I use RF-DC rectifier to power up my battery. My input power is 4 dbm and i used 6 stage rectifier using schottky diode to obtain the appropriate output voltage to match the nominal voltage of my battery but the output current is very low to charge the battery.
what should i do to increase the current in the output ??
This is not the intended usage of our low power RF power transceivers. I don't think you can't get any higher current from this unless you make the rectification stage as efficient as it can be, because the power source itself only gives 4dBm of power at best. What is the battery's voltage and power capacity? Have you tried simulating this circuit?
My battery voltage is 3.7 V and yes i simulated and it give me at the output of the RF-DC rectifier 3.7 V when i increase the charge resistor at 125 Khom but the output current is very low 0.03 mA .
Note: i use full wave rectifier with schottky diode.
By ohm's law, it seems reasonable to get 0.03mA of current. In any case, we don't have any application note or reference design to help you with RF energy harvesting using the low power RF power transceivers. It is best you contact your local FAE to assist you in your application.
The amount of Power you can get from an RF-DC rectifier is mostly depends upon the the input power. By increasing the input power, you can increase output power and hence the current keeping in mind the saturated point of diode.
But In my experience, people mostly use a boost converter like BQ25504EVM ahead of rectifier to charge the battery .