Hello. Thank you for presenting such an interesting work. I understand that the work is mainly related to beam-forming using RF antennas, but I think you plan to use it for wireless power transfer in the future. Can you please tell me how much is the general efficiency of power transfer in case of transmitting it through RF waves? Thank you once again.
Thank you for your interest in my research!
There are various measurement standards for the efficiency of wireless power transmission using RF signals. Among them, I will answer the efficiency using the ratio of transmit power to received power. In general, in RF wireless power transmission system, transmission efficiency is most affected by transmission distance. Additionally, the gain of the transmitting/receiving antenna, the method of combining the power received from multiple antennas (DC power combining, RF power combining, etc.), and the conversion efficiency of the RF-DC rectifier also affect the overall power transmission efficiency. Therefore, it is difficult to determine a general number because the transmission efficiency varies greatly depending on the system design and operating environments. However, to give one example, considering the 2.45GHz frequency, a distance of 4m, the transmit power of 36dBm, the transmit antenna gain of 23dB, the receive antenna gain of 20dB, RF-DC rectification efficiency of 70%, and DC-DC conversion efficiency of 90%, this can achieve a power transmission efficiency of about 5%.
