High power in the higher GHz frequencies? That’s literally how a microwave oven operates to cook our food from the inside out. I have even heard that 5G cell towers where they are in use now, are getting accumulations of dead birds found around them. Microwaves tend to be used as focused in one direction, compared to lower frequencies that tend to spread out and go everywhere (relatively speaking). 5 watts at 5 GHz sounds dangerous to me. 500 watts at 28 MHz, not so dangerous. Some of the AM brodcast radio antennas between 500 KHz and 1500 KHz are close to neighborhoods and transmit up to 50 KW.