The Solar Power Satellite(SPS) is one of the unique and hopeful electric power stations to satisfy ever-increasing energy demand on the ground without destroying the environment of our mother planet. Many　issues, especially microwave power transmission, need further investigations to establish the SPS. We have developed new technologies. The power generator was combined with the transmitter in the sandwich structure. Half frequency of the microwave was used as a pilot signal of a retrodirective antenna to make RF circuit very simple．The efficiency of the high power FET amplifier was improved from 43% to 63%． We propose a new space experiment called by ISPER(International Space Power ExpeRiment)onboard the satellite with the　international collaborations. The ISPER aims at verification of the new SPS concept and new technologies.