rhombic

Create a rhombic antenna

Since R2020b

Description

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.

Creation

Syntax

ant = rhombic

ant = rhombic(Name,Value)

Description

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.

Properties

ArmLength — Length of arm

2 (default) | positive scalar

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

Data Types: double

ArmElevation — Angle between adjacent arms at feed

20 (default) | positive scalar

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

Data Types: double

Width — Width of arm

0.1 (default) | positive scalar

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

Data Types: double

Conductor — Type of metal material

'PEC' (default) | metal object

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

Load — Lumped elements

[1x1 lumpedElement] (default) | lumpedElement object

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)

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates | 'X' | 'Y' | 'Z'

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 — Tilt angle of antenna

0 (default) | scalar | vector

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

show	Display antenna, array structures or shapes
axialRatio	Axial ratio of antenna
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
current	Current distribution on antenna or array surface
design	Design prototype antenna or arrays for resonance around specified frequency
efficiency	Radiation efficiency of antenna
EHfields	Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedance	Input impedance of antenna; scan impedance of array
mesh	Mesh properties of metal, dielectric antenna, or array structure
meshconfig	Change mesh mode of antenna structure
pattern	Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuth	Azimuth pattern of antenna or array
patternElevation	Elevation pattern of antenna or array
rcs	Calculate and plot radar cross section (RCS) of platform, antenna, or array
returnLoss	Return loss of antenna; scan return loss of array
sparameters	Calculate S-parameter for antenna and antenna array objects
vswr	Voltage standing wave ratio of antenna

Examples

Create Default Rhombic Antenna and Plot Radiation Pattern

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.

show(ant);

Plot the radiation pattern of the antenna at 510 MHz.

pattern(ant, 510e6);

References

[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