# helix

Create helix or conical helix antenna on ground plane

## Description

Use the `helix`

object to create a helix or conical helix
antenna on a circular ground plane. The helix antenna is a common choice in satellite
communication.

The width of the strip is related to the diameter of an equivalent cylinder by the equation

$$w=2d=4r$$

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. Commonly, helix antennas are 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 equation for the helix is

$$\begin{array}{l}x=r\mathrm{cos}(\theta )\\ y=r\mathrm{sin}(\theta )\\ z=S\theta \end{array}$$

where

*r*is the radius of the helix.*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.

**Note**

In an array of helix antennas, the circular ground plane of the helix is converted to rectangular ground plane.

## Creation

### Description

### Output Arguments

## 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

## References

[1] Balanis, C.A. *Antenna Theory. Analysis and Design*, 3rd
Ed. New York: Wiley, 2005.

[2] Volakis, John. *Antenna Engineering Handbook*, 4th Ed. New
York: Mcgraw-Hill, 2007.

[3] Zhang, Yan, Q. Ding, J. Chen, S. Lu, Z. Zhu and L. L. Cheng. “A
Parametric Study of Helix Antenna for S-Band Satellite Communications.”
* 9th International Symposium on Antenna Propagation and EM Theory
(ISAPE)*. 2010, pp. 193–196.

[4] Djordjevic, A.R., Zajic, A.G., Ilic, M. M., Stuber, G.L. “Optimization
of Helical antennas (Antenna Designer's Notebook)” * IEEE Antennas and
Propagation Magazine*. December, 2006, pp. 107, pp.115.

[5] B. Young, K. A. O'Connor and
R. D. Curry, “Reducing the size of helical antennas by means of dielectric
loading,” *2011 IEEE Pulsed Power Conference*, 2011, pp.
575-579, doi: 10.1109/PPC.2011.6191490

## Version History

**Introduced in R2015a**

## See Also

`spiralArchimedean`

| `monopole`

| `pifa`

| `helixpitch2spacing`

| `cylinder2strip`

| `helixMultifilar`