E

k

H

S

My name : Khalid Saeed Al-Badri

My supervisor

Yrd. Doç. Dr. EVREN EKMEKÇİ Assistant Professor: Electronics and Communication

Engineering

METAMATERIAL BACKGROUND

Do not depend on the chemical composition

Depend on the geometry of the structure units. [1]

Metamaterials are artificial engineered composite structures.

Not commonly found in nature.[2]

BACKGROUND

0

0

0

0

0

0

0

0

DPS MNG ENG DNG

SNG

𝜀 , 𝜇

METAMATERIAL BACKGROUND

NEGATIVE REFRACTION INDEX

How to achieve negative refraction index ?

rrn

Negative refraction can be achieved when (µr and εr ) are negative

)(1

)(

))()((

)()()(

2/2/

rr

rr

j

rr

jj

rr

jj

rr

e

ee

ee

RIGHT HANDED & LEFT HANDED

E

H

Right-handed Medium

k S

DPS medium

E

k

H

Left-handed Medium

S

DNG medium

NEGATIVE REFRACTION INDEX

DPS

𝑛1 sin 𝜃1 = 𝑛2 sin 𝜃2

DNG

2

NEGATIVE REFRACTION INDEX

Fig. 1. (a) Calculated ray-tracing image of a metal rod in an empty drinking glass. (b) Same

scenery, but the glass is filled with normal water, n 1.3 , leading to ordinary refraction. (c)

The water is replaced by “water” with a fictitious refractive index of n 1.3 .[5]

*Gunnar Dolling and Martin Wegener :Photorealistic images of objects in effective negative-index materials, 6 March 2006 / Vol. 14, No. 5 / OPTICS EXPRESS 1843

OTHER NAMES

Negative Refraction Index Material

Backward Material

Double Negative Material

Left handed Material

E

k H

S

INVERSE DOPPLER EFFECT

NEGATIVE PERMITTIVITY

T THIN WIRE MESH MEDIA

The EM wave:

perpendicular to the

wires

The wires behaves as

an ideal plasma

E H

P

NEGATIVE PERMITTIVITY

T THE IMPORTANT THINKS IN THIN WIRE MESH MEDIA

The lattice constant a

a << λ The radius of wire

r << a

𝜺𝒓𝒛 = 𝜺𝟎 𝟏 −𝒌𝒑

𝟐

𝒌𝟎𝟐−𝒌𝒛

𝟐

z

y

x

𝒌𝒑𝟐 = 𝝎𝒑

𝟐𝜺𝟎𝝁𝟎 ,

𝜸 𝟐 = 𝒌𝟎𝟐 − 𝒌𝒛

𝟐 ,

𝜸 = 𝑹/𝑳

𝒌𝟎𝟐 = 𝝎𝟐𝜺𝟎𝝁𝟎 ,

𝒌𝒛 is the wavevector along the wires’

axis

NEGATIVE PERMITTIVITY

SCHELKUNOFF CONFIGURATION

X

y

H

Metallic closed loop

Loading

loop with capacitor.

Will get -μ above

resonance

f

SCHELKUNOFF CONFIGURATION

Difficult manufacture at microwave frequencies

May be needed hundreds or, perhaps, thousands of elements

The disadvantage in this design

SPLIT RING RESONATOR (SRR)

The dimensions of SRR

is very small comparing

with waveleng

SRR owns –𝝁 within a

frequency band (narrow

bandwidth) and near the

resonant frequency of

the single SRR

EDGE-COUPLED (EC-SRR)

EC-SRR

Print it on dielectric

board

Two metallic

rings

Make smalls

cut in each

rings

Put a space

between two

rings

EDGE-COUPLED (EC-SRR)

EC-SRR EQUIVALENT CIRCUIT:

• The two rings works as

capacitor

• The slot behave as an

electric dielectric

• The high distributed of

charge at the end of ring’s

cut

EDGE-COUPLED (EC-SRR)

Self-inductance

capacitance 𝝅𝒓𝑪𝒑𝒖𝒍

𝒓 = 𝒓𝒆𝒙𝒕 − 𝒄 − 𝒅/𝟐

𝑪𝒑𝒖𝒍 : Capacitance

per unit length

The total capacitance 𝑪

𝟐

𝝎𝟎 =𝟐

𝑳𝑪=

𝟐

𝝅𝒓𝑪𝒑𝒖𝒍𝑳

EDGE-COUPLED (EC-SRR)

The frequency of resonance cannot be

made too small.

