helixMultifilar
Creates bifilar or quadrafilar helix or conical helix antenna on circular ground plane
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
axialRatio | Calculate and/or plot axial ratio of antenna or array |
bandwidth | Calculate and/or plot absolute bandwidth 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 or create AI-based antenna from antenna catalog objects |
efficiency | Radiation efficiency of antenna |
EHfields | Electric and magnetic fields of antennas or embedded electric and magnetic fields of antenna element in arrays |
impedance | 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 |
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 |
rcs | Calculate and plot monostatic and bistatic radar cross section (RCS) of platform, antenna, or array |
resonantFrequency | Calculate and/or plot resonant frequency of antenna |
returnLoss | Return loss of antenna or scan return loss of array |
show | Display antenna, array structures, shapes, or platform |
sparameters | Calculate S-parameters for antennas and antenna arrays |
vswr | Voltage standing wave ratio (VSWR) of antenna or array element |
Examples
Version History
Introduced in R2018b
See Also
helix
| dipoleHelix
| dipoleHelixMultifilar
| cylinder2strip
| helixpitch2spacing