I can't control the beam direction of circular array antenna

[rose]

I'm working on array antenna. When I use Rectangular, it's easy to control the beam direction because there is Scan Angle X and Y available on properties tab. But, there wasn't when I use Circular. There was only Phase Shift and I don't know how to deal with it.

I know the formula to calculate the Array Factor of circular array.

I would like to know how to control the beam direction and also what Phase Shift mean on the Array factor formula. There is theta and phi, so I got really confused with Phase Shift.

Thank you.