Sensor for cellular activity Supervised by : Yossi Hipsh Preformed by : Assaf Haim Ohad Fremder

Project’s Goal Detect existence and pin point cellular activity in a defined room.

Relevant area 8m 4m 3m 6m Supervisor

Presenting the first problem How do we detect the cellular activity in the room?

How do we detect the cellular activity? In order to provide a solution for the question we need the following details: –What is the energy output of a single device? –What is the frequency of the cell-phone? –What is the device needed to recognize such an activity? –How can it alert us when it detected activity?

Experiment In order to find out more details, we have decided to perform an experiment. Spectrum Analyzer 30cm

Experiment’s results

Experiment result - summary P receive (30cm) Frequency range (As Published) Main Frequency Company -65.5dbm Mhz ~830MhzPelephone -24dbm Ghz ~1.725GhzCellcom dbm Mhz ~902.5MhzOrange This results are for specific cellular devices.

Solution In order to detect cellular activity we use Energy Detectors spread out in the class room, connected to a computer.

Energy Detector To recognize the activity we will use an Energy Detector An energy detector will alert us no matter the signal’s modulation. Input for the detector: (We demand a 1.5v, 10mA) –Pin=1.5v*10mA=15mW=~12dbm (To the detector)

Relevant area 8m 4m Energy Detectors Supervisor 3m 6m 1.5m Supervisor

Block Diagram Filter Bank of Filters Mixers Gain Sum Gains Mixer Filter Gain Energy Detector

Antenna 1 Gain1 Mixer LO1 BPF Mhz Gain1 Mixer LO1 BPF Mhz Gain1 Mixer LO1 BPF Mhz Gain1 Mixer LO1 BPF Ghz Gain1 Mixer LO1 BPF Ghz Gain1 Mixer LO1 BPF Ghz Gain1 Mixer LO1 BPF Ghz BPF Mhz Energy Detector Gain2 30db Mixer LO2 381Mhz BPF Mhz Gain 3 40db

Presenting the second problem How do we pin point the location of a cellular device?

In order to solve the problem we ask the following questions: – Is there a cell phone present in the class room? –What kind of a system can pin-point to the cell phone? –How should we position the system in the room?

Solving the second problem We use an array of antennas that will give the location of a cell phone. Each antenna will give us a direction.

We choose to use an array of Multi-Beam antennas, with three(3) different beams. Selected System

Room area 4x8 3m 6m supervisor Relevant area Placing the antennas

Time line PercentageStageDates 45%1 – Finished – %2 – Block diagram (OG) – %3 – Element selection – %4 – Building the system –

Questions?