patchMicrostrip

R2026b

Create regular or AI-based microstrip patch antenna

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.

Creation

Syntax

pm = patchMicrostrip

pm = patchMicrostrip(PropertyName=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(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.

• You can create a standard patchMicrostrip antenna resonating at a desired frequency using the design function. For example, to create a standard patchMicrostrip antenna resonating at 1.2 GHz, use this code.

  >> design(patchMicrostrip,1.2e9)
  

• You can also create an AI-based version of the patchMicrostrip 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 Antenna Toolbox™. For example, to create an AI-based patchMicrostrip antenna resonating at 1.2 GHz, use this code.

  >> design(patchMicrostrip,1.2e9,ForAI=true)
  

  The AI‑based patchMicrostrip antenna retains the Length, Width, and Height properties of the standard antenna as tunable properties and introduces SubstrateEpsilonR as an additional tunable property. All other properties derived from the standard antenna become read‑only. To find the upper and lower bounds of the tunable properties, use the tunableRanges function.

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

Properties

Length — Patch length along x-axis

0.0750 (default) | positive scalar | tunable for patchMicrostrip type AIAntenna

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

Width — Patch width along the y-axis

0.0375 (default) | positive scalar | tunable for patchMicrostrip type AIAntenna

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 — Height of substrate

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

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

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 patchMicrostrip antenna. This property is read-only for the AI-based patchMicrostrip antenna. For more information on dielectric substrate meshing, see Meshing.

Example: dielectric("FR4")

SubstrateEpsilonR — Relative permittivity of dielectric material

positive scalar | tunable for AIAntenna

Since R2026b

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

Example: 4.8000

Data Types: double

GroundPlaneLength — Ground plane length along x-axis

0.1500 (default) | scalar

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

GroundPlaneWidth — Ground plane width along y-axis

0.0750 (default) | scalar

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

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

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

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

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

[–0.0187 0] (default) | two-element vector

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 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

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 regular patchMicrostrip antenna. For more information on metal conductor meshing, see Meshing.

Example: metal("Copper")

Load — Lumped elements

[1x1 lumpedElement] (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.

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	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

Create and View Microstrip Patch Antenna

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: [1×1 dielectric]
    GroundPlaneLength: 0.1200
     GroundPlaneWidth: 0.1200
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

show (pm)

Radiation Pattern of Microstrip Patch Antenna

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: [1×1 dielectric]
    GroundPlaneLength: 0.1200
     GroundPlaneWidth: 0.1200
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

show(pm)

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

figure
pattern(pm,1.67e9)

Impedance of Microstrip Patch Antenna

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: [1×1 dielectric]
    GroundPlaneLength: 0.1500
     GroundPlaneWidth: 0.0750
    PatchCenterOffset: [0 0]
           FeedOffset: [-0.0187 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

show(pm)

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

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

Prototype Antenna Design

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: [1×1 dielectric]
    GroundPlaneLength: 0.2998
     GroundPlaneWidth: 0.2998
    PatchCenterOffset: [0 0]
           FeedOffset: [0.0303 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

show(p)

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

Z = impedance(p,1e9)

Z = 
47.8027 - 7.5678i

Create and Analyze AI-Based Microstrip Patch Antenna

Create an AI-based microstrip patch antenna with a Teflon substrate operating at a frequency of 1.67 GHz.

d = dielectric("Teflon");
pAI = design(patchMicrostrip(Substrate=d),1.67e9,ForAI=true)

pAI = 
  AIAntenna with properties:

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

   Tunable Parameters
                    Length: 0.0601
                     Width: 0.0774
                    Height: 0.0012
         SubstrateEpsilonR: 2.1000

Show read-only properties

Use the tunableRanges function to get the tunable ranges of the antenna properties.

tunableRanges(pAI)

ans = 4×4 table
                                Length                  Width                  Height            SubstrateEpsilonR
                         ____________________    ___________________    _____________________    _________________

                           min         max         min        max         min          max        min      max 
                         ________    ________    _______    ________    ________    _________    _____    _____
                                                                                                                  
    resonantFrequency    0.051069    0.069093    0.06581    0.089037    0.001053    0.0014246     1.785    2.415  
    bandwidth            0.051069    0.069093    0.06581    0.089037    0.001053    0.0014246     1.785    2.415  
    beamwidth            0.051069    0.069093    0.06581    0.089037    0.001053    0.0014246     1.785    2.415  
    peakRadiation        0.051069    0.069093    0.06581    0.089037    0.001053    0.0014246     1.785    2.415  

Set the length and width of the antenna to values within the tunable range.

pAI.Length = 0.06;
pAI.Width = 0.078;

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

[absBW,fL,fU,matchingStatus] = bandwidth(pAI)

absBW = 
1.4642e+07

fL = 
1.6791e+09

fU = 
1.6938e+09

matchingStatus = categorical
     Matched 

Calculate the resonant frequency of the antenna.

fR = resonantFrequency(pAI)

fR = 
1.6856e+09

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

pm = exportAntenna(pAI)

pm = 
  patchMicrostrip with properties:

               Length: 0.0600
                Width: 0.0780
               Height: 0.0012
            Substrate: [1×1 dielectric]
    GroundPlaneLength: 0.1239
     GroundPlaneWidth: 0.1239
    PatchCenterOffset: [0 0]
           FeedOffset: [0.0126 0]
            Conductor: [1×1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1×1 lumpedElement]

References

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

Version History

Introduced in R2015a

R2026b: Substrate support for AI-based rectangular patch antenna

Use the new SubstrateEpsilonR property to set the relative permittivity values for the AI-based antenna designs with dielectric substrates.

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