waveguide

Create regular or AI-based rectangular waveguide

Description

The default waveguide object is an open-ended WR-90 rectangular waveguide resonating around 12.4 GHz. The default rectangular waveguide operates in the X-band. The X-band has a cutoff frequency of 6.5 GHz and ranges from 8.2 GHz to 12.5 GHz.

You can perform full-wave EM solver based analysis on the regular waveguide or you can create a waveguide type AIAntenna and explore the design space to tune the antenna for your application using AI-based analysis.

Creation

Syntax

wg = waveguide

wg = waveguide(Name=Value)

Description

wg = waveguide creates a regular open-ended rectangular waveguide with default property values. The default dimensions are chosen for an operating frequency of around 12.4 GHz.

wg = waveguide(Name=Value) sets properties using one or more name-value arguments. Name is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as Name1=Value1,...,NameN=ValueN. Properties that you do not specify, retain their default values.

For example, wg = waveguide(Length=0.1) creates a rectangular waveguide with a length of 0.1 m. and default values for other properties.

• You can also create a regular waveguide resonating at a desired frequency using the design function. For example, to create a regular waveguide resonating at 10 GHz, use the following syntax:

  >> design(waveguide,10e9)
  

  To analyze this antenna use object functions of the waveguide. Use this workflow to design, tune, and analyze a waveguide using conventional full-wave solvers.

• You can create an AI-based waveguide resonating at a desired frequency using the design function. Using AI-based antenna models over conventional full-wave solvers significantly reduces the simulation time required to fine-tune the antenna to meet your design goals. Set the ForAI argument in the design function to true to create a waveguide type AIAntenna object. To use this feature, you need license to the Statistics and Machine Learning Toolbox™ in addition to the Antenna Toolbox™. For example, to create an AI-based waveguide resonating at 10 GHz, use the following syntax:

  >> design(dipoleHelix,10e9,ForAI=true)
  

  The AI-based waveguide retains the Width, Height, and FeedHeight properties of the regular waveguide as tunable properties. Rest of the properties of the regular waveguide antenna are converted into read-only properties in its AI-based version. To find the upper and lower bounds of the tunable properties, use the tunableRanges function.

  To analyze this antenna use object functions of the AIAntenna. Use this workflow to design, tune, and analyze a waveguide antenna using its AI-based model. To create a regular waveguide antenna from this AI-based antenna, use the exportAntenna function.

Properties

Length — Rectangular waveguide length

0.0240 (default) | scalar in meters

Rectangular waveguide length, specified as a scalar in meters. By default, the waveguide length is 1λ, where:

$$\lambda =c/f$$

• c = speed of light, 299792458 m/s

• f = operating frequency of the waveguide

You can set this property only for a regular waveguide. This property is read-only for the AI-based waveguide.

Example: 0.09

Data Types: double

Width — Rectangular waveguide width

0.0229 (default) | scalar in meters

Rectangular waveguide width, specified as a scalar in meters. You can set this property for both regular and AI-based waveguide antenna. For a regular waveguide, Width value does not have any upper and lower bounds.

For AI-based waveguide antenna, Width value has upper and lower bounds. Use the tunableRanges function to get the upper and lower bound values.

Example: 0.05

Data Types: double

Height — Rectangular waveguide height

0.0102 (default) | scalar in meters

Rectangular waveguide height, specified as a scalar in meters. You can set this property for both regular and AI-based waveguide antenna. For a regular waveguide, Height value does not have any upper and lower bounds.

For AI-based waveguide antenna, Height value has upper and lower bounds. Use the tunableRanges function to get the upper and lower bound values.

Example: 0.0200

Data Types: double

FeedHeight — Height of feed

0.0060 (default) | positive scalar

Height of feed, specified as a scalar in meters. You can set this property for both regular and AI-based waveguide antenna. For a regular waveguide, FeedHeight value does not have any upper and lower bounds.

For AI-based waveguide antenna, FeedHeight value has upper and lower bounds. Use the tunableRanges function to get the upper and lower bound values.

Example: 0.0050

Data Types: double

FeedWidth — Width of feed

6.0000e-05 (default) | positive scalar

Width of feed, specified as a scalar in meters. You can set this property only for a regular waveguide. This property is read-only for the AI-based waveguide.

Example: 5e-05

Data Types: double

FeedOffset — Signed distance of feed point from center of ground plane

[–0.0060 0] (default) | two-element vector

Signed distance of feed point from center of ground plane, specified as a two-element vector in meters. By default, the feed is at an offset of λ/4 from the shortened end on the xy- plane. You can set this property only for a regular waveguide. This property is read-only for the AI-based waveguide.

Example: [–0.0070 0.01]

Data Types: double

Conductor — Type of metal

metal("PEC") (default) | metal object

Type of the metal used as a conductor, specified as a metal object. You can choose any metal from the MetalCatalog or specify a metal of your choice. You can set this property only for a regular waveguide. For more information on metal conductor meshing, see Meshing.

Example: metal("Copper")

Load — Lumped elements

[1x1lumpedElement] (default) | lumpedElement object

Lumped elements added to the antenna feed, specified as a lumpedElement object. You can add a load anywhere on the surface of the antenna. By default, the load is at the feed. You can set this property only for a regular waveguide.

