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1
ELECTRICALLY CONTROLLABLE PCs & METAMATERIALS and THEIR INDUSTRIAL
APPLICATIONS.
ELECTRICALLY CONTROLLABLE PCs & METAMATERIALS and THEIR INDUSTRIAL
APPLICATIONS.
Frédérique
GADOT
Université
Paris Sud -
IEF,Bât. 220, 91405 Orsay, FRANCE
Frédérique
GADOT
Université
Paris Sud -
IEF,Bât. 220, 91405 Orsay, FRANCE
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OutlineOutline
1.
Brief summary on «
left handed material
»
(called LHM)
2.
Controllable wire array
3.
First industrial applications
4.
From the wire lattice to the LHM
5.
Antenna based on controllable metamaterial
6.
Conclusion
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Brief story of LHMBrief story of LHM
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The 4 electromagnetic states of materials.The 4 electromagnetic states of materials.
Left handed material
SE
Hk
E
H
k S0
μ
ε
Right handed material
Imaginary n Evanescent mode
Imaginary nEvanescent mode
Propagative
mode, n: real >0
Propagative
mode, n: real<0
ε
V.G. Veselago, Soviet Physics Uspekhi
10 (1968)
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Material with ε<0 or μ<0Material with ε<0 or μ<0
a
2ra
(by J.B. Pendry, Imperial College)
A lattice of metallic split ring resonators has a negative permeability in some frequency range.
•A lattice of thin metallic wires is a material with a negative permittivity (for ω < ωp
) where ωp
is the plasmon
frequency.
J.B. Pendry, PRL 76, pp.4773-4776 (1996) J.B. Pendry, IEEE MTT 47, pp.2075-2084 (1999)
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Left handed materialLeft handed material
Association of the 2 preceding metallic lattices
Composite Medium with Simultaneously Negative Permeability and Permittivity
D. R. Smith et al., PRL 84, pp. 4184-4187 (2000)
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How to measure the index of refraction of a LHM?How to measure the index of refraction of a LHM?
Experimental verification of a negative index of refractionR. Shelby, D. R. Smith and
S. Schultz, Science, 292, 77 (2001)
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Index of refraction of a LHM: measurementIndex of refraction of a LHM: measurement
Experimental verification of a negative index of refractionR. Shelby, D. R. Smith and
S. Schultz, Science, 292, 77 (2001)
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vacuum
LHM
α
β
Source
LHM
Applications of left handed materials (LHM)Applications of left handed materials (LHM)
Negative refraction makes a perfect lensJ. B. Pendry, Phys. Rev. Lett., 85, 3966 (2000)
ε=-1, μ=-1
Negative
refraction Perfect
lens
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Controllable wire arrayControllable wire array
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-50
-40
-30
-20
-10
0
0 10 20 30 40 50
Tran
smis
sion
(dB
)Frequency (GHz)
a first forbidden band appears
from 0Hz. Frequency
(GHz)
-50
-40
-30
-20
-10
0
0 10 20 30 40 50
Tran
smis
sion
(dB
)
Frequency (GHz)
an allowed band replaces the first forbidden band.
Frequency
(GHz)
Controllable structure: the conceptControllable structure: the concept
Lattice of continuous metallic wires:
Lattice of discontinuous metallic wires:
A. de Lustrac
et al., APL 75 (11), pp.1625-1627 (1999)
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First prototype for EADS (1-5GHz)…First prototype for EADS (1-5GHz)…
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…and its first measurement.…and its first measurement.
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In blue:diode
Wires=Perfect conductors
Box = vacuum
Dark blue:Printed board
-20f (GHz)
d
Plasmon band
Forbidden band
f0
-15
-10
-5
0
diodes ONdiodes OFF13dB
Controllable wiresControllable wires
Incident wave
E
Diodes ON = Continuous wiresDiodes OFF = Cut wires
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2nd
prototype with printed stripes…2nd
prototype with printed stripes…
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… and
its
measurements
(around
10GHz).… and
its
measurements
(around
10GHz).
