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pifa

Create regular or AI-based planar inverted-F antenna

Description

The pifa object is a planar inverted-F antenna. The default PIFA antenna 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 pifa antenna or you can create a pifa type AIAntenna and explore the design space to tune the antenna for your application using AI-based analysis.

Planar inverted-F antenna

Creation

Description

example

pf = pifa creates a planar inverted-F antenna.

example

pf = pifa(Name=Value) sets additional 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 pair arguments in any order as Name1=Value1, ..., NameN=ValueN. Properties that you do not specify retain their default values.

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

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

  • A pifa type AIAntenna has some common tunable properties with a regular pifa antenna for AI-based analysis. Other properties of the regular pifa 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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PIFA antenna length, specified as a scalar in meters. By default, the length is measured along the x-axis. This property is tunable for pifa type AIAntenna object created using the design function.

Example: 75e-3

Data Types: double

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

Example: 35e-3

Data Types: double

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

Example: 37e-3

Data Types: double

Type of dielectric material used as a substrate, specified as an object. For more information see, dielectric. For more information on dielectric substrate meshing, see Meshing.

Note

The substrate dimensions must be equal to the ground plane dimensions.

Example: dielectric("FR4")

Ground plane length, specified as a scalar in meters. By default, ground plane length is measured along the x-axis.

Note

Infinite ground plane length is currently unsupported.

Example: 3

Data Types: double

Ground plane width, specified as a scalar in meters. By default, ground plane width is measured along the y-axis.

Note

Infinite ground plane width is currently unsupported.

Example: 2.5

Data Types: double

Signed distance from the center along length and width of the 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

Shorting pin width of patch, specified as a scalar in meters. By default, the shorting pin width is measured along the y-axis. This property is tunable for pifa type AIAntenna object created using the design function.

Example: 3

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.

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. For more information, see lumpedElement.

Example: 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

showDisplay antenna, array structures, shapes, or platform
infoDisplay information about antenna or array
axialRatioAxial ratio of antenna
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
efficiencyRadiation efficiency of antenna
EHfieldsElectric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna or scan impedance of array
meshMesh properties of metal, dielectric antenna, or array structure
meshconfigChange meshing mode of antenna, array, custom antenna, custom array, or custom geometry
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
rcsCalculate and plot radar cross section (RCS) of platform, antenna, or array
returnLossReturn loss of antenna or scan return loss of array
sparametersCalculate S-parameters for antennas and antenna arrays
vswrVoltage standing wave ratio (VSWR) of antenna or array element

Examples

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Create and view a PIFA antenna with 30 mm length, 20 mm width over a 35 mm x 35 mm ground plane, and feedpoint at (-2 mm,0,0).

pf = pifa
pf = 
  pifa with properties:

               Length: 0.0300
                Width: 0.0200
               Height: 0.0100
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.0360
     GroundPlaneWidth: 0.0360
    PatchCenterOffset: [0 0]
        ShortPinWidth: 0.0200
           FeedOffset: [-0.0020 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(pf)

Figure contains an axes object. The axes object with title pifa antenna element, xlabel x (mm), ylabel y (mm) contains 3 objects of type patch, surface. These objects represent PEC, feed.

Plot the radiation pattern of a PIFA antenna at a frequency of 2.3 GHz.

pf = pifa(Length=30e-3,Width=20e-3,GroundPlaneLength=35e-3,...
          GroundPlaneWidth=35e-3)
pf = 
  pifa with properties:

               Length: 0.0300
                Width: 0.0200
               Height: 0.0100
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.0350
     GroundPlaneWidth: 0.0350
    PatchCenterOffset: [0 0]
        ShortPinWidth: 0.0200
           FeedOffset: [-0.0020 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

pattern(pf,2.3e9);

Figure contains an axes object and other objects of type uicontrol. The axes object contains 3 objects of type patch, surface.

Create a PIFA antenna using a dielectric substrate 'RO4725JXR'.

d = dielectric("RO4725JXR");
pf = pifa(Length=30e-3, Width=20e-3, Height=0.0060, GroundPlaneLength=35e-3, ...
         GroundPlaneWidth=35e-3, Substrate=d)
pf = 
  pifa with properties:

               Length: 0.0300
                Width: 0.0200
               Height: 0.0060
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.0350
     GroundPlaneWidth: 0.0350
    PatchCenterOffset: [0 0]
        ShortPinWidth: 0.0200
           FeedOffset: [-0.0020 0]
            Conductor: [1x1 metal]
                 Tilt: 0
             TiltAxis: [1 0 0]
                 Load: [1x1 lumpedElement]

show(pf)

Figure contains an axes object. The axes object with title pifa antenna element, xlabel x (mm), ylabel y (mm) contains 4 objects of type patch, surface. These objects represent PEC, feed, RO4725JXR.

Calculate the impedance of the antenna over the specified frequency range. GHz.

impedance(pf,linspace(2.2e9,2.5e9,31));

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.

This example shows how to create an AI model based PIFA antenna at 2.4 GHz and calculate its resonant frequency.

pAI = design(pifa,2.4e9,ForAI=true)
pAI = 
  AIAntenna with properties:

   Antenna Info
               AntennaType: 'pifa'
    InitialDesignFrequency: 2.4000e+09

   Tunable Parameters
                    Length: 0.0292
                     Width: 0.0194
                    Height: 0.0097
             ShortPinWidth: 0.0194

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

Vary its length and width and calculate its resonant frequency.

pAI.Length = 0.03;
pAI.Width = 0.0175;
resonantFrequency(pAI)
ans = 2.4006e+09

Convert the AIAntenna to a regular PIFA antenna.

pmC = exportAntenna(pAI)
pmC = 
  pifa with properties:

               Length: 0.0300
                Width: 0.0175
               Height: 0.0097
            Substrate: [1x1 dielectric]
    GroundPlaneLength: 0.0350
     GroundPlaneWidth: 0.0350
    PatchCenterOffset: [0 0]
        ShortPinWidth: 0.0194
           FeedOffset: [-0.0019 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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