Question: Who developed  an advanced active electronically scanned array radar system for the fifth generation aircraft that is the designation intended for a stealth, single-seat, twin-engine jet multirole fighter aircraft designed for air superiority and attack operations ?
Sentence (from "Sukhoi Su-57"): The aircraft is the product of the PAK FA (Russian: ПАК ФА , Russian: Перспективный авиационный комплекс фронтовой авиации , "Perspektivny Aviatsionny Kompleks Frontovoy Aviatsii", literally "Prospective Airborne Complex of Frontline Aviation"), a fifth-generation fighter programme of the Russian Air Force.
Relevant evidence: No