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patchMicrostrip

Create regular or AI-based microstrip patch antenna

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Description

The default patchMicrostrip object is a microstrip patch antenna resonating around 1.75 GHz. The default patch is centered at the origin. The feed point is along the length of the antenna.

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

Microstrip patch antenna

Creation

Syntax

pm = patchMicrostrip
pm = patchMicrostrip(Name=Value)

Description

pm = patchMicrostrip creates a microstrip patch antenna with default property values. The default dimensions are chosen for an operating frequency of around 1.75 GHz.

pm = patchMicrostrip(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.

example

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

  • You can also create a patchMicrostrip antenna from a microstrip patch type AIAntenna object using the exportAntenna function.

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

Properties

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Patch length, specified as a scalar in meters. By default, the length is measured along the x-axis. This property is tunable for patchMicrostrip type AIAntenna object created using the design function.

Example: 50e-3

Data Types: double

Patch width, specified as a scalar in meters. By default, the width is measured along the y-axis. This property is tunable for patchMicrostrip type AIAntenna object created using the design function.

Example: 60e-3

Data Types: double

Height of substrate, specified as a scalar in meters. This property is tunable for patchMicrostrip type AIAntenna object created using the design function.

Example: 37e-3

Data Types: double

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. For more information on dielectric substrate meshing, see Meshing.

Note

The substrate dimensions must be less than the ground plane dimensions.

Example: Substrate=dielectric("FR4")

Example: antenna.Substrate = dielectric("FR4")

Ground plane length, specified as a scalar in meters. By default, ground plane length is measured along x-axis. Setting 'GroundPlaneLength' to Inf, uses the infinite ground plane technique for antenna analysis.

Example: 120e-3

Data Types: double

Ground plane width, specified as a scalar in meters. By default, ground plane width is measured along y-axis. Setting 'GroundPlaneWidth' to Inf, uses the infinite ground plane technique for antenna analysis.

Example: 120e-3

Data Types: double

Signed distance from center along length and width of ground plane, specified as a two-element vector in meters. Use this property to adjust the location of the patch relative to the ground plane.

Example: [0.01 0.01]

Data Types: double

Signed distance from center along length and width of ground plane, specified as a two-element vector. Use this property to adjust the location of the feed point relative to ground plane and patch. Place the feed sufficiently inside the edges of the patch to successfully mesh it during analysis.

Example: [0.01 0.01]

Data Types: double

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")

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.

Example: Load=lumpedElement(Impedance=75)

Example: antenna.Load = lumpedElement(Impedance=75)

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

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

axialRatioCalculate and plot axial ratio of antenna or array
bandwidthCalculate and plot absolute bandwidth of antenna or array
beamwidthBeamwidth of antenna
chargeCharge distribution on antenna or array surface
currentCurrent distribution on antenna or array surface
designDesign prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
efficiencyCalculate and plot radiation efficiency of antenna or array
EHfieldsElectric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
feedCurrentCalculate current at feed for antenna or array
impedanceCalculate and plot input impedance of antenna or scan impedance of array
infoDisplay information about antenna, array, or platform
memoryEstimateEstimate memory required to solve antenna or array mesh
meshMesh properties of metal, dielectric antenna, or array structure
meshconfigChange meshing mode of antenna, array, custom antenna, custom array, or custom geometry
msiwriteWrite antenna or array analysis data to MSI planet file
optimizeOptimize antenna or array using SADEA optimizer
patternPlot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
patternAzimuthAzimuth plane radiation pattern of antenna or array
patternElevationElevation plane radiation pattern of antenna or array
peakRadiationCalculate and mark maximum radiation points of antenna or array on radiation pattern
rcsCalculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequencyCalculate and plot resonant frequency of antenna
returnLossCalculate and plot return loss of antenna or scan return loss of array
showDisplay antenna, array structures, shapes, or platform
sparametersCalculate S-parameters for antenna or array
stlwriteWrite mesh information to STL file
vswrCalculate and plot voltage standing wave ratio (VSWR) of antenna or array element

Examples

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Open Live Script

Create and view a microstrip patch with specified parameters.

pm = patchMicrostrip(Length=75e-3, Width=37e-3, ...
         GroundPlaneLength=120e-3, GroundPlaneWidth=120e-3)
pm = 
  patchMicrostrip with properties:

               Length: 0.0750
                Width: 0.0370
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1200
     GroundPlaneWidth: 0.1200
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show (pm)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Open Live Script

Create a microstrip patch antenna using FR4 dielectric substrate.

d = dielectric("FR4");
pm = patchMicrostrip(Length=75e-3, Width=37e-3, ...
         GroundPlaneLength=120e-3, GroundPlaneWidth=120e-3, ...
         Substrate=d)
pm = 
  patchMicrostrip with properties:

               Length: 0.0750
                Width: 0.0370
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1200
     GroundPlaneWidth: 0.1200
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show(pm)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 6 objects of type patch, surface. These objects represent PEC, feed, FR4.

