fundamentals of array antenna
DESCRIPTION
An array antenna is a very interesting concept to control antenna radiation patterns. By using properly designed array elements, we can design a high gain or beam steering antenna very easily.TRANSCRIPT
Fundamentals of Array Antenna
Antenna Antenna EngineeringEngineering
CHO, Yong HeuiCHO, Yong Heui
Antenna Antenna EngineeringEngineering
EM Wave LabEM Wave Lab2
Array antenna
1. Introduction
High gain antenna
Linear array Planar array Conformal array: nonplanar surface, aircraft Phased array
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Microstrip patch antenna
1. Introduction
Single patch antenna
Linear array: series feedingPlanar array: parallel feeding
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Conformal array antenna
1. Introduction
Conformal array: microstrip patch and cavity (Alcatel)
Spot beam of LEO satellite
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EM Wave LabEM Wave Lab5
Two-element array
2. Array antenna
AF (Array Factor): far field
cos
22
11
21
1ˆsin4
ˆsin4
ˆsin4
21
jkdjkr
jkrjkr
t
ejkr
zeI
jkr
zeIjk
r
zeI
EEE
cos
2cos21AF cos2/cos kd
ee jkdjkd
cos , 21 drrrr
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EM Wave LabEM Wave Lab6
Array factor
2. Array antenna
AF and element factor Maximum value of AF:
)2/sin(
)2/sin(
1
1
1AF
2/)1(1
0
)1(2
Ne
e
ee
eee
Njj
jNN
n
jn
Njjj
0at N
)2/sin(
)2/sin()(
N
Nf
coskd
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Active integrated antenna
3. Active antenna
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Receiving module for active antenna
3. Active antenna
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Self structuring antenna
3. Active antenna