patchMicrostripCircular

Create standard or AI-based probe-fed circular microstrip patch antenna

Description

Use the default patchMicrostripCircular object to create a probe-fed circular microstrip patch antenna resonating around 1 GHz. By default, the patch is centered at the origin with feed point along the radius and the ground plane on the xy- plane at z = 0.

Circular microstrip antennas are used as low-profile antennas in airborne and spacecraft applications. These antennas also find use in portable wireless applications because they are lightweight, low cost, and easily manufacturable.

You can perform full-wave EM-solver-based analysis on the standard patchMicrostripCircular antenna, or you can create an AIAntenna object and use AI‑based analysis to explore the design space and tune the antenna for your application.

Creation

Syntax

circularpatch = patchMicrostripCircular

circularpatch = patchMicrostripCircular(PropertyName=Value)

Description

circularpatch = patchMicrostripCircular creates a standard (full-wave EM) probe-fed circular microstrip patch antenna with default property values. The default dimensions are chosen for an operating frequency of around 1 GHz.

circularpatch = patchMicrostripCircular(PropertyName=Value) sets properties using one or more name-value arguments. PropertyName is the property name and Value is the corresponding value. You can specify several name-value arguments in any order as PropertyName1=Value1,...,PropertyNameN=ValueN. Properties that you do not specify, retain their default values.

For example, circularpatch = patchMicrostripCircular(Radius=0.2) creates a circular patch of radius 0.2 m.

• You can create a standard patchMicrostripCircular antenna resonating at a desired frequency using the design function. For example, to create a standard patchMicrostripCircular antenna resonating at 1 GHz, use:

  >> design(patchMicrostripCircular,1e9)
  

• You can also create an AI-based version of the patchMicrostripCircular antenna resonating at a desired frequency using the same design function. Set the ForAI argument in the design function to true to create an AIAntenna object. To use this feature, you need a license for the Statistics and Machine Learning Toolbox™ in addition to the Antenna Toolbox™. For example,

  >> design(patchMicrostripCircular,1e9,ForAI=true)
  

  The AI-based patchMicrostripCircular antenna retains the Radius and Height properties of the standard antenna and adds the SubstrateEpsilonR property as tunable properties. All remaining properties of the standard antenna become read‑only in the AI‑based version. To find the upper and lower bounds of the tunable properties, use the tunableRanges function.

  To create a standard patchMicrostripCircular antenna from the AI‑based antenna, use the exportAntenna function.

Properties

Radius — Patch radius

0.0798 (default) | positive scalar

Patch radius, specified as a scalar in meters. The default radius corresponds to an operating frequency of 1 GHz. You can set this property for both standard and AI-based patchMicrostripCircular antenna.

• For the standard patchMicrostripCircular antenna, this property does not have any upper or lower bounds.

• For AI-based patchMicrostripCircular antenna, this property has upper and lower limits determined by the AI model. Use the tunableRanges function to query the valid range for this parameter.

Example: 0.2

Data Types: double

Height — Height of patch

0.0060 (default) | positive scalar

Height of patch above the ground plane along the z-axis, specified as a scalar in meters. You can set this property for both standard and AI-based patchMicrostripCircular antenna.

• For the standard patchMicrostripCircular antenna, this property does not have any upper or lower bounds.

• For AI-based patchMicrostripCircular antenna, this property has upper and lower limits determined by the AI model. Use the tunableRanges function to query the valid range for this parameter.

Example: 0.001

Data Types: double

GroundPlaneLength — Ground plane length

0.3000 (default) | positive scalar

Ground plane length along the x-axis, specified as a scalar in meters. Setting 'GroundPlaneLength' to Inf, uses the infinite ground plane technique for antenna analysis. You can set this property only for the standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna.

Example: 120e-3

Data Types: double

GroundPlaneWidth — Ground plane width

0.3000 (default) | positive scalar

Ground plane width along the y-axis, specified as a scalar in meters. Setting 'GroundPlaneWidth' to Inf, uses the infinite ground plane technique for antenna analysis. You can set this property only for the standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna.

Example: 120e-3

Data Types: double

Substrate — Type of dielectric material

dielectric("Air") (default) | dielectric object

Type of dielectric material used as a substrate, specified as a dielectric object. You can choose any dielectric material from the DielectricCatalog or specify a dielectric material of your choice. The substrate dimensions must be equal to the ground plane dimensions. You can set this property only for a standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna. For more information on dielectric substrate meshing, see Meshing.

