Stealth technologies refer to a wide range of techniques used to make aircraft, ships, submarines, missiles, satellites and ground vehicles less visible (ideally invisible) to radar, infrared or other detection systems. Often this is done to avoid detection, but it may also be used as a strategy for countering detection.
The secretive United States Military program stealth was created after World War II. The goal was to find a way to protect aircraft from enemy radar bombing and spotting.
Even though stealth technologies have been classified, we do know some basic information.
Low observability
Stealth design can use many surface materials and coatings which reflect radio waves to delay their reflection on enemy radars. Some designs include smooth, rounded shapes, and the use of hidden engines and other devices that reduce reflectivity.
Radar can see aircraft
First, ensure that all parts of the aircraft are cool. This is a key step to stealth. This includes avoiding heat-emitting materials, such as engine exhaust gases, and wing surfaces. Heat-seeking missiles and other weapons zero in on this radiation to target aircraft, so keeping it as low as possible is a critical design objective.
Planar shape
Planar design is the best stealth technology for aircraft. It is a simple technique that allows engineers to make an aircraft invisible to radar, minimizing the size and cross-section of its radar cross-section.
You can achieve this by designing the aircraft's body with a large surface area to volume ratio, and a small physical cross-section. This reduces radar reflections to a minimum, and helps improve aerodynamic efficiency.
Another stealth technology is radar-absorbing materials, also known as RAMs. These materials can be made of a variety of polymers including glass-fiber composites or multi-walled carbon nanotubes.
Radar absorbing materials can be applied directly onto the aircraft's exterior or embedded into a structure. This is the most common and has many advantages over the first.
The RAM absorbs radar energy and does not generate it. It is often a thin layer that covers the entire aircraft's surface. It is a very thin layer that can be difficult to detect, although it is not completely invisible to radar.
A RAM material with high RF absorption can greatly reduce the reflected light from a target. This reduces the probability of a target becoming detected by a radar system with limited frequency coverage or bandwidth.
Plasma stealth
Plasma stealth is a new form of stealth technology. Plasma stealth works with very narrow beam widths, which is the main benefit of this technology. It is not like traditional antennas. Instead, it uses a series of parallel tubes which are filled with gas. Then they are energized.
This antenna can send multiple signals, but only when the aircraft is at subsonic speed. Currently, however, it is too costly to install a large array of plasma stealth antennas on military aircraft.