discone

Create discone antenna

Description

The default discone object creates a discone antenna resonating around 2.13 GHz. A discone antenna 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

d = discone

d = discone(Name=Value)

Description

d = discone creates a discone antenna with default property values. The default dimensions are chosen for an operating frequency of around 2.13 GHz. The default discone has a feed point at the center of the disc.

d = discone(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, d = discone(Height=1) creates a discone antenna with a cone of height 1 meter and default values for other properties.

Properties

Height — Vertical height of cone

0.0744 (default) | positive 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 positive scalar in meters.

Example: 1

Data Types: double

ConeRadii — Broad and narrow radii of cone

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

Broad and narrow radii of the cone, specified as a positive 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: [6.3300e-04 0.0546]

Data Types: double

DiscRadius — Radius of disc

0.0298 (default) | positive scalar

Radius of the disc, specified as a positive scalar in meters.

Example: 0.0050

Data Types: double

FeedHeight — Gap between cone and disc

3.1980e-04 (default) | positive scalar

Gap between the cone and the disc, specified as a positive scalar in meters.

Example: 0.0034

Data Types: double

FeedWidth — Width of feed

4.2640e-04 (default) | positive scalar

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

Example: 0.0050

Data Types: double

Conductor — Type of metal material

metal("PEC") (default) | metal object

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")

Load — Lumped elements

[1x1 lumpedElement] (default) | lumpedElement object

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 — Tilt angle of antenna

0 (default) | scalar | vector

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

TiltAxis — Tilt axis of antenna

[1 0 0] (default) | three-element vector | 2-by-3 matrix | "X" | "Y" | "Z"

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

axialRatio	Calculate and plot axial ratio of antenna or array
bandwidth	Calculate and plot absolute bandwidth of antenna or array
beamwidth	Beamwidth of antenna
charge	Charge distribution on antenna or array surface
coneangle2size	Calculates equivalent cone height, broad radius, and narrow radius
current	Current distribution on antenna or array surface
design	Design prototype antenna or arrays for resonance around specified frequency or create AI-based antenna from antenna catalog objects
efficiency	Calculate and plot radiation efficiency of antenna or array
EHfields	Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays
feedCurrent	Calculate current at feed for antenna or array
impedance	Calculate and plot input impedance of antenna or scan impedance of array
info	Display information about antenna, array, or platform
memoryEstimate	Estimate memory required to solve antenna or array mesh
mesh	Mesh properties of metal, dielectric antenna, or array structure
meshconfig	Change meshing mode of antenna, array, custom antenna, custom array, or custom geometry
msiwrite	Write antenna or array analysis data to MSI planet file
optimize	Optimize antenna or array using SADEA optimizer
pattern	Plot radiation pattern and phase of antenna or array or embedded pattern of antenna element in array
patternAzimuth	Azimuth plane radiation pattern of antenna or array
patternElevation	Elevation plane radiation pattern of antenna or array
peakRadiation	Calculate and mark maximum radiation points of antenna or array on radiation pattern
rcs	Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array
resonantFrequency	Calculate and plot resonant frequency of antenna
returnLoss	Calculate and plot return loss of antenna or scan return loss of array
show	Display antenna, array structures, shapes, or platform
sparameters	Calculate S-parameters for antenna or array
stlwrite	Write mesh information to STL file
vswr	Calculate and plot voltage standing wave ratio (VSWR) of antenna or array element

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