radeng:
100 watts into a 20dB gain antenna gives 10kW ERP: however, there is only 100 watts available to heat somebody up.
That 100 watts is pulsed power, maximum of 1500 pulses per second, of about one microsecond width. 1,500/1,000,000 = 0.15% duty cycle = 0.15 watts average power. You probably generate that much electricity with your saliva.
Fearing modern radars is spitting in the wind.
GB