Stealth technology refers to many techniques used to hide aircraft, ships and other ground vehicles from radar, infrared and other detection systems. It is used to avoid detection, but may also be used to combat detection.
After World War II ended, the United States Military started a stealth program. It was designed to provide an effective method of saving aircraft from enemy airborne bombings and radar 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 have smooth, rounded forms, while others use hidden engines or 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 hot materials like engine exhaust gas and wing surfaces emitting infrared radiation. To avoid heat-seeking missiles and other weapons, keep this radiation as low as you can.
Planar shape
Planar design is the most important stealth technology in aircraft. This is a simple technique which allows engineers make aircraft invisible to radar. It reduces the size and cross section of radar cross-sections.
This can be achieved by designing an aircraft's body to have a high surface area to volume ratio and a low physical cross-section. This allows for low radar reflections, which in turn helps improve aerodynamic efficiency.
Another stealth technology involves using radar absorbing materials, or RAMs. These materials can be made from a number of different polymers, including glass-fiber composites and multi-walled carbon nanotubes.
Radar absorbing material is available in two forms. It can be applied directly over the aircraft's surface or embedded within a structure. The latter is more popular and offers many benefits over the former.
RAM can absorb radio energy without creating it. As such, it is typically a thin layer which extends across the entire surface. Although it is invisible to radar, it is difficult to detect.
Effective RAM material can absorb a great deal of RF energy so it can significantly reduce the reflected signal. This lowers the chances of a target being identified by radar systems with limited frequency and bandwidth.
Plasma stealth
Plasma stealth has been introduced as a new stealth technology. Plasma stealth works with very narrow beam widths, which is the main benefit of this technology. Instead of using traditional antennas it uses a series o parallel tubes that are filled up with gas and then energized.
This antenna can send many signals but is only useful when the aircraft is flying at very low speeds. Currently, however, it is too costly to install a large array of plasma stealth antennas on military aircraft.