9S36

The 9S36 (NATO designation: "Chair Back") is a C-band (IEEE) or H-band (NATO) missile control radar, part of the Buk M1 (NATO designation: S-27 "Grizzly") medium-range anti-aircraft missile system. For missile guidance, it functions as a target illumination radar operating in the X-band (IEEE) or I-band (NATO). The radar, which has an instrumented range of 100 km, can be mounted on a 2S36 telescopic mast to engage low-flying targets and features an elliptical passive phased-array antenna housed within its radome.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/06.missile/karte021.en.html