1

A Term Paper

On

CELL PHONE JAMMER

Submitted by:

Sameer Gupta B.Tech (E&C), III Semester

Under the Guidance of

Ms. Sally Goyal

Amity School of Engineering

AMITY UNIVERSITY RAJASTHAN

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CERTIFICATE

This is to certify that the Report entitled Cell Phone jammer

submitted by Sameer Gupta with Enrolment No.A20405110036

on October 2011 is his own work and has been carried out under

my supervision. It is recommended that the candidate may now

be evaluated for his work by the University.

(STUDENT) (GUIDE) Signature: Signature:

Designation:

Date:

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ACKNOWLEDGEMENT

The completion of any task is not only the reward to the persons actively

involved in accomplishing it, but also the people involved in inspiring,

guiding and helping those people.

I take opportunity here to thank all those who have helped me in the completion of

this seminar, without whom the seminar indeed would have been, quite a difficult

task.

I would like to express my deepest gratitude to my Mentor,

Ms. Sally Goyal for his able guidance during the course of preparation of this

seminar.

B.Tech.

Second Year

Electronics and communication Engg.

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------------Index------------

1. Abstract-----------------------------------------------------5

2. History------------------------------------------------------6

3. Introduction to cell phone jammer---------------------8

4. Cell phone jamming basics------------------------------8

5. Cell phone jammer device-------------------------------8

6. Design Parameters----------------------------------------9

7. Component cell phone jammer-------------------------11

7.1 Power supply--------------------------------------11

7.2 Circuitry--------------------------------------------12

7.3 Antenna---------------------------------------------12

8. How cell phone jammer work---------------------------12

9. jamming techniques---------------------------------------13

10. Types of cell phone jammer device---------------------14

11. Cell phone jammer applications-------------------------19

12. Cell phone jammer legal issues--------------------------20

13. Alternatives to cell phone jamming---------------------21

14. Conclusion--------------------------------------------------22

15. Bibliography------------------------------------------------23

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1. Abstract

The last few years have witnessed a dramatic boom in the wireless communications industry,

hence increasing the number of users of mobile communication devices. This magnified the need

for a more efficient and reliable signal scrambler. This paper deals with the Mobile Jamming

Technology. The concept of jamming technology is studied in a step-by-step approach. The

mobile jammer in the frequency range of 890MHz to 960MHz (GSM) is developed. Its circuit

analysis simulation is performed using Speace-spice Software. Antenna simulation is done by

using IE3D software [8]. The jammer circuit is designed with minimum cost and high efficiency.

The jammer jams the signal within five meter effective radius. Index terms– Antenna, Jammer,

Wide band frequency.

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2. History

The rapid proliferation of cell phones at the beginning of 21st century to near ubiquitous status

eventually raised problems such as their potential use of invade privacy or contribute to rampant

and egregious academic cheating. In addition public black lash privacy or contribute to rampant

The rapid proliferation of cell phones at the beginning of the 21st century to near

ubiquitous status eventually raised problems such as their potential use to invade privacy or

contribute to rampant and egregious academic cheating. In addition public backlash was growing

against the intrusive disruption cell phones introduced in daily life. While older analog cell

phones often suffered from chronically poor reception and could even be disconnected by simple

interference such as high frequency noise, increasingly sophisticated digital phones have led to

more elaborate counters. Cell phone jamming devices are an alternative to more expensive

measures against cell phones, such as Faraday cages, which are mostly suitable as built in

protection for structures. They were originally developed for law enforcement and the military to

interrupt communications by criminals and terrorists. Some were also designed to foil the use of

certain remotely detonated explosives. The civilian applications were apparent, so over time

many companies originally contracted to design jammers for government use switched over to

sell these devices to private entities. Since then, there has been a slow but steady increase in their

purchase and use, especially in major metropolitan areas.

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Cell phone jammer

Device

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3. Introduction to cell phone jammer

Cell phones are everywhere these days. According to the Cellular Telecommunications

and Internet Association, almost 195 million people in the United States had cell-phone service

in October 2005. And cell phones are even more ubiquitous in Europe.

It's great to be able to call anyone at anytime. Unfortunately, restaurants, movie theaters,

concerts, shopping malls and churches all suffer from the spread of cell phones because not all

cell-phone users know when to stop talking. Who hasn't seethed through one side of a

conversation about an incredibly personal situation as the talker shares intimate details with his

friend as well as everyone else in the area?

