The simple principle of stealth aircraft stealth?

There are three main methods for aircraft stealth:

First, reduce the radar reflection surface of the aircraft. From a technical point of view, the main measures are to design a reasonable aircraft shape, use absorbing materials, actively cancel and passively cancel.

The second is to reduce infrared radiation, mainly by taking measures such as heat insulation and cooling for the parts of the aircraft that are prone to infrared radiation;

The third is to use hidden color to reduce the visibility to the naked eye.