Compact helical antenna with a sinusoidal profile modulating a fractal pattern

Patent metadata

Field	Value
Publication number	US-9698474-B2
Application number	US-201314386566-A
Country	US
Kind code	B2
Filing date	Mar 21, 2013
Priority date	Mar 21, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

The invention concerns a helical antenna comprising a shape of revolution and a plurality of radiating strands helically wound around the shape of revolution, characterized in that each radiating strand is defined by a repetition of a fractal pattern comprising segments formed by a sinusoidal curve.

First claim

The invention claimed is:

1. A helical type antenna having a rotational shape and a plurality of radiating strands coiled in a helix around the rotational shape, wherein each radiating strand is defined by a repetition of a fractal pattern comprising a sequence of segments, a sinusoidal curve having been applied on each segment of the sequence of the fractal pattern, so that each segment of each radiating strand corresponds to a half-period of a sinusoidal curve having a direction defined by the corresponding segment of the fractal pattern.

2. The helical type antenna according to claim 1 , wherein each segment corresponds to a half-period of a sinusoidal curve defined by

y
⁡

(
x
)

=

S
·
k
·

L
′

·

sin
⁡

(

π

L
′

·
x

)

,

where: S is an integer with a value within {−1; +1}, k is the ratio of the amplitude of the sinusoid and its half-wavelength, L′ is the horizontal width of the pattern.

3. The helical type antenna according to claim 1 , wherein each segment of the fractal pattern has an identical length.

4. The helical type antenna according claim 1 , wherein the fractal is of the von Koch type, each straight line whereof being replaced by a sinusoidal segment.

5. The antenna according claim 1 , wherein each of the radiating strands consist of a specified metal-clad zone, coiled in a helix on the lateral surface of a sleeve, such that the director axis of each strand is separated from the axis of the following strand by a specified distance, defined along any perpendicular to any director line of the sleeve as the distance between two points, each defined by an intersection between the axis of a strand and a perpendicular to any director line of the sleeve.

6. The antenna according to claim 1 , wherein the rotational shape is cylindrical or conical.

7. The antenna according to claim 1 , wherein the antenna includes four identical radiating strands.

Assignees

• Centre Nat De La Rech Scient (Cnrs)
• Centre Nat D'Etudes Spatiales

Inventors

• Aubert Hervé
• Diez Hubert
• Belot Daniel
• Takacs Alexandru

Classifications

• H01Q1/362 Primary

  for broadside radiating helical antennas · CPC title

• H01Q11/08 Primary

  Helical antennas · CPC title