Hey Physics Forum! So I will try to give as much detail as possible and needed without dragging on. We have an RF source at 5.8 GHz producing -17dBm and we eventually amplify it close to 27dBm (so we get as close to 30dBm out of source antenna as possible). We are using 5.8 GHz slot antennas on receiving and sending end. We have a stub rectenna circuit to convert the RF into a DC which we plan to charge up an energy bank (super cap or battery) to then power a sensor bluetooth MCU. Problem with super caps: they match the source voltage which without boosting is like 20-100mV (no good for super cap -> MCU). We have looked into a ultra low voltage booster by Linear Tech but we also were considering batteries which could charge up slowly to capacity. Any recommendations on batteries or methods for banking this RF->DC? Current is on the order or 30uA so we are also worried that if we boost from mV to V that the current will just be awful. Any ideas on any of this?