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# sparameters

S-parameter object

## Syntax

``sobj = sparameters(filename)``
``sobj = sparameters(data,freq)``
``sobj = sparameters(data,freq, Z0)``
``sobj = sparameters(filterobj,freq)``
``sobj = sparameters(filterobj,freq,Z0)``
``sobj = sparameters(circuitobj,freq)``
``sobj = sparameters(circuitobj,freq,Z0)``
``sobj = sparameters(netparamobj)``
``sobj = sparameters(netparamobj, Z0)``
``sobj = sparameters(rfdataobj)``
``sobj = sparameters(rfcktobj)``
``sobj = sparameters(mnobj)``
``sobj = sparameters(mnobj,freq)``
``sobj = sparameters(mnobj,freq,Z0)``
``sobj = sparameters(mnobj,freq,Z0,circuitindices)``
``sobj = sparameters(antenna,freq,Z0)``
``sobj = sparameters(array,freq,Z0)``

## Description

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 given reference impedance `Z0`.```
````sobj = sparameters(filterobj,freq)` calculates the S-parameters of a filter object, `filterobj` with the default reference impedance. ```
````sobj = sparameters(filterobj,freq,Z0)` calculates the S-parameters of a filter object, `filterobj` with a given reference impedance `Z0`. ```
````sobj = sparameters(circuitobj,freq)` calculates the S-parameters of a `circuit` object with the default reference impedance. ```

example

````sobj = sparameters(circuitobj,freq,Z0)` calculates the S-parameters of a `circuit` object with a given reference impedance `Z0`. ```
````sobj = sparameters(netparamobj)` converts the network parameter object, `netparamobj`, to S-parameter object with the default reference impedance. ```

example

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

example

````sobj = sparameters(rfdataobj)` extracts network data from `rfdataobj` and converts it into S-parameter object.```
````sobj = sparameters(rfcktobj)` extracts network data from `rfcktobj` and converts it into S-parameter object.```
````sobj = sparameters(mnobj)` returns the s-parameters of the best created matching network, evaluated at a frequency list constructed from source and load impedance.```
````sobj = sparameters(mnobj,freq)` returns the s-parameters of the best created matching network at each specified frequency and characteristic impedance.```
````sobj = sparameters(mnobj,freq,Z0)` returns the s-parameters of the best created matching network at each specified frequency.```
````sobj = sparameters(mnobj,freq,Z0,circuitindices)` returns the s-parameters of the best created matching network at each specified frequency.```

example

````sobj = sparameters(antenna,freq,Z0)` calculates the complex s-parameters for an `antenna` object over specified frequency values and for a given reference impedance, `Z0`.```

example

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

## Examples

collapse all

Extract S-parameters from file default.s2p and plot it.

```S = sparameters('default.s2p'); disp(S)```
``` sparameters: S-parameters object NumPorts: 2 Frequencies: [191x1 double] Parameters: [2x2x191 double] Impedance: 50 rfparam(obj,i,j) returns S-parameter Sij ```
`rfplot(S)`

Create a resistor element R50 and add it to a circuit object `example2` . Calculate the S-parameters of `example2` .

```hR1 = resistor(50,'R50'); hckt1 = circuit('example2'); add(hckt1,[1 2],hR1) setports (hckt1, [1 0],[2 0]) freq = linspace (1e3,2e3,100); S = sparameters(hckt1,freq,100); disp(S)```
``` sparameters: S-parameters object NumPorts: 2 Frequencies: [100x1 double] Parameters: [2x2x100 double] Impedance: 100 rfparam(obj,i,j) returns S-parameter Sij ```

Extract Y-parameters from file default.s2p. Convert the resulting Y-parameters to S-parameters.

```Y1 = yparameters('default.s2p'); S1 = sparameters(Y1,100); disp(Y1)```
``` yparameters: Y-parameters object NumPorts: 2 Frequencies: [191x1 double] Parameters: [2x2x191 double] rfparam(obj,i,j) returns Y-parameter Yij ```
`disp(S1)`
``` sparameters: S-parameters object NumPorts: 2 Frequencies: [191x1 double] Parameters: [2x2x191 double] Impedance: 100 rfparam(obj,i,j) returns S-parameter Sij ```
```file = 'default.s2p'; h = read(rfdata.data, file); S = sparameters(h)```
```S = sparameters: S-parameters object NumPorts: 2 Frequencies: [191x1 double] Parameters: [2x2x191 double] Impedance: 50.0000 + 0.0000i rfparam(obj,i,j) returns S-parameter Sij ```

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 Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement] ```
` sparameters (h, 70e6)`
```ans = sparameters: S-parameters object NumPorts: 1 Frequencies: 70000000 Parameters: 0.1866 - 0.0092i 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; sparameters(h,70e6)```
```ans = sparameters: S-parameters object NumPorts: 4 Frequencies: 70000000 Parameters: [4x4 double] Impedance: 50 rfparam(obj,i,j) returns S-parameter Sij ```

## Input Arguments

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S-parameter data, specified as an array of complex numbers, of size N-by-N-by-K.

Circuit object. The function uses this input argument to calculate the S-parameters of the circuit object.

RF filter, specified as an `rffilter` object.

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

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');```

Antenna object, specified as a scalar handle.

Array object, specified as a scalar handle.

S-parameter frequencies, specified as a vector of positive real numbers, sorted from smallest to largest.

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.

RF data object. Specify `rfdataobj` as either `rfdata.data`, or `rfdata.network` object.

RF network object. Specify `rfcktobj` as any analyzed `rfckt` type object, such as `rfckt.amplifier`, `rkckt.cascade` object.

Matching network, specified as a `matchingnetwork` object.

Data Types: `char` | `string`

Index of the matching network circuit, specified as a scalar.

Data Types: `double`

## Output Arguments

collapse all

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`.