biconeStrip

Create strip bicone antenna

Since R2020b

Description

The biconeStrip object creates a strip bicone antenna. The strip bicone antenna is an approximation of a solid bicone antenna, where strips are used to approximate the two cones. The strip configuration makes these antennas lightweight and reduces wind loading. These antennas are more suitable for use at low frequencies. Strip bicone antennas are popular for their wide-impedance bandwidth and omnidirectional radiation coverage. These antennas are used in applications like emission testing, field monitoring, and chamber characterization.

There are two types of bicone strip antennas, open-ended and phantom biconical. Specify the HatHeight property to create a phantom strip bicone antenna.

Creation

Syntax

ant = biconeStrip

ant = biconeStrip(Name,Value)

Description

ant = biconeStrip creates a strip bicone antenna with dimensions for a resonant frequency of 363.2 MHz.

ant = biconeStrip(Name,Value) sets Properties using one or more name-value pairs. For example, ant = biconeStrip('NumStrips', 8) creates a strip bicone antenna with eight strips.

Properties

NumStrips — Number of strips to form cones

16 (default) | scalar in the range [6,64]

Number of strips to form the two cones of strip bicone antenna, specified a scalar integer in the range [6,64].

Example: 'NumStrips',8

Example: ant.NumStrips = 8

Data Types: double

StripWidth — Width of strip

18e-3 (default) | positive scalar

Width of each strip, specified as positive scalar in meters.

Example: 'StripWidth',0.02

Example: ant.StripWidth = 0.02

Data Types: double

HatHeight — Vertical height of hats

0 (default) | scalar | two-element vector

Vertical height of the two hats, specified as either of the following:

• 0— This creates open-ended strip bicone antenna.

• Positive scalar in meters— This creates two cone hats of same height.

• Two-element vector with each element unit in meters— This creates two cone hats of different heights. In the two-element vector, the first element specifies the hat height of the top cone, and the second element specifies the hat height of the bottom cone.

Example: 'HatHeight',0.045

Example: ant.HatHeight = 0.045

Data Types: double

ConeHeight — Vertical height of cones

665e-3 (default) | scalar | two-element vector

Vertical height of the two cones, specified as either of the following:

• Positive scalar in meters: This creates two cones of same height.

• Two-element vector with each element unit in meters: This creates two cones of different heights. In the two-element vector, the first element specifies the height of the top cone, and the second element specifies the height of the bottom cone.

Example: 'ConeHeight',0.5

Example: ant.ConeHeight = 0.5

Data Types: double

NarrowRadius — Radius of apex

70e-3 (default) | scalar | two-element vector

Radius at the apex of the cones, specified as either of the following:

• Positive scalar in meters: This creates two cones with the same narrow radius.

• Two-element vector with each element unit in meters: This creates two cones with different narrow radii. In the two-element vector, the first element specifies the narrow radius of the top cone, and the second element specifies the narrow radius of the bottom cone.

Example: 'NarrowRadius',0.04

Example: ant.NarrowRadius = 0.04

Data Types: double

BroadRadius — Radius at broad opening of cone

647e-3 (default) | scalar | two-element vector

Radius at the broad opening of the cones, specified as either of the following:

• Positive scalar in meters: This creates two cones with the same broad radius.

• Two-element vector with each element unit in meters: This creates two cones with different broad radii. In the two-element vector, the first element specifies the broad radius of the top cone, and the second element specifies the broad radius of the bottom cone.

Example: 'BroadRadius',0.7

Example: ant.BroadRadius = 0.7

Data Types: double

FeedHeight — Height of feed

45e-3 (default) | positive scalar

Height of the feed spanning the gap between the two cones, specified as positive scalar in meters.

Example: 'FeedHeight',0.04

Example: ant.FeedHeight = 0.04

Data Types: double

FeedWidth — Width of feed

40e-3 (default) | positive scalar

Width of the feed of the antenna, specified as a positive scalar in meters.

Example: 'FeedWidth',0.03

Example: ant.FeedWidth = 0.03

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

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

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'

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. For more information, see lumpedElement.

Example: 'Load',lumpedElement. lumpedElement is the object for the load created using lumpedElement.

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

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

Create Open-ended Strip Bicone Antenna

Create a strip bicone antenna with default properties.

ant = biconeStrip

ant = 
  biconeStrip with properties:

       NumStrips: 16
      StripWidth: 0.0180
       HatHeight: 0
      ConeHeight: 0.6650
    NarrowRadius: 0.0700
     BroadRadius: 0.6470
      FeedHeight: 0.0450
       FeedWidth: 0.0400
       Conductor: [1x1 metal]
            Tilt: 0
        TiltAxis: [1 0 0]
            Load: [1x1 lumpedElement]

View the antenna using the show function.

show(ant);

Plot the S-parameters of the antenna over the frequency span of 150-550 MHz.

s = sparameters(ant,linspace(150e6,550e6,101));
rfplot(s)

Create Strip Bicone Antenna with Hat

Create a strip bicone antenna with hat.

ant = biconeStrip("NumStrips",6,"StripWidth",12e-3,"HatHeight",53e-3, ...
    "ConeHeight",465e-3,"NarrowRadius",40e-3,"BroadRadius",257e-3, ...
    "FeedHeight",144e-3,"FeedWidth",25e-3);

View the antenna using the show function.

show(ant)

Calculate antenna impedance over the frequency span of 10-300 MHz.

impedance(ant,10e6:10e6:300e6)

More About

Parametric Analysis Guidelines

To understand how the properties of the biconeStrip antenna object influence the antenna design, use the following parametric analysis guidelines.

• To increase the operating frequency, decrease the dimensions of the biconeStrip antenna.

• To increase the impedance bandwidth, use the NumStrips property to increase the number of strips in the biconeStrip antenna object.

• To improve average input impedance, decrease the narrow radii and feed height of the antenna using the NarrowRadius and the FeedHeight properties.

References

[1] Brian A. Austin, Andre P. C. Fourie "Characteristics of the Wire Biconical Antenna Used for EMC Measurements", IEEE Transaction on Electromagnetic Compatibility, vol. 33, no. 3, August 1991.

Version History

Introduced in R2020b