MULTIBAND JAMMER

By

MUHAMMAD NAOU BAHARReg. No.92036

ABDULLAH TAHIRReg. No.92044USMAN ALIReg. No.92093

A Report submitted to theDepartment of Electrical Engineering

In partial fulfillment of the requirements for the degree ofBACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

Federal Urdu University of Arts, Science and TechnologyIslamabad, 44000, Pakistan

July, 2013

Copyright 2013 by FUUAST

All rights reserved. Reproduction in whole or in part in any form requires the prior written permission of Group members (as mention above) or designated representative.

ii

Dedication

We dedicate our beloved parents and respected teachers………………….

iii

CERTIFICATE OF APPROVAL

It is certified that the final year project’s work titled “MULTIBAND JAMMER” is carried out by Muhammad Naou Bahar Reg. No. 92036, Abdullah Tahir Reg. No 92044, Usman Ali Reg.No.92093 under the supervision of Engr. MUHAMMAD SAEED, at Federal Urdu University of Arts Science and Technology, Islamabad. It is fully adequate, in scope and in quality, as a thesis for the degree of BS of Electronic Engineering.

Supervisor: -------------------------Engr. Muhammad Saeed

Assistant Professor Dept. of Electrical Engineering

Federal Urdu University of Arts, Science, and Technology, Islamabad

Internal Examiner: --------------------------

ProfessorDept. of Electrical Engineering

Federal Urdu University of Arts, Science, and Technology, Islamabad

External Examiner: ----------------------------Engr. Syed Junaid Nawaz

Assistant Professor Dept. of Electrical Engineering

CIIT, Islamabad

Head of Department: ----------------------------Dr. M. Zamin Ali Khan

Dept. of Electrical EngineeringFederal Urdu University of Arts, Science, and Technology, Islamabad

iv

ACKNOWLEDGMENT

Many of our friends and our lab engineer’s support us in our project. We got extra literature related with our project from them.

I wish to express my appreciation to my project supervisor Engr. Muhammad Saeed, who provided many valuable suggestions and constructive criticism that greatly

influenced this project.

DECLARATION

It is declared that the work entitled “MULTIBAND JAMMER” presented in this report is an original piece of my own work, except where otherwise acknowledged in text and references. This work has not been submitted in any form for another degree or diploma at any university or other institution for tertiary education and shall not be submitted by me in future for obtaining any degree from this or any other University or Institution.

MUHAMMAD NAOU BAHARReg. No.92036

ABDULLAH TAHIRReg. No. 92044

USMAN ALIReg. No.92093

July 2013

PREFACE

Project is important in the curriculum for those students who are studying professional education. Its successful is very important.

The study remains incomplete without the useful/practical knowledge. Academic knowledge is not sufficient so one requires practical knowledge also. So it is important for every student to undertake a project.

Now days in the competitive age having a different perspective providing a Leading edge .Electronics projects provides insight to students about the way the Work is done in industries. It helps in systematically aligning students with the work Culture of Practical Area.

ABSTRACT

Now days, privacy is a serious issue due to rapid growth in mobile communication; Mobile phones became a part of our life, even if we are in meeting, public library, schools, and Conference centers which interrupt the privacy. Moreover there is high chance of surprises leakage of defense meeting and terrorists use technological tools for terrorist activities.

This report contained a concise design of multiband mobile phone jammer that could jam the signals by providing a dead zone to the communication media and that can also be used by special personalities while travelling to any other place to protect from any terrorist activities.

This project completed in two steps:

Step 1: Study the best and cost effective jamming technique, establishing the system design and select suitable components.

Step 2: Buying the components, drawing the simulations, fabricate the components, taking measurements and testing of multiband jammer.

At the end this designed jammer was successful in jamming the FM, AM, TV channels and GSM-signals at the end of report.

