Bart,

Can you send me a photo or two of the internals of one of these sector antennas? I’ve done some work with 2.4 but not 5.8. I’m curious to know if they are flat panels or if they are contoured (rounded or otherwise shaped).

I’m thinking along the lines of your sheet metal shields. Depending on the internal design, I’m wondering if we can’t apply some different approaches here.

The potential downside of a sheet metal shield is parasitic reflections, unless they are spaced such that they enhance the signal (ala a reflector) as well as shield from adjacent RF.

Using it as a reflector then gets me thinking of applying some other geometries – how about a yagi or log periodic design for 5.8? Given the frequencies involved, it likely would fit into a similar footprint.

I need to do some calcs and brainstorming. There’s definitely advantages to having off the shelf equipment, and if possible it would be good to launch with standard items if they work, but there may be longer-term advantages to using some of the benefits of our “amateur” roots if we can get them to be stable and reliable.

Cheers,

Rob

From: PSDR [mailto:psdr-bounces@hamwan.org] On Behalf Of Bart Kus
Sent: Wednesday, February 06, 2013 9:45 PM
To: psdr@hamwan.org
Subject: [HamWAN PSDR] Improved radiation pattern software and new antennas on the way

Hello,

I've taken some time tonight to improve the radiation pattern measurement software. The algorithm for auto-centering the rotation of the pattern won't be fooled now by the presence of a non-centered peak lobe. Full description of the software function and the software itself have both been published to the Antenna Analysis labs page. The radiation pattern for the Laid sector has been updated and you can see the wonky alignment is now gone!

Since neither of these antennas are thrilling performers in the HamWAN Labs tests, a couple more candidates have been added to the Sector Antenna - 120deg component engineering page. A HamWAN community member who wishes to remain anonymous has generously purchased sample antennas of the Teletronics and RF Elements brands for lab testing. They should arrive some time next week.

In the meantime, I've had a thought about how to improve F/B ratios in these sector antennas. Using a sheet of aluminum and my sheet metal brake, I should be able to manufacture traditional RF shields, like this:

VARIA
14-19dBi
variable sector antenna 45-120°, 2.4-2.5GHz

but without fancy holes or adjustable features. It might be enough to keep that nasty high power adjacent RF out.

--Bart