Probably no need to get too involved in electromagnetic wave stuff/hardcore microwave for RFIC circuits at <5GHz. So and analogue IC background is good, as is Tom Lee's book. I would also recommend Razavi's RF microelectronics.
It is though very useful to have at least an undergraduate understanding of em waves (transmission lines, standing waves etc.) and of scattering parameters (s parameters) for effectcive practical RFIC design. For LNA/PA design its more important to be familiar with matching (conjugate, noise, noise gain circles, stability criteron, Gain (stable, available etc) which is best understood using s-parameters. Idon;t know Pozar, but recommend Chris Bowick's RF Design as a gentle intro to s-parameters and matching, before tackling more indepth microwave engineering books.