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A Seminar Report

On

INTERACTIVE VOICE RESPONSE

SYSTEM

Bachelor of Technology

In

Electronics & Communication Engineering

Semester- VI

Submitted By

BHUVNESH KUMAR

(2902831001)

DEPARTMENT OF ELECTRONICS & COMM. ENGG.

IDEAL INSTITUTE OF TECHNOLOGYGHAZIABAD (INDIA)

2010-11(Even Sem)

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TABLE OF CONTENT

1. Introduction.................................................................................................................... ..1

2. Background............................................................ ......................................3

2.1 Target Size...3

2.2 Environmental Considerations....3

2.3 Adaptive Active Phased Array Radar.....4

2.3.1 Active Arrays.4

2.3.2 Adaptive Radar Features5

3. Operational Requirements...6

3.1 Radar Roles....6

3.1.1 Volume Surveillance.....6

3.1.2 Detection And Confirmation.7

3.1.3 Target Tracking.7

3.1.4 Target Identification..7

3.1.5Target Trajectory Calculation....8

3.1.6 Tracking Of ECM Emissions...8

3.1.7 Kill Assessment.....8

3.1.8 Missile Communication....8

4. AAPAR Design.......9

4.1 System Design.....9

4.2 Performance Drives...10

4.3 Choice of Frequency.....10

4.4 0perating Bandwidth.....11

4.5 Array Design.....12

4.5.1 Choice Of Elements And Spacing12

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4.5.2 Transmitter Receiver Module...13

4.5.3 Sub Arrays....13

4.5.4 Digital Adaptive Beam Forming..13

4.6 Signal Generation...14

4.7 Signal Processing...15

4.8 Radar Management.....15

5. Summary....16

6. References..17

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1. INTRODUCTION:

In this era of modernization, electricity has become the cup of life. A moment without

electricity makes your thinking go dry. The major source of conventional form of

electricity is through wires. The continuous research and development has brought

forward a major breakthrough, which provides electricity without the medium of wires.

This wonder baby is called WiTricity. There are certain small but very useful discoveries

made in history, which changed the world for ever, Newtons gravitational law, Watts

steam engine, Thomsons bulb and many more. But a renaissance occurred with the

invention of Electromagnetic Waves by Maxwell. Sir Jagdish Chandra Bose successfullygenerated electromagnetic waves having wavelength in the range of 5mm to 25 mm.

Thereafter an Italian scientist named Marconi succeeded in transmitting electromagneticwaves up to a distance of several miles. And with this there started new era called

WIRELESS TECHNOLOGY. Today, as we can see the word wireless is common inday to day life. Wireless communication has made the world smaller. Almost each

and everything is wireless or cordless. Cordless mouse, cordless keyboard, satellite

communication, mobiles, cordless microphones and headphones, wireless internet servicei.e. WIFI, etc. And these have definitely increased the standard of living. In fact it dates

back to the 19th century, when Nikola Tesla used conductionbased systems instead of

resonance magnetic fields to transfer wireless power. As it is in Radiative mode, most of

the Power was wasted and has less efficiency. Further, in 2005, Dave Gerding coined the

term WiTricity which is being used by the MIT researchers today. Moreover, we all are

aware of the use ofelectromagnetic radiation (radio waves) which is quite well known for

wireless transfer of information. In addition, lasers have also been used to transmit energy

without wires. However, radio waves are not feasible for power transmissions because the

nature of the radiation is such that it spreads across the place, resulting into a large

amount of radiations being wasted. And in the case of lasers, apart from requirement of

uninterrupted line of sight (obstacles hinders the transmission process). It is also very

dangerous WiTricity is nothing but wirelesselectricity. Transmission of electrical energyfrom one object to another without the use of wires is called as WiTricity. WiTricity willensure that the cellphones, laptops, iPods and other power hungry devices get charged on

their own, eliminating the need of plugging them in. Even better, because of WiTricitysome of the devices won't require batteries to operate

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2. HISTORY

Nikola Tesla was the first to experiment with wireless electricity, but ultimately failed afterlosing his key financial backings in late 1800s

Nikola Tesla in late 1890s Pioneer of induction techniques His vision for World

Wireless System The 187 feet tall tower to broadcast energy. Tesla was able to transfer

energy from one coil to another coil He managed to light 200 lamps from a distance of

40km The idea of Tesla is taken in to research after 100 years by a team led by Marin

Solace from MIT. The project is named as WiTricity.

The discussion of wireless power transmission as an alternative to transmission linepowerdistribution started in the late 19

th

century. Both Heinrich Hertz and Nicolai Tesla

theorized the possibility of wireless power transmission. Tesla demonstrated it in 1899 by

powering fluorescent lamps 25 miles from the power source without using wires (1).

