Home-Brew Antennae: Difference between revisions
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===Sectoral Antenna=== | ===Sectoral Antenna=== | ||
A sectoral antenna provides the best of both worlds in terms of gain as well as beam-width and can be applied to many situations in mesh networking. | |||
====Turn an Omni into a Sector==== | ====Turn an Omni into a Sector==== | ||
The reflector designs shown, found at [http://www.freeantennas.com/ Freeantennas.com] can be applied to a standard omni and will turn the omni into a sectoral antenna. | The reflector designs shown, found at [http://www.freeantennas.com/ Freeantennas.com] can be applied to a standard omni and will turn the omni into a sectoral antenna. | ||
[[Image:Template.jpg|thumb]] | [[Image:Template.jpg|thumb|left]] | ||
[[Image:Wet-11.jpg|thumb]] | [[Image:Wet-11.jpg|thumb|left]] | ||
Metal sheeting can be used for the reflector, however, the ideal would be some sort of mesh metal, with holes smaller than 1/4 wavelength (<3cm), so that the antenna is not affected by wind as much. | Metal sheeting can be used for the reflector, however, the ideal would be some sort of mesh metal, with holes smaller than 1/4 wavelength (<3cm), so that the antenna is not affected by wind as much. | ||
Revision as of 15:41, 18 November 2005
Omnidirectional Antennae
It is possible to make a homebrew omnidirectional antenna, as shown in the guides listed on Links#Antennae.
Directional Antennae
Cantenna
The instructions shown the websites listed on Links#Antennae were used ti build some cantennae as shown in the pictures:
Conical Feed element
Cantenna with bicycle spoke element
This File:Circular waveguide optimise.xls can be used to optimise the variables when building a cantenna.
Sectoral Antenna
A sectoral antenna provides the best of both worlds in terms of gain as well as beam-width and can be applied to many situations in mesh networking.
Turn an Omni into a Sector
The reflector designs shown, found at Freeantennas.com can be applied to a standard omni and will turn the omni into a sectoral antenna.
Metal sheeting can be used for the reflector, however, the ideal would be some sort of mesh metal, with holes smaller than 1/4 wavelength (<3cm), so that the antenna is not affected by wind as much.
.
Simulation
NEC 2 was used to generate the simulated field pattern for a cantenna with the dimensions used in our first test cantenna.
