This presentation is interested with the Radar, Stealth Technology and Radar Absorption Materials.
The category of this presentation is Science and Engineering. Also it is important for the next generation of the Defense Technologies.
You can find the information about the these topic very easily.
Wikipedia is the base of the information.
If you have any questions, contact me. I would be happy to help.
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2. 1-What is the RADAR ?
2-How does RADAR works ?
3-Stealth Technology
4-How does Stealth Technology works ?
5-Radar Absorbtion Materials (RAMS)
K.U.TUMEN 2018/2019 1
Outline
3. K.U.TUMEN 2018/2019 2
What is the RADAR?
•RADAR is an object-detection system that uses radio waves to determine the range, altitude,
direction, or velocity of objects.
•RADAR means that RAdio Detection And Ranging.
•RADAR works on the principle of Microwaves.
•It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather
formations, and land. (For defense and security purposes)
https://en.wikipedia.org/wiki/Radar
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How does RADAR works?
• The RADAR antennas transmits radio waves that bounces off (jump) the object in their
path and get back to radar.
• The object returns a tiny part of wave’s energy to the antenna that is located at the
same site as the transmitter.
https://en.wikipedia.org/wiki/Radar
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Stealth Technology
Radar Cross Section
•RCS is the measure of a target's ability to reflect radar signals in the direction of radar receiver.
•Radar cross-section is used to detect airplanes in a wide variation of ranges. For example, a stealth
aircraft will have design features that give it a low RCS, as opposed to a passenger airliner that will
have a high RCS.
•RCS is related to:
- Aircraft’s physical geometry
- Direction of radar signal
- Frequency of radar signal
- Material of aircraft
https://en.wikipedia.org/wiki/Stealth_technology
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Stealth Technology
•It corresponds to military camouflage for these parts of the electromagnetic spectrum.
•Scientifically known as LOW OBSERVATORY TECHNOLOGY (LOT)
•Used in military aviation
•Reduces detection range of an aircraft
•Partial invisibility to RADAR
•Similar to camouflage tactics used by soldiers
https://en.wikipedia.org/wiki/Stealth_technology
7. There are two aspects of RCS minimization techniques:
Vehicle shape
It’s tail should be at ACUTE (sharp) angle.
Planes wings has to kept at ANGLE.
Design of NOSE.
K.U.TUMEN 2018/2019 6
How does Stealth Technology works?
https://en.wikipedia.org/wiki/Stealth_technology / https://www.mypatentprints.com/product/stealth-aircraft-patent-airplane-blueprint-aviation-art-airplane-art-pilot-gift-aircraft-decor-airplane-poster-northrop-air-force/
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How does Stealth Technology works?
https://en.wikipedia.org/wiki/Stealth_technology
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Radar (Radiation) Absorbent Materials - RAMS
• Radiation-absorbent material, usually known as RAM, is a material which has been specially
designed and shaped to absorb incident RF radiation (non-ionising radiation).
• A common misunderstanding is that RAM makes an object invisible, used in stealth technology to
disguise a vehicle or structure from radar detection.
• The more effective the RAM, the lower the resulting level of reflected RF radiation.
https://en.wikipedia.org/wiki/Radiation-absorbent_material
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Radar (Radiation) Absorbent Materials - RAMS
Type of RAMS :
• Foam Absorber
• Jaumann Absorber
• Split Ring Resonator Absorber
• Iron Ball Paint Absorber
• Carbon nanotube
• Silicon carbide
https://en.wikipedia.org/wiki/Radiation-absorbent_material
11. K.U.TUMEN 2018/2019 10
Radar (Radiation) Absorbent Materials - RAMS
https://en.wikipedia.org/wiki/Radiation-absorbent_material
Foam Absorber
•Foam absorber is used as lining of anechoic chambers for electromagnetic radiation
measurements.
•This material typically consists of a fireproofed urethane foam loaded with conductive carbon
black in mixtures between 0.05% and 0.1% and cut into square pyramids with dimensions set
specific to the wavelengths of interest.
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•The tip of the pyramid has the lowest percentage of particles and the bottom contains the highest
density of particles. This presents a "soft" impedance change to incoming radar waves and further
reduces reflection (echo).
Radar (Radiation) Absorbent Materials - RAMS
https://en.wikipedia.org/wiki/Radiation-absorbent_material / https://hollandshielding.com/PU-foam-based-pyramid-absorbers
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Radar (Radiation) Absorbent Materials - RAMS
Jaumann Absorber
•A Jaumann absorber or Jaumann layer is a electromagnetic resonant-absorber.
•Electromagnetic absorber such as Jaumann Absorber is materials that can limit the reflection of
electromagnetic radiation.
•Jaumann layer is made with materials such as dielectrics combined with metal plates spaced at
intervals or wavelengths and also it is consisted of two equally spaced reflective surfaces and a
conductive ground plane.
https://en.wikipedia.org/wiki/Radiation-absorbent_material / https://www.slideshare.net/ShaunakAphale1/radar-absorbing-materials-by-shaunak-aphale
14. K.U.TUMEN 2018/2019 13
https://en.wikipedia.org/wiki/Terahertz_radiation / https://albertsradarproject.wordpress.com/chemistry-and-stealth-technology/
Radar (Radiation) Absorbent Materials - RAMS
Iron Ball Paint
• It contains tiny spheres coated with carbonyl iron or ferrite.
• Radar waves induce molecular oscillations from the alternating structure in this paint,
which leads to conversion of the radar energy into heat.
• The heat is then transferred to the aircraft and dissipated.
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https://en.wikipedia.org/wiki/Radiation-absorbent_materia
Radar (Radiation) Absorbent Materials - RAMS
Carbon Nanotubes
• Radars work in the microwave frequency
range, which can be absorbed by multi-wall
nanotubes (MWNTs).
• Applying the MWNTs to the aircraft would
cause the radar to be absorbed and therefore
seem to have a smaller radar cross-section.
• Current limitations in manufacturing,
however, mean that current production of
nanotube-coated aircraft is not possible.
Silicon Carbide
• This material in finely powdered form is
added to standard heat-resistant paint base
to absorb radar on stealth aircraft.
• To check radar or general electromagnetic
wave absorption of materials, they can be
tested in an ordinary microwave oven.
• Most metals reflect radio waves so they are
also detected by radar, and thus cannot be
used or heated in a microwave oven.
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Radar (Radiation) Absorbent Materials - RAMS
Coating and Absorber RAMS
• RAMs dissipate the energy of the radar wave to prevent the reception of reflected signals.
• The dissipation process converts the radio frequency (RF) energy to a negligible quantity of heat.
• It deflects, absorbs and reduce the detection of RADAR range.
Conclusion
• As a result, there will be progress in stealth technology with the development of Radar Absorption
materials. Also, the work on anti-stealth technology will increase.
• It is an military force race in around the world.
