What about evolving an antenna using a genetic algorithm
https://en.wikipedia.org/wiki/Evolved_antenna

Ryan

On Thu, 12 Jul 2018 at 08:41, Sean Breheny <shb7@cornell.edu> wrote:

> Thanks!
>
> On Wed, Jul 11, 2018 at 4:05 PM, Van Horn, David <
> david.vanhorn@backcountryaccess.com> wrote:
>
> > Very nice!
> >
> > -----Original Message-----
> > From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> On Behalf Of
> Sean
> > Breheny
> > Sent: Wednesday, July 11, 2018 1:56 PM
> > To: Microcontroller discussion list - Public. <piclist@mit.edu>
> > Subject: Re: [EE] Antenna design?
> >
> > I would recommend reading appendix A of my master's thesis :)
> >
> > https://ecommons.cornell.edu/bitstream/handle/1813/8346/
> > thesis%20formatted.pdf?sequence=3D1&isAllowed=3Dy
> >
> > It is an 11-page summary of antenna theory (that I had to include becau=
se
> > my thesis advisor was not an antenna expert)
> >
> > With an efficient passive antenna (no amplifiers and no major losses th=
at
> > you can reduce), you can't get more gain without being more directive. =
In
> > other words, if you cannot be directional, then making your antenna
> bigger
> > than a half wavelength does nothing for you. This is true for BOTH
> transmit
> > AND receive because passive antennas are reciprocal devices.
> >
> > A patch antenna is probably best for you. Any kind of linear antenna is
> > going to have a null along the long axis of the antenna. This can be a
> > problem for the case where the robot is on one floor and the operator i=
s
> on
> > another floor.
> >
> > Colinear arrays only make this worse - they direct more radiation in a
> > flat disk and have an even wider null along the long axis. They are
> > commonly used for cell towers because all of the cell phones that need =
to
> > access the tower are in a narrow range of vertical angle - radiation
> going
> > up into the sky (or listening for radiation from the sky) is a waste.
> >
> > Sean
> >
> >
> > On Wed, Jul 11, 2018 at 2:37 PM, Neil <picdude3@narwani.org> wrote:
> >
> > > Okay antenna gurus, I can use some help here please...
> > >
> > > I'm using a 5.8Ghz video transmitter/receiver system on a robot (2D
> > > driving, indoor).  These systems are popular with the drone-racing
> > > crowd, but most of the good antennas are either circular-polarized (s=
o
> > > they are uniformly effective at most angles) or patch antennas which
> > > are apparently very unidirectional.  Linear antennas have mostly gone
> > > away for this purpose.
> > >
> > > I'm trying to maximize signal strength/reception so the operator can
> > > be in a different room and on a different floor.  For my purposes, I'=
m
> > > thinking a linear antenna on the transmitter side (robot) may be best
> > > though, as I can mount it vertically in the robot body, and perhaps
> > > use a patch antenna on the receiver side as that would have minimal
> > > movement.  Or linear as well for the receiver.  I understand that whi=
p
> > > antennas are really crappy so would a straight piece of wire work
> > > better?  I also discovered "collinear antennas" while searching.
> > >
> > > I have about 18-20" of room to put an antenna vertically inside the
> > > robot ... would having an antenna length of a multiple of the
> > > wavelength work better than just a single-wavelength antenna?
> > >
> > > So what say ye?
> > >
> > > Cheers,
> > > -Neil.
> > >
> > >
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