EKTA SEMINAR. on nano antenna

7/29/2019 EKTA SEMINAR. on nano antenna

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NANTENNAMADE BY:EKTA SRIVASTAVA10333321012EN BRANCH3RD YEAR


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INTRODUCTION

HISTORY

THEORY

PRODUCTION

ADVANTAGES

DISADVANTAGES

APPLICATIONS

FUTURESCOPE


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INTRODUCTION

A nantenna (nanoantenna) is ananoscopic rectifying antenna thatconverts solar radiation into electricity,

an idea first proposed by Robert L.Bailey in 1972.It is an electromagnetic collector

designed to absorb specificwavelengths that are proportional tothe size of the nantenna.


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HISTORY


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Currently, Idaho NationalLaboratories has designed a

nantenna to absorb

wavelengths in the range of 3

15 m These wavelengths

correspond to photon energies

of 0.08-0.4 eV.


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Alvin M. Marksreceived apatent in 1984for a deviceexplicitlystating the useof sub-micron

antennas forthe directconversion oflight power toelectrical

power.


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E-beam lithography

was used to fabricatethe arrays of loopnantenna metallicstructures.

The nantenna consists ofthree main parts: theground plane, the opticalresonance cavity, and theantenna


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Nantenna arrays can be designed

to absorb any frequency of light.The frequency of a nantenna canbe selected by varying its length.

Nantenna has high theoreticalefficiency when compared to the

theoretical efficiency of singlejunction solar cells (30%).


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1) At frequencies above infrared,almost all of the current iscarried near the surface of thewire which reduces the effectivecross sectional area of the wire,leading to an increase inresistance. This effect is also

known as theskin

effect
http://en.wikipedia.org/wiki/File:Skin_Effect.pnghttp://en.wikipedia.org/wiki/File:Skin_Effect.pnghttp://en.wikipedia.org/wiki/File:Skin_Effect.pnghttp://en.wikipedia.org/wiki/File:Skin_Effect.pnghttp://en.wikipedia.org/wiki/File:Skin_Effect.png


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2) Another complication- diodes used inlarger scale nantennas cannot operate at THzfrequencies without large loss in power. Thelarge loss in power is a result of the junctioncapacitance (also known as parasitic

capacitance) found in p-n junction diodes andSchottky diodes, which can only operateeffectively at frequencies less than 5 THz.Therefore, alternative diodes need to be used

for efficient power conversion.


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3.Economical large-scale fabrication wouldsupport applications,such as, coating theroofs of buildings .

2. It is usedelectronic devices

for chargingpurposes.

1.The nantennadevices can beoptimized for

collection ofdiscrete bands of emenergy, buildinginsulations and heatdissipation in deviceslike computers.


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Present-day diodes are unable to efficiently

rectify at frequencies which are higher. A

rectifier must be designed that can properly

turn the absorbed light into usable energy.

Another focus of research will be how to

properly upscale the process to mass-marketproduction. New materials will need to be

chosen and tested that will easily comply.

We encourage the scientific community to

consider this technology along with others assources for solar energy.


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EKTA SEMINAR. on nano antenna

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