CDMA Cellular Phone Jammer

EE413 – Communication Electronics Instructor: Pao-Lo Liu TA: Saurav K. Bandyopadhyay

Michael D. KaprowJustin R. AntesAdam J. Pace

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Presentation Outline

• Goals of Project • Description and Analysis of Circuit• Demonstration of Circuit• Accomplishments• Questions

EE 413 Communication Electronics

Spring 05’

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Project Goals• To create a device that will disrupt cellular

communication with respect to the following:- Operate in the 1900 MHz band.- Disallow any communication of phones that

use that band. (Denial of Service)- Have a two meter effective blocking radius.

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EE 413 Communication Electronics

Spring 05’

Circuit Description

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EE 413 Communication Electronics

Spring 05’

TL074 Quad Op Amp

EE 413 Communication Electronics

Spring 05’

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Square Wave GeneratorGenerates the signal that will be manipulated to control the VCO.

EE 413 Communication Electronics

Spring 05’

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Integrator-The Integrator takes the square wave and transforms it into triangular wave.

- This triangular wave is what allows the VCO to sweep the band of CDMA frequencies.

EE 413 Communication Electronics

Spring 05’

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BufferBuffer prevents the noise from interfering with the Square wave generator and Integrator.

EE 413 Communication Electronics

Spring 05’

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Noise Generator-Operate a Zener diode in reverse bias to create noise.

-Amplified with 2N3904 transistor and the LM386 audio amplifier

EE 413 Communication Electronics

Spring 05’

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-Noisy signal is what overloads the frequencies.

Mixer-The mixer is where the triangular wave and the nose get mixed.

-The tuning circuit adjusts amplitude of wave and amount of noise being coupled to signal.

EE 413 Communication Electronics

Spring 05’

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Voltage Controlled Oscillator(VCO)

- An oscillator designed so the output frequency can be changed by applying a voltage to its control port or tuning port

- Crystek CVCO55BE- 1650-2050

Actual Circuit

EE 413 Communication Electronics

Spring 05’

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VCO

Quad OpAmp

LM386

Potentiometer

Demonstration

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EE 413 Communication Electronics

Spring 05’

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Weeks 1 2 3 4 5 6 7 8 9

1.0 Research and Development                  

                   

1.1 research technology                  

                   

1.2 Develop circuit diagram                  

                   

1.3 Select and order Componets                  

                   

2.0 Construct Project                  

                   

2.1 Build Circuit                  

                   

2.2 Evaluate Circuit                  

                   

2.3 Debug Circuit                  

                   

3.0 Prototype Design + Evaluate                  

                   

3.1Test Final Build                  

                   

3.2 Demo                  

                   

3.3 Documentation                  

                   

Possible Improvements

• We can add another VCO to block the 800MHz digital roam feature on some phones. (Verizon comes standard)

• We can also add amplifiers that can boost the area that is affected.

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Accomplishments

• We were able to block communication coming into and going out from a CDMA phone operating on the 1900MHz frequency band.

• We were able to reach the 2 meter blocking radius.

• We were able to keep the cost under 50 dollars.

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Questions

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