RE: [amsat-bb] patch antenna round or square?

["Frederick M. Spinner" <fspinner@xxxxxxxxxxx>]

It can be either, but I've had better results with round patches for 
circular polarization (and square ones for other ham uses that are linear- 
as they are easier to build if you don't need CP).  For AO-40 and 
prime-focus dishes no one has yet to beat a G3RUH or a W0LMD design for 
efficiency.  If you are using an offset-fed reflector, I'd look into a helix 
as a feed.  Remember in any case the feed has to be LHCP so after it's 
reflected off the dish surface it's RHCP.

See http://www.ultimatecharger.com/dish.html for the W0LMD 
reverse-engineered design and check the amsat-bb archives for my 
modifications to improve the tuning and CP of W0LMD's design.

Fred



>From: "gerald horn" <k6txd@AMSAT.Org>
>Reply-To: k6txd@AMSAT.Org
>To: "amsat-bb" <amsat-bb@AMSAT.Org>
>Subject: [amsat-bb] patch antenna round or square?
>Date: Mon, 19 Jan 2004 19:06:55 -0800
>
>Hello all
>
>I am going to make a patch antenna for my dish antenna.  I wonder does the
>reflector need to be round can it be square??
>
>
>Gerald Horn K6TXD
>ghorn666@earthlink.net
>AMSAT member
>----
>Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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