ELECTRICALLY CONTROLLABLE PCs & METAMATERIALS and THEIR INDUSTRIAL APPLICATIONS. Frédérique GADOT

Transcription

1 ELECTRICALLY CONTROLLABLE PCs & METAMATERIALS and THEIR INDUSTRIAL APPLICATIONS. Frédérique GADOT Université Paris Sud --IEF, Bât. Bât. 220, 220, Orsay, FRANCE 1

2 Outline 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 2

3 Brief story of of LHM 3

4 The 4 electromagnetic states of of materials. Imaginary n Evanescent mode k E S 0 H Left handed material Propagative mode, n: real<0 μ H Right handed material Propagative mode, n: real >0 E ε k S Imaginary n Evanescent mode V.G. Veselago, Soviet Physics Uspekhi 10 (1968) ε 4

5 Material with ε<0 or or μ<0 a (by J.B. Pendry, Imperial College) a 2r A lattice of thin metallic wires is a material with a negative permittivity (for ω < ω p ) where ω p is the plasmon frequency. A lattice of metallic split ring resonators has a negative permeability in some frequency range. J.B. Pendry, PRL 76, pp (1996) J.B. Pendry, IEEE MTT 47, pp (1999) 5

6 Left 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 (2000) 6

7 How to to measure the index of of refraction of of a LHM? Experimental verification of a negative index of refraction R. Shelby, D. R. Smith and S. Schultz, Science, 292, 77 (2001) 7

8 Index of of refraction of of a LHM: measurement Experimental verification of a negative index of refraction R. Shelby, D. R. Smith and S. Schultz, Science, 292, 77 (2001) 8

9 Applications of of left handed materials (LHM) Negative refraction Perfect lens α β vacuum LHM Source LHM ε=-1, μ=-1 Negative refraction makes a perfect lens J. B. Pendry, Phys. Rev. Lett., 85, 3966 (2000) 9

10 Controllable wire array 10

11 Lattice of continuous metallic wires: a first forbidden band appears from 0Hz. Lattice of discontinuous metallic wires: an allowed band replaces the first forbidden band. Controllable structure: the concept Transmission (db) Transmission (db) A. de Lustrac et al., APL 75 (11), pp (1999) Frequency (GHz) Frequency (GHz) Frequency (GHz) Frequency (GHz) 11

12 First prototype for EADS (1-5GHz) 12

13 and its first measurement. 13

14 Controllable wires 0 Box = vacuum Plasmon band d In blue: diode -5 13dB diodes ON diodes OFF Dark blue: Printed board -10 E Wires= Perfect conductors -15 Forbidden band f 0 Incident wave -20 Diodes ON = Continuous wires Diodes OFF = Cut wires f (GHz) 14

15 2 nd nd prototype with printed stripes 15

16 and its measurements (around 10GHz) All diodes ON Transmission (db) (1) (2) (3) (4) Central board diodes OFF Backward board diodes OFF All diodes OFF -40 9, , ,5 12 Frequency (GHz) 16

17 Application: controllable radome Applications: Applications: radomes radomes intelligents intelligents Application: controllable radome Antenne seule diodes ON diodes OFF Amplitude (db) plaques espacées de 9 mm devant une antenne patch à GHz. 350 Patch antenna working at 12GHz Pattern diagram of the patch antenna with radome at 12,01GHz. 17

18 Industrial applications: Conformable and Controllable structures for antennas 18

19 Base Station for mobile communication 5 layers of wires with diodes 15 Schematical design of the base station antenna Wide-band antenna GHz 19

20 Characterization of of the first prototype at at 0.9GHz 20

21 Multilayers structure: optimization of of the aperture of of the 2 nd nd prototype Does it work for the 3 frequency bands? (db) 2.17GHz 1.8GHz 1GHz 0.89GHz Source seule

22 Fabrication of of the 2 nd nd prototype 22

23 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 23

24 4 layers 2 nd nd prototype: one aperture one beam Measurements and simulations at at 0.9, 1.75 and 2.0GHz measurements simulations 24

25 Spherical and Controllable radome 25

26 Goals 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 wires 2. 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. 26

27 Design of of the structure z 3 configurations : Continuous wires (allowed band) Discontinuous wires with p1=11mm (forbidden band) Discontinuous wires with p2=5.5mm (allowed band) O p y a Discontinuities simulated as capacitance C=30fF. Diameter 32 cm. p1 and p2 are the projections on the horizontal plane. x Schematic structure simulated in Microstripes 27

