I have a linear horizontally polarized transmitting antenna and a dipole antenna, polarization mismatch losses can be approximated by 20log(cos(x)) where x is the misalignment angle.
What is happening inside the receiving antenna that causes the losses?
My explanation would be the following: the electric field component of the electromagnetic wave causes the free charges inside the receiving antenna to move across it's length (the length of the receiving antenna) inducing a voltage across it. The direction of the electric field is important here because as we misalign the antenna, the free charges move along a different path, with 90° being the worst case as the electrons only move across the diameter of the dipole.
Is this the correct way to think about it?