TABLE OF CONTENTS

Acknowledgment ..................................................................................................... v

Declaration .............................................................................................................. vi

Preface……………………………………………………………………………viiAbstract. ................ ……………………………………………………………... viii

Table of Contents .................................................................................................... ix

List of Figures ......................................................................................................... xi

List of Tables ........................................................................................................xiii

List of Acronyms/Abbreviations ...........................................................................xiv

Chapter 1Introduction and Jamming Histroy ....................................21.1 History of jamming……………………………………………………….3

1.2 World War 2……………………………………………………………....3

1.3 Cold war era………………………………………………………………..3

1.4 Mobile jamming history……………………………………………………4

Chapter 2Literature review ..................................................................6Chapter 3Tools and techniques …………...........................................83.1 Jamming Techniques .................................................................................... 8

3.2 Jamming design Parameters ......................................................................... 9

3.1 Frequency bands ………………………………………………………....10

3.2 Distance to be jammed…………………………………………………...11

3.3 Jamming-to-signal ratio…………………………………………………...11

3.4 Free path losses…………………………………………………………...11

3.5 Power calculations………………………………………………………..12

Chapter 4Methodologies and Implementation ..................................144.1 Circuit Analysis………………………………………………………….17

4.1.1 The IF-section…………………………………………………………....20

4.1.2 The RF-section…………………………………………………………...30

4.1.3 Antenna…………………………………………………………………..35

Chapter 5Results and Analysis

5.1 Hardware Results ........................................................................ 42

Chapter 6Conclusion ...........................................................................50

References ............................................................................50

LIST OF FIGURE

Figure-2.1 Figure Caption ....................................................................................... 6

Figure-3.1 Figure Caption ....................................................................................... 9

Figure-4.1 Figure Caption ..................................................................................... 15

Figure-4.2 Figure Caption ..................................................................................... 16

Figure-4.3 Figure Caption ..................................................................................... 17

Figure-4.4 Figure Caption ..................................................................................... 17

Figure-4.5 Figure Caption ..................................................................................... 18

Figure-4.6 Figure Caption ..................................................................................... 19

Figure-4.7 Figure Caption ..................................................................................... 20

Figure-4.8 Figure Caption ..................................................................................... 21

Figure-4.9 Figure Caption ..................................................................................... 22

Figure-4.10 Figure Caption ................................................................................... 23

Figure-4.11 Figure Caption ................................................................................... 24

Figure-4.12 Figure Caption ................................................................................... 25

Figure-4.13 Figure Caption ................................................................................... 26

Figure-4.14 Figure Caption ................................................................................... 26

Figure-4.15 Figure Caption ................................................................................... 27

Figure-4.16 Figure Caption ................................................................................... 28

Figure-4.17 Figure Caption ................................................................................... 28

Figure-4.18 Figure Caption ................................................................................... 29

Figure-4.19 Figure Caption ................................................................................... 29

Figure-4.20 Figure Caption ................................................................................... 30

Figure-4.21 Figure Caption ................................................................................... 31

Figure-4.22 Figure Caption ................................................................................... 31

Figure-4.23 Figure Caption ................................................................................... 32

Figure-4.24 Figure Caption ................................................................................... 32

Figure-4.25 Figure Caption ................................................................................... 33

Figure-4.26 Figure Caption ................................................................................... 34

Figure-4.27 Figure Caption ................................................................................... 35

Figure-4.28 Figure Caption ................................................................................... 36

Figure-4.29 Figure Caption ................................................................................... 38

Figure-4.30 Figure Caption ................................................................................... 39

Figure-5.1 Figure Caption ..................................................................................... 43

Figure-5.2 Figure Caption ..................................................................................... 43

Figure-5.3 Figure Caption ..................................................................................... 44

Figure-5.4 Figure Caption ..................................................................................... 44

Figure-5.5 Figure Caption ..................................................................................... 45

Figure-5.6 Figure Caption ..................................................................................... 48

LIST OF TABLES

Table-3.1 Caption of table ..................................................................................... 10

Table-3.2 Caption of table ..................................................................................... 10

Table-4.1 Caption of table ..................................................................................... 33

Table-4.1 Caption of table........................................................................................4

LIST OF ACRONYMS

FUUAST Federal Urdu University of Arts Science and Technology

FYP Final Year Project

GSM Global System for Mobile Communication

EMI Electro Magnetic Interference

PTA Pakistan Telecommunication Authority

SNR Signal to Noise Ratio

RF Radio Frequency

AC Alternating Current

DC Direct Current

VHF Very High frequency

IF Intermediate Frequency

Chapter 1

Introduction & History

1.1 IntroductionWith so many people using cell Mobiles phones now days, one of the measures that have popped- up on the market are cell phone jammers.

So, for those people that are tired of hearing endless cell phone conversations or constantly being interrupted by incessant cell phone ring tones, a cell phone jammer seems like the perfect device.

