How 2 build Sector Antenna?

Can any one help me to find information on building an Sector antenna
for 2.4GHz of following working parameters: Above 15dbm ; min 80
degree horizontal coverage ; min 70 degree virtical coverage.

I searched on internet on above a dozen search engines but i got none
designs for Sector Antenna, i still wonder y? Though there are many
for yagi, omni, parabolic etc.

"Jack" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Can any one help me to find information on building an Sector antenna
> for 2.4GHz of following working parameters: Above 15dbm ; min 80
> degree horizontal coverage ; min 70 degree virtical coverage.
>

The antenna you're describing is not possible. The maximum theoretical gain
for an antenna with that beamwidth is nowhere near 15 dBm. The wider the
angle of coverage, the lower the gain figure. Most sector antennas have a
very narrow vertical beamwidth. That's how they achieve higher gain and
that's also the reason you see them in clusters on cell sites, pointed
slightly down.


> I searched on internet on above a dozen search engines but i got none
> designs for Sector Antenna, i still wonder y? Though there are many
> for yagi, omni, parabolic etc.

This is because the mechanical tolerances of sector antennas is beyond the
capability of most home-brew antenna builders. Most sector antennas are
slotted waveguide designs and the slots are usually machined to extremely
close tolerance.

Try here:
http://www.trevormarshall.com/waveguides.htm

Saying that its impossible to have a sector antenna of 15db is not
true. You can follow the following URL to see
(http://www.hyperlinktech.com/web/ant...out_sector.php) from
15 to 20dbi antennas of 90 to 180 degrees.

Now anyone can say how to build sector antenna of 90 degrees beam and
15 or 17dbi power.

"Jack" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Saying that its impossible to have a sector antenna of 15db is not
> true. You can follow the following URL to see
> (http://www.hyperlinktech.com/web/ant...out_sector.php) from
> 15 to 20dbi antennas of 90 to 180 degrees.
>
> Now anyone can say how to build sector antenna of 90 degrees beam and
> 15 or 17dbi power.

I didn't say a 15 dBi sector antenna is impossible. I wrote "The antenna
you're describing is not possible." The antenna you described was:
"Above 15dbm ; min 80 degree horizontal coverage ; min 70 degree virtical
coverage"

Read on in the hyperlinktech page and tell me if you find any antenna with
such broad coverage with "Above 15dbm". FYI, the HG2415P-180 has only a 10
degree vertical angle. You specified 70 degrees, that's 7 times the
coverage area which knocks almost 4 dBi off the antenna gain.

Note that I also wrote:
"The wider the angle of coverage, the lower the gain figure. Most sector
antennas have a very narrow vertical beamwidth. That's how they achieve
higher gain and that's also the reason you see them in clusters on cell
sites, pointed slightly down."

The antenna you initially described is not possible.

Don W.

"Don W." <dNOSPAMwiddersAThotmail.com> wrote in message
news:NOOcnY5HL4d7IOCiXTWc-(E-Mail Removed)...
> "Jack" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed) om...
> > Saying that its impossible to have a sector antenna of 15db is not
> > true. You can follow the following URL to see
> > (http://www.hyperlinktech.com/web/ant...out_sector.php) from
> > 15 to 20dbi antennas of 90 to 180 degrees.
> >
> > Now anyone can say how to build sector antenna of 90 degrees beam and
> > 15 or 17dbi power.
>
> I didn't say a 15 dBi sector antenna is impossible. I wrote "The antenna
> you're describing is not possible." The antenna you described was:
> "Above 15dbm ; min 80 degree horizontal coverage ; min 70 degree virtical
> coverage"
>
> Read on in the hyperlinktech page and tell me if you find any antenna with
> such broad coverage with "Above 15dbm". FYI, the HG2415P-180 has only a
10
> degree vertical angle. You specified 70 degrees, that's 7 times the
> coverage area which knocks almost 4 dBi off the antenna gain.
>
> Note that I also wrote:
> "The wider the angle of coverage, the lower the gain figure. Most sector
> antennas have a very narrow vertical beamwidth. That's how they achieve
> higher gain and that's also the reason you see them in clusters on cell
> sites, pointed slightly down."
>
> The antenna you initially described is not possible.
>
> Don W.
>

It appears I made two errors that almost cancel each other. In the end your
description is still an impossible antenna.

First, I wrote that the HG2415P-180 has only a 10 degree vertical angle.
The vertical beamwidth is actually + or - 10 degrees, so it has a 20 degree
beamwidth. I went on to say that one seventh the gain is minus 4 dB. One
seventh the gain is really close to minus 6 dB, but I should have said that
70 degrees represents a 71.4% increase in coverage area over the HG2415P-180
and a reduction in gain of .286 times or a gain decrease of almost 5.5 dB.

You also specified 80 degrees horizontal coverage and the HG2415P-180 has
180 degree coverage, so this will increase the gain of your antenna by a
factor of 2.25 or 3.5 dB, so your antenna ends up at about 15 - 5.5 + 3.5 =
13 dBi which is about a 58% decrease in gain from the HG2415P-180. So using
the same efficiency factor as the HG2415P-180, your specs render a 13 dBi
antenna. I'm not saying the efficiency of the HG2415P-180 cannot be
improved upon, but I don't believe an additional 2 dBi (58%) improvement in
efficiency is possible.

Don W.