Creates bifilar or quadrafilar helix or conical helix antenna on circular ground plane
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 X-Y 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.
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 X-Y 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.
show | Display antenna or array structure; display shape as filled patch |
axialRatio | Axial ratio of antenna |
beamwidth | Beamwidth of antenna |
charge | Charge distribution on metal or dielectric antenna or array surface |
current | Current distribution on metal or dielectric antenna or array surface |
design | Design prototype antenna or arrays for resonance at 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 or 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 |
returnLoss | Return loss of antenna; scan return loss of array |
sparameters | S-parameter object |
vswr | Voltage standing wave ratio of antenna |
cylinder2strip
| dipoleHelix
| dipoleHelixMultifilar
| helix
| helixpitch2spacing