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biquad

Create biquad or double-biquad antenna

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Description

The default biquad object creates a biquad antenna resonating around 2.74 GHz. The antenna is center fed and symmetric about its origin.

The width of the strip is related to the diameter an equivalent cylinder:

w=2d=4r

, where:

  • d is the diameter of equivalent cylindrical dipole.

  • r is the radius of equivalent cylindrical dipole.

For a given cylinder radius, use the cylinder2strip utility function to calculate the equivalent width. The default strip dipole is center-fed. The feed point coincides with the origin. The origin is located on the yz- plane.

Creation

Syntax

b = biquad
b = biquad(Name=Value)

Description

b = biquad creates a biquad antenna with default property values. The default dimensions are chosen for an operating frequency of around 2.74 GHz.

b = biquad(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.

For example, b = biquad(NumLoops=4) creates a double biquad antenna with default values for other properties.

example

Properties

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Number of loops for the biquad, specified as one of the following options:

  • 2 — to create a biquad antenna.

  • 4 — to create a double biquad antenna.

Example: 4

Data Types: double

Length of two arms, specified as a positive scalar in meters.

Example: 0.0206

Data Types: double

Angle formed by biquad arms to the xy- plane, specified as a positive scalar in meters.

Example: 50

Data Types: double

Biquad arm width, specified as a positive scalar in meters.

Example: 0.006

Data Types: double

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. 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 a biquad antenna with arm angles at 50 degrees and view it.

bq = biquad(ArmElevation=50);
show(bq)

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

Open Live Script

Calculate the impedance of a biquad antenna over a frequency span 2.5GHz-3GHz.

bq = biquad(ArmElevation=50);
impedance(bq,linspace(2.5e9,3e9,51));

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

Create and view a double biquad antenna using default property values.

ant = biquad(NumLoops=4)
ant = 
  biquad with properties:

        NumLoops: 4
       ArmLength: 0.0305
    ArmElevation: 45
           Width: 1.0000e-03
       Conductor: [1x1 metal]
            Tilt: 0
        TiltAxis: [1 0 0]
            Load: [1x1 lumpedElement]


show(ant)

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

Version History

Introduced in R2015b

See Also

Objects

Functions

Topics