Whoever designed that is an idiot.
In the first place, to expect 0.58V from the antenna is unrealistic unless you place it directly underneath a high power transmitter antenna, normal ambient RF radiation only produces microvolts of output. Then to put it through many stages of voltage multiplication, each losing about 0.5V means nothing would reach the output anyway. I guess it was designed by someone who imagines the RF power levels around us are massively greater than they actually are and that the power comes from nowhere in the first place. If you want it to work, place it directly underneath your local radio stations antenna. Of course you could just plug into their electricity supply and extract thousands if not millions of times more power for none of the cost!
Brian.