RadioBanter - View Single Post

May 7th 06, 03:01 PM posted to rec.radio.amateur.antenna

On Tue, 02 May 2006 06:35:50 -0700, wrote:

Hi Group,

D-link has a vertical antenna for WiFi applications which is about a
foot long and operates at 2.4 GHz with a stated 7dbi gain.

Since the antenna is a vertical, I thought that the best low-angle
radiation is 5/8 wave for verticals, anything longer would put the
lobes higher and would result in a lower low angle gain.

If this is the case then the antenna should only be about 3.5 inches
long. ?

I am going to check, but I bet the true antenna is only about this
lenght and the rest of the lenght is the plastic, so the appeal is
bigger is better.

Any thoughts on this?

I suspect that antenna is a collinear antenna with elevated Feed.
Probably 1/2 of the of the antenna or more is simply transmission line.
They want the active elements be to in "Free Space" above any surrounding
equipment.
Its amazing what people will do with electronics and wonder why it does
not perform as advertised.

KD