discone

Create discone antenna

Since R2019b

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

Syntax

ant = discone

ant = discone(Name,Value)

Description

ant = discone creates a discone antenna with dimensions for a resonant frequency of 2.12 GHz. The default discone has a feedpoint at the center of the disc.

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.

Properties

Height — Vertical height of cone

0.0744 (default) | real-valued scalar

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

ConeRadii — Radii of cone

[5.3300e-04 0.0426] (default) | vector

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

DiscRadius — Radius of disc

0.0298 (default) | real-valued scalar

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

Example: 'DiscRadius',0.0050

Example: ant.DiscRadius = 0.050

Data Types: double

FeedHeight — Gap between cone and disc

3.1980e-04 (default) | real-valued scalar

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

FeedWidth — Width of feed

4.2640e-04 (default) | real-valued scalar

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

Example: 'FeedWidth',0.0050

Example: ant.FeedWidth = 0.0050

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) | lumped element object

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

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

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

Note

The wireStack antenna object only accepts the dot method to change its properties.

Data Types: double

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: TiltAxis = 'Z'

Data Types: double

Object Functions

coneangle2size	Calculates equivalent cone height, broad radius, and narrow radius for cone
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
optimize	Optimize antenna or array using SADEA optimizer
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

Default Discone Antenna and Radiation Pattern

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)

Impedance and Radiation Pattern of Custom Discone Antenna

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.

Version History

Introduced in R2019b