While most of us just grumble and move on, some people are actually going to extremes

to retaliate. Cell phones are basically handheld two-way radios. And like any radio, the signal

can be disrupted, or jammed.

4. Cell Phone Jamming Basics

Disrupting a cell phone is the same as jamming any other type of radio communication.

A cell phone works by communicating with the service network through a cell toweras base

station. Cell towers divide a city into small areas,or cells. As a cell phone user drives down the

street, the signal is handed from tower to tower. Jammer disrupting the communication between

the phone and the cell phone base station in the tower. It’s called denial-of-service attack.

The jammer denies service of the radio spectrum to the cell phone users within range of

the jamming device as shown in figure bellow.

5. Cell Phone Jamming Device

Jamming devices overpower the cell phone by transmitting a signal on the same

frequency and at a high enough power that the two signals collide and cancel each other out.

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Cell phones are designed to add power if they experience low-level interference, so the

jammer must recognize and match the power increase from the phone.

Cell phones are full-duplex devices, which means they use two separate frequencies, one

for talking and one for listening simultaneously. Some jammers block only one of the

frequencies used by cell phones, which has the effect of blocking both. The phone is tricked into

thinking there is no service because it can receive only one of the frequencies.

Less complex devices block only one group of frequencies, while sophisticated jammers

can block several types of networks at once to head off dual-mode or tri-mode phones that

automatically switch among different network types to find an open signal. Some of the high-end

devices block all frequencies at once, and others can be tuned to specific frequencies.

To jam a cell phone, all you need is a device that broadcasts on the correct frequencies.

Although different cellular systems process signals differently, all cell-phone networks use radio

signals that can be interrupted. GSM, used in digital cellular and PCS-based systems, operates in

the 900-MHz and 1800-MHz bands in Europe and Asia and in the 1900-MHz (sometimes

referred to as 1.9-GHz) band in the United States. Jammers can broadcast on any frequency and

are effective against AMPS, CDMA, TDMA, GSM, PCS, DCS, iDEN and Nextel systems. Old-

fashioned analog cell phones and today's digital devices are equally susceptible to jamming.

The actual range of the jammer depends on its power and the local environment, which

may include hills or walls of a building that block the jamming signal. Low-powered jammers

block calls in a range of about 30 feet (9 m). Higher-powered units create a cell-free zone as

large as a football field. Units used by law enforcement can shut down service up to 1 mile (1.6

km) from the device.

6. Design Parameters

Based on the above, our device which is related to the DOS technique is transmitting

noise on the same frequencies of the two bands GSM 900 MHz, and GSM 1.8 GHz (known also

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as DCS 1800 band). We focused on some design parameters to establish the device

specifications. These parameters are as follows:

6.1 The distance to be jammed (D)

This parameter is very important in our design, since the amount of the output power of the

jammer depends on the area that we need to jam. Later on we will see the relationship between

the output power and the distance D. Our design is established upon D=10 meters for DCS 1800

band and D=20 meters for GSM 900 band.

6.2 The frequency bands

UPLINK

(Handset

transmit)

DOWNLINK

(Handset

receive)

USED IN

JORDAN

BY:

GSM 900 890-915

MHz 935-960

MHz

Zain + Orange

DCS 1800 1710-1785

MHz

1805-1880

MHz

Umniah

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6.3 Jamming–to-signal ratio {J/S}

Jamming is successful when the jamming signal denies the usability of the

communication transmission. In digital communications, the usability is denied when the error

rate of the transmission can not be compensated by error correction. Usually, a successful

jamming attack requires that the jammer power is roughly equal to signal power at the receiver

(mobile device).

The general equation of the jamming-to-signal ratio is given as follows:

where: Pj=jammer power, Gjr= antenna gain from jammer to receiver, Grj=antenna gain from

receiver to jammer, Rtr=range between communication transmitter and receiver,

Br=communication receiver bandwidth, Lr =communication signal loss, Pt=transmitter power,

Gtr= antenna gain from transmitter to receiver, Grt=antenna gain from receiver to transmitter,

Rjr=range between jammer and communication receiver, Bj=jammer bandwidth, and

Lj=jamming signal loss.