-40
-35
-30
-25
-20
-15
-10
-5
0
9,5 10 10,5 11 11,5 12
Tran
smis
sion
(dB
)
(4)
(3)
(2)
(1)
Frequency
(GHz)
All diodes ON
All diodes OFF
Central boarddiodes OFF
Backward
boarddiodes OFF
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Applications: radomes intelligents…Applications: radomes intelligents…
-60
-55
-50
-45
-40
-35
-30
-25
0
10
20
30
40
50
6070
8090100110
120
130
350
Antenne seulediodes ON diodes OFF
Am
plitu
de (d
B)
2 plaques espacées de 9 mm devant une antenne patch à 12.01 GHz.
Patch antenna working at 12GHz
Pattern diagram of the patch antenna with radome at 12,01GHz.
Application: controllable radomeApplication: controllable radome
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Industrial applications: Conformable and Controllable structures
for antennas
Industrial applications: Conformable and Controllable structures
for antennas
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Base Station for mobile communicationBase Station for mobile communication
Wide-bandantenna
0.8-2.1GHz
5 layers of wires with diodes
15°
Schematical
design ofthe
base station antenna
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Characterization of the first prototype at 0.9GHzCharacterization of the first prototype at 0.9GHz
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0 (dB)-10-20-30 0°
30°
60° 90°
120°
150°
180°
210°
240° 270°
300°
330°
2.17GHz 1.8GHz 1GHz 0.89GHz Source seule
Does it work for the 3 frequency bands?
Multilayers
structure: optimization of the aperture of the 2nd
prototype
Multilayers
structure: optimization of the aperture of the 2nd
prototype
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Fabrication of the 2nd
prototypeFabrication of the 2nd
prototype
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Project “BIP”: 3G base station. Four layers prototype with wide band antenna
Project “BIP”: 3G base station. Four layers prototype with wide band antenna
Beam
control over
360°. Beam
aperture: 30°.
Wide
band
antenna: (0.8 -> 2.1GHz).
Antenna realized by France Télécom
R&D Corresponding diagram pattern
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measurements
simulations
4 layers 2nd
prototype: one aperture –
one beam Measurements and simulations at 0.9, 1.75 and 2.0GHz
4 layers 2nd
prototype: one aperture –
one beam Measurements and simulations at 0.9, 1.75 and 2.0GHz
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Spherical and Controllable radomeSpherical and Controllable radome
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GoalsGoals
Conformal EBG structure on a spherical radome.
Commutation of the transmitted signal at around 10GHz.
2 configurations:1. A set of continuous and discontinuous metallic wires2. A set of two discontinuous metallic wires with different
discontinuities’ periods.
Electronically active radome in aeronautic field with active switches like PIN diodes and/or photoresistances.
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Design of the structureDesign of the structure
x
y
z
O
a
p
3 configurations :
•Continuous wires (allowed band)•Discontinuous wires with p1=11mm (forbidden band)
•Discontinuous wires with p2=5.5mm(allowed band)
•Discontinuities simulated as capacitance C=30fF.•Diameter 32 cm.•p1 and p2 are the projections on the horizontal plane. Schematic structure
simulated in Microstripes
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Simulations of the spherical and controllable radomeSimulations of the spherical and controllable radome
-60
-50
-40
-30
-20
-10
0
8.5 9 9.5 10 10.5 11 11.5 12
continuous wireshorn
discontinuous wires p1=11mmdiscontinuous wires p2=5.5mm
Tran
smis
sion
(dB
)
Frequency (GHz)
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Prototype: Design and Test with a horn antenna.Prototype: Design and Test with a horn antenna.
•Discontinuities’ width 0.1mm•Wires’ width 1mm printed on a flexible support
Foam (permittivity close to 1)
Horn antenna inside the radome.
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Measurements of the prototype with the antennaMeasurements of the prototype with the antenna
24dB
9.3GHz
9.3GHz
19dB
=11mm
-30
-20
-10
0
10
20
8.5 9 9.5 10 10.5 11 11.5 12
antenna alonediscontinuous wires p1continuous wiresdiscontinuous wires p2= 5.5mm
Gai
n (d
B)
Frequency (Ghz)-20
-15
-10
-5
0
5
10
15
20
-80 -60 -40 -20 0 20 40 60 80
horncontinuous wiresdiscontinuous wires p1discontinuous wires p2
Gai
n (d
B)
Angle (degree)
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Measurements of the prototype with the weather radar antenna
Measurements of the prototype with the weather radar antenna
Weather radar antenna
-10
-5
0
5
10
15
20
25
30
-80 -60 -40 -20 0 20 40 60 80
weather antennacontinuous wiresdiscontinuous wires p2=5.5mmdiscontinuous wires p1
Gai
n (d
B)
angle (�)
15dB
•The switching level is 15dB.•The directivity of the antenna is unchanged.
