Millimeter-wave wireless power transfer technology for space applications

Technologies enabling the development of compact systems for wireless transfer of power through radio frequency waves (RF) continue to be important for future space based systems. For example, for lunar surface operation, wireless power transfer technology enables rapid on-demand transmission of power to loads (robotic systems, habitats, and others) and eliminates the need for establishing a traditional power grid. A typical wireless power receiver consists of an array of rectenna elements. Each rectenna element consists of an antenna together with a high speed diode and a storage capacitor configured in a highly tuned narrowband circuit for this purpose. The conversion of the microwave energy into DC in this fashion is almost instantaneous. Using a high power rectenna array in concert with a fast charging high performance battery can enable charging of the battery at very short time with a large power burst and discharge of it at a lower rate for an extended operation time for remote electronic assets. We have designed and fabricated a novel T-Slot antenna coupled rectenna array at 94 GHz for demonstrating efficient wireless power transfer in this frequency band. Assembly and testing of these devices are under progress now, and are showing great promise.