Lower-cost architectures for large arrays of small antennas

Future plans for NASA's Deep Space Network (DSN) call for the construction of arrays of small antennas to compliment and eventually replace the existing network of large single antennas. The motivation for this transformation is the need to support much higher downlink data rates in the future, along with the realization that the most cost-effective way to do this is though a large increase in total collecting area on the ground. As currently designed, the DSN arrays will consist of approximately four hundred 12-m diameter antennas at each of three longitudes, operating at X and Ka bands (8 and 32 GHz). A possible near-term option is the construction of large arrays operating at X-band only. Such an array could be built more rapidly and less expensively than an X/Ka band array, and would be able to support the majority of space missions planned for the next 20 years, which will not require bandwidths wider than the 50 MHz X-band allocation. Cost-saving advantages of an X-band only array include the use of COTS antennas much smaller than 12 m in diameter, uncooled receivers, and direct optical transfer of signals from antennas to a central signal processing area