As with other radio jamming, cell phone jammers block cell phone use by sending out radio waves along the same frequencies that cellular phones operate on. It causes enough nosiness with the communication between cell phones and towers to render so that the phones are becomes unused able. On the Mobile phones, the network simply appears as out of range. Cell phones use different bands to send and receive communications from towers. Jammers work by either disrupting phone to tower frequencies or tower to phone frequencies. Type A Jammer block all bands from 40MHz to 1900MHz within a 15-foot range (5 meters). Small devices tend to use the previous method, in which larger more costly models may interfere directly with the tower. The distance of jamming can range from a dozen feet for pocket models to kilometers for more dedicated units.

Older jammers sometimes were limited to working on phones using only analoge or older digital mobile phone principles. Latest Jammer such as the double and triple band jammers can block all widely used GSM Networks and are even very effective against newer phones which hop to different frequencies and systems when interfered with. Due to the principal network technology and frequencies used for mobile phones vary worldwide; some work only in particular countries like Europe, North America or Pakistan.

The effect of Jammer can vary widely that depend on factors such as proximity to towers, indoor and outdoor settings, presence of buildings and landscape, even temperature and humidity play a role.

1.1 History of Jamming

During World War II ground radio operators would attempt to mislead pilots by false information in their own Codes, in what was more indeed a deceiving attack than jamming. Jamming of radar is also important to disrupt use of radar used to guide an enemy’s aircrafts and missiles. Latest safe communication techniques use such methods as spread spectrum modulation to resist the deleterious effects of jamming.

Jamming of foreign radio broadcast stations has often been used in wartime (and during periods of tense international relations) to prevent or deter citizens from listening to broadcasts from opponent/enemy’s countries. But such jamming is usually of limited effectiveness because the affected station usually varies/changes frequencies, placed on additional frequencies and/or increase transmission power.

Jamming has also occasionally been used by the Governments of Germany (during WW2), Israel, Cuba, Iraq, Iran, China, North and South Korea and numerous Latin American countries, also by Ireland against pirate radio stations e.g. Radio Nova.US government used to coordinated, distinctly located transmitters to jam the foreigner radio ship, Radio North Sea International off the coast of Britain in 1970.

1.2 World War Two

In occupied Europe the Nazis attempted to jam broadcasts to the continent from the BBC and other associated stations. Laterally with increasing transmitter power and adding further frequencies, efforts were made to counteract the jamming by dropping leaflets over cities instructing listeners to construct a directional loop aerial that would enable them to hear the stations through the jamming. In the Netherlands such jammer were nicknamed "moffenzeef".

1.3 Cold War era

In the Cold War Soviet jamming of some Western broadcasters led to a "power race" in which broadcasters and jammers alike repeatedly increased their transmission power, used highly directional antennas and added extra frequencies to the already heavily overcrowded shortwave bands to such an extent that many broadcasters not directly targeted by the jammers (including pro-Soviet stations) suffered from the rising levels of noise and interference.

To make Radio Free Europe and its sister service Radio Liberty were the main target of Soviet jammers followed by Voice of America and the BBC World Service.

Other stations targeted by the Soviet jammers (but not to the same extent as RFE/RL/VOA/BBC) included Deutsche Welle and sometimes Radio disabler. Jamming frequently took place during programming in languages widely spoken in Eastern Bloc countries (e.g., Russian, Polish, etc.).

Certain parts of the world were more impacted by these broadcasting practices than others

Eurasia (worst affected, including medium wave frequencies particularly

720 kHz used by RFE)

North Asia, Americas and Sub-Saharan Africa (partly affected)

Australasia, South America (rarely affected)

1.4 Mobile Jamming History

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 attack privacy, contribute to academic cheating, or even help in industrial intelligence. So In addition public backlash was growing against the intrusive disruption cell phones introduced in daily life. Older analogue cell phones often suffered from chronically poor reception and could even be disconnected by simple interference e.g. high frequency noise, increasingly sophisticated digital phones have led to more explained counters. Jammers are an alternative to more expensive measures against mobile phones, for example Faraday cages, those are mostly suitable as built in protection for structures. They were basically developed for law enforcement and the military to interrupt communications by criminals/terrorists. The civilian applications seemed, so many companies originally contracted to design jammers for government use switched over to sell these devices to personal things. There has been a slow but steady increase in their purchasing and using, especially in major urbanite areas.