28 Simulations of of the spherical and controllable radome 0-10 Transmission (db) horn continuous wires discontinuous wires p1=11mm discontinuous wires p2=5.5mm -60 Frequency (GHz)

29 Prototype: Design and Test with a horn antenna. Horn antenna inside the radome. Discontinuities width 0.1mm Wires width 1mm printed on a flexible support Foam (permittivity close to 1) 29

30 Measurements of of the prototype with the antenna GHz horn continuous wires discontinuous wires p1 discontinuous wires p2 0 24dB dB Gain (db) antenna alone discontinuous wires p1 =11mm continuous wires discontinuous wires p2= 5.5mm Gain (db) Frequency (Ghz) -15 Angle (degree) GHz

31 Measurements of of the prototype with the weather radar antenna Weather radar antenna Gain (db) dB weather antenna continuous wires discontinuous wires p2=5.5mm discontinuous wires p1 0-5 angle () The switching level is 15dB. The directivity of the antenna is unchanged. 31

32 From the wire lattice to to the LHM 32

33 Control of of the permittivity diodes on diodes off diodes off diodes on transmission(db) real(eps) f(ghz) f(ghz) boards of metallic wires with PIN diodes: the switch of the transmission and the permittivity for the 2 states of the diodes. 33

34 Transmission of of metallic stripes diodes ON diodes OFF -10 diodes ON diodes OFF transmission (db) E transmission (db) E diodes Incident wave frequency (GHz) frequency (GHz) Comparison of the transmission through 1 and 2 boards of metallic wires with PIN diodes 34

35 Permeability of of the Split Ring Resonators r = 1.5 mm, c=d=e=0.25mm. The permeability is negative at the beginning and the end of the rejection. c r e d 0 10 Transmission (db) real (permeability) simulation measurement Frequency (GHz) frequency (GHz) calculation for 1 disc 35

36 A first passive prototype 36

37 Transmission of of the LHM: measurement and calculation 2mm 0 simulation measurement mm transmission (db) The first prototype. -50 f (GHz)

38 Measurement of of the whole controllable LHM 38

39 The whole metamaterial: the design. 15cm Split ring resonators (SRR) 20cm k 1cm E H Metallic wires 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. PIN diodes 11mm 39

40 The whole controllable metamaterial: transmission diodes OFF -20 transmission (db) frequency (GHz) 40

41 The whole controllable metamaterial: transmission -10 diodes ON -15 diodes OFF -20 transmission (db) frequency (GHz) Switching between both states of the material -Diodes OFF: reflective material. -Diodes ON: left handed material. 41

42 Measurement of of the negative refraction 1 Incident wave LHM Refracted wave Displacement (measured) normalized transmission n<0 n>0 air CLHM Detector location (cm) The refractive index equals

43 Active Variable Phase Metamaterial Cavity for Directive Antenna 43

44 1D and 2D metamaterials: an old but new concept? 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 V φ.v g < 0 Use of metallic motifs with LC resonances D. Sievenpiper, High impedance electromagnetic surfaces, PhD 1999 C. Caloz et al., Transmission line approach of left-handed, IEEE Trans. Antennas 2004 top patch top patch via post caps sub-patches ground plane ground plane Unit cell 44

45 Goals Planar Directive Antenna in X band. Compactness (Thickness << λ/4). Reconfigurable antenna. 45

46 Fabry-Perot cavity antenna: operating principle Maximum power at boresight 1 (θ = 0) is obtained when : Φprs+Φr- 4 π h / λo = 2 N π The resonance thickness is: ho = (Φprs+Φr) *λo / (4 π) + N* λo / 2 We must minimize (Φprs+Φr) to reduce h. φ =2πh/λ cos(θ) Eo e -jφ Eo e -jφ e -j(2φ+φprs+ Φr) Eo e -jφ e -2j (2φ+Φprs+ Φr) Eo e -jφ e -(n-1)j (2φ+Φprs+ Φr) h θ Partially Reflective Surface (Φprs) Patch antenna 1 G.V. Trentini, IRE Transactions on Antennas and Propagation, Vol 4, p , oct Perfect Reflector (Φr) 46

