How to test BSA pattern with +45/-45deg X-POL dipoles

guys,

I want test the Horizontal and Vertical 3dB beamwidth of a BSA with +45/-45deg X-POL. There are 2 ways: 1)DUT is rotated 45deg 2)source antenna is rotated 45deg.Which is right? I hope get your suggestion.

Thanks!
XuQing

Either antenna can be rotated around the axis to generate the same pattern, with advantages and disadvantages.
This document may help getting the answer for a particular application.
http://www.ets-lindgren.com/manuals/768CE.pdf

That's a good paper.
If source antenna is rotated 45deg to suit BSA which placed vertically, and test horizontal pattern. The POL direction will cross with source antenna's POL when BSA rotate 180deg in horizontal plane.
So the right way must be rotating BSA +45deg/-45deg, and the source antenna keep vertical POL, when test horizontal pattern.

Thanks a lot!
XuQing

Anyone can give me some advice?

Thanks!
XuQing