Stealth aircraft use advanced technologies to reduce detection by radar, infrared, visible light, radio frequencies, and sound. Radar systems work by sending out radio waves that bounce off objects and return to the sender, revealing the object's location and velocity. Stealth aircraft are designed through careful shaping of surfaces, use of radar-absorbing materials, and other methods to minimize radar reflection and detection. Future stealth designs aim to further reduce detection through innovations like canards and new materials.

1. USAMAH ABD LATIF
1118597
HABIBAH HANIM MOHMED @ SALLEH
1118968
NIK MUHAMMAD SYAFIQ NIK MAT DAUD
1119409
ADVISOR : DR SANY IZAN IHSAN
COORDINATOR : DR ASIF HODA

2. • Stealth aircraft are designed to avoid detection using a
variety of advanced technologies that reduce
reflection/emission of radar, infrared,[1] visible light,
radio-frequency (RF) spectrum, and audio, collectively
known as stealth technology.
• While no aircraft is totally invisible to radar, stealth aircraft
make it difficult for conventional radar to detect or track
the aircraft effectively, increasing the odds of a successful
attack.

4. • What is radar system and how it
works?
• Various design of stealth aircraft
and its effect.
• Improvement in future stealth
aircraft.

5. • Radar system is a system that
help pilot in navigating while fly in
space
• It uses a continuous wave and
frequency to keep in touch with
• This system is widely used around
the world

6. • There are 2 main components for
this system to work
• There are sender and receiver
that have been installed on
ground and aircraft as well
• By radar system we could know
how far the object is and it velocity

7. Sender
(on
ground/
aircraft)
Hit aircraft body
/ antennas on
ground
Receiver (on
ground/
aircraft)
It sends out radar
probe( Frequency
Modulated Continuos
Wave)
Bounce back to
antennas on
ground / aircraft
1. Information received is
fed in into computer
system
2. Signal processing
system converts
analog information to
digital format
3. Then performs Fast
Fourier Transformation
on data
4. It calculate the
position& velocity of
the nearby object or
aircraft

8. Aircraft
design
• Two major factors:
Materials
been used

9. Aircraft
design
Sharp edge
and flat
surface
Engine
Makes wave not be
able to bounce back
efficiently
Extreme
aerodynamics :
- Minimize air
turbulence
- cut down flying
noise
Hot fumes is mixed
with cool air before
leaving aircraft
Uses a low noise
engine

10. Radar absorbing
materials -RAM
Radar absorbing
structures- RAS
Material
s used
in
designin
g stealth
aircraft

11. “wesch
”
• Has been used by German in WW II
• it comprises rubber substrate loaded with iron
carbonyl powder
• The powder dissipate radar energy into substrate
materials
Halper
n anti-
radiatio
n paint
• Used by US, it carries within rubber matrix
aluminum fakes & carbon black particles
Salisbu
ry
screen
• It is a sheet of resistive material overlays a
conductive backplane
• Separated by dielectric materials( quarter of subject’s
radar wavelength in thick)
• Incident radar waves penetrate outer layer, then
reflected from inner and backplane layer
• For internal reflection, waves that 180° shifted meets
other waves and cancel out each other

12. • Low weigh RAS can be made from
glass & carbon fibre composites
lattice which voids are occupied by
microwave absorbent foam
• This absorption effectiveness is
related to volume fraction of grid cell
structure & distance between
elements

13. • Carbon composites can be used
to absorb radio/radar frequency
• It can metallize fabrics &
conductive polymer

14. Goal of Stealth Technology
O To make aircraft invisible by reducing
radar, IR, visual, and acoustic signature.

15. Principle of Stealth
Technology
 Infrared detection.
 Visual detection.
 Acoustic detection.
 Radar detection.
Reduction in these detection is the principle
of stealth technology.

16. O Method to decrease the IR signature of the
engines is to use exhaust masking.
O This is accomplished by placing the engines on
top of the body and the wings, by which
exhausts cannot be seen from below.

