[Cu-wireless] Major breakthroughs on the antenna theory front

niteshad at whopper.de niteshad at whopper.de
Fri May 17 15:51:18 CDT 2002

	After months of struggling to find the proper sources, I believe that I
now have in hand the requisite mathematical treatments that will lead to a
proper theory of operation for the Vertical Collinear Array omnidirectional
antenna (henceforth, VCL).  For those of you who attended the last CU-wireless
meeting, the omnidirectional antenna which Dave Young passed around was a
5dB VCL.  As Dave has noted in posts to the list, this antenna design was
presented with absolutely no theory as to how it generated its gain.  The other
VCL presented on guerrilla.net, a 10dB VCL constructed from LMR-400 co-ax
and brass tubing, contained a theory section, which unfortunately, was so
filled with errors as to render it useless (the theory, not necessarily the
	However, in my literature search last night, I ran across another
omnidirectional microwave antenna design which appears to be far superior to the
VCL: the slotted wave-guide antenna (henceforth SWG).  Even professionally
constructed VCLs are typically limited to gains in the 10-15dBi range; to
achieve these gains, the arrays are typically on the order of two meters tall. 
In contrast, the SWG design that I found (which was designed by an electrical
engineer, as opposed to those two gray-hat hackers on guerrilla.net) is
designed for gains in the range of 15-17.5 dBi; in real world testing the SWG
omni outperformed a 19.1 dBi commercial grade dish!  Basically, the SWG is an
_omnidirectional_ antenna which far surpasses the range and performance of
the directional Pringles Can Yagi. of teh 

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