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Singapore
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Facts about Singapore
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A city country of 5.3 million residents (3.1 million local Singaporeans, 74.2% are Chinese) Land area of 704 km2 GDP per capita: $511 in 1965 to $54,775 in 2013 Key economy revenue: oil refinery, manufacturing, trade, and services
Microstrip-fed patch antenna
Radiation mechanism
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Our Interest
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Microstrip-Fed Slot Antennas
Ground-plane
Microstrip feed line
Substrate
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Previous Studies
My Research Interests
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Analysis and Design of Antennas
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Frequency-Selective Structures and Absorbers
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Outline
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Brief Introduction to Slot Antennas Previous Studies on Microstrip-Fed Slot Antennas Our Recent Work
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Microstrip-Fed Slot Antenna
ws 2.9mm
Ls 44.3mm
wm 4.8mm
r 2.2
h 1.6mm
Lm 12.8mm
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Simulated Results
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Microstrip-Fed T-Slot Antenna
T s lo t e tc h e d o n g ro u n d p la n e L s1 = 9 8 m m L s2 = 6 3 m m L d = 2 8 .5 m m W s= 6 m m W d= 3 m m W f= 4 .6 4 m m W s 11 11
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Experimental studies of narrow- and wideslot antennas Numerical techniques for analyzing the microstrip-fed slot antennas. Among the proposed methods, Green’s function in conjunction with the method of moments appears to be the most efficient. Extraction of equivalent circuits
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The Founder of Slot Antenna
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The most important technical advance in antennas after Hertz is the invention of the resonant slot as radiating element. In 1938, A. D. Blumlein (1903-1942) filed a patent for a slotted tube as antenna. Genius Engineer
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Microstrip-Fed T-Slot Antenna (cont.)
0 -5
-10
-15
S11 (dB)
-20
measured data simulated data
– It retains all the advantages (lowprofile, light weight, ease of integration) that patch antennas have – wider bandwidth – smaller effect of a finite groundplane – smaller mutual coupling in the array configuration

r
2 . 45 , h 1 . 575 mm
M ic ro s trip fe e d lin e L s2 W
f
L s1 W
d
L f= 1 2 8 m m
Ld
[2] Z. Shen, C. T. Sze and C. L. Law, “A circularly polarized microstrip-fed T-slot antenna,” IEEE AP-S International Symposium Digest, pp. 1008-1010, 200n
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Definition: A slot antenna consists of a metal surface, usually a flat plate, with a hole or slot cut out. The metal surface can be a conducting plane, a waveguide wall, the ground plane of a microstrip line, etc. The slot cut can also take various forms: rectangular, circular, T-type, cross, etc. Slot antennas are extremely useful in many applications where low-profile or flush installations are required such as on high-speed aircrafts and missiles.
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Simplest Slot Antenna
Dipole /4 /4 /4 Feed line /4 Metal sheet
Z1Z 2
0 2
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35476
Babinet’s principle by Henry Booker
[1] H. G. Booker, “Slot aerials and their relation to complementary wire aerials (Babinet’s principle)”, J. I. E. E., 93, pp.620-626, 1946.
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Suggestions for Future Work
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The Pioneers
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The very first wire antenna was due to Joseph Henry (1842). Heinrich Hertz invented both dipole and loop antennas (1887). Guglielmo Marconi received a signal across Atlantic ocean in 1901 .
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Applications of Slot Antennas
Why Slot, Not Patch Antenna?
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Microstrip patch antenna is basically a two-slot antenna array. Slot antenna is better because
The Theory Maxwell’s Equations
H
E
D
D J t B t
B 0
In 1864, James Clark Maxwell laid the theoretical foundation for electromagnetics.
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School of EEE
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One of the four founding schools There are 6 divisions (power, circuits and systems, information, control, communication and microelectronics) in the School. We have about 150 academic staff, 3500 undergraduate students, more than 1000 graduate students. Well equipped with world-class facilities .sg/eee 7
MICROSTRIP-FED SLOT ANTENNAS
Zhongxiang Shen
School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Avenue, Singapore 639798 Email: ezxshen@.sg
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Nanyang Technological University
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NTU’s Key Figures
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Four colleges: Engineering, Science, Nanyang Business School, College of Humanities, Arts, and Social Sciences Undergraduate Students: 23,500 Graduate Students:10,000 Ranked 41st globally by QS World Rankings in 2013, with its Electrical Engineering Program ranked 31st worldwide. NTU is one of the fastestgrowing research universities in the world.