Microwave power transmission experiment using breadboard model for small scientific satellite toward SPS

We are developing a bread board model for a microwave wireless power transmission (WPT) from a satellite in orbit to the ground toward a solar power satellite (SPS). WPT using microwaves is inherent and critical technology of the SPS. We have carried out a conceptual design and proposed a space experiment using a small scientific satellite. The purposes of the space experiments are to demonstrate a precise directional control of WPT technology and to clarify the propagation characteristics of the microwave power in the ionosphere. The model is formed a thin panel structure with a thickness of 6 cm, and the panel consists of a transmission antenna layer, microwave amplification layer and thermal radiation layer, respectively. Performances of the breadboard were measured and evaluated. Additionally, the microwave beam steering experiments by the software retro-directive method were demonstrated.