The document discusses research into using microstrip patch antennas to reduce electromagnetic scattering and radar cross-section of objects. Microstrip patches placed on objects and excited with the proper signals can cancel out the scattered field from the object. Simulations showed the scattered field was reduced by over 50 dB using this approach, demonstrating its potential to make objects invisible to radar. Future work will focus on implementing designs using practical electronics.

1. Active Electromagnetic Control of Scattering by Objects
Arian Pourmotamed and Chris Gay
Department of Electrical and Computer Engineering
Advisor: Prof. David R. Jackson
• The main goal of this research work is to
reduce electromagnetic scattering when an
object is exposed to microwaves (i.e., Radar
waves).
• The studied approach is based on
transmitting counter radiation through
microstrip patch antennas placed on objects
to cancel the scattered field.
• This approach results in the reduction of the
radar cross section of an object (e.g., an
aircraft).
• This research topic is new and the
understanding on this topic is limited.
• The team members are pursuing BSc in
Electrical Engineering, concentrating in
Electromagnetics.
Radar operates as a sender/receiver. Canceling the
reflected waves will result in cancellation of the
radar cross section of the object.
BACKGROUND METHODOLOGY
By studying incident fields with varying angles,
the following conclusion is obtained:
• The microstrip patch antenna can cancel the
scattered field at any given angle (zero degrees is
chosen in the example below).
• Using the optimum excitation of the patch, its
radiation exactly cancels the natural scattered
field from the object.
• The scattered field is reduced (in simulation) by
more than 50 dB.
RESULTS
-70
-60
-50
-40
-30
-20
-10
0
-100 -80 -60 -40 -20 0 20 40 60 80 100
dB
Theta
Patch inactive
CONCLUSIONS
• The scattering from objects can
be controlled and reduced using
patch antennas on the objects.
• The proper excitation of patch
antennas on objects can result in
a cancellation of their radar cross
section in a certain direction.
• We have demonstrated the
possibility of making objects
invisible to radar using patch
antennas.
• Future work will involve
implementing the designs with
practical electronics.
• Sohini Sengupta (Graduate student mentor)
• UH Undergraduate SURF Program
• HFSS program tutorials, Ansys, Inc.
• Pozar, D. M. (2012) Microwave Engineering.
• The scattering of a metal plate with a microstrip
antenna on it is studied by simulations using HFSS
program.
• HFSS is the industry standard electromagnetic design
simulation program.
• Microsoft Excel was used for comparison and better
illustration of the results.
With patch active
ACKNOWLEDGMENTS
REFERENCES