Re: [amsat-bb] Patch antenna behavior questions (kinda long)

[Bill Hurlock <bill@xxxxxxxxxxx>]

I tried to look at your near field animated pix's on your page but I get a 401
error page not found.

Tim Zibrat wrote:

> I have been working on a patch antenna for 2400 MHz.  I have one simulated
> using Ansoft Ensemble SV and I'm pretty sure I have a winner, but I am
> unsure of a few things.  I figure some of you antenna gurus can help me out.
>
> 1. To obtain circular polarization, I've been told that an Axial Ratio as
> close to 1 as possible is most desirable.  My latest design achieves this.
> When I plot the Near E-Field, and animate it through a phase offset of
> 0-360º, it sure looks like LHCP to me.  My question is, what is the desired
> Near H-Field behavior?  I have also plotted this parameter and I'm not sure
> what I am supposed to get.
>
> 2. I've also plotted the Current vectors through a phase offset of 0-360º
> and it too looks like LHCP to me.  This sounds right to me but confirmation
> from someone who knows would be appreciated.
>
> 3. The program plots what they call a Scattering Matrix.  I was told this
> has to do with the S-parameters.  However, I don't see a way to separate out
> S11, S12, etc.  What I get is a plot of Scattering Matrix magnitude in dB,
> which shows that at the design frequency of 2.4 GHz, the plot lies
> around -10.5 dB.  Is this good or bad?  I do have a choice to plot
> magnitude, phase, real and imaginary parameters.  Does this correspond to
> S11, S12, S21, S22?
>
> 4. There is a lot of reference to Phi and Theta.  What do these correspond
> to?  I plotted the Magnitude of the Real E-Field (V) vs. Theta in polar
> coordinates and it looks to me like a beamwidth plot (which is what I'm
> after).  I don't think that is what it is however.
>
> I know, so many questions....  any help would be appreciated.  Anybody know
> of some good reference materials that you don't have to have a Ph.D. to
> understand?
>
> If you need to see some pictures of the plots I'm talking about, jump on
> over to my website at:
> http://home.adelphia.net/~tzibrat/2400mhzpatch/patch1.html
>
> It seems to change everyday!
>
> Thanks in advance!!!
>
> Regards,
> K3TZ
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org