Progress in smart radar absorbers

Conventional (i.e. passive) radar absorbers are widely used for modifying the radar cross-section (RCS) of current military platforms but such absorbers may not have adequate performance to satisfy future requirements. Active absorbers, however, offer the potential to overcome the so-called Rozanov performance limit and to enable additional 'smart' functionality such as monitoring damage, adaptive control of RCS or target appearance, Identification-Friend-or-Foe (IFF) and Absorb-While-Scan (AWS) This paper outlines the concept and basic properties of a novel type of active radar absorber, the so-called Phase-Switched Screen (PSS). The basic PSS topology is then modified so as to enable it to operate as a smart radar absorber when used together with an external sensor and feedback control loop. The theoretical predictions are confirmed using data measured on transmission-line analogues of the smart PSS structure.