802.11b Wireless LAN Web Page
VERY CHEAP CO-LINEAR ANTENNA
Don't have an antenna for your 802.11b wireless LAN equipment yet. Can't afford
to spend $80 on a 8dbi commercial antenna. Well build this 6dbi Co-linear antenna
for the cost of a piece of wire and a connector !
802.11 REVERSE SMA CONNECTORS
HOME MADE 2GHz VSWR METER
Many Wireless LAN experimenters want to build their own
antennas as some of the commercial units are quite expensive. The commercial
antennas are often very simple in design, they just have a nice pretty casing.
Building antennas is very easy, but you really need some way of testing your
home made antenna and one of the best ways of doing this is measuring its
"return loss". Return loss gives you an idea how efficient your antenna is. It
assumes that what ever power is not transmitted into the air is sent back down
the coax to the transmitter. The more reflected power the worse the antenna. To
measure the reflected power we use a thing called a "reflectometer" or a VSWR
meter as it is commonly known. (SWR Meter to CBer's). This is an article on how
to build a VSWR meter for 2GHz.
HOW TO MAKE A PANEL ANTENNA
I have noticed many panel antennas for sale on the net
and people are paying good money for them too. I have worked with these sorts of
antennas commercially and they are very simple in their design. There are many
variations on the theme, but the basics of panel antennas is that they are all
just "Phased Arrays" of Dipole antennas. A very good example of a phased array
can be seen as UHF TV antennas. This article is how to make your very own panel
antenna with just a few pieces of plastic, metal and circuit board.
A QUICK PRIMER ON MAKING PRINTED CIRCUIT BOARDS
Rather than make you search around the net for information on how to etch printed circuit boards. I have
included a short primer on this web page. Circuit boards are ideal for making
antennas especially at low microwave frequencies. I know of so many designs that
it will take me quite a while to create a page for each one.
THE IDIOT TOLLERANT "LOOP YAGI" ANTENNA
This is an antenna that is relatively easy to build and most importantly is wide bandwidth which helps make
it idiot proof. Dipole yagis have the nasty characteristic at high frequencies
of narrow bandwidth. This makes them difficult to build. Ham radio operators
have been using loop yagis on 1.2GHz for many years and making them for 2.4GHz
is just as easy.
FIELD STRENGTH METER
A useful project that you can build in minutes with parts available from your local
electronics shop. You can skimp a few dollars and use cheap parts in this project or
go all the way using high quality meters and die cast boxes. With a little bit of added
circuitry this meter can be made very sensitive and with some fancy features you'll
be the envy of most ham radio operators.
1/4 WAVE TEST ANTENNA
This antenna is extremely easy to build. It will serve well as a basic indoor omni-directional antenna,
but is designed to be a test antenna. The antenna is pictured on the right hand side and is made from
a piece of semi rigid coax. The dimensions are shown. The ground plane is a piece of copper or brass sheet
metal, but may be replaced by radial wires instead. The plot is the RELECTION LOSS, or the VSWR.
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