I've been reading over Balanis' Advanced Engineering Electromagnetics in an effort to teach myself a bit about Electromagnetism. I've stumbled across a question (not one in the book) that I can't seem to wrap my head around. If there's a lossy dielectric or medium, how does the reflection coefficient change/get effected as opposed to a lossless medium or dielectric? It's easy to determine the reflection coefficient for a lossless medium, I'm fine with that portion, but I'm having trouble understanding how to do it for a lossy medium. I've googled around, but can't seem to find an answer. As a side, but possibly unrelated note, is reflection coefficient the same as the complex propagation constant for the case of a lossy dielectric/medium? That's about all I was able to find on the topic. Hope someone can clear this up!