Wavelength Dependent Microwave Devices Based on Metamaterial Technology. Professor Bal Virdee BSc(Eng) PhD CEng FIET

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1 Wavelength Dependent Microwave Devices Based on Metamaterial Technology by Professor Bal Virdee BSc(Eng) PhD CEng FIET

Conventional material Meta material Polarizable

2 EM response of materials are determined by the spatial distribution of its atoms and molecules. Conventional material Meta material Polarizable atoms Artificial atoms Magnetic polarizability Form effective medium

Metamaterials (eft-handed Materials ) Artificially structured materials in sub-wavelength scale Electromagnetic (EM) properties derive from shape and distribution of constituent units (usually

3 Metamaterials (eft-handed Materials ) Artificially structured materials in sub-wavelength scale Electromagnetic (EM) properties derive from shape and distribution of constituent units (usually metallic & dielectric components) EM properties not encountered in natural materials EM properties Electrical permittivity Magnetic permeability Enables the engineering of electromagnetic properties

4 Metamaterials Negative electrical permittivity () Negative magnetic permeability () n n v 1 v 1 Z Negative ε, μ, n Novel and unique propagation characteristics in those materials!

5 If both ε and µ are negative, how does n = -1? 1 e 1 e e e e e n Metamaterials 1 e

6 E-field EM wave propagation in a real materials k E vg v p S > 0, > 0 (ight-handed) H propagation H-field

7 E-field Novel phenomena in left-handed materials E vg v p k S k S H H > 0, > 0 < 0, < 0 (ight-handed) (eft-handed) E vg v p S E H E-field propagation propagation H-field H-field Backwards propagation (opposite phase & energy velocity)

8 H propagation phenomena

$Negative efraction H material n > 0 n > 0 n < 0 Snell s aw n1 sin n sin$

9 Negative efraction H material n > 0 n > 0 n < 0 Snell s aw n1 sin n sin i 1 n 1 t sin sin i n t ight bends in the wrong way for n 1 > 0 and n < 0

10 Applications Miniaturization High-speed circuits High resolution imaging systems Highly sensitive biomedical sensors Superlens Cloaking

Historical background Victor Veselago Sir John Pendry David Smith V G

$Nauk 9, 517-56 (1967) J B Pendry, Negative refraction makes a perfect lens,$ PHYSICA EVIEW ETTES 85, 3966-3969 (1999) D Smith, et al.

11 Historical background Victor Veselago Sir John Pendry David Smith V G Veselago, The electrodynamics of substances with simultaneously negative values of eps and mu, Usp. Fiz. Nauk 9, (1967) J B Pendry, Negative refraction makes a perfect lens, PHYSICA EVIEW ETTES 85, (1999) D Smith, et al., Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefficients, Phys. ev. B, 65, 1-5, (000)

12 How to create arbitrary? z p (a) Thin-wire structure ε < 0, μ > 0 if E z pe pe pe r ( ) 1 1 ( ) r 0, for pe

13 How to create arbitrary and? (a) Thin-wire structure ε < 0, μ > 0 if E z (b) Split-ring resonator (S) structure ε > 0, μ < 0 if H y 0 0 ) ( ) ( 1 ) ( ) ( 1 1 ) ( m m r pe pe pe r F F pm m m r pe r F 1 for 0, for 0, 0 0 y p z p

14 esonance interpretation in terms of equivalent circuits DS C: capacitance per unit length : inductance per unit length S l l g / l g /: half-wavelength split-ring resonator

15 S medium will have a magnetic dipole moment per unit volume: Calculation Pendry et al, 99

16 S medium will have a magnetic dipole moment per unit volume: Around resonance, large induced currents lead to strong magnetic dipole response. Calculation Pendry et al, 99

17 Copper S, 0.7 cm size 1 cm pitch lattice, l=.5 cm S medium will have a magnetic dipole moment per unit volume: Around resonance, large induced currents lead to strong magnetic dipole response. r F 1 o Q o Calculation Pendry et al, 99

Experimental Verification Detector Microwave absorber ε < 0, μ < 0 Microwave beam Sample Microwave absorber H material (Prism) Unit cell: 5 mm Operating

18 Experimental Verification Detector Microwave absorber ε < 0, μ < 0 Microwave beam Sample Microwave absorber H material (Prism) Unit cell: 5 mm Operating wavelength: 3 cm (8-1 GHz) adius of circular plates: 15 cm Detector was rotated around the circumference of circle in 1.5 degree steps UCSD, Science 9,

19 Experimental Verification. A. Shelby, D.. Smith and S. Schultz, Experimental verification of a negative refractive index of refraction, Science, vol. 9, pp , Apr. 001.

