Evaluation of superconducting coil for microwave power transmission

We suggest a microwave power transmission using a superconductor in order to realize long distance and high efficiency transmission systems. In this paper, superconducting coils for the microwave power transmission are discussed at 12.5 GHz. These coils consist of thin Nb films deposited by magnetron sputtering. The film is confirmed that it is suitable for the power transmission coils. An attenuation constant of a transmission line is compared with superconductive and normal conductive states by electromagnetic simulator. The superconductive transmission line has almost zero loss. By considering Q-factors and radiation patterns of three coils, it is revealed that a winding coil is most suitable for the MPT in this research. Therefore, transmission efficiency of the winding coil is evaluated. Power transmission using the winding coil can transfer 92 % power at 12.5 GHz in 50 mm distance.