sparameters

Calculate S-parameters for antenna or array

Syntax

sobj = sparameters(antenna,freq)

sobj = sparameters(antenna,freq,Z0)

sobj = sparameters(array,freq)

sobj = sparameters(array,freq,Z0)

sobj = sparameters(filename)

sobj = sparameters(data,freq)

sobj = sparameters(data,freq,Z0)

sobj = sparameters(netparamobj)

sobj = sparameters(netparamobj,Z0)

sobj = sparameters(___,UseParallel = true)

Description

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.

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.

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.

sobj = sparameters(___,UseParallel = true) uses the Parallel Computing Toolbox™ to perform S-parameter calculations for each frequency in parallel. To use this feature, you need a license to the Parallel Computing Toolbox.

Examples

Calculate S-Parameter Matrix For Antenna

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 with properties:

      Impedance: 50
       NumPorts: 1
     Parameters: 0.1872 - 0.0028i
    Frequencies: 70000000

Calculate S-parameter Matrix For Array

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

   0.3044 - 0.0811i  -0.0579 - 0.2369i  -0.0580 - 0.2369i  -0.0248 - 0.0707i
  -0.0579 - 0.2369i   0.3045 - 0.0812i  -0.0248 - 0.0707i  -0.0580 - 0.2370i
  -0.0580 - 0.2369i  -0.0248 - 0.0707i   0.3044 - 0.0811i  -0.0579 - 0.2369i
  -0.0248 - 0.0707i  -0.0580 - 0.2370i  -0.0579 - 0.2369i   0.3045 - 0.0812i

Extract and Plot S-Parameters data from Touchstone File

Extract S-parameters from corrugatedconicalhorn.s2p touchstone file.

sobj = sparameters("corrugatedconicalhorn.s2p");
display(sobj)

sobj = 
  sparameters with properties:

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

Plot the S-parameters data using rfplot function.

rfplot(sobj)

Input Arguments

antenna — Antenna to calculate S-parameters

antenna object | array object | custom 2-D mesh or geometry object | custom 2-D and 3-D antenna object | pcbStack object | installedAntenna object | measuredAntenna object

Antenna to calculate S-parameters, specified as one of the following options:

• Antenna object from the antenna catalog.

• customAntennaMesh object.

• customAntennaGeometry object.

• customAntenna object.

• customAntennaStl object.

• pcbStack object.

• installedAntenna object.

• measuredAntenna object.

Example: dipole

array — Array to calculate S-parameters

array object | custom array object | pcbStack object

Array to calculate S-parameters, specified as one of the following options:

• Array object from the array catalog.

• customArrayMesh object.

• customArrayGeometry object.

• Array of pcbStack object.

Example: linearArray

Example: array(pcbStack,"linear")

freq — Frequency to calculate S-parameters

positive scalar | positive vector

Frequency to calculate S-parameters, specified as a scalar for a single frequency or a vector for a frequency range in Hertz. For vector frequencies, specify the values in lowest to highest order.

Example: [500e6 550e6 600e6]

Z0 — Reference impedance in Ohms

50 (default) | positive real scalar

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.

data — S-parameter data

array of complex numbers

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

netparamobj — Network parameter object

network parameter object

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.

filename — Touchstone data file

character vector | string scalar

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");

UseParallel — Option to enable parallel pool

false or 0 (default) | true or 1

Option to enable parallel pool, specified as a logical value. The default value is false. Set the flag to true or 1 to enable the parallel pool. Use parallel pool to speedup the S-parameter calculations at multiple frequencies for computationally large antennas and arrays.

Example: UseParallel=true

Data Types: logical

Output Arguments

sobj — S-parameter data

S-parameter object

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