I'm trying to throw together a helix antenna, similar to one shown he
http://www.antenna-theory.com/antenn...ling/helix.php

I'm trying to get it to have circular polarization, but it deviates away from that pretty quickly away from the main beam. If my receive antenna is also circularly polarized, is there a way to estimate the polarization mismatch loss based on how skewed the polarization is? Like if its elliptically polarized, how can you figure out how much power a circularly polarized antenna would receive from this?