Example: dielectric("FR4")

SubstrateEpsilonR — Relative permittivity of dielectric material

positive scalar | tunable for AIAntenna

Relative permittivity of the dielectric material, specified as a positive scalar. You can specify this property only for the AIAntenna object created from the patchMicrostripCircular object. To enable this property, specify a substrate in the patchMicrostripCircular object using the supported dielectric material from the DielectricCatalog before passing it to the design function. The supported dielectric materials are "Air", "FR4", "RO4725JXR", "Teflon", "TMM3", "TMM4", and "TMM6".

Example: 4.8000

Data Types: double

PatchCenterOffset — Signed distance from center along length and width of ground plane

[0 0] (default) | two-element real vector

Signed distance from center along length and width of ground plane, specified as a two-element real vector with each element unit in meters. Use this property to adjust the location of the patch relative to the ground plane. You can set this property only for the standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna.

Example: [0.01 0.01]

Data Types: double

FeedOffset — Signed distance from center along length and width of ground plane

[–0.0525 0] (default) | two-element real vector

Signed distance from center along length and width of ground plane, specified as a two-element real vector with each element unit in meters. Use this property to adjust the location of the feedpoint relative to the ground plane and patch. You can set this property only for the standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna.

Example: [0.01 0.01]

Data Types: double

Conductor — Type of metal material

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 standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna. 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 standard patchMicrostripCircular antenna. This property is read-only for the AI-based patchMicrostripCircular antenna.

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	Create antenna, array, or AI-based antenna resonating at specified frequency
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	Generate and view mesh for antennas, arrays, and custom shapes
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 and array catalog elements using SADEA or TR-SADEA algorithm
pattern	Plot radiation pattern of antenna, array, or embedded element of 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, AI-based antenna, platform, or shape
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

Circular Microstrip Patch

Create and view a default circular microstrip patch.

cp = patchMicrostripCircular

cp = 
  patchMicrostripCircular with properties:

               Radius: 0.0798
               Height: 0.0060
            Substrate: [1×1 dielectric]
    GroundPlaneLength: 0.3000
     GroundPlaneWidth: 0.3000
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0525 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

show(cp)

Radiation Pattern and Impedance of Circular Microstrip Patch

Create a circular patch antenna using given values. Display the antenna.

cp = patchMicrostripCircular(Radius=0.0798, Height=6e-3,...
        GroundPlaneLength=0.3, GroundPlaneWidth=0.3,...
        FeedOffset=[-0.0525 0]);
show(cp)   

Plot the pattern of the patch antenna at 1GHz.

pattern(cp,1e9);

Calculate the impedance of the antenna over a frequency span of 0.5 GHz to 1.5 GHz.

f = linspace(0.5e9,1.5e9,61);
impedance(cp,f);

Create AI-Based Circular Microstrip Patch Antenna

This example shows how to create an AI-based circular microstrip patch antenna at 1GHz and calculate its resonant frequency.

pAI = design(patchMicrostripCircular(Substrate=dielectric("FR4")),1e9,ForAI=true)

pAI = 
  AIAntenna with properties:

   Antenna Info
               AntennaType: 'patchMicrostripCircular'
    InitialDesignFrequency: 1.0000e+09

   Tunable Parameters
                    Radius: 0.0371
                    Height: 0.0038
         SubstrateEpsilonR: 4.8000

Show read-only properties

Vary its radius and height and calculate its resonant frequency.

pAI.Radius = 0.033;
pAI.Height = 0.0035;
pAI.SubstrateEpsilonR = 5.5;
resonantFrequency(pAI)

ans = 
1.0773e+09

Convert the AIAntenna to a standard circular microstrip patch antenna.

pmC = exportAntenna(pAI)

pmC = 
  patchMicrostripCircular with properties:

               Radius: 0.0330
               Height: 0.0035
            Substrate: [1×1 dielectric]
    GroundPlaneLength: 0.1387
     GroundPlaneWidth: 0.1387
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0121 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

Version History

Introduced in R2017b

R2026a: Substrate support for AI-based circular patch antenna

Use the new SubstrateEpsilonR property to explore antenna designs with different dielectric relative permittivity.

R2023b: 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 patchMicrostripCircular type AIAntenna. To use this feature, you need license to the Statistics and Machine Learning Toolbox in addition to the Antenna Toolbox.