The Sh-121 consists of the N036 Byelka radar system and L402 Himalayas electronic countermeasures system. Developed by Tikhomirov NIIP Institute, the N036 consists of the main nose-mounted N036-1-01 X band active electronically scanned array (AESA) radar, or active phased array radar (, "Aktivnaya Fazirovannaya Antennaya Reshotka", , "AFAR") in Russian nomenclature, with 1,552 T/R modules and two side-looking N036B-1-01 X-band AESA radars with 358 T/R modules embedded in the cheeks of the forward fuselage for increased angular coverage. Moreover, the side-looking radar could enable the Su-57 to employ extreme beaming tactic (fighter turns 90 degrees away / perpendicular to an enemy's pulse doppler radar array, so that the enemy's radar would not detect / misinterpret it as a non-moving object) while still able to guide its own missile. The suite also has two N036L-1-01 L band transceivers on the wing's leading edge extensions that are not only used to handle the N036Sh Pokosnik (Reaper) friend-or-foe identification system but also for electronic warfare purposes. Computer processing of the X- and L-band signals by the N036UVS computer and processor enable the system's information to be significantly enhanced.