# How to change the direction(theta and phi) of the main beam of Circular Array antenna?

I'm working on the tutorials on Phased Array Antenna(Rectangular). After I finished, I changed the shape type to the circular one(because of my research).
I wanted to change the beam direction like θ=30°,Φ=45°, but I couldn't. I thought the way to do it was to set up the each phase of the elements(in my case, there are 8 elements), but it wasn't.
Does its phase mean "phase difference when excitation is applied", right?

My question is,

1. Is there any way to change the beam direction?
2. What will happen when I change the phase?
For example, I set up each phase to 0° at first. And I rotated by 30° at each elements in the next Analysis.
As a result, although the shape of the beam had changed, the direction hadn't changed. Why?

Thank you!

@rose in first approximation, the beam direction is given by the product of the radiation pattern of a single element and the "array factor" of the antenna. The array factor depends only on the relative positions of the antenna elements and on excitation applied at each element (usually only the phase).
I would suggest you read about phased-array antennas and understand how the "array factor" `AF(theta, phi)` is calculated for different array geometries (starting from a linear array, then a rectangular array, then a circular array). There are plenty of books/articles on the subject.

I hope this helps