Beam shaping

[parinaz_h]

hello
I want to design an antenna array with phase only chang on elements.
first I consider the desired patern and next with the ifft-synthesis, I want to calculate each elements phase, but if I have the absolute of pattern the result of ifft is numbers whit phase and amplitude change for each element,
This is not accurate becuse I need phase chang only for my array.
how can I calculate elements phases whith ifft to have phase only change in result?
Thanks in advance

 

[Georgy.Moshkin]

I did not try this method, but from my understanding in this iterative method you must do fft after ifft, update amplitude coefficients and continue with next ifft iteration.
Take a look at this paper: https://jpier.org/PIERM/pierm43/15.15072504.pdf
page 4, step 4: "Compute the updated excitation E0 for the adapted AF by using the K×K−pointdirect FFT. Extract the amplitude A and phase P of E0 by ...", and in step 5 you can set all amplitudes to 1.0, and repeat steps 2-5

 

[vfone]

If you know the array antenna pattern, the array shape and number of elements, doing ifft you can calculate the phase of each element., but not the amplitude. Shaping the amplitude of the elements is done mainly for reducing grating lobes, operation which will change also the main beam shape.
I think that to calculate the amplitude of each element you need to have calibration information of that array antenna.