Miniature antennas for lunar and planetary surface communications

Surface communications assets in future NASA exploration scenarios such as robotic rovers, human extravehicular activities (EVA), and probes will necessitate small size, lightweight, low power, and robust antenna elements. With the availability of space in these devices being a major concern, miniature antennas provide a potential solution toward addressing these issues. The current problem with miniature antennas, however, is their inherently low efficiencies, which will be unacceptable for low power applications. At the NASA Glenn Research Center (GRC), prototypes of several potentially useful miniature antenna designs for lunar and planetary surface communications have been investigated. Specifically, two novel candidate designs which hold promise, the folded Hilbert curve fractal antenna (fHCFA) and the compact microstrip monopole antenna (CMMA), are described in this paper. Both demonstrate comparable performance to a quarter-wavelength monopole, but at smaller than 1/3 the size, making them more suitable for integration in communications systems with stringent size and volume requirements (i.e., wireless sensors, space suits and others).