Re: circuit design help
I did not mean offense.
If you build a simple crystal set receiver, tune it to the nearest strongest station you can find and measure the diode current you will find it is only one or two µA and the voltage is only a few µV. The station is probably transmitting a few kilowatts. The amount transferred to the antenna is very, very, very small and not usable as a power source for other equipment.
Where high power IS intentionally transferred wirelessly, the transmitting antenna is specially shaped to concentrate the power in a small confined area and the range is usually no more than a few cm.
Brian.