as k=0. Values of k greater than zero are for diagonals above the main diagonal, and values of k less than zero are for diagonals below the main diagonal.

`ax` — Axes object
`axes` object | `uiaxes` object

Axes object, specified as an axes or a uiaxes object.

Output Arguments

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`hline` — Line
line handle

Line containing the S-parameter plot, returned as a line handle.

`haxes` — Axes
axes handle

Axes of the rfplot, returned as an axes handle.

More About

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Upper Triangular

The upper triangular portion of a matrix includes the main diagonal and all elements above it. The shaded elements in this graphic depict the upper triangular portion of a 6-by-6 matrix.

Lower Triangular

The lower triangular portion of a matrix includes the main diagonal and all elements below it. The shaded elements in this graphic depict the lower triangular portion of a 6-by-6 matrix.

Version History

Introduced before R2006a

expand all

R2022a: Plot S-parameter data with multiple indices

Use the 'diag', part, and k input arguments in the rfplot function to plot S-parameter data with multiple indices.

rfplot

Syntax

Description

Examples

Plot S-Parameter Data

Plot S-Parameters in Specified Range

Plot Specific S-Parameters

Plot Reflection and Transmission Coefficients

Input Arguments

s_obj — S-parameters network parameter object

i — Row index scalar | vector | cell array

j — Column index scalar | vector | cell array

LineSpec — Line style, marker, and color character vector | string

plotflag — Plot types 'db' (default) | 'real' | 'imag' | 'abs' | 'angle'

filter — RF filter rffilter object | lcladder object

frequencies — Frequencies to plot magnitude response vector

part — Portion of S-parameters matrix 'triu' | 'tril'

k — Diagonals to include 0 (default) | scalar

ax — Axes object axes object | uiaxes object

Output Arguments

hline — Line line handle

haxes — Axes axes handle

More About

Upper Triangular

Lower Triangular

Version History

R2022a: Plot S-parameter data with multiple indices

See Also

`s_obj` — S-parameters
network parameter object

`i` — Row index
scalar | vector | cell array

`j` — Column index
scalar | vector | cell array

`LineSpec` — Line style, marker, and color
character vector | string

`plotflag` — Plot types
`'db'` (default) | `'real'` | `'imag'` | `'abs'` | `'angle'`

`filter` — RF filter
`rffilter` object | `lcladder` object

`frequencies` — Frequencies to plot magnitude response
vector

`part` — Portion of S-parameters matrix
`'triu'` | `'tril'`

`k` — Diagonals to include
`0` (default) | scalar

`ax` — Axes object
`axes` object | `uiaxes` object

`hline` — Line
line handle

`haxes` — Axes
axes handle