47 All-metamaterial-based Cavity Design PRS unit cell 1.2 mm 3.6 mm 3.8 mm Ground plane unit cell h Patch antenna Epoxy substrate permittivity : 3.9 Dissipation factor : Thickness : 1.2 mm Lattice : d = 4 mm Partially Reflective Surface (Φprs) Perfect Reflector (Φr) 47

48 Normal Incidence Reflection Coefficients Phase Incident wave Incident wave Ground plane unit cell PRS unit cell 48

49 Composite metamaterial based subwavelength cavities h Partially Reflective Surface (Φprs) Perfect Reflector (Φr) ε r =3.9 δ= h=1.2 mm a=5 mm b=4.8 w=2.2 mm Resonance thickness High directivity (22 db) h = λ 30 49

50 The Fabry-Perot Cavity antenna: realization. PRS-AMC h Antenna HIS-AMC 50

51 Optimized Metamaterial-based Cavity Radiation Patterns H Plane E Plane Radiation patterns of the Resonant mode at 9.7 GHz for h=1 mm 51

52 Steerable Metamaterial-based cavity operating principle φ 1 φ 2 φ 3 φ n PRS h h E Patch antenna Metallic ground plane θ φ 1 φ 2 φ 3 φ n a Phased array n 52

53 One dimensional composite metamaterial PRS conception E E PRS inductive grid E E Antenna PRS capacitive grid Substrate Composite metamaterial PRS unit cell Metallic ground plane 53

54 a Composite metamaterial PRS Analysis Reflection coefficient phase (deg) g φ PRS (deg) w ε r =3.9 δ= h=1,2 mm a=5 mm w=2,2 mm g(µm) Reflection coefficient phase (deg) φ PRS (deg) Frequency (GHz) Reflection phase variation as a function of g at 11 GHz 54

55 Metamaterial-based subwavelength cavity analysis g=600 µm, h=2 mm h = λ ( φspr + φr ) ± 4π N λ 2 Thickness h (mm) Return loss (db) Frequency (GHz) Frequency (GHz) 55

56 Metallic gap width variation effect h g-3δg g-2δg g- δg g g+1δg g+2δg g+3δg Return loss (db) Frequency (GHz) Metamaterial-based cavity : g=600 µm, δg=100 µm and h=2 mm 56

57 PRS disposition Beam steering PRS disposition E g-3δg g-2δg g- δg g g+1δg g+2δg g+3δg _ + E Beam steering by equivalent capacitance variation 57

58 Realization and characterization Metamaterial-based cavity : g=400 µm, h=1 mm. h~λ/30 δg=0 µm δg=50 µm δg=100 µm 58

59 Active Metamaterial Antennas 59

60 Active Metamaterial-based Cavity Antenna 60

61 Phase and transmission control. 61

62 First operating mode: resonance frequency control. h~λ/75 Electronic frequency control of the cavity resonant mode Eplane Hplane Antenna directivity increase 62

63 Measured diagram pattern E-plane (φ = 90 ) H-plane (φ = 0 ) The directivity is improved with the presence of metamaterial 63

64 Conclusions for the controllable photonic crystals 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 64

65 Conclusions 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). 65

66 Conclusions Conclusions on metamaterial + antenna Antenna directivity enhancement and compactness due to the composite metamaterial PRS based cavity Passive adjustable steering beam subwavelength cavity antenna. Active antenna: 1st mode: Electronic frequency control of the cavity resonance. 2nd mode: Electronic steering beam subwavelength antenna. Perspectives Conformal active antenna. 66

67 Perspectives ε<0 ε<0 μ<0 μ>0 LHM evanescent mode ε<<0 ε~-1 μ<0 μ ~-1 LHM LHM with no transmission ε<0 μ<0 ε>0 μ>0 LHM RHM ε<0 μ<<0 ε>0 μ<0 LHM evanescent mode with no transmission 67

68 Many thanks for your attention! 68

69 Active Active EBG EBG structures structures with with variable variable resistors. resistors. 0 p p y layers of metallic wires with variable resistors. Transmission (db) S21(15k) S21(5k) -60 S21(500) S21(150) S21(50) -70 S21(0) 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. 69

70 Simulation s process process Rectangular TE port Magnetic wall Electric wall Rectangular TE port Meshing 70

71 Spherical and controllable radome 1 st st prototype and measurements 71