Chapter 2

LITERATURE REVIEW

2.1 Literature Review

Electrical & electronic devices are part of our daily life and some of them are become necessary for us or our need like computer, microwave oven, fridge, ETC.

In past few years a new device had made its place in this list and we will not be wrong if we say that now it is part of our life, which is Mobile or Cell Phone. The production of mobile phone has increased rapidly and now almost 1/2 of the population of the world use Mobile phone in their daily routine and no one will oppose us if we say that Mobile have many benefits. Here is a graph showing the rate of making and using of mobile in 2004 & 2103.

Figure 2.1

On the other hand everything has two expects one is good and other is bad and we as an engineer have to rectify that bad expects.Cell phone use has increased so much that almost every person has one in his pocket and also using it in prohibited areas, where mobile phone use is not allowed. As in the library, colleges, army area, mosques etc. To stop the use of mobile in these areas we made this device naming Mobile phone jammer to prevent the use of Mobile in these areas.

CHAPTER 3

Tools and Techniques

3.1 JAMMING TECHNIQUES

There are following techniques to design a mobile phone jammer.

A. Type “A” Device (JAMMERS)Type ‘A’ uses the oscillator circuits to transmit different frequencies, which are used by communication media or mobile phones. Type A has also the Noise signal circuitry. This noise signal when carried with the carrier frequencies creates a noise to the mobile phones.The Mobile phones become unresponsive because of noise interferes with the mobile. B. Type “B” Device As type A, Type B devices are not communicating/transmitting a signal that interface with cell phone. Such type of devices when placed in a selected area, play a role of ‘detector’.There is a specific in such devices ‘ID’ for communicating with the base station (BS).

C. Type “C” Device Type C devices are not transmitting a signal which will interface with on the switching frequencies. When such types of devices are located in a specific area, perform work as a ‘beacon’ and are capable jamming/disabling a particular application of cell phone inside the ‘beacon’ coverage area.

D. Type “D” Device This type of jammer behaves as a mini base station, which can communicate wisely or stupidly to the mobile phone. These devices are in receiving mode of operation and wisely choose to interrelate and block the cell phone directly if it is surrounded by proximity of the jammer.

E. Type E DeviceThis technique is using electromagnetic interference (EMI) mechanism to make a room that is known as ‘Faraday cage'. This ‘faraday cage’ blocks all electromagnetic radiation entering or leaving the ‘room’.

3.2 JAMMER DESIGN PARAMETERAs described earlier we will block frequencies at which cell phones operate. So we must have the knowledge of these frequencies at which mobile phones operate in Pakistan.We consult with PTA (Pakistan telecommunication authority) officials and other internet resources to have these following figure and table.

Figure 3.1

The frequency of the transmitted signal will cover following frequency ranges.

GSM 900 Uplink890MHz-915MHz

Downlink925MHz-960MHz

GSM 1800 Uplink1710MHz-1780MHz

Downlink1805MHz-1880MHz

Table 4.1

Since our project is ‘MULTIBAND JAMMER’

So other bands covered by jammer by transmitting frequencies are as follow.

Device Name whose Frequency to be jammed

Band

FM 60MHz-130MHz

TV(Cable) 160 MHz -230 MHz

TV(Cable) 370 MHz -450 MHz

TV(Cable) 680 MHz -770 MHz

3.2 Distance to be jammedThis parameter is very important in our project, as the amount of the output power of the jammer depends on the area that to be jammed. We made the jammer that covers the distance of five meters for GSM (900&1800), FM, and some TV Bands.

3.3 Jamming–to-signal ratio J/S

Jamming is successful when the cell phones stop communication with the base station/network. The best jammer is having the transmitting power equals to the communicating signal’s power used by mobile phones or any transmitter or receiver. The general equation of the jamming-to-signal ratio is given as follows:

J/s=PjGjrGrjR^2trLrBr/PtGtrGrtR^2jrLjBj

To successfully jam a specific area, we need to consider a very important parameter the signal to noise ratio (SNR). Every device that working on radio communication principles can only stand noise in a signal up to a certain level. This is called the SNR handling capability of the device. Mostly cellular devices have a SNR handling capability of around 12dB. A device having a SNR handling capability 9dB is a very good device. So To ensure jamming of these devices, we need to reduce the signal to noise ratio up to 9dB. Free space loss F

We can get the free path loses using this Equation.

