02-01-2013, 12:48 PM
METAMATERIAL ANTENNA
[attachment=46128]
INTRODUCTION
What is an antenna?
What is metamaterial?
What is metamaterial antenna?
METAMATERIAL
Materials may be categorized by their constitutive parameters ε and μ
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition
Metamaterials consist of periodic structures. An electromagnetic metamaterial affects electromagnetic waves by having structural features smaller than the wavelength of the respective electromagnetic wave.
Single Negative Metamaterials (SNG)
either relative permittivity (εr) or relative permeability (µr) are negative, but not both
Epsilon negative media (ENG) and Mu-negative media (MNG)
In ENG, εr is negative while µr is positive
In MNG, εr is positive while µr is negative
In ENG and MNG, the waves are not allowed to propagate into uniform medium
PROPERTIES OF METAMATERIALS
Negative refractive index
Reverse Doppler effect
Backward Cerenkov effect
Reversal of goos-hanchen effect
Lensing effect
Subwave length focusing
the phase velocity would be anti-parallel to the direction of Poynting vector
Reverse Doppler effect
When a moving receiver detects the radiation coming from a source at rest in a uniform medium, the detected frequency of the radiation depends on the relative velocity of the emitter and the receiver. This is the Doppler effect
if the medium is a left-handed material, wave propagation is backward
Backward Cerenkov effect
Cerenkov radiation occurs when a charged particle enters an ordinary medium at a velocity higher than the velocity of light in such a medium.
If the deceleration of this particle is not too high, its velocity can be considered constant
METAMATERIAL TRANSMISSION LINE
Resonant and Non-resonant(Transmission line) approaches
In resonant, it has lossy, Narrow bandwidth, High Q-factor, SRR’s
In Non-resonant, lossless, wide bandwidth
CRLH is a combination of RH and LH materials
Metamaterial microstrip Antenna
A resonance structure called split ring resonator (SRR) is selected for the MTM design
SRR can generate a magnetic resonance causing a negative real part of permeability
The antenna is designed to operate at 2.4 GHz. The size of the antenna is 48mm x 48mm
returning loss of S11 is at 2.45GHz
The directions of the excitation wave (k), electric (E) and magnetic (H) fields influence the occurrence of magnetic resonance.
CONCLUSION
Metamaterials are artificial materials engineered to have properties that may not be found in nature
Metamaterial technology provide an opportunity to design an antenna of smaller size at lower cost with better radiation performance
Metamaterial antennas have few commercial applications. Mobile phone type BL-40 from LG, and a wireless router from Netgear use them.
[attachment=46128]
INTRODUCTION
What is an antenna?
What is metamaterial?
What is metamaterial antenna?
METAMATERIAL
Materials may be categorized by their constitutive parameters ε and μ
Metamaterials are artificial materials engineered to have properties that may not be found in nature. Metamaterials usually gain their properties from structure rather than composition
Metamaterials consist of periodic structures. An electromagnetic metamaterial affects electromagnetic waves by having structural features smaller than the wavelength of the respective electromagnetic wave.
Single Negative Metamaterials (SNG)
either relative permittivity (εr) or relative permeability (µr) are negative, but not both
Epsilon negative media (ENG) and Mu-negative media (MNG)
In ENG, εr is negative while µr is positive
In MNG, εr is positive while µr is negative
In ENG and MNG, the waves are not allowed to propagate into uniform medium
PROPERTIES OF METAMATERIALS
Negative refractive index
Reverse Doppler effect
Backward Cerenkov effect
Reversal of goos-hanchen effect
Lensing effect
Subwave length focusing
the phase velocity would be anti-parallel to the direction of Poynting vector
Reverse Doppler effect
When a moving receiver detects the radiation coming from a source at rest in a uniform medium, the detected frequency of the radiation depends on the relative velocity of the emitter and the receiver. This is the Doppler effect
if the medium is a left-handed material, wave propagation is backward
Backward Cerenkov effect
Cerenkov radiation occurs when a charged particle enters an ordinary medium at a velocity higher than the velocity of light in such a medium.
If the deceleration of this particle is not too high, its velocity can be considered constant
METAMATERIAL TRANSMISSION LINE
Resonant and Non-resonant(Transmission line) approaches
In resonant, it has lossy, Narrow bandwidth, High Q-factor, SRR’s
In Non-resonant, lossless, wide bandwidth
CRLH is a combination of RH and LH materials
Metamaterial microstrip Antenna
A resonance structure called split ring resonator (SRR) is selected for the MTM design
SRR can generate a magnetic resonance causing a negative real part of permeability
The antenna is designed to operate at 2.4 GHz. The size of the antenna is 48mm x 48mm
returning loss of S11 is at 2.45GHz
The directions of the excitation wave (k), electric (E) and magnetic (H) fields influence the occurrence of magnetic resonance.
CONCLUSION
Metamaterials are artificial materials engineered to have properties that may not be found in nature
Metamaterial technology provide an opportunity to design an antenna of smaller size at lower cost with better radiation performance
Metamaterial antennas have few commercial applications. Mobile phone type BL-40 from LG, and a wireless router from Netgear use them.