frequencySweep

Create frequency sweep object

Since R2025a

Description

Create a frequency sweep object to setup the interpolation parameters for frequency sweep with a full-wave solver.

Creation

Syntax

h = frequencySweep

Description

h = frequencySweep creates a default interpolating sweep object.

You can set the properties of this object only after its creation. Properties that you do not specify, retain their default values.

For example, h = frequencySweep; h.NumFreqs = 150; creates a default frequency sweep object and sets the number of frequency points to 150.

Properties

SweepType — Type of interpolating frequency sweep

"interp" (default) | "interpWithGrad"

Type of interpolating frequency sweep, specified as:

• "interp" uses interpolation with the minimum possible set of points within the specified frequency range.

• "interpWithGrad" uses a gradient-based interpolation technique to predict the next point within the specified frequency range.

Example: "interpWithGrad"

Data Types: string

ErrTol — Maximum error tolerance in subsequent fitting iterations

-80 dB (default) | negative scalar

Maximum error tolerance in subsequent fitting iterations, specified as a negative scalar. The default error tolerance is -80 dB.

Example: -90

Data Types: double

NumFreqs — Number of points to discretize frequency range

100 (default) | positive integer

Number of points to discretize frequency range, specified as a positive integer.

Example: 150

Data Types: double

NumIters — Maximum number of iterations for fitting

25 (default) | positive integer

Maximum number of iterations for fitting, specified as a positive integer.

Example: 50

Data Types: double

Object Functions

getRationalModel

Read rational fitting parameters

Examples

Use Frequency Sweep Interpolation to Calculate S-parameter

Create a frequency sweep object for using a gradient-based interpolating sweep.

h = frequencySweep;
h.SweepType = "interpWithGrad";
h.NumFreqs = 200;

Create a dipole antenna. Calculate its S-parameter in the range 60 MHz to 80 MHz using frequency sweep interpolation.

d = dipole; 
[s,sweeptype] = sparameters(d,[60e6,80e6],SweepOption=h)

s = 
  sparameters with properties:

      Impedance: 50
       NumPorts: 1
     Parameters: [1×1×200 double]
    Frequencies: [200×1 double]

sweeptype = 
  frequencySweep with properties:

    SweepType: "interpWithGrad"
       ErrTol: -80
     NumFreqs: 200
     NumIters: 25

View rational fit parameters of the interpolated sweep.

g = getRationalModel(sweeptype)

g = 
  rational with properties:

      NumPorts: 1
      NumPoles: 5
         Poles: [5×1 double]
      Residues: [1×1×5 double]
    DirectTerm: 0.0936
         ErrDB: -161.8124

Plot the S-parameter.

figure
rfplot(s)

Version History

Introduced in R2025a