[Ham-80211] "Commodity Class Phased Array Antennas" for HSMM?

[Gerry Creager N5JXS]

While the design of the antenna element only has to be done once, its 
implementation has to be done many times, as does the interconnect.  The 
steering logic, which drives the elements in a manner to derive 
horizontal and vertical tilt, and gain, has to be designed and built. 
The phasing array or harness has to be fabricated.

The costs are not simply limited to the patch antenna design...

In the atmospheric sciences world, we'd *love* to go phased array 
antennas for weather radar: no moving parts, faster volume scans, more 
precise steering than mechanical dish controls.  At least currently, we 
don't see this happening.  The military employs them, but the prices 
still haven't come down.  The costs for the 160 or so NWS, DoD and FAA 
radars that contribute to the national network of NEXRAD wouldn't drive 
costs down enough to make it feasible to proceed, so we're waiting for 
someone else to find a reason to drive costs down.

If Kumar or Kajiya have a plan, some of us would LOVE to see it.  I'll 
look at your referenced site with some interest.

73, gerry n5jxs

David Young wrote:
> If you are interested in steerable antennas for HSMM:
> 
> P.R. Kumar at UIUC told me about a presentation Jim Kajiya gave at the
> Microsoft Mesh Summit, called "Commodity-class Phased Array Antennas".
> Kajiya estimates a $5 bill of materials for a software-steerable antenna
> manufactured from a printed circuit board, an alumina dielectric,
> and a voice coil.  I'm seeking opinions whether this is something
> that a hobbyist could build affordably.  Seems to me that the hard
> part would be to create the design for the patch antenna, but you
> only have to do it once.  Kumar seemed to think that a loudspeaker
> would serve as the voice coil.  Kajiya's presentation is listed at
> <http://research.microsoft.com/meshsummit/techprogram.aspx>.  Note that
> his inscrutable PowerPoint slides are mis-linked under the preceding
> header.  The video is 38MB huge, but well worth a look.
> 
> Dave
> 

-- 
Gerry Creager -- gerry.creager at tamu.edu
Network Engineering -- AATLT, Texas A&M University	
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