N036 Belka (Russian: Белка, literally Squirrel) is an active electronically scanned array radar system developed by Tikhomirov NIIP for the fifth generation Sukhoi Su-57 fighter aircraft.

The radar is a part of Sh121 multifunctional integrated radio electronic system (MIRES) onboard the Su-57.

[1][2] The suite also has two N036L-1-01 L-band arrays on the wing's leading edge extensions that are not only used for friend-or-foe identification but also for electronic warfare purposes.

Computer processing of the X- and L-band signals enable the systems information to be significantly enhanced.

The L402 "Himalayas" electronic countermeasures (ECM) suite made by the KNIRTI institute uses both its own arrays and that of the N036 radar.