Several documents in a collection discuss a proposal to use clusters of appropriately phased, relatively small microwave antennas to obtain high levels of effective isotropically radiated power (EIRP) for transmission of data from spacecraft to Earth during exploration of distant planets. The advantages of such a cluster, relative to a single larger antenna of equivalent EIRP, would include the following:
- The cluster would have less mass and volume.
- Power densities in amplifiers, waveguides, and other transmitting components feeding the antennas would be lower. Therefore, problems of preventing overheating and high-voltage breakdown would be less severe.
- Phases could be made electronically adjustable for beam steering to increase pointing accuracy.
- Failure of one antenna or its feed system would reduce the EIRP but would not disable the entire transmitting system. Beam-steering capability would remain as long as at least three antennas (and their feed systems) in a triangular arrangement remained functional.
The documents summarize the applicable basic principles of antenna design and requirements that would govern the design of an antenna cluster for a specific proposed mission [the Jupiter Icy Moons Orbiter (JIMO)]. Candidate design concepts for realizing the aforementioned and other advantages for JIMO are analyzed.
This work was done by Robert Clauss, Richard Lovick, Narayan Mysoor, and John Zitzelberger of Caltech for NASA’s Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Electronics/Computers category.