Free space loss F =Path loss (dB) =32.44+20log d (km) +20log f (MHz)

Here ‘f’ is the frequency in ‘MHz’, and‘d’ is the distance in kilometers. Using the GSM900 resonant frequency (915MHz) and a jamming radius of 5m, we get the value of path 65.64dBm. This path loss is for free space only, and the path losses in air will be greater. This means that the jamming radius will be less than the 5m used to calculate this value.

Free space loss F =Path loss (dB) =32.44+20log d (0.05) +20log f (915)

F=65.64

3.5 Power Calculations

Here, we need to find the power that is needed to transmit to jam any cell phone, FM and TV within a distance of around 5 meters. So using above considerations, we can find output power required by device which is given below. Using SNR=9 dB and the maximum power signal for mobile receiver= -15 dBm,

SNR=S/NWe Know S=-15 & SNR=9:

J= -15/9J=N= -15-9

J= -24 J = -24dBm.

Thus we have needed jamming signal strength of -24dBm at the mobile device’s reception to successfully jam it. However, our transmitted signal will undergo some attenuation while transmitting through antenna of the jammer and in exposed air. So this path loss can be calculated using the simple free space path loss approximation. To obtain resultant output power we will add the value of ‘ J’ the value of free path loss.

Output power=-24dBm+65.64dB = 41.64dBm

Summary

So there are different methods /techniques of jamming as described above. We have implemented type A because it is simple and easy to make such type jammer. Others are complex and their components availability is difficult.

After selection of type we decide other jamming design parameters those are important for designing jammer, due to Law enforcement and device working.

Chapter 4

Implementation and methodology…………….

4.1 Hardware Designing

Here is a block Diagram of Multiband Jammer

Figure 4.1

Circuit Diagram

Figure 4.2

Explanation of Block and Circuit Diagram

4.2.1Power supply

Power supply is required to derive others components.

Here is a block diagram for power supply.

Figure 4.3

Transformer

A 12V AC Step down Transformer is used to convert 220V into 12V DC.

Figure 4.4

Step down Transformer

Bridge Rectifier Filter220VAC DC

O/P

Rectifier

We used a ‘Bridge rectifier’ for converting Ac voltages into DC.

Figure 4.5Bridge Rectifier has two types:

i) Half wave bridge rectifierii) Full wave bridge rectifier

In half Wave Bridge rectifier only positive cycle pass and negative blocked.In full wave bridge rectifier both positive and negative cycle of AC passed.

Filter Filter is used to remove ripple factor in DC part, to make it pure DC.We used a 2200uf capacitor for this purpose.

Following figure shows the half and full wave bridge rectifier.

Figure 4.6

4.1.1 Triangle Wave Generator:

To generate a saw tooth wave (triangular) form we used LM555 timer.

It has following pin configuration and characteristics.

Pin configuration

Figure 4.7

Characteristics

It is a stable device and can operate at 4 to 15 volts easily. It can be replaced by SE 555 and NE 555. It is avail in eight pin package IC. It is used pulse generation, pulse modulation, time delay, pulse position modulation.

Modes of OperationsIt has two modes of operations i) Mono stable only positive cycle or there is only high output.ii) A stable in which both +ve & -ve cycles comes on output.So we have used As table operation due to generating continues triangular wave form.

Astable Operation of 555 in our project

In A stable mode the NE555 can use as an oscillator. The applications of A stable mode are LED and flashers, pulse generation and security system etc.As we want to generate a clock which will generate the frequency of 105 KHz and voltage of 0 to 5V, A stable mode is the best configuration to produce this frequency as in our project we will need a simple clock pulse. The circuit configuration for A stable mode is given in figure below.

Figure 4.8

The main component of the A stable mode of NE555 is the capacitor. In A stable mode it can divide into two parts charging and discharging of a capacitor, repeat continuously. The charging and discharging of a capacitor through resistors connected either to Vcc.

Working Principle of 555 Timer in A stable Operation Mode

555 Timer is used to create the triangular wave. Its operation includes the simple charging and discharging of a capacitor. The main components through which it charges and discharges are the two resistors and capacitors. We used one of the resistors as variable resistor and other of 1K ohm. The circuit is simple RC circuit. The detailed operation of Timer can be explained by 4 different stages along with their operating diagrams as shown below:

Figure 4.9

Stage1

At first stage Supply Voltage (Vcc) is applied, this time the capacitor is empty and there is practically no charge on the capacitor because, the lower comparator of the timer has more negative input than the positive of it. That creates a signal to the output of the comparator which set the flip flop. This leads to the high output of the Timer.

