https://5ghub.us/5g-transmit-power-and-antenna-radiation/
With (real) 5G there is a need for multiple antennas because of MIMO and much shorter range where only one was needed before, so maybe that's what you refer to?
Can you add more context to this? The most I've been able to push through a mobile antenna (HF) is 5000 watts. Finding mobile antennas rated for more than 5kw is challenging.