Antenna Theory (2016)
This is a great summary. I too have struggled to get decent information on the web about antenna theory and design. As it turned out, I was searching wrong :-) The keyword is 'electrodynamics' and the canonical text is "Classic Electrodynamics" by Jackson. I am told that if you can understand the contents of this book, antennas are pretty straight forward. I started in on it, got whacked upside the brain a number of times, then backed off to "Introduction to Electrodynamics" by Griffth which is the undergraduate version and does a bit more math review, which was essential in my case. My plan is that once I am through that I'll go back and re-start Jackson.The fun bit here is that if you look for computer code to simulate this stuff you will run into a lot of Fortan code. So if you ever wanted to learn Fortran this will give you some code to puzzle over.