Cannot be reduced in practice

much smaller than 𝝀/𝟏𝟎

Cpul cannot be increased too much

by reducing d

EDGE-COUPLED (EC-SRR)

Cross-polarization effects in the EC-SRR

Electric and

magnetic excitation.

Magnetic excitation

only.

Electric excitation

only.

No excitation.

THE BROADSIDE-COUPLED SRR BC-SRR

Two metallic

rings

printed at both sides

Both

sides of

dielectric

THE BROADSIDE-COUPLED SRR BC-SRR

Frequency of resonance and normalized electrical size (2rext/ 𝜆)

for several EC-SRRs external radius rext = 0.6 mm and ring width

c= 0.2mm, printed on several dielectric substrates

THE NONBIANISOTROPIC SRR NB-SRR

Avoid EC-SRR

bianisotropy.

f of resonance and

equivalent circuit same

as of EC-SRR with similar

dimensions.

THE NONBIANISOTROPIC SRR NB-SRR

Electric and magnetic

excitation.

Magnetic excitation

only.

No excitation.

No excitation.

SPIRALS 2-SR

fresonance= 𝟏

𝟐 frequency of EC-SRR.

The electrical size can still be

reduced by increasing the number

of turns

2-SR nonbianisotropic design.

SWISS ROLL

Anisotropic metamaterial.[3]

It is well suited to operation in (RF) range, because it has a

low resonant frequency and a strong magnetic response.[4]

Example: Swiss Roll

material operating at

21.5 MHz for which

λ/a > 1000 (where a

is the unit cell size).

DOUBLE-SIDED SRR (DSRR)

EC-SRR(1)

dielectric board

EC-SRR(2)

EFFECTIVE MEDIUM

There are many possible periodic or nonperiodic combinations of

SRRs that provide an effective medium

EFFECTIVE MEDIUM

𝝎𝟏 = 𝝎𝟎 𝟏 +𝜶𝒆

𝟑𝑲𝜺𝟎𝒂𝟑+

𝝁𝟎𝜶𝒎

𝟑𝒂𝟑

−𝟏

Where:

𝑲 = 𝟏 −𝜶𝟎

𝟑𝒂𝟑𝜺𝟎 ,

𝜶𝒎 =𝝅𝟐𝒓𝟒

𝑳 ,

𝜶𝒆 = 𝟒𝒅𝟐𝒆𝒇𝒇

𝒓𝟐𝑪𝒑𝒖𝒍𝟐𝑳

𝝎𝟎𝟐

𝝎

𝟐

METAMATERIAL BASED ON THIN WIRES AND SRRS

REFERENCES

[1] Tatjana Asenov,Nebojša Dončovm ,Bratislav Milovanović: Application of Metamaterials for the Microwave Antenna

Realisations, SERBIAN JOURNAL OF ELECTRICAL ENGINEERING Vol. 9, No. 1, February 2012, 1-7

[2] MARQUES, RICARDO , FERRAN MARTIN and MARIO SOROLLA. Metamaterials with Negative Parameters:

Theory, Design, and Microwave Applications. John Wiley & Sons, Inc., 2008.

[3] M. C. K. Wiltshire and J. V. Hajnal, Metamaterial endoscope for magnetic field transfer: near field imaging with

magnetic wires, 2003 OSA 7 April 2003 / Vol. 11, No. 7 / OPTICS EXPRESS 713

[4] M C Kwiltshire, J B Pendry, An effective medium description of 'Swiss Rolls', a magnetic metamaterial, IOP

PUBLISHING JOURNAL OF PHYSICS: CONDENSED MATTER, 19 (2007) 456216 (16pp)

[5] Gunnar Dolling and Martin Wegener :Photorealistic images of objects in effective negative-index materials, 6 March

2006 / Vol. 14, No. 5 / OPTICS EXPRESS 1843

[6] A. Ishimaru, S. Jaruwatanadilok, and Y. Kuga by there research ( GENERALIZED SURFACE PLASMON

RESONANCE SENSORS USING METAMATERIALS AND NEGATIVE INDEX MATERIALS) Progress In

Electromagnetics Research, PIER 51, 139–152, 2005