Japan's Millimeter Wave Satellite Communication Program

Japan has proceeded with the program for millimeter wave satellite communications since 1967, in addition to the programs of preoperational experiment for communications and broadcasting satellites in lower frequencies. The program is composed of two satellites, Engineering Test Satellite Type II (ETS-II) and Experimental Communication Satellite (ECS). ETS-II carries a beacon transmitter with three coherent frequencies including a millimeter wave and was launched in February 1977. ECS has a millimeter wave transponder and will be launched in February 1980. This paper describes the outline of the ETS-II/ECS project, the preliminary results of ETS-II, and the experimental plan of ECS.