12-04-2011, 09:09 AM
Presented by:-
Saurav Dwivedi
malviya pandit 36.ppt (Size: 602.5 KB / Downloads: 165)
Over view of antenna
A fractal antenna is an antenna that uses a fractal, self-similar design to maximize the length, or increase the perimeter (on inside sections or the outer structure), of material that can receive or transmit electromagnetic radiation within a given total surface area or volume.
Fractal antennas are also referred to as multilevel and space filling curves, but the key aspect lies in their repetition of a motif over two or more scale sizes,[1]or "iterations". For this reason, fractal antennas are very compact, are multiband or wideband, and have useful applications in cellular telephone and microwave communications.
history
The first fractal "antennas" were, in fact, fractal "arrays", with fractal arrangements of antenna elements, and not recognized initially as having self-similarity as their attribute. Log-periodic antennas are arrays, around since the 1950s (invented by Isbell and DuHamel), that are such fractal arrays. They are a common form used in TV antennas, and are arrow-head in shape.
An example of a fractal antenna: a space-filling curve
features
The physical size of the antenna is unrelated to its resonant or broadband performance.
Fractal element antennas are shrunken compared to conventional designs, and do not need additional components.
Electrical resonances may not be directly related to a particular scale size of the fractal antenna structure.
Advantages of fractal
• minituratization.
better input impedance matching
wideband/multiband (use one antenna instead of many)
frequency independent (consistent performance over huge frequency range)
reduced mutual coupling in fractal array
Didvantages
• gain loss
• complexity
• numerical limitations
APPLICATIONS OF FRACTALANTENNAS
Applications include in personal hand held wire less device such as laptops on wireless LAN.
It can also enrich application that include multiband transmission.
Dual mode phone to device integrating.
CONCLUSION
Many variations of fractal geometries have been incorporated into the design of antennas. Further work is required to get an understanding of the relationship between the performance of the antenna and the fractal dimension of the geometry that is utilized in its construction.
Saurav Dwivedi
malviya pandit 36.ppt (Size: 602.5 KB / Downloads: 165)
Over view of antenna
A fractal antenna is an antenna that uses a fractal, self-similar design to maximize the length, or increase the perimeter (on inside sections or the outer structure), of material that can receive or transmit electromagnetic radiation within a given total surface area or volume.
Fractal antennas are also referred to as multilevel and space filling curves, but the key aspect lies in their repetition of a motif over two or more scale sizes,[1]or "iterations". For this reason, fractal antennas are very compact, are multiband or wideband, and have useful applications in cellular telephone and microwave communications.
history
The first fractal "antennas" were, in fact, fractal "arrays", with fractal arrangements of antenna elements, and not recognized initially as having self-similarity as their attribute. Log-periodic antennas are arrays, around since the 1950s (invented by Isbell and DuHamel), that are such fractal arrays. They are a common form used in TV antennas, and are arrow-head in shape.
An example of a fractal antenna: a space-filling curve
features
The physical size of the antenna is unrelated to its resonant or broadband performance.
Fractal element antennas are shrunken compared to conventional designs, and do not need additional components.
Electrical resonances may not be directly related to a particular scale size of the fractal antenna structure.
Advantages of fractal
• minituratization.
better input impedance matching
wideband/multiband (use one antenna instead of many)
frequency independent (consistent performance over huge frequency range)
reduced mutual coupling in fractal array
Didvantages
• gain loss
• complexity
• numerical limitations
APPLICATIONS OF FRACTALANTENNAS
Applications include in personal hand held wire less device such as laptops on wireless LAN.
It can also enrich application that include multiband transmission.
Dual mode phone to device integrating.
CONCLUSION
Many variations of fractal geometries have been incorporated into the design of antennas. Further work is required to get an understanding of the relationship between the performance of the antenna and the fractal dimension of the geometry that is utilized in its construction.