Despite the novelty of Teslas demonstration and his personal efforts to commercializewireless power transmission, he soon ran out of funding because was much less expensive

to lay copper than to build the equipment necessary to transmit power throughradiowaves.

William C. Brown contributed much to the modern development of microwave powertransmission which for many reasons dominates research and development of wireless

transmission today. In the early 1960s brown invented the rectenna which directly

converts microwaves to DC current. He demonstrated its ability in 1964 by powering ahelicopter from the solely through microwaves.

In 1982, Brown (Raytheon) and James F. Trimer (NASA) announced the development

of a thin-film plastic rectenna using printed-circuit technology that weighed only one-

tenth as much as any previous rectenna (2). This new, lighter weight rectenna led to the

development of the Stationary High Altitude Relay Platform (SHARP). The purpose of

the sharp program, as its name suggests, was to develop unmanned aircraft that would

maintain a circular trajectory above a microwave antenna field for the purpose of relaying

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communications from ground terminals. No commercial development past the prototypestage has been funded.

Despite these advances wireless power transmission has not been adopted for commercialuse except for the sole exception of pacemakers and electric toothbrush rechargers.

However, research is ongoing because of the many promising applications suited for

wireless power transmission.

3. WIRELESS POWER SYSTEM REQUIREMENTS:

The four key parameters identified for the wireless power transfer system design of

interest are: Power must be beamed from four solar power generation stations to five fixed load

Stations. Power received at each facility must be at least 10 kW;

Load stations must receive power from minimum of two generation stations;

Distance between transmitters and receiver ranges from 0.5 km to 2 km.

The beaming frequency, transmit and receive apertures sizes, and overall architecture are

parameters varied in this study to show trends and the potential optimization.

This study considers the following system aspects of a wireless beaming system with

respect to the specifications given above:

1. Top level system architecture this includes a discussion of the distribution of power

from 4 solar power generation stations to 5 load stations, as well as a high-level system

block diagram.

2. Solar power generation overviews the state of the art in PV arrays and discusses

requirements in terms of size and mass for the required 50kW of received power at the

five sites.

3. Power management and distribution describes how the output of the PV arrays is

managed and distributed to microwave transmitters.

4. System grounding on the lunar surface electrostatic and other means are discussed.5. Energy storage describes alternatives and strategies for storage at the transmitter and

site ends.6. RF wireless power transmission consists of a discussion of choice of frequency,

transmitter technology, transmit aperture for given distance, towers for line-of-sightTransmission, rectenna array size and DC reconfiguration. This is the central part of the

study, but it cannot be considered properly without the other parts of the system.

7. System considerations including potential harm to astronauts and thermal issues are

outlined for future more detailed study.

8. Mass and cost of the system is estimated. This is a very rough estimate since there is

significant new work, and detailed analyses and design have not been performed.

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4. OVERALL ARCHITECTURE

The overall architecture for the lunar Wireless Power Transfer (WPT) system is shown inFigure1. Four transmission towers power a total of five load stations, such that each

facility may be powered by at least two towers, and each tower can power up to three

facilities. Each tower can send power in up to three directions using three separate

microwave transmitting antennas. Each arrow represents a directional microwave beam

Figure 1. Top-level diagram of the notional lunar Wireless Power Transfer (WPT)system provides 10 kW to multiple load stations at distances between 0.5 and 2.0 km.

Each arrow represents a directional microwave beam. The length of the arrow is an

indicator of the aperture size of that particular transmit antenna the larger the beaming

distance, the larger the aperture for a given beaming efficiency.

The distances between the transmitters and rectenna arrays are between 0.5 and 2km,

meaning that the farthest facility will be four times further with sixteen times more power

attenuation than the closest facility (assuming identical aperture sizes). The farthest

facility5, is powered by Transmission Tower 2 Transmission Tower 3 Facility 1

Transmission Tower1 Transmission Tower 4 Facility 2 Facility 3 Facility 5 Facility 4

four beams in this scenario, which enables all transmitters to have the same total output

power,. Alternatively, Transmitters 1 and 4 could produce more power than Transmitters

2 and 3, eliminating the beams shown in dashed lines in Figure 1.1.

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Figure 2. Overall power transfer system block diagram for a single powering beam(powering channel). The dashed shaded block outlines the portion of the wireless power

beaming system that should be compared to traditional power transmission lines.

Table 1 : Efficiency budget

The third column shows best reported results for efficiencies, which are not at consistent

frequencies, power levels, etc. Thus, these numbers show an upper limit on the overallefficiency of WPT of around 45%. A relevant comparison needs to take into account

grounding, mass, cost/ease of deployment and reconfigurability, in addition to theefficiency (loss). The WPT approach has the potential to have advantages in terms of

grounding, reconfigurability, mass and cost.