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From the wire lattice to the LHMFrom the wire lattice to the LHM
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-80
-70
-60
-50
-40
-30
-20
-10
0
2 4 6 8 10 12 14 16
diodes ondiodes off
trans
mis
sion
(dB
)
f(GHz)
Control of the permittivity.Control of the permittivity.
2 boards of metallic wires with PIN diodes: the switch of the transmission and the permittivity for the 2 states of the diodes.
-150
-100
-50
0
50
100
150
2 4 6 8 10 12 14 16
diodes offdiodes on
real
(eps
)
f(GHz)
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Transmission of metallic stripes.Transmission of metallic stripes.
Comparison of the transmission through 1 and 2 boards of metallic wires with PIN diodes
-50
-40
-30
-20
-10
0
8 10 12 14 16
diodes ONdiodes OFF
trans
mis
sion
(dB
)
frequency (GHz)
-50
-40
-30
-20
-10
0
8 10 12 14 16
trans
mis
sion
(dB
)
frequency (GHz)
diodes ONdiodes OFF
diodes
E EIncident
wave
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Permeability of the Split Ring ResonatorsPermeability of the Split Ring Resonators
-40
-30
-20
-10
0
8 10 12 14 16
simulationmeasurement
Tran
smis
sion
(db)
Frequency (GHz)
•r = 1.5 mm, c=d=e=0.25mm. •The permeability is negative at the beginning and the end of the rejection.
rc
de
-4
-2
0
2
4
6
8
10
4 6 8 10 12 14 16
real
(per
mea
bilit
y)
frequency (GHz)
calculation for 1 disc
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A first passive prototypeA first passive prototype
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Transmission of the LHM: measurement and calculationTransmission of the LHM: measurement and calculation
The
first
prototype.
2mm
150mm
-50
-40
-30
-20
-10
0
8 10 12 14 16
simulation measurement
f (GHz)
trans
mis
sion
(dB
)
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Measurement of the whole controllable LHMMeasurement of the whole controllable LHM
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The whole structure is the association of 2 lattices:
a) Lattice of wires with diodes:-2 parallel boards: height 150mm, width 200mm and thickness 0.4mm.-Metallic wires of 1mm width spaced by 4mm. -PIN diodes on these wires every 1cm.
b) Lattice of SRR:-Exterior diameter : 3mm and the interior one: 1.75mm.-Discs spaced by 3.1mm (center to center).-Boards spaced every 4mm.-Boards' width: 11mm.
The whole metamaterial: the design.The whole metamaterial: the design.
PIN diodes
Metallic wires
Ek H
11mm
20cm
1cm
Split ringresonators
(SRR)
15cm
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The whole controllable metamaterial: transmissionThe whole controllable metamaterial: transmission
-40
-35
-30
-25
-20
-15
-10
7 8 9 10 11 12
diodes OFF
frequency (GHz)
trans
mis
sion
(dB
)
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Switching between both states of the material-Diodes OFF: reflective material.-Diodes ON: left handed material.