Figure 4.10

Stage2

At second stage, the capacitor's charging increases. The output of the Timer is high, because of the latch of flip flop. But the output of the lower comparator is low.

Figure 4.11

Stage3:At third stage, the capacitor is charged up to 2/3 of the Vcc voltage. At this stage, the upper comparator's positive input is more than its negative input. The output of the upper comparator is now become high and will cause the reset of 'Flip Flop'. The Timer's output will now become low.

Figure 4.12

Stage4When the preceding procedure occurs, the output of the Timer becomes low due to the reset of 'Flip Flop' of upper comparator. Now the negative output Q (bar) will become active. This will give a signal to the base of transistor so that the pin7 becomes input of the Timer. Now the transistor conducts through collector and emitter, and finally the capacitor starts discharging. These phenomena of charging and discharging of capacitor will continue and a triangular wave is generated due to the charging and discharging of capacitor. This triangular wave is basically our Noise signal.

Figure 4.13Output of LM 555 This figure shows the output of LM 555 timer on oscilloscope it is a saw tooth wave form.

Figure 4.14

Calculations of Charging and Discharging Time Period:

The charging time period of capacitor can be determine by using formula:

T1=0.693(RA+RB) C1

For charging both resistor are used. For discharging time period, the capacitor will discharge only by a resistor RB. The following formula is used to determine the discharging time period:

T2=0.693(RB) C1 So total time period is given by

T=T1+T2As we know that frequency is inversely proportional to time period so the output frequency can be calculated as: f=1/TBy putting values of T we get

f=1.44/ (RA+2RB) C1

In our project, we used RA =1KΩ RB = 8 KΩ with C=0.0008 µF, then the output frequency is 105 KHz Since we use +12 V power supply, the amplitude of output signal will be bounded from 4 V (Vcc/3) to 8Volts (2Vcc/3).The output of the 555 timer is shown in the figure below:

Figure 4.15

Noise AmplificationFor noise amplification we used LM386. It has following pin configuration and characteristics.

Figure 4.16

Characteristics

Low voltage consumption high frequency power amplifier.it has low quiescent current and voltages.It has voltage gain from 20 to 200 dB and low distortion.It is used as RF Power Amplifiers on VHF Band Mobile, AM-FM Radio Applications and TV sound system.

LM386 has different pin connection for obtaining different gain. Since in jammer we have required maximum gain so if its pin eight and one are common through a capacitor then it gives high gain 200dB.

Following figure shows this high gain pin confectioning.

Figure 4.17

Amplification through LM 386 in our Project

For amplification the noise, we use LM386, noise power amplifier which is design for use in low voltage consumption applications. The internal gain of LM386 is internally set to 20 to keep the external part at low count, but by adding some resistor and capacitor externally between the pin 1 and pin 8 that will increase the value of gain up to 200 or may be adjustable.We use pin 3 which is available for +ve input for amplification. We put our input to pin 3 which have no phase shift. As pin 7 is bypass pin we bypass it by using a capacitor. We put the input pin 2 to the ground which is use for –ve input, because we don’t need the phase shift of 180 degree. The input voltage for LM386 not less than 0.4v therefore we use coupling capacitor and variable resistor which increase or decrease the voltage up to this level. From this we can get desire output from amplifier. The output of LM386 comes from pin 5 which gives to the RF section.

Figure 4.18

This figure shows the output of LM 386 on oscilloscope.Figure 4.19

THE RF-SECTIONRF Section is the most important part of jammer device; because the output of RF section interferes with the cell phone.

The RF-section consists of

(1) RF amplifier

(2) Oscillator (3) Antenna

The complete circuit diagram of RF section is show below:

Figure 4.20

Above circuit have four main parts

(1) Regulated circuit

(2) RF amplifier

(3) LC circuit

(4) Leakage resistor

Regulated circuit

Behind the transistor is the regulated circuit which is to make the input according to in input of transistor. So that the signal coming from IF section is input of RF section this regulated circuit will make that input according to transistor.