20 Experimental Verification. A. Shelby, D.. Smith and S. Schultz, Experimental verification of a negative refractive index of refraction, Science, vol. 9, pp , Apr. 001.

$Schultz, Experimental verification of a negative refractive index of refraction,$

21 Cloaking at microwaves. A. Shelby, D.. Smith and S. Schultz, Experimental verification of a negative refractive index of refraction, Science, vol. 9, pp , Apr. 001.

22 Cloaking at microwaves A A: Naked metal cyllinder exposed to microwave

23 Cloaking at microwaves A B A: Naked metal cyllinder exposed to microwave B: Metal cyllinder wrapped with metamaterial structure

24 Cloaking at optical wavelengths Invisible man become a reality?

25 C Z C Y g p c C v C v C Y Z Z C C Z Y (H T series /shunt C) unit-cell

26 C C Z 1 Y 1 C Z C Y g p c C v C v C Y Z Z C C C Z Y g p c C v C v C Y Z Z C C Z Y Anti-parallel (H T series /shunt C) (H T series C/shunt ) unit-cell unit-cell

27 Composite ight/eft-handed Metamaterial C (Fm) C (Hm) se C < / unit-cell sh < / ight-hand gap C (Fm) c (Hm) < / purely H se CH c eft-hand gap l g

28 Composite ight/eft-handed Metamaterial C (Fm) C (Hm) se C < / unit-cell sh < / ight-hand gap c C (Fm) < / (Hm) CH purely H sh purely H CH c se (Hm) < / C (Fm) eft-hand gap l g

29 Composite ight/eft-handed Metamaterial C (Fm) C (Hm) se C < / unit-cell sh < / ight-hand gap C (Fm) c purely H l g Balanced CH guide wavelength 1 C 1 C < / purely H (Hm) sh CH c o se CH (Hm) < / C (Fm) eft-hand gap l g

30 CH Transmission-line Implementation unit-cell d microstrip line T-unction series shunt interdigital spiral capacitor inductor unit-cell via to ground interdigital capacitors CH line shorted stub inductors lg/

31 CH Transmission-line ight-hand gap c CH interdigital capacitors CH line sh purely H CH o se purely H shorted stub inductors lg/ c eft-hand gap l g H 0 H

32 Metamaterial Phase Shifter and B Coupler Compact phase shifters 0.1 mm Compact branch-line coupler 7 % size reduction MM branch-line coupler MM phase shifter Plated via to ground 43 % size reduction 8.70 mm Inter-digital capacitor

33 Metamaterial Couplers High coupling edge-coupled coupler (3dB Power splitter implementation) High directivity (over 40 db) and high isolation (over 70 db) coupler 3dB coupler prototype

34 Metamaterial Dual-Band at ace Coupler

35 Metamaterial Filter 5 db/div 1-pole filter Metamaterial design (mm) Conventional design (mm) 1 I = db 1 = db 0. 4 Start GHz GHz Stop GHz Transmission and reflection coefficient response of the 1-pole H microstrip filter

36 Metamaterial Filter 5 db/div 3-pole filter Metamaterial design (mm) Conventional design (mm) I = -3.7 db 1 = db Start GHz GHz Stop GHz Transmission and reflection coefficient response of the 3-pole H microstrip filter

37 Metamaterial Energy Harvester 5-cell MM antenna array Converts ambient F/microwave energy from 3G, 4G, WiFi hub, HDTV etc. into about 7 V of electricity with an efficiency of 36.8% - comparable to a solar cell.

38 Metamaterial eflector A conventional reflector (curved PEC) in the virtual space A flat reflector (flat PEC) in the manipulated physical space

39 Metamaterial eflector Conventional reflector Flat reflector ϕ =0

40 Metamaterial Patch Antenna

Metamaterial Electronically Scanned Antenna series varactor shunt varactor asin k 0 DC block bias wires Preliminary esults Z 0 C C C 1 C 0-1 10 30 o 90 0 o

41 Metamaterial Electronically Scanned Antenna series varactor shunt varactor asin k 0 DC block bias wires Preliminary esults Z 0 C C C 1 C o 90 0 o o 0 V0 0 V 5 V5 5 V 15 V 15 V 7 V 7 V o o o H H 0-90 o 3.49 GHz 3.49 GHz; scanning range is +35 to -9 7V

Cloaking The Road to Realization

Cloaking The Road to Realization by Reuven Shavit Electrical and Computer Engineering Department Ben-Gurion University of the Negev 1 Outline Introduction Transformation Optics Laplace s Equation- Transformation