The RFD-ASSY-01 is a broadband Microwave Energy Harvesting reference design that uses four RFD102A’s (RF-DC converters) and one RFD88A (energy harvesting engine) to deliver higher current to your application. The design can be connected to a log periodic antenna and is able to convert RF/microwave power from 1MHz…6GHz to a DC voltage for use with medium power battery free applications. The design is extremely flexible with header holes for soldering supercaps directly to the circuit board. This design delivers up to 60mA DC from the unregulated DCIN pin and delivers up to 140mA intermittent current on the regulated DCOUT output pin. The default output voltage range is from 5.2V down to 1.0V for a single discharge cycle. By using a jumper on the PCB users may select either 3.0V…1.0V or 2.5V…1.0V ranges for the discharge range. Once 1.0V is reached the DCOUT pin will be switched off and the capacitor will recharge. Additional voltage regulation may be needed.
This design is a great starting point for electromagnetic energy harvesting projects when used with a log periodic or high directivity antenna and a known microwave energy source. When compared to the RFD102A-TB, the RFD-ASSY-01 needs approximately 4x more input power to achieve the same output voltage. However, the RFD-ASSY-01 can produce up to 4x the current at similar RF-DC conversion efficiencies (~40% from 18dBm…30dBm).
Jumpers (not included) are used to set the upper DC voltage out of the design. In the default state the upper output voltage is limited to 5.2V. The upper output voltage can be reduced to be 3.0V by grounding header pin 5 to pin 4. The upper output voltage can be reduced to 2.5V by grounding pin 3 to pin 4. The design will shut off its output pin once the supercapacitor has discharged to 1.0V and it will recharge again until the upper voltage is reached.Please view our datasheet: RFD-ASSY-01_latest