Creating a universal radio frequency front-end for elemental digital beam formed phased arrays

The DARPA Arrays at Commercial Timescales (ACT) program seeks to lower the nonrecurring engineering costs and timeframe of designing and upgrading phased arrays through the use of a common hardware module that can be reused across many phased array missions and array sizes. The ACT program seeks to utilize elemental level digital beamforming to remove many of the fixed choices, e.g. array size, number of beams, center frequency and bandwidth, associated with analog beam-former implementations. One of the main challenges in realizing this vision is the implementation of a common RF front-end that can be used to down/up covert RF signals over a wide range of center frequencies and bandwidths to within the analog bandwidth of typical data converters. The DARPA Radio Frequency Field Programmable Array (RF-FPGA) has yielded flexible and reprogrammable RF front-end systems. This paper describes research from the DARPA ACT and RF-FPGA programs in pursuit of a universal RF front-end.