The S-band GaN-based high power amplifier and rectenna for space energy transfer applications

Gallium nitride (GaN) is one of the most significant elements to achieve effective use of energy in space not only for communications but also for power transmissions. This is because that GaN has the features such as high efficiency, high breakdown voltage, and harsh environment robustness and it is expected to fit the requirements for space use. Using GaN, the flexibilities for future missions in terms of size, weight, and power consumption etc. will be improved significantly. In this research, as a high power and high efficiency device, use of a GaN device was tried in a high power FET amplifier and in a single shunt rectifier diode. Circuits operating at S-band were designed, produced, and evaluated experimentally with the DC-RF conversion of 63.3% in the power amplifier and with the RF-DC one of 35.5% in the rectifier diode. A wireless power transmission (WPT) experiment using HPA and rectenna was conducted. As a result, it was confirmed that a battery could be charged up to 133.7 Ws in about 1500 s (25 min) by the DC power generated by the rectifier, where the EIRP was 57.2 dBm, the rectifier input power was 32.5 dBm, and the distance between a power transmitter and the receiver was 1.2 m.