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Plot of measurement data on Smith chart


p = smithplot(___)
p = smithplot('gco')



smithplot(data) creates a Smith chart based on input data values.


The Smith chart is commonly used to display the relationship between a reflection coefficient, typically given as S11 or S22, and a normalized impedance

smithplot(frequency,data) creates a Smith chart based on frequency and data values.

smithplot(ax,___) creates a Smith chart with a user defined axes handle, ax, instead of the current axes handle. Axes handles are not supported for network parameter objects.


smithplot(hnet) plots all the network parameter objects in hnet.


smithplot(hnet,i,j) plots the (i,j)th parameter of a network parameter object, hnet.

p = smithplot(___) returns a Smith chart function handle so you can customize the plot and add measurements.

p = smithplot('gco') returns a Smith chart function handle of the current plot. This syntax is useful when the function handle, p was not returned or retained.

smithplot(___,Name,Value) creates a Smith chart, with additional properties specified by one or more name-value pair arguments. Name is the property name and Value is the corresponding property value. You can specify several name-value pair arguments in any order as Name1, Value1, ..., NameN, ValueN. Properties not specified retain their default values. To list all the property Name,Value pairs, use details(p). You can use the properties to extract any data from the Smith chart. For example, p = smithplot(data,'GridType','Z') displays the impedance data grid on the Smith chart.

For a list of properties, see SmithPlot Properties.


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Plot the Smith plot of s-parameters data file, passive.s2p.

data = sparameters('passive.s2p')
data = 
  sparameters: S-parameters object

       NumPorts: 2
    Frequencies: [202×1 double]
     Parameters: [2×2×202 double]
      Impedance: 50

  rfparam(obj,i,j) returns S-parameter Sij


Plot the smith chart of S11 of s-parameter data file using an impedance of 75 ohms.

data = sparameters('passive.s2p' );
s = sparameters(data,75);
p = smithplot(s,1,1, 'GridType','ZY');

Plot the smith chart of Y-Parameters data.

amp = read(rfckt.amplifier,'default.s2p');
Ya = yparameters(amp);

Input Arguments

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Input data, specified as a complex vector or complex matrix.

For a matrix D, the columns of D are independent datasets. For N-by-D arrays, dimensions 2 and greater are independent datasets.

Data Types: double
Complex Number Support: Yes

Frequency data, specified as a real vector.

Data Types: double

Network parameter object, specified as an RF Toolbox™ network parameter object.

Data Types: double

Output Arguments

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Smith chart function handle, returned as an object to customize the plot and add measurements using MATLAB® commands.

See Also


Introduced in R2017b

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