The whole controllable metamaterial: transmissionThe whole controllable metamaterial: transmission
-40
-35
-30
-25
-20
-15
-10
7 8 9 10 11 12
diodes ON
frequency (GHz)
trans
mis
sion
(dB
)
diodes OFF
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Measurement of the negative refractionMeasurement of the negative refraction
LHM
Incidentwave
Refractedwave
Displacement (measured)
The refractive index equals -1.5
0
0.2
0.4
0.6
0.8
1
-6 -4 -2 0 2 4 6
airCLHM
norm
aliz
ed tr
ansm
issi
on
Detector location (cm)
n<0 n>0
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Active Variable Phase Metamaterial Cavity for Directive Antenna
Active Variable Phase Metamaterial Cavity for Directive Antenna
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→ L. Brillouin, “Wave Propagation in Periodic Structures: Electric Filters and Crystal Lattices”, Mc Graw Hill, 1946→ J. R. Pierce, Bell Labs, “Traveling-Wave Tubes”, D. Van Nostrand Company, 1950 Vφ
.vg < 0
Use of metallic motifs with LC resonances
top patch
ground plane
capspost
Unit cell
top patch
sub-patches
ground plane
via
→ D. Sievenpiper, “High impedance electromagnetic surfaces”, PhD 1999
→ C. Caloz et al., “Transmission line approach of left-handed …”, IEEE Trans. Antennas 2004
1D and 2D metamaterials: an old but new concept ?1D and 2D metamaterials: an old but new concept ?
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GoalsGoals
Planar Directive Antenna
in X band.
Compactness (Thickness << λ/4).
Reconfigurable antenna.
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Maximum power at boresight
1
(θ
= 0) is obtained when :
Φprs+Φr-
4 π
h / λo = 2 N πThe resonance thickness is:
ho = (Φprs+Φr) *λo / (4 π) + N* λo / 2
Perfect Reflector (Φr)
Partially Reflective Surface (Φprs)
φ
=2πh/λ
cos(θ)
Eoe-
jφ e-j(2
φ+Φ
prs+
Φr)
Eoe-
jφ
Eoe-
jφ e-2j
(2φ+
Φpr
s+ Φ
r)Eo
e-jφ e-
(n-1
)j (2
φ+Φ
prs+
Φr)
hθ
Patch antenna1
G.V. Trentini, IRE Transactions on Antennas and Propagation, Vol
4, p. 666-671, oct. 1956.
Fabry-Perot cavity antenna: operating principle…Fabry-Perot cavity antenna: operating principle…
We must minimize (Φprs+Φr) to reduce h.
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Ground plane unit cell
Epoxy substrate permittivity : 3.9Dissipation factor : 0.0197Thickness : 1.2 mmLattice : d = 4 mm
3.8 mm
3.6 mm
1.2 mmPRS unit cell
Perfect Reflector (Φr)
Partially Reflective Surface (Φprs)
h Patch antenna
All-metamaterial-based Cavity DesignAll-metamaterial-based Cavity Design
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Incident wave
Incident wave
Ground plane unit cell PRS unit cell
Normal Incidence Reflection Coefficients PhaseNormal Incidence Reflection Coefficients Phase
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Perfect Reflector (Φr)
Partially Reflective Surface (Φprs)
h
Resonance thickness30λ
=hHigh directivity (22 dB)
εr
=3.9δ=0.0197h=1.2 mma=5 mmb=4.8w=2.2 mm
Composite metamaterial
based subwavelength
cavitiesComposite metamaterial
based subwavelength
cavities
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50
h
PRS-AMC
HIS-AMC
Antenna
The Fabry-Perot Cavity antenna: realization.The Fabry-Perot Cavity antenna: realization.
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E PlaneH PlaneRadiation patterns of the Resonant mode at 9.7 GHz for h=1 mm
Optimized Metamaterial-based Cavity Radiation PatternsOptimized Metamaterial-based Cavity Radiation Patterns
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h h
PRS
Patch antenna
Metallic ground plane
φ1 φ2 φ3 φn
E
n
φ3
θ
1 2 3 a
φ1 φ2 φn
Phased array
Steerable
Metamaterial-based cavity operating principleSteerable
Metamaterial-based cavity operating principle
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53
EAntenna
PRS inductive grid
PRS capacitive grid
Substrate
Metallic ground plane
E
EE
Composite metamaterial PRS unit cell
One dimensional composite metamaterial
PRS conceptionOne dimensional composite metamaterial
PRS conception
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Ref
lect
ion
coef
ficie
nt p
hase
(deg
)
Frequency (GHz)
Ref
lect
ion
coef
ficie
nt p
hase
(deg
)
g
w
a
εr
=3.9δ=0.0197h=1,2 mma=5 mmw=2,2 mm
g (µm)
φPRS
(deg)
Reflection phase variation as a function of g at 11 GHz
φPRS
(deg)
Composite metamaterial
PRS AnalysisComposite metamaterial
PRS Analysis
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55Frequency (GHz)
Thic
knes
s h (m
m)
g=600 µm, h=2 mm
2)(
4λφφ
πλ Nh rSPR ±+=
Frequency (GHz)
Ret
urn
loss
(dB
)
Metamaterial-based subwavelength
cavity analysisMetamaterial-based subwavelength
cavity analysis
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hgg-2δgg-3δg g+2δgg+1δg g+3δgg- δg
Metamaterial-based cavity : g=600 µm, δg=100 µm and h=2 mm
Frequency (GHz)
Ret
urn
loss
(dB
)Metallic gap width variation effectMetallic gap width variation effect
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Beam steering by equivalent capacitance variation
PRS disposition
E
gg-2δgg-3δg g+2δgg+1δg g+3δgg- δg_ +
E
PRS disposition
Beam steeringBeam steering
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Metamaterial-based cavity : g=400 µm, h=1 mm.
