On 7/16/2011 5:50 PM, Jeff Liebermann wrote:
On Sat, 16 Jul 2011 12:43:16 -0500, wrote:


Hi Jeff,
Why didn't the loop sizes shrink, when the author went from 1296Mhz
to 2400Mhz. First thing I thought about was etching it on a PCB.
But then saw he built the higher freq antenna with the same loop
lengths.
Mikek

I'm not quite sure what you mean. However, I have a guess(tm).

His curtain quad calculations and NEC2 deck are at:
http://home.comcast.net/~ross_anderson/CurtainQuadFigure11.htm

If you scroll down to the bottom of the NEC deck, you'll find the
line:
FR 0 1 0 0 1332 0 'simulation is at 1332 MHz
That's the operating frequency. Change it to 2442 MHz and you have a
2.4GHz antenna.

The element dimensions in the NEC deck are in wavelengths. This makes
it very easy to use a design on different frequency. In order to
obtain construction lengths, simply multiply each element length by
the free space wavelegth. For 2.4GHz, that's about 12.5cm.

Ah.. I'm still confused, For the 1296 antenna he used 2" x 3" fence
material and then the same 2" x 3" for the 2.4Ghz antenna except for
wire diameter.
Mikek