25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 1 Cellular Activity Detection & Identification MidTerm Presentation Supervised By: Yossi Hipsh Introduced By: George Ghantous, Husam Khshaiboun Project : D Spring semester 2007

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 2 Refreshment

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 3 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).

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 4 Our target space: A Classroom Room area 4x8 3m supervisor Relevant area 6m חזור

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 5 Block diagram Antenna A 2 beams Antenna B 2 beams Direction 1 ראה כיתה Direction 2

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 6 Our target space: A Classroom חזור 1m We check the whole idea and its partial implementation on a 1x1 square. If we succeed in the far corner we will succeed in the whole system implementation (with an adjustment of the number of beams and their direction) Area with overlapping beams

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 7 What have we done ???

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 8 A beam in direction θ1 A beam in direction θ2 Energy Detector The ongoing implementation:

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 9 Energy detector R C Out (DC) In (Wave)

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 10 Our needs: High frequency  diode with fast switching Fast charge  a small capacitor medium speed discharge Wont interfere with the charging. When reading the capacitors voltage the discharge can be slow because we are not in a rush after the capacitor is charged

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 11 Choosing the parts RC in charge ~ 10n seconds When charging RC=50C=10n  C=200pF RC in discharge ~ m seconds R1=500kΩ  RC=0.1msec The Diode: Hp Schottky Barrier Diodes for general purpose applications: FARNELL ©, : Low turn on voltage; 0.34V at 1mA. Pico second switching speed (switches perfectly in our working frequencies- less than 1 GHZ at IF)

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun Energy Detector - Final Circuit C=200pF R1=500kΩR2=1kΩ R1=500kΩ C1=100pF C2=100pF Diode R2=1kΩ In Out

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 13 The Antenna A minimum of two beams is needed to find a direction. Two ways to do that: Mechanical shift of two antennas Mono pulse antenna Theoretical material - about mono pulse, starting from electromagnetic radiation going threw antennas, electrical field Fourier transform using for beam pattern synthesis, reaching mono pulse antenna, and beam design networks - was studied. A slight summary in the next slides Yet a mechanical shift will be implemented !

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 14 How radiation radiates ?? Example: Dipole Antenna: Electrical (EM) field is induced so that it follows the direction of the AC current. When the frequency gets high, the field cannot collapse and follow, thus a closed loops of field is created. In the next period another loop is created when pushing the first one and so on: When the length of the dipole is λ/2 (λ/4 from each side) a resonance is achieved because at this length, a complete half wave of current and voltage distribution is accommodated. This ensures maximum power efficiency (resistive impedance). In theory, there is zero ohms (72 ohm in reality) impedance at the centre and infinite at the ends of the Dipole. E I

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 15 Fourier transform The following shows how a window function field is transformed into a sinc or a beam pattern: For a shifted window (x0):

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 16 Mono Pulse Antenna Antennas radiate (receive) an electrically shifted beams using a beam design network. A simple way to look at this is the following: An example for a 10 dipole antenna that radiates 5 beams using electrical shift is given in the next slide Σ,Δ adder ΣΔ Antenna 1Antenna 2

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 17 Mono pulse antenna: 5 beams using 10 dipoles Beam design network Adder 5  1 Adder 5  1 Dipoles Antenna x10

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 18 Amplifiers verification Coaxial Amplifiers from Mini-Circuits ©: ZJL-4G 50Ω medium power, Mhz band Can work as a RF and IF amplifier in our circuits. Measurements were made in the communications lab for the gain response as a function of the working frequency See next slide for results

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 19 Amplifiers verification - results All the amplifiers work perfectly.

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 20 VCO duplication A duplication of a VCO already created was done. One will be used as an generator for mixing purposes. The other will be used as a cellular phone emulator.

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 21 What will we do ??

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 22 What will we do ?? Test the mixers Test the new VCO Test the energy detector Connect the elements Emulate a cell phone and check the system Build the antennas Test the system with a real cell phone in a room room

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 23 Time Schedule Action ItemDue DateStatus Test the mixers01/07/2007 Test the new VCO01/07/2007 Connect the elements07/07/2007 Emulate a cell phone and check the partial system (without the antennas) 12/07/2007 Build the antenna (s)19/07/2007 Test the system with a real cell phone 26/07/2007 Final presentation and Report 2/08/2007

25/6/2007 High Speed Digital Lab George Ghantous, Husam Khshaiboun 24 Thanks For Listening