For GSM, the specified system SNRmin is 9 dB which will be used as the worst case scenario

for the jammer. The maximum power at the mobile device Pr is -15 dBm.

6.4 Free space loss {F}

The free-space loss (or path loss) is given by:

The maximum free space loss (worst case F) happens when the maximum frequency is used in

the above equation. Using 1880 MHz gives:

F (dB) =32.44+20 log 0.01 + 20 log 1880 which gives F =58 dB.

7. Component of Cell Phone Jammers

Electronically speaking, cell-phone jammers are very basic devices. The simplest just have

an on/off switch and a light that indicates it's on. More complex devices have switches to activate

jamming at different frequencies. Components of a jammer include:

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7.1 Power supply

Smaller jamming devices are battery operated. Some look like cell phone and use cell-phone

batteries. Stronger devices can be plugged into a standard outlet or wired into a vehicle's

electrical system.

7.2 Circuitry

The main electronic components of a jammer are:

7.2.1 Voltage-controlled oscillator - Generates the radio signal that will interfere

with the cell phone signal

7.2.2. Tuning circuit - Controls the frequency at which the jammer broadcasts its

signal by sending a particular voltage to the oscillator

7.2.3 Noise generator - Produces random electronic output in a specified

frequency range to jam the cell-phone network signal (part of the tuning

circuit)

7.2.4 RF amplification (gain stage) - Boosts the power of the radio frequency

output to high enough levels to jam a signal

7.2.5 Check your phone - If the battery on your phone is okay, and you'd like to

continue your conversation, try walking away from the area. You may be

able to get out of the jammer's range with just a few steps.

7.3 Antenna

Every jamming device has an antenna to send the signal. Some are contained rical cabinet. On

stronger devices, antennas are external to provide longer range and may be tuned for

individual frequencies.

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8. How Cell Phone Jammers Work

Cell phone jammers work in a similar way to radio jammers by sending out the same

radio frequencies that cell phones operate on. Doing so creates enough interference so that a call

cannot connect with a cell phone. There are two types of cell phone jammers currently available.

The first type are usually smaller devices that block the signals coming from cell phone towers to

individual cell phones. The frequency blocked is somewhere between 800MHz and 1900MHz.

Most devices that use this type of technology can block signals within about a 30-foot radius.

Cell phones within this range simply show no signal.

The second type of cell phone jammer is usually much larger in size and more powerful.

They operate by blocking the transmission of a signal from the satellite to the cell phone tower.

Some powerful models can block cell phone transmissions within a 5 mile radius. It should be

noted that these cell phone jammers were conceived for military use.

Once again, it should be noted that operating or even owning a cell phone jammer is

illegal in most municipalities and specifically so in the United States. Many businesses such as

theaters and restaurants are trying to change the laws in order to give their patrons better

experience instead of being consistently interrupted by cell phone ring tones.

9. Jamming techniques

9.1 Type “A” Device (JAMMERS):

This type of device comes equipped with several independent oscillators transmitting ’jamming

signals’ capable of blocking frequencies used by paging devices as well as those used by cellular

systems control channels for call establishment.

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9.2 Type “B” Device (Intelligent Cellular Disablers):

Unlike jammers, Type ”B” devices do not transmit an interfering signal on the control channels.

The device, when located in a designated ’quite’ area, functions as a ’detector’. It has a unique

identification number for communicating with the cellular base station.

9.3 Type “C” Device (Intelligent Beacon Disablers):

Unlike jammers, Type C devices do not transmit an interfering signal on the control channels.

The device, when located in a designated ’quiet’ area, functions as a ’beacon’ and any

compatible terminal is instructed to disable its ringer or disable its operation, while within the

coverage area of beacon.

9.4 Type “D” Device (Direct Receive & Transmit Jammers):

This jammer behaves like a small, independent and portable base station, which can directly

interact intelligently or unintelligently with the operation of the local mobile phone. The jammer

is predominantly in receive mode and will intelligently choose to interact and block the cell

Phone directly if it is within close proximity of the jammer.

9.5 Type E Device (EMI Shield - Passive Jamming):

This technique is using EMI suppression techniques to make a room into what is called Faraday

cage. Although labor intensive to construct, the Faraday cage essentially Blocks or greatly

attenuates, virtually all electromagnetic radiation from entering or leaving the cage - or in this

case a target room.

