recieving circularly polarized wave with linearly polarized antenna

[BasketballJones]

What is the theoretic loss when recieving a circularly polarized transmission with a linearly polarized antenna? I am thinking it should be 3dB am I correct?

 

[VEBill]

3.01dB to be slightly more exact. ;-)

Of course, in the real world, so-called CP is often eliptical so it'll be plus or minus some amount anyway.