A 5.8 GHz Sensor-Fusion Energy-Harvesting Tag for Sensing Applications in Space

Passive backscatter radio frequency (RF) tags have been used for many terrestrial applications and have the potential for use in many identification and sensing applications in space. Passive RF tags do not require a battery, but operate by harvesting energy from an RF signal emitted by a reader and communicate by modulating the signal scattered from its antenna. Therefore, they consume very little power and can operate without a battery. This paper discusses the design of a passive backscatter RF tag for use on the Radio Frequency Tag Satellite (RFTSat), a 3U cubesat that was designed and launched by a team of undergraduate students. The paper presents the design of the tag’s energy harvester, microstrip patch antennas, and discusses the sensors included on the tag. The paper concludes by presenting the data collected from the RF tag while in orbit. This scientific sensing experiment also proves to be the first in-orbit demonstration of space solar power where microwave energy is collected and used as the sole power source for an electrical system performing useful work in space.