Art

If your question is "is there any written work that pertains to how gain
and sidelobes are related", the answer is Yes. I dont know where back
issues of the IRE Proceedings can be found. But, the Proceedings of the
Professional Group on Antennas will have so much information on current
distribution on a planer array that you may not have enough time left to
read it all.
The current distribution across an antenna aperature has been studdied
very seriously.

I am not qualified to discuss phased arrays. I am convinced that max gain
will not be acheived with the same current distribution as for minimum side
lobes. I realize that you write only "back lobes". But, thats a side lobe
at that special angle
I am rather simple minded when it comes to phased arrays. I use Referance
Data For Radio Engineers as a referance book. It has alot of information on
phased arrays. I suspect all the information I have has already been
concidered by you.

Jerry


" wrote in message
news:2w_Xd.52445$Ze3.8223@attbi_s51...
O.K..O..K Seems like everybody has forgotton the basics of the polygon of
forces
and other uses of vector so I will go over the basics.
At the age of 14 yearsI entered the School of Engineering and Navigation
where they hashed things from first principles, Since I had little
schooling
during those war years it gave me an accelerated course on what I had
missed
during those schoolless years which meant a lot of homework and I had to
work like hell.
From the name of the school it was evident that I would get a quick
introduction
on vectors for forces and navigation
. This went as follows:
When you swim across a swimming pool then you can swim point to point.
If you swim across a river and tried to swim point to point you finish up
on the
other side but down, stream thus to get to the original point of the
endeavor you
must swim upstream. If you are a ship or a plane it is obvious that you
must have enought fuel
to get from point to point so this becomes very important.
Thus going back to the river swim you can draw a vector or line
that follows the path you took first to cross the river. Since you have
units such as time and distance
you can draw that line in scalar form. Then you add on to the tail end of
the line the journey upstream
again in scalar form which will be something less than a 90 degree angle.
If you then look back at the point that you started from it becomes
obvious that when you swim across stream
the angle you must follow is the angle which is shown from the beginning
of the triangle to
the point that you finished up. Next time you are on a plane look
downwards and pick up the flight pattern
of small private planes and you will see that their flight path is
different from the angle projected by the fuselage
All this is in accordance with Newton's law that 'every action has an
equal and opposite reaction.'
Now look below at my original post to what I said and you will see that I
applied a scalar drawing that consisted
of many scalae directions in the same way a sailing ship would do if it
had to keep changing
direction to get to shore. The first vector drawn for an element with
known phase and current was drawn
which happened to be a vertical line of known length. The next line was
then added at the end
to reflect the current and phase of the next element chosen and then onto
the next element chosen.
But this element presented a phase and current that was equal and opposite
to the one previously drawn
which meant that I was back to the tail end of my first vector chosen !
Thes two elements are termed destructive
In fact this happened several times
where vectors cancelled each other so we are just left with a singe vector
in our scalar drawing .This
meant to get back to the point of origin and remembering Newton's law
previously alluded to the scalar
drawing it represents a vector that is equal to the starting vector drawn,
THE SAME PHASE and same
CURRENT. Thus the polygon reflects an array where the phase is constant
but the currents are ADDITIVE
This represents the radiation pattern of a figure eight EXCEPT all the
radiation is now to one
side of the feed point and comprising of a single and larger circle.
All of this reflects exactly what I stated below except I assumed that the
pologon phase drawing was
already known to all, for which I apologise.
With NEC I constructed a model that closely followed this format though
the real world did not
make elements exactly equal but when I rehashed in my mind the basic
priciples the polygon aproach verified
that this aproach does give extraordinary front to back/rear figures that
gave rise to mistrust of the
softwear being used where you may remember that I commented on a model
that I made and where
the response was that the f/b was to high a point that had troubled me for
many a month.
Sorry for the long winded response which reflects what I have gone thru
with my postings which
apparently projected me as a total fool that gave rise to dirisive
comments.
Now I ask again, is there any written work that pertains to max gain and f
to b/rear being on the same frequency?
Best regards to all, no hard feelings
Art KB9MZ................XG




" wrote in
message news:dySVd.30807$r55.174@attbi_s52...
I have just come to realise that if one drew a polygon of element phases
in a array
and all elements were 180 degrees to its companion element and excluding
the
driven element, the max gain and max front to back will occur at the SAME
frequency!
Until now I was of the understanding that these two max figures could not
occur at
the same frequency. Is there anything written about this possibility?
Regards
Art