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sparameters

Calculate S-parameters for antennas and antenna arrays

Description

example

sobj = sparameters(antenna,freq) calculates the complex S-parameter for an antenna over specified frequency values.

sobj = sparameters(antenna,freq,Z0) calculates the complex S-parameter for an antenna over specified frequency values and with a reference impedance Z0.

example

sobj = sparameters(array,freq) calculates the complex S-parameters for an array over specified frequency values.

sobj = sparameters(array,freq,Z0) calculates the complex S-parameters for an array over specified frequency values and with a reference impedance Z0.

example

sobj = sparameters(filename) creates an S-parameter object sobj by importing data from the Touchstone file specified by filename.

sobj = sparameters(data,freq) creates an S-parameter object from the S-parameter data data, and frequencies freq.

sobj = sparameters(data,freq,Z0) creates an S-parameter object from the S-parameter data data, and frequencies freq, with a reference impedance Z0.

sobj = sparameters(netparamobj) converts the network parameter object, netparamobj, to S-parameter object with the default reference impedance.

sobj = sparameters(netparamobj,Z0) converts the network parameter object netparamobj to S-parameter object with a reference impedance Z0.

Examples

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Calculate the complex s-parameters for a default dipole at 70MHz frequency.

 h = dipole
h = 
  dipole with properties:

        Length: 2
         Width: 0.1000
    FeedOffset: 0
     Conductor: [1x1 metal]
          Tilt: 0
      TiltAxis: [1 0 0]
          Load: [1x1 lumpedElement]

 sparameters(h,70e6)
ans = 
  sparameters: S-parameters object

       NumPorts: 1
    Frequencies: 70000000
     Parameters: 0.1869 - 0.0031i
      Impedance: 50

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

Calculate the complex s-parameters for a default rectangular array at 70MHz frequency.

h = rectangularArray
h = 
  rectangularArray with properties:

           Element: [1x1 dipole]
              Size: [2 2]
        RowSpacing: 2
     ColumnSpacing: 2
           Lattice: 'Rectangular'
    AmplitudeTaper: 1
        PhaseShift: 0
              Tilt: 0
          TiltAxis: [1 0 0]

s = sparameters(h,70e6);
s.Parameters
ans = 4×4 complex

   0.3042 - 0.0815i  -0.0575 - 0.2370i  -0.0577 - 0.2369i  -0.0247 - 0.0707i
  -0.0575 - 0.2370i   0.3043 - 0.0815i  -0.0247 - 0.0707i  -0.0576 - 0.2370i
  -0.0577 - 0.2369i  -0.0247 - 0.0707i   0.3042 - 0.0815i  -0.0575 - 0.2370i
  -0.0247 - 0.0707i  -0.0576 - 0.2370i  -0.0575 - 0.2370i   0.3043 - 0.0815i

Extract S-parameters from corrugatedconicalhorn.s2p touchstone file.

sobj = sparameters("corrugatedconicalhorn.s2p");
display(sobj)
sobj = 
  sparameters: S-parameters object

       NumPorts: 1
    Frequencies: [11x1 double]
     Parameters: [1x1x11 double]
      Impedance: 50

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

Plot the S-parameters data using rfplot function.

rfplot(sobj)

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_{11}).

Input Arguments

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Antenna to calculate S-parameter, specified as either of these objects:

  • antenna catalog element

  • customAntennaMesh

  • customAntennaGeometry

  • customAntennaStl

  • customAntenna

  • pcbStack

Example: dipole

Example: customAntenna

Array to calculate S-parameters, specified as either of these objects:

  • array catalog element

  • customArrayMesh

  • customArrayGeometry

  • pcbStack

Example: linearArray

Example: array(pcbStack,"linear")

Frequencies to calculate S-parameters, specified as a vector of positive real numbers, sorted from smallest to largest.

Example: [500e6 550e6 600e6]

Reference impedance in ohms, specified as a positive real scalar. You cannot specify Z0 if you are importing data from a file. The argument Z0 is optional and is stored in the Impedance property.

S-parameter data, specified as an array of complex numbers, of size N-by-N-by-K where K represents number of frequency points.

Network parameter object. The network parameter objects are of the type: sparameters (RF Toolbox), yparameters (RF Toolbox), zparameters (RF Toolbox), gparameters (RF Toolbox), hparameters (RF Toolbox), abcdparameters (RF Toolbox), and tparameters (RF Toolbox).

Example: S1 = sparameters(Y1,100). Y1 is a parameter object. This example converts Y-parameters to S-parameters at 100 ohms.

Touchstone data file, specified as a character vector, that contains network parameter data. filename can be the name of a file on the MATLAB® path or the full path to a file.

Example: sobj = sparameters("defaultbandpass.s2p");

Output Arguments

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S-parameter data, returned as an object. disp(sobj) returns the properties of the object:

  • NumPorts — Number of ports, specified as an integer. The function calculates this value automatically when you create the object.

  • Frequencies — S-parameter frequencies, specified as a K-by-1 vector of positive real numbers sorted from smallest to largest. The function sets this property from the filename or freq input arguments.

  • Parameters — S-parameter data, specified as an N-by-N-by-K array of complex numbers. The function sets this property from the filename or data input arguments.

  • Impedance — Reference impedance in ohms, specified as a positive real scalar. The function sets this property from the filename or Z0 input arguments. If no reference impedance is provided, the function uses a default value of 50.

Version History

Introduced in R2015a