Regarding the EPC9065 development board, I need to know the load range impedance requirements to obtain a good result on the EPC9065 development board. When I connect my experimental setup to 6.78MHz, I get a low efficiency at a 4 cm transfer distance and I’d like to enhance my results. Also, I would like to know if the weather in my country is 50 C. Could I use the board for few hours, or it is harmful to the board.
More details on voltages, currents or power requirements are needed to optimize the performance. For instance, if the design is operating at 10% load, efficiency is typically low. One note on the coil design: it looks like you are attributing low efficiency to the amplifier but in WiPo systems the coil is an integral and critical component. Coil inductance, tuning schematic, coupling factor, rectifier, load range need to be comprehended. The board can operate in 50°C as long as none of the components exceed rated max. temperatures during operation; use an IR camera to verify operating temperatures.