helixMultifilar
Creates bifilar or quadrafilar helix or conical helix antenna on circular ground plane
Since R2018b
Description
The helixMultifilar
object creates a bifilar or quadrafilar
helix or conical helix antenna on a circular ground plane. You can create both
short-circuited and open-ended helix multifilar antennas. Bifilar and quadrafilar helix
antennas are used in aerospace and defense applications.
The width of the strip is related to the diameter of an equivalent cylinder by the equation
where:
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 helix antenna is end-fed. The circular ground plane is on the
xy- plane. Helix antennas are commonly used in axial mode. In
this mode, the helix circumference is comparable to the operating wavelength, and the
helix has maximum directivity along its axis. In normal mode, the helix radius is small
compared to the operating wavelength. In this mode, the helix radiates broadside, that
is, in the plane perpendicular to its axis. The basic equations for the helix are
where:
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.
Creation
Description
creates a
bifilar or quadrafilar helix or conical helix antenna operating in the axial
mode. The default multifilar helical antenna is end-fed and has a circular
ground plane on the xy- plane. The default operating
frequency is around 2 GHz.ant
= helixMultifilar
sets properties using one or more name-value pairs. For example,
ant
= helixMultifilar(Name,Value)ant = helixMultifilar('Radius',28e-03)
creates a
multifilar helix with turns of radius 28e-03 m.
Properties
Object Functions
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
Version History
Introduced in R2018b
See Also
helix
| dipoleHelix
| dipoleHelixMultifilar
| cylinder2strip
| helixpitch2spacing