6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Cellular Activity Detection & Identification

Final Presentation Supervised By: Yossi Hipsh

Introduced By: George Ghantous , Husam Khshaiboun

Project : D0426 - Spring Semester 2007

High Speed Digital Systems Lab – The Technion

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Refreshment

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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General Problem Definition

We want to build a system that detects a cellular phone activity and finds the coordinates of its source in a predefined space.

Different cellular companies use different frequency ranges. they also use different codes (for each phone), communication protocols and modulation methods. Thus, the cell phones we want do detect differs not only because the companies differ. We want to detect each and every kind of phone.

Cellular radio pulses can be transmitted in a small time periods. We want our system to be able to detect these pulses (example: SMS messages).

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Block diagram

Antenna A

2 beams

Antenna B

2 beams

Direction 1

Direction 2

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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What have we done???

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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5082-2835

Energy Detector - Final Circuit

C=200pFR1=500kΩR2=1kΩ

R1=500kΩ

C1=100pF C2=100pF

Diode 5082-2835

R2=1kΩ

In

Out

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Amplifiers verification

Coaxial Amplifiers from Mini-Circuits ©: ZJL-4G 50Ω medium power, 20-4000Mhz band Measurements were made in the communications lab for the gain

response as a function of the working frequency

All the amplifiers work perfectly with12db amplification

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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VCO duplication A duplication of a VCO already created was done. The V.C.Os can be

used for mixing purposes or as a cell phone emulator.

frequency [GHz] vs Vtune [V]y = 0.0427x + 1.2582

R2 = 0.9903

1.51.551.6

1.651.7

1.751.8

1.851.9

1.952

2.052.1

8 9 10 11 12 13 14 15 16 17 18 19

Vtune [V]

f [G

hz]

freq

Linear (freq)

Pout (hold max) vs frequency

-10-9-8-7-6-5-4-3-2-1012345

1.50E+09 1.60E+09 1.70E+09 1.80E+09 1.90E+09 2.00E+09 2.10E+09

frequency [Hz]

Po

ut

[db

m]

trace (max hold)measurement

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Antenna building

A reference antenna designed for 1.4 GHz was used as a reference dipole antenna.

The new antenna was built by changing all the wavelength related parameters to suit the new frequency: 1.7Ghz.

The new dipole was duplicated to build a dipole array transmitting a directional beam

The power is then divided equally between the dipoles.

Micro strip technology was used.

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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MicroStrip Line Impedance*

/ 1

1

/ 1

120 8ln( 0.25 )

2

1201.393 0.667ln( 1.444)

w h

re

w h

re

h wZ

w h

w wZ

h h

*Micostrip Lines and Slotlines- K.C.Gupta –ARTECH HOUSE 1979

Matlab code was written for iteration over w values according to the needed impedance

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Some photos

The ref. dipole antenna

The new dipole array antenna

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Antenna building cont.

Measurements were done to test S11:

Another array antenna was built similar to the first one. (to be used in the final experiment)

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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The Final Experiment

The goal is to prove the theoretical solution feasibility

The reference antenna will emulate a cell phone; the difference in frequency is reflected in minor inefficiency.

Instead of using the designed V.C.O, a pulse generator will be used.

The energy detector will not be used. The pulses will be seen in a fast scope instead.

Mechanical shift will be used to shift antenna beams and search for maximum reception.

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Final Experiment Equipments

1. Two new antennas (designed for 1.7 Ghz)

2. One reference antenna (emulating a cell phone)

3. 2 amplifiers (Mini-Circuits© ZJL-4G)

4. A pulse generator (Hewlett Packard © 8133A)

5. A fast scope (Hewlett Packard © 83480A)

6. DC power supply (Technion I.I.T – 10-399A)

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Final Experiment Setup

12V Power Supply

Technion I.I.T 10-399A

Antenna 1 Antenna 2

Cell phone emulator

2 Channel Scope

Hewlett Packard ©

83480A

Pulse Generator

Hewlett Packard ©

8133A

Trigger

Ch.1

Ch.2

Rotating axis Rotating axis

Height of antenna 1 & 2 plane: 2.15m

Height of emulator plane: 1.76 m

1.2 m range of emulator movement

12db

12db

-10db

-10db

6/5/2008 High Speed Digital Systems Lab George Ghantous, Husam Khshaiboun

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Lets take a look !!!