Why US should worry about this Chinese radar?

Amid tensions with Washington over the Taiwan issue, Chinese researchers claim to have developed a small infrared radar capable of detecting fast-moving aircraft, including stealth ones such as the US F-22 and F-35, from an unusually long distance.
Heat-seeking radar
According to South China Morning Post, the new infrared search-and-track system can pick up the heat signature from a distance of 285km, a significant breakthrough given most infrared cameras cannot see beyond a range of 20km.
The heat-seeking radar can also emit a powerful laser beam to illuminate the target aircraft to gather more information, such as the number of windows on the plane, the report said quoting a paper published in the peer-reviewed Chinese journal 'Infrared and Laser Engineering'.
Anti-stealth tech
Although a stealth aircraft can evade traditional radar, its body and engines emit heat, which can be picked up by a long-range infrared radar.
Because of its smaller size, the new radar can be mounted on a car, aircraft or even satellite for a wide range of applications, such as surveillance and missile early warning, the researchers were quoted as saying.