Example: lumpedElement(Impedance=75)

Tilt — Tilt angle of antenna

0 (default) | scalar | vector

Tilt angle of the antenna in degrees, specified as a scalar or vector. For more information, see Rotate Antennas and Arrays.

Example: 90

Example: Tilt=[90 90],TiltAxis=[0 1 0;0 1 1] tilts the antenna at 90 degrees about the two axes defined by the vectors.

Data Types: double

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector | 2-by-3 matrix | "X" | "Y" | "Z"

Tilt axis of the antenna, specified as one of these values:

• Three-element vector of Cartesian coordinates in meters. In this case, each coordinate in the vector starts at the origin and lies along the specified points on the x-, y-, and z-axes.

• Two points in space, specified as a 2-by-3 matrix corresponding to two three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points.

• "x", "y", or "z" to describe a rotation about the x-, y-, or z-axis, respectively.

For more information, see Rotate Antennas and Arrays.

Example: [0 1 0]

Example: [0 0 0;0 1 0]

Example: "Z"

Data Types: double | string

Object Functions

axialRatio	Calculate and plot axial ratio of antenna or array
bandwidth	Calculate and plot absolute bandwidth of antenna or array
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
design	Design prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
efficiency	Calculate and plot radiation efficiency of antenna or array
EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
feedCurrent	Calculate current at feed for antenna or array
impedance	Calculate and plot input impedance of antenna or scan impedance of array
info	Display information about antenna, array, or platform
memoryEstimate	Estimate memory required to solve antenna or array mesh
mesh	Mesh properties of metal, dielectric antenna, or array structure
meshconfig	Change meshing mode of antenna, array, custom antenna, custom array, or custom geometry
msiwrite	Write antenna or array analysis data to MSI planet file
optimize	Optimize antenna or array using SADEA optimizer
pattern	Plot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
patternAzimuth	Azimuth plane radiation pattern of antenna or array
patternElevation	Elevation plane radiation pattern of antenna or array
peakRadiation	Calculate and mark maximum radiation points of antenna or array on radiation pattern
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequency	Calculate and plot resonant frequency of antenna
returnLoss	Calculate and plot return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
sparameters	Calculate S-parameters for antenna or array
stlwrite	Write mesh information to STL file
vswr	Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

Default Rectangular Waveguide

Create a rectangular waveguide using default dimensions. Display the waveguide.

wg = waveguide

wg = 
  waveguide with properties:

        Length: 0.0240
         Width: 0.0229
        Height: 0.0102
     FeedWidth: 6.0000e-05
    FeedHeight: 0.0060
    FeedOffset: [-0.0060 0]
     Conductor: [1x1 metal]
          Tilt: 0
      TiltAxis: [1 0 0]
          Load: [1x1 lumpedElement]

show(wg)

Radiation Pattern of WR-650 Rectangular Waveguide

Create a WR-650 rectangular waveguide and visualize it.

wg = waveguide(Length=0.254,Width=0.1651,Height=0.0855,...
    FeedHeight=0.0635,FeedWidth=0.00508,FeedOffset=[0.0635 0]);
show(wg)

Plot the radiation pattern of this waveguide at 1.5 GHz.

figure
pattern(wg,1.5e9)

Create AI-Based Waveguide

This example shows how to create an AI-based waveguide operating at 9.45 GHz and calculate its resonant frequency.

pAI = design(waveguide,9.45e9,ForAI=true)

pAI = 
  AIAntenna with properties:

   Antenna Info
               AntennaType: 'waveguide'
    InitialDesignFrequency: 9.4500e+09

   Tunable Parameters
                     Width: 0.0298
                    Height: 0.0132
                FeedHeight: 0.0078

Use 'showReadOnlyProperties(pAI)' to show read-only properties

Vary the width and height of the wavguide. Calculate its resonant frequency.

pAI.Width = 0.031;
pAI.Height = 0.01389;
fR = resonantFrequency(pAI)

fR = 
9.4500e+09

Convert the AIAntenna to a regular waveguide.

dh = exportAntenna(pAI)

dh = 
  waveguide with properties:

        Length: 0.0312
         Width: 0.0310
        Height: 0.0139
     FeedWidth: 7.9310e-05
    FeedHeight: 0.0078
    FeedOffset: [-0.0078 0]
     Conductor: [1x1 metal]
          Tilt: 0
      TiltAxis: [1 0 0]
          Load: [1x1 lumpedElement]

References

[1] Balanis, Constantine A.Antenna Theory. Analysis and Design. 3rd Ed. New York: John Wiley and Sons, 2005.

Version History

Introduced in R2016a

R2024a: AI model based antenna analysis

Design, tune, and analyze this antenna using an AI model. Using AI-based antenna models over conventional full-wave solvers significantly reduces the simulation time required to fine-tune the antenna to meet your design goals. Set the ForAI argument in the design function to true to create a waveguide type AIAntenna. To use this feature, you need license to the Statistics and Machine Learning Toolbox in addition to the Antenna Toolbox.