waveguide

Create regular or AI-based rectangular waveguide

Description

The waveguide object is an open-ended rectangular waveguide. The default rectangular waveguide is the WR-90 and functions 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 an open-ended rectangular waveguide.

wg = waveguide(Name=Value) creates a rectangular waveguide with additional Properties specified by one, or more name-value pair arguments. Name is the property name and Value is the corresponding value. You can specify several name-value pair arguments in any order as Name1=Value1,...,NameN=ValueN. Properties not specified retain their default values.

• You can also create a waveguide resonating at a desired frequency using the design function.

• You can also create a waveguide from a waveguide type AIAntenna object using the exportAntenna function.

• A waveguide type AIAntenna has some common tunable properties with a regular waveguide for AI-based analysis. Other properties of the regular waveguide are retained as read-only in its AIAntenna equivalent. To find the upper and lower bounds of the tunable properties, use tunableRanges function.

Properties

FeedHeight — Height of feed

0.0060 (default) | positive scalar | tunable for waveguide type AIAntenna

Height of feed, specified as a scalar in meters. By default, the feed height is chosen for an operating frequency of 12.5 GHz. This property is tunable for waveguide type AIAntenna object created using the design function.

Example: 0.0050

Data Types: double

FeedWidth — Width of feed

6.0000e-05 (default) | positive scalar | tunable for waveguide type AIAntenna

Width of feed, specified as a scalar in meters. This property is tunable for waveguide type AIAntenna object created using the design function.

Example: 5e-05

Data Types: double

Length — Rectangular waveguide length

0.0240 (default) | scalar in meters | tunable for waveguide type AIAntenna

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

This property is tunable for waveguide type AIAntenna object created using the design function.

Example: 0.09

Data Types: double

Width — Rectangular waveguide width

0.0229 (default) | scalar in meters | tunable for waveguide type AIAntenna

Rectangular waveguide width, specified as a scalar in meters. This property is tunable for waveguide type AIAntenna object created using the design function.

Example: 0.05

Data Types: double

Height — Rectangular waveguide height

0.0102 (default) | scalar in meters | tunable for waveguide type AIAntenna

Rectangular waveguide height, specified as a scalar in meters. This property is tunable for waveguide type AIAntenna object created using the design function.

Example: 0.0200

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.

Example: [–0.0070 0.01]

Data Types: double

Conductor — Type of metal material

"PEC" (default) | metal object

Type of the metal used as a conductor, specified as a metal material object. You can choose any metal from the MetalCatalog or specify a metal of your choice. For more information, see metal. For more information on metal conductor meshing, see Meshing.

Example: metal("Copper")

Load — Lumped elements

[1x1 lumpedElement] (default) | lumped element object

Lumped elements added to the antenna feed, specified as a lumped element object. For more information, see lumpedElement.

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/or plot axial ratio of antenna or array
bandwidth	Calculate and/or plot absolute bandwidth of antenna
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	Radiation efficiency of antenna
EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
impedance	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
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
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequency	Calculate and/or plot resonant frequency of antenna
returnLoss	Return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
sparameters	Calculate S-parameters for antennas and antenna arrays
vswr	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 display 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 Model Based Waveguide

This example shows how to create an AI model based waveguide at 9.45GHz 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™.