home 
wiki
wiki
OmniAntenna
Omni Antenna have a broad propagation field, designed to be basically uniform in all directions.
In practice, this is not spherical, but often more Smarties-like, wide, but not high. The higher the gain, the flatter the Smarties.
Typical gain of omni's are in the 3dbi-15dbi range.
One common and relatively easy to construct type of omnidirectional antenna is the CoaxCollinear.
Some omni-directional Antenna plans:
Vertical Colinear from Guerrilla.net- Easy Homebrew 2.4Ghz Omni
- The Slim Jim (not 2.4Ghz)
At this stage, we have not yet seen a homebrew omni with the combination of decent gain and a suitable radiation pattern (the Smarty is tilted up rather than be level) for the >1km links we're trying to make at MW. Any results to the contrary would be much appreciated!
If you want to buy a commercial omni antenna, D-Link sells an 8dbi outdoor omni, as does
Rojone. That is, if you missed out on The Incredible Bulk purchase of a few squillion lately. Higher gain ones are available from several US vendors, but the propagation pattern starts to get kinda thin and often has quite a deal of downtilt (which is great if you're on the top of a hill, not so great otherwise). If you really need that kind of gain, maybe you should consider a YagiAntenna or ParabolicAntenna.
Version 3 (current) modified Mon, 26 Jul 2021 12:49:29 +0000 by graybeard
[EditText] [Spelling] [Current] [Raw] [Code] [Diff] [Subscribe] [VersionHistory] [Revert] [Delete] [RecentChanges]