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Create a rhombic antenna

Since R2020b


The rhombic object creates a rhombic antenna. It consists of a rhombus with a feed at one acute angles and a termination resistor at the other acute angle. It has a simple design and is highly directional. These antennas are used in shortwave radio broadcasting and point-to-point communications.

Rhombic antenna geometry, default radiation pattern, and impedance plot.




ant = rhombic creates a rhombic antenna. The dimensions are chosen for resonant frequency of 510 MHz. The default rhombic antenna is fed at one acute angle and the other acute angle is terminated with a load of 500 ohms.

ant = rhombic(Name,Value) sets Properties using one or more name-value pairs. For example, ant = rhombic('ArmLength', 3) creates a rhombic antenna with an arm of length 3 meters.


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Length of each of the rhombus, specified as a scalar in meters.

Data Types: double

The acute angle between the adjacent arms at the feed location, specified as a scalar in degrees.

Data Types: double

Width of the arm of the rhombus, specified as a scalar in meters.

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: m = metal('Copper'); 'Conductor',m

Example: m = metal('Copper'); ant.Conductor = m

Lumped elements added to the antenna feed, specified as a lumpedElement object. The load element is located opposite the feed at one of the acute angles of the rhombus. For more information, see lumpedElement.

Example: 'Load',lumpedElement, where lumpedElement is the where lumpedElement is the load added to the antenna feed.

Example: ant.Load = lumpedElement('Impedance',75)

Tilt axis of the antenna, specified as:

  • 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, each specified as three-element vectors of Cartesian coordinates. In this case, the antenna rotates around the line joining the two points in space.

  • A string input describing simple rotations around one of the principal axes, 'X', 'Y', or 'Z'.

For more information, see Rotate Antennas and Arrays.

Example: 'TiltAxis',[0 1 0]

Example: 'TiltAxis',[0 0 0;0 1 0]

Example: ant.TiltAxis = 'Z'

Tilt angle of the antenna, specified as a scalar or vector with each element unit in degrees. For more information, see Rotate Antennas and Arrays.

Example: 'Tilt',90

Example: ant.Tilt = 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

Object Functions

axialRatioCalculate and/or plot axial ratio of antenna or array
bandwidthCalculate and/or plot absolute bandwidth 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
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
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 monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequencyCalculate and/or plot resonant frequency of antenna
returnLossReturn loss of antenna or scan return loss of array
showDisplay antenna, array structures, shapes, or platform
sparametersCalculate S-parameters for antennas and antenna arrays
vswrVoltage standing wave ratio (VSWR) of antenna or array element


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Create a default rhombic antenna.

ant = rhombic
ant = 
  rhombic with properties:

       ArmLength: 2
    ArmElevation: 20
           Width: 0.1000
       Conductor: [1x1 metal]
            Tilt: 0
        TiltAxis: [1 0 0]
            Load: [1x1 lumpedElement]

View the antenna using the show function.


Plot the radiation pattern of the antenna at 510 MHz.

pattern(ant, 510e6);


[1] Decker, R. “The Influence of Gain and Current Attenuation on the Design of the Rhombic Antenna.” IRE Transactions on Antennas and Propagation 7, no. 2 (April 1959): 188–196.

Version History

Introduced in R2020b