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5. TYPES & TECHNIQUES OF WPT:

Near-field techniques: - Inductive Coupling, Resonant Inductive Coupling, Air Ionization

Far-field techniques : - Microwave Power Transmission (MPT), LASER power

5.1NEAR-FIELD TECHNIQUES:

5.1.1INDUCTIVE COUPLING:

Inductive coupling Primary and secondary coils are not connected with wires. Energytransfer is due to Mutual Induction Transformer is also an example Energy transfer

devices are usually air-cored Wireless Charging Pad(WCP),electric brushes are some

examples On a WCP, the devices are to be kept, battery will be automatically charged

5.1.2RESONANCE INDUCTIVE COUPLING (RIC):

Resonance Inductive Coupling (RIC) Combination of inductive coupling and resonance

makes two objects interact very strongly Inductance induces current

5.1.3AIR IONISATION:

Air Ionization Toughest technique under near-field energy transfer techniques ionizes air

only when there is a high field. Needed field is 2.11MV/m Natural example: Lightening

Not feasible for practical implementation.

ADVANTAGES OF NEAR-FIELD TECHNIQUES:

y No wires no e-waste,

y Need for battery is eliminated,

y Efficient energy transfer using RIC Harmless, if field strengths under safety levels

y Maintenance cost is less.

DISADVANTAGES OF NEAR-FIELD TECHNIQUES:

y Distance constraint Field strengths have to be under safety levels,

y Initial cost Distance is high,

y In RIC, tuning is difficult,

y High frequency signals must be the supply,y Air ionization technique is not feasible.

5.2FAR-FIELD TECHNIQUES:

y Microwave Power Transmission (MPT)

y Laser transmission

y Solar Power Satellite (SPS).

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5.2.1MICROWAVE POWER TRANSFER (MPT):

Microwave Power Transfer (MPT) Transfers high power from one place to another. Two

places being in line of sight usuallySteps: Electrical energy to microwave energy

Capturing microwaves using rectennaMicrowave energy to electrical energy.

AC cannot be directly converted to microwave energy. AC is converted to DC first, DC isconverted to microwaves using magnetron. Transmitted waves are received at rectenna

which rectifies, gives DC as the output DC is converted back to AC

5.2.2LASER TRANSMISSION:

LASER is highly directional, coherent Not dispersed for very long but, gets attenuated

when it propagates through atmosphere Simple receiver Photovoltaic cell Cost-efficient.

5.2.3SOLAR POWER SATELLITE (SPS):

To provide energy to earths increasing energy need To efficiently make use of renewableenergy i.e., solar energy SPS are placed in geostationary orbits. Solar energy is captured

using photocells Each SPS may have 400 million photocells Transmitted to earth in theform of microwaves/LASER Using rectenna/photovoltaic cell, the energy is converted to

electrical energy Efficiency exceeds 95% if microwave is used.

ADVANTAGES OF FAR-FIELD TECHNIQUES:

y Efficient Easy Need for grids, substations etc are eliminated

y Low maintenance cost

y More effective when the transmitting and receiving points are along a line-of-sight

y Can reach the remote areas.

DISADVANTAGES OF FAR-FIELD TECHNIQUES:

y Initial cost is high

y When Initial LASERs are used, conversion is inefficient Absorption loss is highy When microwaves are used, interference may arise.

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6. WPTAPPLICATIONS:

Consumer Electronics

Automatic wireless charging of mobile electronics (phones, laptops, game controllers,

etc.) in home, car, office, Wi-Fi hotspots while devices are in use and mobile. Direct wireless powering of stationary devices (flat screen TVs,digital picture frames,

home theater accessories, wireless loudspeakers, etc.) eliminating expensive customwiring, unsightly cables and wall-wart power supplies.

Direct wireless powering of desktop PC peripherals: wirelessmouse, keyboard, printer,

speakers, display, etc eliminating disposable batteries and awkward cabling.

INDUSTRIAL:

Direct wireless power and communication interconnections across rotating and movingjoints (robots, packaging machinery, assembly machinery, machine tools) eliminating

costly and failure-prone wiring.

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Direct wireless power and communication interconnections at points of use in harshenvironments (drilling, mining, underwater, etc.) where it is impractical or impossible

to run wires. Direct wireless power for wireless sensors and actuators, eliminating the need for

expensive power wiring or battery replacement and disposal

TRANSPORTATION:

Automatic wireless charging for existing electric vehicle classes:golf,carts,

industrial vehicles.

Automatic wireless charging for future hybrid and all-electric passenger and

commercial vehicles, at home, in parking garages, at fleet depots, and at remote kiosks.

Direct wireless power interconnections to replace costly vehicle wiring harnesses and

slip rings.

