An active phased array antenna consists of a large number of cone-shaped cells installed under a transparent-to-radio-waves cap on the nose of the missile. Each cell receives only a part of the signal, but once digitally processed, the information from all cells is summarized into a “full picture,” enabling the K-77M missile to immediately respond to sharp turns of the target, making interception practically inevitable.

A similar technology is used in widely known Patriot surface-to-air missile (SAM) system, manufactured by Raytheon in the United States.

But the K-77M missile is much smaller, because it is supposed to fit into the interior bays of the PAK-FA fighter jet to ensure its stealth capabilities. Yet for the K-77M missile itself, a stealth aircraft or a UAV is a legitimate target it would track and destroy ordinarily.

The advanced missile system is fully compatible with the digital communication system of the fifth generation fighter jet, but also could be used on modernized fighter jets of the previous generation.

The Active Phased Array Antenna is the most modern radar technology today, and every such device is extremely expensive to produce. Yet the price of the target a missile equipped with APAA can destroy is much higher, so if the K-77M missile can guarantee hitting the target, it is worth the cost, Aleksandr Khramchikhin, an expert from the Institute of Political and Military Analysis, told Izvestia.