10. Types of cell phone jammer device

There are many types of cell phone jammer device which is used in our daily life .as

we take a example of class room ,where we does not want to use of cell phone than there we

can use cell phone jammer device .by this we can produce the interface between the cell phone

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station and jamming device. resulting it disconnect the cell from base station .and wecan not

recive the any calls from base station.

For this there are many types of cell phone jammer devices which is given as below:

o cell phone jammer

o Portable cell phone jammer

o Remote control cell phone jammer

o Adjustable cell phone jammer

o School &prison phone jammer

o Explosion-proof cell phone jammer

o Police &military phone jammer

One of the cell phone jammer device is “single knight brand ultra-thin cell phone jammer”

Model: SK-6 Ultra-thin Cell phone Jammer

Introduction:

SK-6 cell phone jammer is more and more popular used in examination halls, examination

rooms, test rooms, libraries and so on. The cell phone jammer is the best instrument can help

examiners to prevent students cheating with cellular phones in the examinations. SK-6 cell

phone jammer is the latest electronic product which transmits low power radio signals to block

the communication signal bandwidths in GSM, CDMA, PHS, DCS, IDEN, UMTS, GPS, WiFi,

Bluetooth, etc. Beijing Signal Knight is a professional cell phone jammer manufacturer based in

China Beijing; we can design and develop any types of cell phone jammers for different clients’

demands. Nowadays, the cell phone jammer has become the necessity for schools, universities,

testing centers, and so on.

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Features of SK-6 Cell phone Jammer

Show the working power on the shell with green lights

Prevent cheating by using cellphone in the examinations

Keeping you away from the noise or disturbance of unexpected cellphone calls or SMS in the

class time or meeting time.

Mini-size medium power cellphone jammer

Low weight and Nice texture and color

To block wireless phone communication links within an effective area.

No transmissions or receptions of cellphone call in coverage area.

All specified frequency bands will be blocked simultaneously.

How to Install:

1. Install this device at the height about 1.5-1.7m will get the best jamming result, keep all the

antennas in vertical.

2. Never install this device close to the wall; the wall will affect the interference signals. Put

this device 30-50cm away from the wall.

3. One set of this device can block all types of cellular system including analog (AMPS,

TACS, NMT) and digital (GSM, DCS, PDC, TDMA, PHS, PCS, iDEN, CDMA,

WCDMA) signals up to 30m radius, covers an individual room of around 2800 square

meters.

4. To cover an area bigger than 2800 square meters, please install multiples of this device to

ensure better jamming effect, e.g. in an individual space of 3500 square meters, you should

need to install 2 or more devices working together.

5. This device is not able to cover different spaces divided with walls. Install individual

jammers in different partition of a building to ensure the best jamming effect.

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Specification:

SK-6 Ultra-thin Cellphone Jammer SPECIFICATION

Jamming Area 0.5meters to 30meters

(Depends on signal strength, at the site to be jammed)

Cellular Systems

Output Frequency

Option A for Asian Market

CDMA 860-894MHz

GSM 925-960MHz

PHS 1900-1925MHz

3G 1990-2170MHz

Option B for Europe Market

CDMA 860-894Mhz

GSM 925-960MHz

DCS 1805-1850MHz

3G 1990-2170MHz

Option C for American Market

CDMA 850-894Mhz

GSM900 920-960Mhz

GSM1800 1710-1880MHz

CDMA2000, 3G 1990-2170Mhz

Power Adapter Input AC160V-240V, DC5V

Total Output Power 8Watt

Dimension Product Antennas off: L 23x W 9 x H 2 cm Package: L

29x W 15x H 11 cm

Weight Product weight:0.2kg Package weight: 1.5kg

Accessory 1 power adapter, 1 jammer, 4 antennas

Working Time 12 hours/ Day

Relative Humidity 20%--95%

Working

Temperature -40~ +55 deg C

Antennas installation Install the antennas corresponding to the channel label. If not,

the jammer will be very hot when it works.

