RF Voltage Multiplier
You must have enough voltage to overcome the forward drop of the diodes. (ignoring the reality of lots of capacitance at 2.4GHz)

Diode drop is not much when you start with 500V, which is the CW case, but not if you start with 100mV.

There are plenty of ways of transforming any DC voltage, from mV, up to 3V.

So you want to get your RF impedance as high as possible, so the voltage will as high as you can get. Then rectify with a Schottky or point-contact diode.

Folded dipoles have a high impedance, maybe 200ohm, so might be a good place to start.