Request and Roadmap for Microwave Power Transmission System of Space Solar Power System (SSPS)

Paper number

IAC-05-C3.2.08

Author

Dr. Naoki Shinohara, Kyoto University, Japan

Coauthor

Mr. Yasumasa Hisada, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Masahiro Mori, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

JAXA SSPS WG4 Team, Japan Aerospace Exploration Agency (JAXA), Japan

Year

2005

Abstract

A microwave power transmission (MPT) Systems which is a key component for the Space Solar Power System (SSPS) will be required for higher DC-RF conversion efficiency with higher accurate phased array than satellite systems, and had ever been operated like SAR, Geographical explorer and communication etc. There were some previous MPT experiments, but not enough to reach the SSPS technologies. For example, one of the experiments were focused only on raising conversion efficiency of the high power DC-RF-DC electric systems, and the others were focused on microwave beam control technologies by means of retro-directive methods with electrical phase control of phased array antenna, one of antenna system considered for the SSPS. To achieve finale goal of the SSPS, we have to make it clear the present problems, such as, which technologies have already been proven and which technologies we should develop, and so on. In Japan, a committee for the SSPS is organized by JAXA (Japan Aerospace Exploration Agency).  The committee consists of one main steering committee and 12 working groups (WGs) studying elemental issues for the SSPS. The WG-4 we belong to focuses on the MPT research and technologies to manage and revise technology development roadmap. 
The increasing system cost of the SSPS depends on the system size, weight and the orbit on which the system will be operated. We should pay attention to maximize microwave correction efficiency in the minimum system cost. From the point of view of minimizing system cost, several errors affecting beam pointing should be optimized, i.e. phase, flatness of antenna structure, phase shifter and more. The phase error increases side lobe level and decreases beam collection efficiency on the rectenna. We will show the results of calculation of the beam collection efficiency with considerable phase errors, and also we will show a technology development roadmap to realize the SSPS in the future. In the roadmap, we present near term preliminary but important experiments for obtaining the data to scale up plan for the next experimental system. We will show some plan for power transmission experiments on orbit with scale down satellite which could be launched by single H-IIA class rocket. We propose some missions of the MPT in the experimental satellite. We show possibility of the MPT experiment with the available size of satellite in 5 to 10 years in future. 

Abstract document

IAC-05-C3.2.08.pdf

Manuscript document

IAC-05-C3.2.08.pdf (🔒 authorized access only).

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