Distributed Antenna for Counter UAS

We consider the technical feasibility of a wirelessly distributed antenna array for C-UAS using directional microwave frequency energy. Importantly, the large possible size of the distributed antenna permits engagement of UAS and UAS swarms within the near-field region, enabling highly localized effects, ~ 5 meters at a range of 1 kilometer when operating at 1 GHz. In addition to near-field operation, combining N coherent emitters gives an N² enhancement of irradiance over that of a single emitter, enabling extension of system range by a factor N or a reduction in total system power requirement of N^-1 for to achieve an equivalent effect. Systems operating at 1-GHz require precise synchronization of order 100 picoseconds to ensure a high degree (> 90%) of coherence at target and therefore would require semiconductor power amplifiers rather than vacuum electron devices which are typically used as high power microwave sources. The authors develop a mathematical model implemented in software to explore the potential performance of a wirelessly distributed antenna for C-UAS and suggest some approaches for realization of such a technology.