Plot the radiation pattern of the antenna at a frequency of 1.67 GHz.

figure
pattern(pm,1.67e9)

Figure contains 2 axes objects and other objects of type uicontrol. Axes object 1 contains 6 objects of type patch, surface. This object represents FR4. Hidden axes object 2 contains 17 objects of type surface, line, text, patch. This object represents FR4.

Open Live Script

Create a microstrip patch antenna using FR4 dielectric substrate. 

d = dielectric("FR4");
pm = patchMicrostrip(Substrate=d)
pm = 
  patchMicrostrip with properties:

               Length: 0.0750
                Width: 0.0375
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1500
     GroundPlaneWidth: 0.0750
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show(pm)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 6 objects of type patch, surface. These objects represent PEC, feed, FR4.

Calculate and plot the impedance of the antenna over the specified frequency range.

impedance(pm,linspace(0.5e9,1e9,11));

Figure contains an axes object. The axes object with title Impedance, xlabel Frequency (GHz), ylabel Impedance (ohms) contains 2 objects of type line. These objects represent Resistance, Reactance.

Open Live Script

Design a prototype microstrip patch antenna that resonates at a frequency of 1 GHz.

p = design(patchMicrostrip,1e9)
p = 
  patchMicrostrip with properties:

               Length: 0.1439
                Width: 0.1874
               Height: 0.0030
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.2998
     GroundPlaneWidth: 0.2998
    PatchCenterOffset: [0 0]
           FeedOffset: [0.0303 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]


show(p)

Figure contains an axes object. The axes object with title patchMicrostrip antenna element, xlabel x (mm), ylabel y (mm) contains 5 objects of type patch, surface. These objects represent PEC, feed.

Calculate the impedance of the above antenna at the same frequency.

Z = impedance(p,1e9)
Z = 
47.8027 - 7.5678i

This example uses:

Open Live Script

This example shows how to create an AI-based microstrip patch antenna operating at 1.67 GHz, and calculate its bandwidth and resonant frequency.

Use the design function with the ForAI argument set to true to create an AI-based microstrip patch antenna operating at 1.67 GHz. To use the ForAI argument in the design function you need a license to the Statistics and Machine Learning Toolbox™.

pAI = design(patchMicrostrip,1.67e9,ForAI=true)
pAI = 
  AIAntenna with properties:

   Antenna Info
               AntennaType: 'patchMicrostrip'
    InitialDesignFrequency: 1.6700e+09

   Tunable Parameters
                    Length: 0.0862
                     Width: 0.1122
                    Height: 0.0018

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

Explore the design space by changing its length and width with values within the tunable range of these properties. You can get the tunable range of a property by using tunableRanges function on the AI-based antenna object. 

pAI.Length = 0.0855;
pAI.Width = 0.113;

Calculate the absolute bandwidth of the antenna and its lower and upper bounds.

[absBW,fL,fU,matchingStatus] = bandwidth(pAI)
absBW = 
2.3422e+07

fL = 
1.6679e+09

fU = 
1.6913e+09

matchingStatus = categorical
     Matched

Calculate the resonant frequency of the antenna. 

fR = resonantFrequency(pAI)
fR = 
1.7016e+09

Convert the AI-based microstrip patch antenna to a regular microstrip patch antenna.

pm = exportAntenna(pAI)
pm = 
  patchMicrostrip with properties:

               Length: 0.0855
                Width: 0.1130
               Height: 0.0018
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.1795
     GroundPlaneWidth: 0.1795
    PatchCenterOffset: [0 0]
           FeedOffset: [0.0181 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

References

[1] Balanis, Constantine A. Antenna Theory: Analysis and Design. Fourth edition. Hoboken, New Jersey: Wiley, 2016.

Version History

Introduced in R2015a

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See Also

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