China's fifth generation fighter aircraft
China, the rising power of today's world in all respects, has achieved significant success in the production of warplanes in parallel with the great leaps it has made in the field of air and space technology. China has put its first stealth or stealth aircraft into the service of its own air force since 2017. China's fifth generation fighter jet, known as the Chengdu J-20, is known to have the features to perform the roles expected from the US's F-22 and F-35 aircraft of similar categories. The J-20 fighter aircraft is compared with the F-22 and F-35 aircraft in the literature, including the Russian Su-57 aircraft. As China's efforts to further develop its fifth-generation fighter aircraft continue, at the same time, efforts to build stealth strategic bombers have accelerated.
As it is known, a new aircraft design work continues to replace the B-1B Lancer and B-2 Spirit aircraft in the inventory of the US Air Force. In this context, the design work of the first prototype of the strategic bomber called the B-21 Raider is about to end. The B-21 Raider program, which was put into use as a supply package of 80-100 aircraft in 2015, was later revised and turned into a program with an estimated cost of 40-50 billion USD, with 200 aircraft removed. According to the information leaked to the press, the B-21 aircraft is thought to both eliminate the problem areas of the B-2 that require high maintenance and in the difficult maintenance process, and to respond to the need for strategic bombers in case the USA has to fight with China in the Asia-Pacific. The generic mission of this aircraft has been defined by the US Joint Chiefs of Staff as "to hit or neutralize any target at any time, anywhere in the world". While performing this defined mission, the B-21's ability to perform its flight in the worst weather conditions, successfully resisting and avoiding any engagements that may come from all known air defense systems and air defense aircraft is based on. In particular, the flying wing design was considered as the basic design feature for the B-21, thus avoiding radars at all frequencies with its stealth capabilities.
Following the footsteps of the USA in the aircraft industry, China stands out as the country that invests the most in secret technologies after the USA. It is known that Chinese scientists are planning to use an electromagnetic wave model in the H-20 design. It is envisaged that this will not only make the aircraft lighter and cheaper, but also increase the stealth of the H-20 against radar detection. Work carried out at the Chinese Academy of Sciences at the Chengdu Institute of Optics and Electronics has created a mathematical model to precisely describe the behavior of electromagnetic waves, including radar waves, when they strike a piece of metal engraved with microscopic patterns. Studies are intensifying that this model will enable the development of a membrane known as the "metasurface" that can eliminate radar waves in the widest spectrum, as well as the latest developments in material production. It is known that stealth armor provided by stealth aircraft against radars is not valid for all radar wavelengths. Therefore, such “metasurface” studies, which will eliminate the detection ability of long-wave radars that can make stealth planes from being ghosts, could make a big leap for the Chinese aerospace industry.
It is currently known that stealth aircraft operate in an effective range of 4-18 gigahertz using absorption technology. Considering the capabilities of the Russian-made S-400 air defense system, China aims to increase functionality in the radar spectrum that this system cannot see in its aircraft development tests. Thus, in the future, China envisions increasing this absorption range to frequencies between 0.3-40 gigahertz, thus gaining an aircraft “stealth” capability that will enable to evade radars in a wide spectrum, thus making a leap in stealth technology.
