Software defined antenna


#1

Hi all,

After being on-frequency here for a little while I can see that the
range of experience/expertise is wide. Which is great.

I’m curious if any long-timers have begun to look at software defined
antennas? Or is there any effort at all anywhere in the public domain?
I guess military and universities don’t really count for public as much
as they once did, but I’d guess they’re working toward SDA also.


#2

rhubbell wrote:

Hi all,

After being on-frequency here for a little while I can see that the
range of experience/expertise is wide. Which is great.

I’m curious if any long-timers have begun to look at software defined
antennas? Or is there any effort at all anywhere in the public domain?
I guess military and universities don’t really count for public as much
as they once did, but I’d guess they’re working toward SDA also.

I’m not sure just what you mean by “software defined antenna” but Vic
Kean, K1LT, has been using an array of short vertical antennas fed to
multiple ADCs and phased in software to receive on the 160M amateur
band. I don’t have URLs handy, but I know he’s made some postings about
his work. Searching for “K1LT” and “SDR” would be a good start.

John


#3

On Fri, Oct 10, 2008 at 4:20 PM, John Ackermann N8UR removed_email_address@domain.invalid
wrote:

as they once did, but I’d guess they’re working toward SDA also.

I could see a software controlled antennae, using software to control
reed
switches and servos, but not a strictly software defined antennae, more
like
a robotic antennae that could be populated with standard or predefined
settings for the antennae configuration, as well as manual control.

I have a software controlled wifi antennae on my chimney, the software
just
controls a servo for direction.

I have this guy, which kicks butt and has come down in price quite a bit
http://cgi.ebay.com/WiFi-USB-24-dBi-YAGI-ANTENNA-2-4GHz-ULTRA-LONG-RANGE_W0QQitemZ270284630828QQihZ017QQcategoryZ86720QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Haven’t used it in ice/snow but i assume that will be a problem and
require
some kind of covering to keep the elements that stick off, jerking the
servo
takes care of water build up from rain that can and does degrade wifi
signals.


#4

On Saturday 11 October 2008 09:14:48 Steve T. wrote:

as they once did, but I’d guess they’re working toward SDA also.
switches and servos, but not a strictly software defined antennae, more

Haven’t used it in ice/snow but i assume that will be a problem and require
some kind of covering to keep the elements that stick off, jerking the
servo takes care of water build up from rain that can and does degrade wifi
signals.

Systems such as an over-the-horizon radar, such as the Jindalee project
in
Australia, are possibly as close as it gets to be a SDA. It involves a
little
more than just an antenna rotator controller…

73, Berndt
VK5ABN


#5

On Fri, 2008-10-10 at 16:20 -0400, John Ackermann N8UR wrote:

I’m not sure just what you mean by “software defined antenna” but Vic

An antenna defined by software.
Apparently it’s known as beam-forming. But I don’t know much about it.

Kean, K1LT, has been using an array of short vertical antennas fed to
multiple ADCs and phased in software to receive on the 160M amateur
band. I don’t have URLs handy, but I know he’s made some postings about
his work. Searching for “K1LT” and “SDR” would be a good start.

Thanks will have a look.


#6

beam-forming

They are also called ‘smart antennas’.

Basically (very basically) you adjust the gain on different elements
of an antenna which changes the beam properties (gain and width) of
the overall array.

Try here as a starting point: http://en.wikipedia.org/wiki/Smart_antenna


#7

On Sat, 2008-10-11 at 11:08 +1030, Berndt Josef W. wrote:

I guess military and universities don’t really count for public as much
I could see a software controlled antennae, using software to control reed
Item

Haven’t used it in ice/snow but i assume that will be a problem and require
some kind of covering to keep the elements that stick off, jerking the
servo takes care of water build up from rain that can and does degrade wifi
signals.

Systems such as an over-the-horizon radar, such as the Jindalee project in
Australia, are possibly as close as it gets to be a SDA. It involves a little

That sounds interesting. Will have a look.

more than just an antenna rotator controller…

Right, not antenna position control.