Hello. I'm thinking about building a rf energy harvesting circuit and would like to know how to figure out exactly how much voltage I would get from a transmitter saying I'm using rabbit ear dipole antenna and the transmission is at 12,000 watts from sources. Is inverse square law the only way to find out, is there another way and if it's inverse square law how do I formulate this with only knowing the watts and distance from transmitter. Also where I could have caring distances from transmitter can I use zenner diodes to regulate the voltage. And where I don't burn out the zener diode should I incorporate a resistor or PNP transistor before the diode. Thanks.