sparameters

S-parameter object

Syntax

sobj = sparameters(filename)

sobj = sparameters(data,freq)

sobj = sparameters(data,freq,Z0)

sobj = sparameters(rfobj,freq)

sobj = sparameters(rfobj,freq,Z0)

sobj = sparameters(netparamobj)

sobj = sparameters(netparamobj,Z0)

sobj = sparameters(rfdataorckt)

sobj = sparameters(mnobj)

sobj = sparameters(mnobj,freq)

sobj = sparameters(mnobj,freq,Z0)

sobj = sparameters(___,circuitindices)

sobj = sparameters(antenna,freq,Z0)

sobj = sparameters(array,freq,Z0)

Description

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(rfobj,freq) calculates the S-parameters of a RF object such as a filter object, circuit object, transmission line object, series RLC object, shunt RLC object, attenuator object or RF antenna object with the default reference impedance.

sobj = sparameters(rfobj,freq,Z0) calculates the S-parameters of a RF object such as a filter object, circuit object or transmission line 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.

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

sobj = sparameters(rfdataorckt) extracts network data from rfdataobj or 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.

sobj = sparameters(mnobj,freq,Z0) returns the S-parameters of the best created matching network at each specified frequency and characteristic impedance, Z0.

sobj = sparameters(___,circuitindices) returns an array of S-parameter objects, one object for each circuit indicated in circuitindices. Use this option with any of the input argument combinations in the previous syntaxes.

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.

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

Extract and Plot the S-Parameters of File

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)

Calculate the S-Parameters of Circuit Object

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

Convert Y-Parameters to S-Parameters

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

Convert RF Data Object to S-parameters

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 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: S-parameters object

       NumPorts: 1
    Frequencies: 70000000
     Parameters: 0.1887 - 0.0045i
      Impedance: 50

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

Calculate S-parameter Matrix For Array

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

Calculate the S-Parameters of a Matching Network Circuit

This example shows how to calculate the S-Parameters for a newly created matching network for the auto-generated circuit #2 with a reference impedance of 100 Ohm.

n       = matchingnetwork('LoadImpedance',100,'Components',3);
freq    = linspace(n.CenterFrequency-n.Bandwidth/2,n.CenterFrequency+n.Bandwidth/2);
RefZ0   = 100;
ckt_no  = 2;
s       = sparameters(n,freq,RefZ0,ckt_no)

s = 
  sparameters: S-parameters object

       NumPorts: 2
    Frequencies: [100x1 double]
     Parameters: [2x2x100 double]
      Impedance: 100

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

S-parameters of RLCG Transmission Line

Create an RLCG transmission line using the these specifications:

• Resistor : 100 ohms

• Capacitor : 1 pF

rlcglinetxline = txlineRLCGLine('R',100,'C',1e-12)

rlcglinetxline = 
  txlineRLCGLine: RLCGLine element

           Name: 'RLCGLine'
      Frequency: 1.0000e+09
              R: 100
              L: 0
              C: 1.0000e-12
              G: 0
       IntpType: 'Linear'
     LineLength: 0.0100
    Termination: 'NotApplicable'
       StubMode: 'NotAStub'
       NumPorts: 2
      Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}

Calculate the S-parameters of the transmission line at 1 GHz.

sparam = sparameters(rlcglinetxline,1e9);

Input Arguments

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.

rfobj — RF object

circuit object | rffilter object | transmission line object | seriesRLC object | shuntRLC object | attenuator object | rfantenna object

RF object, specified as one of the following:

Circuit object	circuit
RF Filter object	rffilter
Transmission line objects	txlineCoaxial, txlineMicrostrip, txlineCPW, txlineParallelPlate, txlineRLCGLine, txlineTwoWire, txlineEquationBased, txlineDelayLossless, and txlineDelayLossy
Series and Shunt RLC objects	seriesRLC, and shuntRLC
Attenuator object	attenuator
RF antenna object	rfantenna

netparamobj — Network parameter object

network parameter object

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

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');

antenna — Antenna object

scalar handle

Antenna object, specified as a scalar handle.

array — Array object

scalar handle

Array object, specified as a scalar handle.

freq — S-parameter frequencies

vector of positive real numbers

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

Z0 — Reference impedance

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.

rfdataorckt — RF data or circuit object

RF data object | RF network object

RF data or circuit object. Specify rfdataobj as either rfdata.data, or rfdata.network object or specify rfcktobj as any analyzed rfckt type object, such as rfckt.amplifier, rkckt.cascade object.

mnobj — Matching network

matchingnetwork object

Matching network, specified as a matchingnetwork object.

Data Types: char | string

circuitindices — Index of matching network

scalar

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

Data Types: double

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.