Figure 4.21

RF Amplifier

We used a 2SC1970 transistor as RF amplifier, Intermediate frequency is given at the base and output is taken from collector which is given to an oscillator circuit for amplification.

Figure 4.22It has following main characteristics 2SC1970 is a Silicon NPN Transistor designed for RF Power Amplifiers on VHF Band Mobile Radio Applications.

It has High Power Gain.

Output Power range is from 0.8-1 Watt.

Tanks Circuit

The combination of capacitor and inductor that exchange energy back and forth is called Tank circuit. An inductor stores energy as a magnetic field and a capacitor stores energy as an electric field. The exchange of energy between them would go on forever; but we need a refilling signal practically. By choosing the suitable values of components, the frequency or energy of exchange can be obtained.

Figure 4.23

Above is the tanks circuit which we have used in our project. And we use 12V DC power supply to refill the signal or continue oscillation.

LC circuits

A capacitor is used to stores energy in electric field between its plates, which depend on the voltage across it; on the other hand an inductor is used to stores energy in magnetic field that depends on the current flowing through the inductor. If a capacitor is charged and connected across an inductor charge will flow through the inductor and generate a magnetic field around the inductor, and reduce the voltage on the capacitor. Until the capacitor completely discharge. The current will flow because inductors resist change in current and energy will discharge from the magnetic field to keep the current flow. This flow of current will charge the capacitor with a voltage of opposite

polarity. When the magnetic field is totally dissipated the current will stop and the charge stored in the capacitor will flow through the inductor with the opposite polarity and the cycle is completed.

Figure 4.24

Resonance effect

The resonance effect takes place when inductive reactance and capacitive reactance are equal in value. Resonance is the effect in a system to produce oscillation at larger amplitude at certain frequencies than other frequencies. These frequencies are the resonant frequencies

Resonant frequency is given by

W=1/2pi*under root LC

Where

L is the inductance in H

C is the capacitance in F

‘W’ is the Angular frequency.

F=omega/2pi=w/2pi= W=1/2pi*under root LC

The value of C and L for required band are given below

Sr.No Frequency Range in MHz

Central frequency

Band width InductancenH

CapacitancepF

BAND1 60 130 fc=95MHZ BW= 70MHZ

35 35

BAND2 160 230 fc=195MHZ BW= 20 35

70MHZ BAND3 370 450 fc=410MHZ BW=

80MHZ 6 25

BAND4 680 770 fc=725MHZ BW= 90MHZ

4 12

BAND5 870 960 fc=905MHZ BW= 90MHZ

4 7.7

BAND6 1770 1860 fc=1715MHZ BW= 90MHZ

1 8.3

Figure 4.25

Leakage Resistors

Figure 4.26Leakage current is the major drawback in any circuit; from these resistors we can prevent leakage current. Leakage is the gradual loss of energy from a charged capacitor. It is caused by electronic devices that attached to the capacitors, like a transistors, these devices conduct a low value current even when they are turned off. This current is called off current, because of this current less magnitude current pass through the device when it is on; this current still discharges the capacitor. There is another kind of leakage which is called dielectric leakage, contributor due to the imperfection of some dielectric materials used in capacitors, due to this dielectric material having some non-zero conductivity which causes the leakage of current from the capacitor and capacitor discharged. If these resistors are not used in circuit then this leakage current will disturb the output of the circuit and also disturb the output frequency

Antenna:

An aerial/antenna is a ‘transducer’ made to transmit or receive electromagnetic waves or convert electromagnetic waves into electrical currents and so on. Aerial/ Antennas are used in radio and television distribution, steeplechase radio communication, wireless LAN, radar etc.. . Antennas frequently work in air but can also be run under water or soil and rock at certain frequencies for specific distances.Antenna is important for each wireless system and our jammer is also transmitting frequencies in air that is why we also need an antenna for this reason. A suitable antenna is required to transmit the jamming signal magnificently. In order to have optimal power transfer, the antenna system must be corresponding to the transmission system. In our project, we used six (6) antennas, with fifty Ω i/p impedance so that the antennas are matched to the system. We used monopole antenna later the radiation pattern is Omni-directional.Specifications:

Frequency: 40Hz-1GHz Length=234/fInput impedance 50Ω VSWR<2

Figure 4.27

Circuit Performance on Software

Circuit performance is performed using livewire software. Current and voltage simulation is done by using livewire software. Following figures are showing voltages and current.

