76T6 and 77T6 Radars
Precise details of these radars are unavailable. They are thought to be active phased-array systems using gallium nitride (GaN) substrate that operate in the X-band, and are used for target tracking and engagement at long range. From published schematics, the 76T6 multimode engagement radar is shown with the antenna head module of a 92N6E ‘Grave Stone' and is assessed to potentially be a derivative of that system. The radar uses a telescopic datalink mast with cylindrical antennae elements. The 76T6 will provide fire control and missile guidance against medium- and low-flying air targets. While little information on the system has been released, replacement of the phased-array antenna with an active AESA array is a likely improvement.
Based on concept imagery, the 77T6 engagement radar is understood to have an enlarged version of the 76T6/92N6E radar head and is intended to be used for ABM engagement. While not much information on the specifications of this radar has been obtained, it is speculated that the AESA unit developed for the 77T6 radar set may consist of 256 transceiver channels. Sergey Druzin, a Deputy Director General Designer from Almaz-Antei, has stated that the radars use relatively small amplifiers that use a 27 V system, as opposed to a 30–40 kV electric vacuum system as used in some radars.
91N6AM missile Guidance Radar
The 91N6A(M) ‘Big Bird' multifunctional adaptive radar system (MARS) is understood to be an upgraded 91N6 radar of the S-400. The primary role of the radar will be to search ballistic missile threats. The radar can be mounted on a 23 m-high 40V6M mast for increased detection range of 2,000 km (against ballistic missile targets) and is assessed to operate on a scan rate of five rotations per minute, like the 91N6.
96L6 Tracking Radar
The 96L6-TsP ‘Cheese Board' is an upgrade of the 96L6E battery acquisition radar of the S-400. The radar can interface with the other command posts in the IADA through radio-frequency datalinks. In April 2018, Russian television released an image of a radar referred to as the Yenisey all-altitude radar, associating it with the S-500 system and being used for long-range testing of air-defence systems at the Ashuluk testing range. The Yenisey radar was shown with a significantly modified array mounted on an enlarged rotating base. From the image shown it is assumed that this radar is the 96L6-TsP. The range of this radar is unknown.