δg=50 µm δg=100 µm
h~λ/30
δg=0 µm
Realization and characterizationRealization and characterization
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Active Metamaterial
AntennasActive Metamaterial
Antennas
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Active Metamaterial-based Cavity AntennaActive Metamaterial-based Cavity Antenna
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Phase and transmission control.Phase and transmission control.
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h~λ/75
Electronic frequency control of the cavity resonant mode
Antenna directivity increase
E plane H plane
First operating mode: resonance frequency control.First operating mode: resonance frequency control.
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The directivity is improved with the presence of metamaterial
Measured diagram patternMeasured diagram pattern
E-plane (φ
= 90°) H-plane (φ
= 0°)
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These kind of materials can be applied as spatial filters or frequential filters
Can be conformable
Many industrial applications in Telecommunications and Aeronautics
But: huge size at the low frequencies
Solution: the use of metamaterials
Conclusions for the controllable photonic crystalsConclusions for the controllable photonic crystals
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Conclusions about the
radomeConclusions about the
radome
Conclusions:
• Simulations and realization of passive prototypes.• Simulated switching of 27dB at 10GHz. • Measured switching of 24dB at 9.3GHz.• The switching does not alter the directivity of the antenna.
Perspectives:
• Simulations with active elements represented by an equivalent electrical circuit. (PIN diodes and/or photoconductors).• The realization of active prototypes is underway.• Test of the active structure in a real aeronautical radome
(ATR 42).
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Conclusions on metamaterial
+ antennaConclusions on metamaterial
+ antenna
Conformal active antenna.
Passive adjustable steering beam subwavelength cavity antenna.
Antenna directivity enhancement and compactness due to the composite metamaterial
PRS based cavity
Active antenna:1st mode: Electronic frequency control of the cavity resonance.2nd mode: Electronic steering beam subwavelength
antenna.
Conclusions
Perspectives
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PerspectivesPerspectives
ε<0μ<0
ε<0μ>0
ε<0μ<<0
ε>0μ<0
ε<<0μ<0
ε~-1μ
~-1
ε<0μ<0
ε>0μ>0
LHM evanescent
mode LHM LHMwith
no
transmission
LHM evanescent
modewith
no
transmission
LHM RHM
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Many thanks for your attention!Many thanks for your attention!
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-80
-70
-60
-50
-40
-30
-20
-10
0
0 5 10 15 20 25 30 35 40
p p y
S21(15k)
S21(5k)S21(500)
S21(150)S21(50)
S21(0)
Tran
smis
sion
(dB
)
Frˇquence (GHz)
•Transmission of a planar EBG structure made of metallic wires incorporating variable resistors.•The red arrows show the evolution of the allowed and forbidden frequency bands when the
values of the resistors are reduced.
Active EBG structures with variable resistors.Active EBG structures with variable resistors.
3 layers of metallic wires with variable resistors.
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Simulation’s processSimulation’s process
Rectangular TE port
Rectangular TE port
Electric wallMagnetic wall
Meshing
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Spherical and controllable radome 1st
prototype and measurements
Spherical and controllable radome 1st
prototype and measurements