Voltage flowFollowing figure showing the voltage flow through each component, so circuit is completely checked.

Figure 4.28

Current flow

Following figure is showing the current flowing through each component. The green line is showing the flow of current through each component.

Figure 4.29

Complete Functional Hardware

Following figure is showing our complete functional hardware.

Figure 4.30

Summary

A triangular wave is generated and is amplified which is used as ‘noise’ or as ‘intermediate frequency’. We used 555 time IC for creating ‘noise’ of 104 kHz frequency. This noise is then amplified by LM386 and fed at the base of 2SC1970 which is NPN silicon RF amplifier. The output of this amplifier from collector is given to oscillator circuit and amplified and transmitted through omni directional antenna.

Chapter 5

Results and Analysis………………………………….

5.1 ResultAs we tested our jamming device, the consequence was a full achievement. The expedient was able to jam all the systems. The actual jamming range was between 5 meters. This is more than what it was intended for. The reason is that in our controls, we measured the worst case of having the cell phone close to the base station. It is predictable that as the distance between the cell phone and the base station increases, the real jamming distance will increase. This is due to the datum that the amount of power reaching the cell phone from the base station reductions as the cell phone moves past from the base station. The Number displays the consequences. It can be obviously seen that the signal is "ON" when the jammer is "OFF", while the signal vanishes when the jammer is "ON".

Testing of GSM 900 & 1800 We have tested our jammer on all networks available in Pakistan.When jammer is off a network on cell phone has full signal and jammer is on then there is no signal. All results shown in following figures Figure 5.1

Jammer off Jammer on

Figure 5.2

Jammer off Jammer on

Figure 5.3

Jammer off Jammer on

Figure 5.4

Jammer off Jammer on

FM radio testingWe test the jammer for FM. when jammer is off the FM is on and when jammer is on then it starts tuning as shown in following figures.

Figure 5.5

Jammer off

Jammer on

Applications

Multiband Jammer is widely used in the offices, Conference rooms, Police, Army and in all that places where security is required.Some of the common applications of Jammer are as under:

Meeting and Conference Rooms.

By Millitary forces against enemies.

By Police against terrorists, thieves and robbers etc.

Masjids for creating silence.

In Jail against prisoners communication.

Hospitals to make doctors attention only for patients.

Examination Halls to avoid cheating.

Oil and Gas Storage/Pumps.

Factories where usage of the mobile phone is prohibited.

ClassRooms to make students focusing on study.

In libraries to create silence.

At Homes to save from youngsters the access use of mobile phones.

Applications

Following figure showing the practiacl applications of cell phones jammer.

Figure 5.6

Chapter 6

Conclusion…………………..

6.1 Consluion

Every technology has its own merits and demerits.it depends upon users how he uses it.Mobile phones jamming is technolgy which is used to jammng cell phones.We have designed a mobile phone jammer which simplest to operate and have very low cost.Through this project we learned about single stage passive components and their working in detail.we have also got a lot knowledge about wierless communication and mobile phones technology especially about GSM.Law prohibits the use of jammer because it blocks signal and funcitoning of device stops.for example jammer can stop the working of GSM alarm installed in industry or at home for security purpose.So we should use jammer for good purpose not for bad ones.

References

[1] Randall K. Nichols, Wireless Security, Tata McGraw-Hill Edition 2006[2] Richard A.Poisel, Modern Communications Jamming: Principles and Techniques, http:// books.google.com.pk[3] John L. B. Walker, Handbook of RF and Microwave Power Amplifier, Cambridge University Press, 2012[4] Luis Moura, Introduction to Linear Circuit Analysis and Modelling: From DC to RF, http:// books.google.com.pk[5] ARTCON 2010, Advances in Recent Trends in Communication and Network, Allied Publishers, Printing Division, Maya Puri, New Delhi, 2010[6] Intellin Organization, Electronic Circuits, USA, 2008[7] Marian K. Kazimierczuk, RF Power Amplifiers, John Wiley and Sons, United Kingdom, 2008 [8] http://en.wikipedia.org[9] http://www.seminarsonly.com [10] http://dtzone.com/electronics [11] http://ieeexplore.ieee.org[12] NE555 Complete Data Sheet[13] LM386 Complete Data Sheet[14] 2SC1970 Complete Data sheet[15] http://hem.passagen.se[16] http://electroschematics.com[17] http://allaboutcircuits.com