discone

Create discone antenna

Description

The discone object creates a discone antenna that consists of a circular disc and a cone whose apex approaches the center of the disc. A small gap exists between the disc and the cone through which the feed is connected.

A discone antenna is an omnidirectional vertically polarized antenna. This antenna has an exceptionally large coverage, offering a frequency range ratio of up to 10:1 between the upper cutoff frequency and the lower cutoff frequency. The discone antenna wideband coverage makes it useful in commercial, military, amateur radio, and radio scanner applications.

Creation

Description

example

ant = discone creates a discone antenna with dimensions for a resonant frequency of 2.09 GHz. The default discone has a feedpoint at the center of the disc.

example

ant = discone(Name,Value) sets properties using one or more name-value pairs. For example, ant = discone('Height',1) creates a discone antenna with a cone of height 1 meter.

Output Arguments

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Discone antenna, returned as a discone object.

Properties

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Vertical height of the cone from the center of the lower base of the cone to the center of the upper base of the cone, specified as a real-valued scalar in meters.

Example: 'Height',1

Example: ant.Height = 1

Data Types: double

Radii of the cone consisting of the broad radius and the narrow radius, specified as a vector with each element unit in meters. The first element of the vector is the narrow radius, and the second element of the vector is the broad radius.

Example: 'ConeRadii',[6.3300e-04 0.0546]

Example: ant.ConeRadii = [6.3300e-04 0.0546]

Data Types: double

Radius of the disc, specified as a real-valued scalar in meters.

Example: 'DiscRadius',0.0050

Example: ant.DiscRadius = 0.050

Data Types: double

Gap between the cone and the disc, specified as a real-valued scalar in meters.

Example: 'FeedHeight',0.0034

Example: ant.FeedHeight = 0.0034

Data Types: double

Diameter of the feed, specified as a real-valued scalar in meters.

Example: 'FeedWidth',0.0050

Example: ant.FeedWidth = 0.0050

Data Types: double

Lumped elements added to the antenna feed, specified as a lumped element object handle. 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: 'Load',lumpedelement. lumpedelement is the object handle for the load created using lumpedElement.

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

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: 'Tilt',[90 90],'TiltAxis',[0 1 0;0 1 1] tilts the antenna at 90 degree about two axes, defined by vectors.

Data Types: double

Tilt axis of the antenna, specified as:

  • Three-element vectors of Cartesian coordinates in meters. In this case, each 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'

Object Functions

showDisplay antenna or array structure; Display shape as filled patch
axialRatioAxial ratio of antenna
beamwidthBeamwidth of antenna
chargeCharge distribution on metal or dielectric antenna or array surface
currentCurrent distribution on metal or dielectric antenna or array surface
designDesign prototype antenna or arrays for resonance at specified frequency
EHfieldsElectric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays
impedanceInput impedance of antenna; scan impedance of array
meshMesh properties of metal or dielectric antenna or array structure
meshconfigChange mesh mode of antenna structure
patternRadiation pattern and phase of antenna or array; Embedded pattern of antenna element in array
patternAzimuthAzimuth pattern of antenna or array
patternElevationElevation pattern of antenna or array
returnLossReturn loss of antenna; scan return loss of array
sparametersS-parameter object
vswrVoltage standing wave ratio of antenna

Examples

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Create and view a default discone antenna.

ant = discone;
show(ant)

Plot the radiation pattern of the antenna at 2.09 GHz.

pattern(ant,2.09e9)

Create and view a discone antenna with specific dimensions.

ant = discone('Height',0.0925,'ConeRadii',[0.666e-3 53.2e-3],...
      'DiscRadius',37.25e-3,'FeedHeight',399.7e-6,'FeedWidth',0.553e-3);
show(ant) 

Calculate the impedance of the antenna over the frequency span of 500 MHz to 3 GHz and plot the S-parameters.

impedance(ant,linspace(0.5e9,3e9,51));

s = sparameters(ant,linspace(0.5e9,3e9,51));
figure;
rfplot(s);

Plot the radiation pattern of the antenna at 1.7 GHz.

pattern(ant,1.7e9);

References

[1] Verma, Saritha, Abhilash Mehta, and Rukhsana Khan. "Analysis of Variation of Various Parameters on Design of Discone Antenna." Advanced Computational Techniques in Electromagnetics. Volume 2012, 2012, pp.1-5.

Introduced in R2019b