Create helical dipole antenna
dipoleHelix object is a helical dipole antenna. The
antenna is typically center-fed. You can move the feed along the antenna length using
the feed offset property. Helical dipoles are used in satellite communications and
wireless power transfers.
The width of the strip is related to the diameter of an equivalent cylinder by this equation
w is the width of the strip.
d is the diameter of an equivalent cylinder.
r is the radius of an equivalent cylinder.
For a given cylinder radius, use the
cylinder2strip utility function to calculate the equivalent width. The
default helical dipole antenna is center-fed. The circular ground plane is on the X-Y
plane. Commonly, helical dipole antennas are used in axial mode. In this mode, the
helical dipole circumference is comparable to the operating wavelength, and has maximum
directivity along its axis. In normal mode, the helical dipole radius is small compared
to the operating wavelength. In this mode, the helical dipole radiates broadside, that
is, in the plane perpendicular to its axis. The basic equation for the helical dipole
r is the radius of the helical dipole.
θ is the winding angle.
S is the spacing between turns.
For a given pitch angle in degrees, use the
helixpitch2spacing utility function to calculate the spacing between the
turns in meters.
creates a helical
dipole antenna. The default antenna operates around 2 GHz.
dh = dipoleHelix
creates a helical dipole antenna, with additional properties specified by
one or more name–value pair arguments.
dh = dipoleHelix(Name,Value)
Name is the
property name and
Value is the corresponding value. You
can specify several name-value pair arguments in any order as
ValueN. Properties not specified retain their default
Radius— Turn radius
0.0220(default) | scalar
Turn radius, specified as a scalar in meters.
Width— Strip width
1.0000e-03(default) | scalar
Strip width, specified as a scalar in meters.
Strip width should be less than
Turns— Number of turns of helical dipole
3(default) | scalar
Number of turns of the helical dipole, specified a scalar.
Spacing— Spacing between turns
0.0350(default) | scalar
Spacing between turns, specified as a scalar in meters.
WindingDirection— Direction of helical dipole turns (windings)
Direction of helical dipole turns (windings), specified as
Load— Lumped elements
Lumped elements added to the antenna feed, specified as a lumped element
object handle. For more information, see
lumpedelement is the object handle for the load
FeedOffset— Signed distance of feedpoint from origin
0(default) | two-element vector
Signed distance from center along length and width of ground plane, specified as a two-element vector in meters. Use this property to adjust the location of the feedpoint relative to the ground plane and patch.
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.
ant.Tilt = 90
'TiltAxis',[0 1 0;0 1 1]
tilts the antenna at 90 degrees about the two axes, defined by vectors.
wireStack antenna object
only accepts the dot method to change its properties.
TiltAxis— Tilt axis of antenna
[1 0 0](default) | three-element vector of Cartesian coordinates | two three-element vectors of Cartesian coordinates |
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.
'TiltAxis',[0 1 0]
'TiltAxis',[0 0 0;0 1 0]
ant.TiltAxis = 'Z'
wireStack antenna object only accepts the dot method to change its
|Display antenna or array structure; display shape as filled patch|
|Display information about antenna or array|
|Axial ratio of antenna|
|Beamwidth of antenna|
|Charge distribution on metal or dielectric antenna or array surface|
|Current distribution on metal or dielectric antenna or array surface|
|Design prototype antenna or arrays for resonance at specified frequency|
|Electric and magnetic fields of antennas; Embedded electric and magnetic fields of antenna element in arrays|
|Input impedance of antenna; scan impedance of array|
|Mesh properties of metal or dielectric antenna or array structure|
|Change mesh mode of antenna structure|
|Radiation pattern and phase of antenna or array; Embedded pattern of antenna element in array|
|Azimuth pattern of antenna or array|
|Elevation pattern of antenna or array|
|Return loss of antenna; scan return loss of array|
|Voltage standing wave ratio of antenna|
Create a default helical dipole antenna and view it.
dh = dipoleHelix
dh = dipoleHelix with properties: Radius: 0.0220 Width: 1.0000e-03 Turns: 3 Spacing: 0.0350 WindingDirection: 'CCW' FeedOffset: 0 Tilt: 0 TiltAxis: [1 0 0] Load: [1x1 lumpedElement]
Create a four-turn helical dipole antenna with a turn radius of 28 mm and a strip width of 1.2 mm.
dh = dipoleHelix('Radius',28e-3,'Width',1.2e-3,'Turns',4); show(dh)
Plot the radiation pattern of the helical dipole at 1.8 GHz.
 Balanis, C. A. Antenna Theory. Analysis and Design. 3rd Ed. Hoboken, NJ: John Wiley & Sons, 2005.
 Volakis, John. Antenna Engineering Handbook. 4th Ed. New York: McGraw-Hill, 2007.