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7. FEATURES & BENEFITS:

y HIGHLY RESONANT STRONG COUPLING PROVIDES HIGHEFFICIENCY OVER DISTANCE:

WPT mode of wireless power transfer is highly efficient over distances ranging fromcentimeters to several meters. Efficiency may be defined as the amount of usable

electrical energy that is available to the device being powered, divided by the amount of

energy that is drawn by the WPT source. In many applications, efficiency can exceed

90%. And WPTsources only transfer energy when it is needed. When a WPT powered

device no longer needs to capture additional energy, the WPT power source will

automatically reduce its power consumption to a power saving idle state.

y ENERGY TRANSFER VIA MAGNETIC FIELD CAN PENETRATE& WRAP AROUND OBSTACLES:

The magnetic near field has several properties that make it an excellent means oftransferring energy in a typical consumer, commercial, or industrial environment. Most

common building and furnishing materials, such as wood, gypsum wall board, plastics,

textiles, glass, brick, and concrete are essentially transparent to magnetic fields

enabling WPT technology to efficiently transfer power through them. In addition, the

magnetic near field has the ability to wrap around many metallic obstacles that might

otherwise block the magnetic fields. WPT applications engineering team will work with

you to address the materials and environmental factors that may influence wireless energy

transfer in your application

7y NON-RADIATIVE ENERGY TRANSFER IS SAFE:

WPT technology is a non-radiative mode of energy transfer, relying instead on the

magnetic near field. Magnetic fields interact very weakly with biological organisms

people and animalsand are scientifically regarded to be safe. Professor Sir John Pendry

of Imperial College London, a world renowned physicist, explains: The body really

responds strongly to electricfields, which is why you can cook a chicken in a microwave.

But it doesn't respond to magnetic fields. As far as we know the body has almost zero

response to magnetic fields in terms of the amount of power it absorbs." Evidence of the

safety of magnetic fields is illustrated by the widespread acceptance and safety of

household magnetic induction cooktops.

Through proprietary design of the WPT source, electric fields are almost completely

contained within the source. This design results in levels of electric and magnetic fields

which fall well within regulatory guidelines. Thus WPT technology doesnt give rise to

radio frequency emissions that interfere with other electronic devices, and is not a sourceof electric and magnetic field levels that pose a risk to people or animals.

y SCALABLE DESIGN ENABLES SOLUTIONS FROM Mw TO Kw:

WPTsystems can be designed to handle a broad range of power levels. The benefits of

highly efficient energy transfer over distance can be achieved at power levels ranging

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applications as diverse as powering a wireless mouse or keyboard (milliwatts) torecharging an electric passenger vehicle (kilowatts). WPT technology operates in a load

following mode, transferring only as much energy as the powered device requires.

y FLEXIBLE GEOMETRY:

WPT technology is being designed so that it can be easily embedded into a wide variety

of products and systems. The physics of resonant magnetic coupling enables WPTengineers to design power sources and devices of varying shapes and sizes, to match both

the packaging requirements and the power transfer requirements in a given OEMapplication. WPT has designed power capture devices compact enough to fit into a cell

phone.

8. CONCLUSIONS:

Transmission without wires- a reality Efficient Low maintenance cost. But, high initialcost better than conventional wired transfer Energy crisis can be decreased Low loss In

near futureThis concept offers greater possibilities for transmitting power with negligible losses and

ease of transmission than any invention or discovery here to fore made. Dr. Neville ofNASA states You dont need cables, pipes, or copper wires to receive power. We can

send it to you like a cell phone call where you want it, when you want it, in real time.We can expect with certitude that in next few years wonders will be brought by its

applications if all the conditions are favourable.

9. FUTURE SCOPE

This technology opened up the possibility of constructing power stations on the moon.

These power stations will be capable of transmitting power to earth using microwave

energy. These microwave energy would then be converted into electricity using a vast

array of rectenna receivers on the earth.

Moon-based power stations, however, would require maintenance and supervision in

order to be sustainable. Satellite networks would also be needed to transmit microwave

energies to the parts of the earth that are not at the direct line of sight of the moons

power stations. Theres also protest against constant microwave exposure.

Even with all these challenges that face wide-scale application of this new technology,

long-distance wireless power transmission is still being considered as a next-generation

power transmission system for specialized applications.

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10. REFRENCES:

1. http://www.seminarprojects.com

2. Nikola Tesla, My Inventions, Ben Johnston, Ed., Austin, Hart Brothers, p. 91,1982.

3.Nikola Tesla, The Transmission of Electrical Energy Without Wires as a Means forFurthering Peace, Electrical World and Engineer. Jan. 7, p. 21, 1905.

4.W.C. Brown, J.R. Mims and N.I. Heenan, An Experimental Microwave-Powered

Helicopter, 965 IEEE International Convention Record, Vol. 13, Par IEEE Spectrum, May2009

5.http://www.WiTricity.com

6.http://www.WiTricitypower.com

7. http://www.sciencemag.org/cgi/data/1143254/DC1/1