How many carriers for phased array?

[sophiecentaur]

as far as the angular range to operate is concerned, the desirable limit would be 5 degrees,

What do you mean by this statement? How does this relate to the situation?

 

[Esquilo]

What do you mean by this statement? How does this relate to the situation?

I mean it would be desirable to have a very collimated and directional beam with the same directionality as a laser, but with that wavelength it would be difficult, that was just my guess

 

[Esquilo]

@sophiecentaur So, what antenna size is best for my purpose? I'm just missing this information, but I can't seem to find the right path. I believe the half-wave antenna will provide more stability, but I'm looking for your opinion, which is much more valuable.

 

[sophiecentaur]

@sophiecentaur So, what antenna size is best for my purpose? I'm just missing this information, but I can't seem to find the right path. I believe the half-wave antenna will provide more stability, but I'm looking for your opinion, which is much more valuable.

You haven't stated your "purpose" so there is no answer. Are you aware of the theory that applies to multiple element antennae?

I mean it would be desirable to have a very collimated and directional beam with the same directionality as a laser,

This is nonsense in the context of a small array and the RF frequency you propose. Are you aware of the formula for the limiting width of a beam, given the wavelength and aperture of the array? I think some homework is called for. There's no point in my telling you about this; you have to do some searching about multi-element arrays. Google is full of that information and you need to have an idea about it if you plan to have a working system.
I suspect you may be in the world of simulation and not the practical world

 

[Esquilo]

@sophiecentaur yes yes I already knew that the focal point of the array depends on the aperture of the array itself and on the wavelength, and I did the calculations for near field focusing and the Frasnel distance is around 50 and 70 cm away, but I don't understand what this has to do with the choice of the size of the antenna, whether half wave or quarter wave, yes I am a beginner and I study every topic that I don't know, but since I am a beginner I am here asking questions, if I knew everything I wouldn't be here.

 

[renormalize]

but I don't understand what this has to do with the choice of the size of the antenna, whether half wave or quarter wave, yes I am a beginner and I study every topic that I don't know, but since I am a beginner I am here asking questions, if I knew everything I wouldn't be here.

Perhaps you can gain intuition regarding the kind of beams that can be formed from a phased array of antennas by playing with on-line calculators. For example, here's one that allows you to adjust the number of antenna elements, their spacing and relative phase shifts:
https://www.desmos.com/calculator/ ahcf6sjs7z

Here's another that lets you choose the specific type of the individual antennas:
https://antennaarraycalculator.blogspot.com/p/calculator.html

But do bear in mind that these calculators model a linear (1D) $n$-element array of antennas. If you desire a beam that is narrow in both transverse directions, you require a 2D rectangular array of $n^2$ elements. That amounts to 100 antennas for the second case above and a whopping 324 in the first!

 

[Esquilo]

@renormalize yes, to have 5 degrees like lasers, I would need arrays with sides of many meters and therefore with many antennas also considering the frequency, but no, as already said, I will operate in the non-radiative near field (Fresnel) and therefore with the waves not yet propagating, therefore in near field focusing, as already said the distance is about 50 or even less, however, the fact of using a rectangular array rather than a square one I did not know, I will have to find out more, the spacing between the antennas will still be half a wavelength, but returning to my original question and that is what size to choose for the antennas, I believe that the half-wavelength solution is the most suitable choice because having ground planes with quarter-wavelengths distorts the lines, do you agree too??

 

[sophiecentaur]

I will operate in the non-radiative near field

When you say "operate", are you trying to do Direction Finding or position finding? I have asked several times about the actual application because this could be very relevant. There is a long history of working navigation system designs - so called Hyperbolic systems which use phase / timing difference between the reception of two transmissions from different directions to produce a locus of possible positions (on a hyperbola). Adding a third transmitter source will locate position at the intersection of two hyperbola. If you haven't considered this and if the dimensions of your system are suitable (actual distances and available aperture) then it could be worth while researching the basics of the Decca Navigator system.

All this is far more relevant than the choice of radiating elements so it needs to be decided upon and stated first. Look carefully in the above post from @renormalize. The overall pattern that's quoted is for omnidrectional elements; the direction and width of the 'main beam' is largely independent of the element pattern. Have you taken that on board?