17. Infra-red stealth
O Infra-red radiation are emitted by all
matter above absolute temperature zero
O Hot zones such as engine exhaust , wing
surface [ friction due to air ] get heated
which rather increases the visibility
O These part should be kept cool as
possible it can be ,
O Option would be mixing of cool air with the
hot engine exhaust

18. Infra-red stealth

19. Reduction of Infrared
Emission
O IF emission is occur due to heat.
O All substances with a temperature above
absolute zero (0° K, or -273.15° C, or -
459.67° F), emit electromagnetic waves.
The heat content of a material produces
molecular vibrations which cause electron
oscillations. These oscillations provide
electromagnetic coupling that produces an
emission of energy.

20. Visual stealth
O Low visibility is desirable for all military
applications
O Earlier stealth aircraft were painted black
and thus could be used during nights
O Now days an electro chromic polymer is
being developed for daytime stealth
O These polymer sheets sense nature of the
surrounding and change there color
accordingly

21. Visual stealth

22. Reduction in Acoustic Detection
O In this we reduce mechanical noise.
O For reduction of mechanical noise we use
different muffler, slow turning propeller.
O Acoustic cells involves the sound waves to
detect the target
O Knowing the fact that’s sound waves moves too
slowly as compared to radio wave so it
functionality should be directed towards low
altitude flying aircraft.

23. Reduction in Radar Detection
 Radar mainly work on electromagnetic wave
reflection.
 If we avoid these reflection towards the radar
receiver than we can reduce radar cross
section of object.
 Radar cross section
(RCS) is a measure of how detectable a
object is with a radar.

24. RCS Reduction Technique
(Reduction in Radar Detection)
 Purpose shaping :
The shape of the target’s reflecting surfaces is
designed such that they reflect energy away from the
source.
 Radar absorbent material :
As an addition to highly reflective surfaces.
 Active Cancellation :
Target generates a radar signal equal in intensity but
opposite in phase to the predicted reflection of an
incident radar signal

25. SHAPE DESIGN
O Conventional
aircraft
- Use round shape cone
as it support principle
of aerodynamics.
O Stealth aircraft
- Made up of flat surface
and very sharp edges
Radar signal heating the stealth plane are
scattered in all directions by this.

26. Shaping
O Normal design O Curved design

27. F117 A NIGHTHAWK

28. Radar Absorbing Material
O RAM material absorb EM wave and convert this
energy into heat.
O Metallic surfaces generally reflect the radar signals.
O There stealth aircraft should be coated with radar
absorbent materials.
O Which deflect , absorbed incoming radar waves
and reduce the detection range.
O Radar absorbent layer is present below the surface
coating of aircraft using corner reflector.

30. Active Cancellation
O In this method we have some RF source
on object(plane, ship) which modify radar
signal but in opposite phase that
generate
destructive interference.
- Thus by the use of these three method
we can reduce RCS of our plane and can
make them low observable.

32. Deceiving of Eye
O In this method we make the object visually
invisible.
O In this we use different color and different
lightning system, by which system
generate illusion.

35. Improvement in Design of
Future Stealth Aircraft
O The main objective is to design an aircraft that can
penetrate and reflect the radar waves very well.
O From the research, South Korea has come out
with a new design of stealth aircraft called stealthy
next-gen fighter.
O The KF-X is a twin-engine stealth fighter with a
design goal of achieving maneuverability, speed
and range performance between a Lockheed
Martin F-16 and a Boeing F-15.

37. Example of Future Stealth
Aircraft
Sukhoi T-50 PAK FA (2016)
O Similar to Western stealth fighters like the
F-22, the airframe incorporates planform
alignment in its leading and trailing edges
and saw tooth edges for its skin panels.
O Incorporate radar blockers to hide the
compressor face from all angles.
O The production T-50 is estimated to have
reduced the radar cross-section to that of
a tennis ball from optimal angles.

39. Chengdu J20 (2017)
O Analysts noted that J-20 uses similar
stealth shaping design as the F-22 and F-
35, providing good stealth capability at the
front.
O It uses canard and low observable design
for radar deflection.

40. O McDonnell Douglas and NASA's X-36
featured the use of canards and was
shown to be extremely stealthy.
O The Eurofighter managed to reduce its
Radar Cross Section (RCS) by controlling
the deflection of its canards through the
flight control software

42. Conclusion
O Well to conclude the current scenario
appears some things similar to the cold
war both sides are accumulating weapons
to counter each other and each side can
be termed as ‘stealth technology’ and the
other as ‘anti-stealth technology’.
O Its an arm race except it isn’t between
specific countries .