Electro-Optic Terminal Protection for Radar Systems

Recent advances in directed energy weapons (DEW) require radar systems to implement front door protection against high power signals. Although nonlinear protection elements have been successfully employed in the past, fast ultra wideband (UWB) and high power microwave (HPM) signals are not successfully blocked by most current circuit protection technologies. This proposal details the development of a quasi-passive, solid state electro-optic terminal protection system (EOTPS) to effectively block UWB and HPM signals from the front end of radar systems. The device uses power from the incoming transient to switch the signal line to ground. But because the system as a whole requires no external power other than the transient, it can be considered a passive device. Inherent delay in the system permits the switch to become fully conductive before the transient arrives, effectively creating a system with a negative switching time. This allows the entire transient to be reflected, in contrast to other high power terminal protection techniques which allow part of the transient to pass to the LNA.