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

2

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

3

Brief story of LHMBrief story of LHM

4

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)

5

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)

6

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)

7

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)

8

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)

9

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

10

Controllable wire arrayControllable wire array

11

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0

0 10 20 30 40 50

Tran

smis

sion

(dB

)Frequency (GHz)

a first forbidden band appears

from 0Hz. Frequency

(GHz)

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-30

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-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)

12

First prototype for EADS (1-5GHz)…First prototype for EADS (1-5GHz)…

13

…and its first measurement.…and its first measurement.

14

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

15

2nd

prototype with printed stripes…2nd

prototype with printed stripes…

16

… and

its

measurements

(around

10GHz).… and

its

measurements

(around

10GHz).

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-25

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-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

17

Applications: radomes intelligents…Applications: radomes intelligents…

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-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

18

Industrial applications: Conformable and Controllable structures

for antennas

Industrial applications: Conformable and Controllable structures

for antennas

19

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

20

Characterization of the first prototype at 0.9GHzCharacterization of the first prototype at 0.9GHz

21

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

22

Fabrication of the 2nd

prototypeFabrication of the 2nd

prototype

23

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

24

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

25

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.

27

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

28

Simulations of the spherical and controllable radomeSimulations of the spherical and controllable radome

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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)

29

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.

30

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

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horncontinuous wiresdiscontinuous wires p1discontinuous wires p2

Gai

n (d

B)

Angle (degree)

31

Measurements of the prototype with the weather radar antenna

Measurements of the prototype with the weather radar antenna

Weather radar antenna

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-5

0

5

10

15

20

25

30

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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.

32

From the wire lattice to the LHMFrom the wire lattice to the LHM

33

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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)

34

Transmission of metallic stripes.Transmission of metallic stripes.

Comparison of the transmission through 1 and 2 boards of metallic wires with PIN diodes

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-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

35

Permeability of the Split Ring ResonatorsPermeability of the Split Ring Resonators

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-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

36

A first passive prototypeA first passive prototype

37

Transmission of the LHM: measurement and calculationTransmission of the LHM: measurement and calculation

The

first

prototype.

2mm

150mm

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-10

0

8 10 12 14 16

simulation measurement

f (GHz)

trans

mis

sion

(dB

)

38

Measurement of the whole controllable LHMMeasurement of the whole controllable LHM

39

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

40

The whole controllable metamaterial: transmissionThe whole controllable metamaterial: transmission

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-10

7 8 9 10 11 12

diodes OFF

frequency (GHz)

trans

mis

sion

(dB

)

41

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

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-15

-10

7 8 9 10 11 12

diodes ON

frequency (GHz)

trans

mis

sion

(dB

)

diodes OFF

42

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

43

Active Variable Phase Metamaterial Cavity for Directive Antenna

Active Variable Phase Metamaterial Cavity for Directive Antenna

44

→ 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 ?

45

GoalsGoals

Planar Directive Antenna

in X band.

Compactness (Thickness << λ/4).

Reconfigurable antenna.

46

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.

47

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

48

Incident wave

Incident wave

Ground plane unit cell PRS unit cell

Normal Incidence Reflection Coefficients PhaseNormal Incidence Reflection Coefficients Phase

49

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

50

h

PRS-AMC

HIS-AMC

Antenna

The Fabry-Perot Cavity antenna: realization.The Fabry-Perot Cavity antenna: realization.

51

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

52

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

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

54

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

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

56

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

57

Beam steering by equivalent capacitance variation

PRS disposition

E

gg-2δgg-3δg g+2δgg+1δg g+3δgg- δg_ +

E

PRS disposition

Beam steeringBeam steering

58

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

59

Active Metamaterial

AntennasActive Metamaterial

Antennas

60

Active Metamaterial-based Cavity AntennaActive Metamaterial-based Cavity Antenna

61

Phase and transmission control.Phase and transmission control.

62

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.

63

The directivity is improved with the presence of metamaterial

Measured diagram patternMeasured diagram pattern

E-plane (φ

= 90°) H-plane (φ

= 0°)

64

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

65

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).

66

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

67

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

68

Many thanks for your attention!Many thanks for your attention!

69

-80

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-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.

70

Simulation’s processSimulation’s process

Rectangular TE port

Rectangular TE port

Electric wallMagnetic wall

Meshing

71

Spherical and controllable radome 1st

prototype and measurements

Spherical and controllable radome 1st

prototype and measurements