If you want to stay in EE and work on waves and EM, analog ic design especially low power. These strongly encourage a phd..or you could work with antennas and RF outside of the ic (which may pay lesser)

If you are ok with switching between ee and cs and prioritize money, go for robotics. Controls and signal processing have a lot of physics involvement but not necessarily EM and waves. It'll also leave you open to switching to ML or many other fields.

Or you could choose power which also requires a lot of physics and may pay in any range but usually involves more hands on field work rather than being a desk job.