# 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.```

example

````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.```

example

````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`.```

example

````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

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

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 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

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

Example: `dipole`

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

Example: `linearArray`

Example: `array(pcbStack,"linear")`

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]`

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");`

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

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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