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How to operate the SK-6 Cellphone Jammer:

1. Install the antennas fully correctly in vertical firstly.

2. Plug the power adaptor into the electricity outlet (110V-240V)

3. Before turn on the power switch, always check if the antennas are installed securely. If you

turn on the power switch without the antennas installed on this device, it shall heavily

damage this device. Never remove the antennas when the device is working; otherwise

you will void the warranty.

Notice of Use SK-6 Cell phone Jammer:

Be sure to connect all the antennas firstly before the power supply is switch on. Please do

not take off antennas when the machine is working. Otherwise, it should cause heavy damage to

the device and cause the device out of work. It will also void warranty.

Antennas shall be used vertical to the ground, working more efficiently.

Please don’t put the jammer in the water and fire to avoid using in the bad. Condition of

over-wet, over-hot, high-voltage and high magnetism.

Use several units in the same place will get bigger coverage area.

For better performance indoors, use this device in an individual space. The device is not

able to cover different spaces divided with walls. Install individual jammer in different partition

of a building to ensure the best jamming result.

The jamming area is influenced by the location of the cell tower and the obstacles

between cell tower & the cell phone jammer. It means that in normal condition if the distance is

close between the cell tower & the cell phone jammer, it will have very less jamming area.

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Likewise, if there are obstacles & walls between the cell tower & the cell phone, the cell phone

jammer will give less jamming area.

Usually, at the same place, you will get longer jamming distance indoor, because the wall

and floor will reduce the base station signal strength.

Any ruin and disrepair caused by incorrect operation and disassembly will exclude from the

repair with free of charge.

1. Unauthorized repair or dismantle of this device will void all the warranties.

2. Antennas shall be used vertical to the ground, working more efficiently.

3. Please do not take off antennas when the machine is working. Otherwise, it should cause

heavy damage to the device and cause the device out of work. It will also void warranty.

4. Install the antennas before switch on the device, otherwise will heavy damage the jammer.

5. Persons with Pacemaker implants are prohibited from using this device.

6. Avoid water; over-wet, over-hot, high-voltage and high magnetism.

7. Do not store this device in an excessively hot place.

8. Avoid knocks or dropping this device.

Effect is worse in outdoor. Strictly speaking, whether using indoor or outdoor, the effective

distance of interference is related to the surrounding around, for example the distance

between different base stations, positions of installation etc.

11. Cell Phone Jammer Applications

Cell phone jamming devices were originally developed for law enforcement and the

military to interrupt communications by criminals and terrorists. The bombs that blew up

commuter trains in Spain in March 2004, as well as blasts in Bali in October 2002 and Jakarta in

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August 2003, all relied on cell phones to trigger explosives. It has been widely reported that a

cell-phone jammer thwarted an assassination attempt on Pakistani President Musharraf in

December 2003. When President Bush visited London in November 2004, it was reported that

British police considered using jammers to protect the president's motorcade through London.

During a hostage situation, police can control when and where a captor can make a phone

call. Police can block phone calls during a drug raid so suspects can't communicate outside the

area. Cell-phone jammers can be used in areas where radio transmissions are dangerous, (areas

with a potentially explosive atmosphere), such as chemical storage facilities or grain elevators.

The TRJ-89 jammer from Antenna System & Supplies Inc. carries its own electrical generator

and can block cellular communications in a 5-mile (8-km) radius.

Corporations use jammers to stop corporate espionage by blocking voice transmissions and

photo transmissions from camera phones. On the more questionable end of the legitimacy

spectrum, there are rumors that hotel chains install jammers to block guests' cell-phone usage

and force them to use in-room phones at high rates

.

12. Cell Phone Jamming Legal Issues

In the United States, United Kingdom, Australia and many other countries, blocking cell-

phone services (as well as any other electronic transmissions) is against the law. In the United

States, cell-phone jamming is covered under the Communications Act of 1934, which prohibits

people from "willfully or maliciously interfering with the radio communications of any station

licensed or authorized" to operate. In fact, the "manufacture, importation, sale or offer for sale,

including advertising, of devices designed to block or jam wireless transmissions is prohibited"

as well.

Jamming is seen as property theft, because a private company has purchased the rights

to the radio spectrum, and jamming the spectrum is akin to stealing the property the company has

purchased. It also represents a safety hazard because jamming blocks all calls in the area, not

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just the annoying ones. Jamming a signal could block the call of a babysitter frantically trying to

contact a parent or a someone trying to call for an ambulance.

