Investigation on beam collection efficiency in microwave wireless power transmission.

The beam collection efficiency (BCE), which defined as the microwave power transfer efficiency between the transmitting and receiving aperture, plays a key role in the overall transmission efficiency of the microwave wireless power transmission (MWPT) system. However, due to many long distance MWPT applications are near-field microwave power transmission and transmitting antennas are not designed with optimal Gaussian aperture field distributions, widely used Friis formula and Gouban formula may result in considerably errors. This work explores evaluating the BCE using a numerical integration method that is based on the transmitting antenna’s three-dimensional (3D) radiation pattern. Furthermore to facilitate engineering applications of MWPT, a revised formula is proposed, which is based on the numerical integration results and modified from the Gaubau formula. Moreover, a MWPT system working at X band (10 GHz) is designed and its BCE under various transmission distances is measured. Through a comparative analysis, the accuracy of the proposed numerical integration method and modified formula is validated. [ABSTRACT FROM AUTHOR]