The Federal Communications Commission is charged with enforcing jamming laws.

However, the agency has not yet prosecuted anyone for cell-phone jamming. Under the U.S.

rules, fines for a first offense can range as high as $11,000 for each violation or imprisonment for

up to one year, and the device used may also be seized and forfeited to the government.

In most countries, it is illegal for private citizens to jam cell-phone transmission, but

some countries are allowing businesses and government organizations to install jammers in areas

where cell-phone use is seen as a public nuisance. In December 2004, France legalized cell-

phone jammers in movie theaters, concert halls and other places with performances. France is

finalizing technology that will let calls to emergency services go through. India has installed

jammers in parliament and some prisons. It has been reported that universities in Italy have

adopted the technology to prevent cheating. Students were taking photos of tests with their

camera phones and sending them to classmates.

With phones ringing in movies, weddings and classrooms, it's no wonder people want to

tone down the intrusion. So what legally can be done to stop annoying cell-phone use?

13. Alternatives to Cell Phone Jamming

While the law clearly prohibits using a device to actively disrupt a cell-phone signal, there

are no rules against passive cell-phone blocking. That means using things like wallpaper or

building materials embedded with metal fragments to prevent cell-phone signals from reaching

inside or outside the room. Some buildings have designs that block radio signals by accident due

to thick concrete walls or a steel skeleton.

Companies are working on devices that control a cell phone but do not "jam the signal."

One device sends incoming calls to voicemail and blocks outgoing calls. The argument is that

the phone still works, so it is technically not being jammed. It is a legal gray area that has not

been ruled on by the FCC as of Apr-+il 2005.

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Cell-phone alerters are available that indicate the presence of a cell-phone signal. These

have been used in hospitals where cell-phone signals could interfere with sensitive medical

equipment. When a signal is detected, users are asked to turn off their phones.

For a less technical solution, Coudal Partners, a design firm in Chicago, has launched the

SHHH, the Society for HandHeld Hushing. At its Web site, you can download a note to hand

to people conducting annoying cell-phone conversations, expressing your lack of interest in what

they're talking about.

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14. Conclusion

On observing the output of the frequency spectrum the VCO output is varies from 890MHz to

960MHz. This output is fed to MMG3001 and it is found that the mobile jammer blocks the

mobile signal in 8-meter effective radius. All the circuit output are constructed and observed

using the Electronic work bench. The simulation result and practical result are found to be

approbatory equal. The gain of the project is that we are able to block communication coming

into and going out from a GSM phone operating on the 890MHz to 960MHz frequency band.

We are also able to reach 8-meter effective blocking radius and keep the cost less.

At last we can say every device is acts as good aspects as well as bad aspects. In many

place cell phone jammer is useful but at many place it is a problem .for this we can take a

example that if at any place cell phone jammer is on than anybody wants to use than there

creates some problems.

But it’s overall performance is very good and helpful in our life.

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15. Bibliography

www.HowStuffWork.com

En.wikipedia.org/wiki/Mobile_phone _jammer

Multitopic conference,2008.INMIC 2008.IEEE International

"Zone of silence [cell phone jammer]," Spectrum, IEEE , vol.42, no.5,

18, May 2005

Sami Azzam, Ahmad Hijazi, Ali Mahmoudy. ”Smart Jammer for mobile phone

systems”

Mobile & Personal Communications Committee of the Radio Advisory Board of

Canada, “Use of jammer and disabler Devices for blocking PCS, Cellular & Related

Services”

"Zone of silence [cell phone jammer]," Spectrum, IEEE , vol.42, no.5, 18, May 2005

G. K. H. Lui and R. D. Murch, Compact dual frequency PIFA designs using LC

resonators, IEEE Trans Antennas Propagat., vol. 49, pp. 10161019, July 2001.

M. T. Huynh and W. L. Stutzman, Ground plane effects on PIFA antennas, USNC/URSI

Radio Science.Meeting Digest, p. 223, 2000.

IE3D, Zeland Software. IE3D Users Manual Release 8, Zeland Software Incorporated.

M. Ali, S. S. Stuchly, and K. Caputa, A wide band dual meandersleeve antenna, J.

Electromagn. Waves

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