This document outlines a project by group no. 05, detailing the development of a compact cell phone detector designed to identify active mobile phones by detecting their signals. The report includes a list of members, equipment used, a step-by-step implementation guide, issues faced during the project, and potential applications for the device. Future work aims to enhance the detector's capability to identify active mobile phones even when not in use.

2. Group No. 05
Members-
• 1.Nurjahan Begum (ID-011 123 046)
• 2.Farzana Gisan (ID-011 131 167)
• 3.Zahidul Islam Razu (ID-011 132 047)
• 4.Shubhra Sarker (ID-011 132 056)
• 5.Rownok Alahi Islam (ID-011 132 075)
• 6.Pankaj Debnath (ID-011 132 076)
Submitted to : Abu Shafin Mohammad Mahdee Jameel
Senior Lecturer, Dept. of CSE

3. Cell phone detector
Cell phone detector is a handy, pocket sized mobile detector
which is one of the most common electronic equipment used
in modern era.
A cell phone transmits signal s between 0.9 to 3 Ghz.
A cell phone detector detects the activity of a cell phone by
detecting the incoming and outgoing calls and messages.

4. Equipments
 Breadboard
 Battery 9V
 IC CA3130
 Transistor BC548

5.  Capacitor 47pF, 0.22uF, 100uF
 Resistor 1k, 100k, 2.2M
 LED
 Battery Clip

6. CIRCUIT DIAGRAM

7.  Insert BC548 transistor, LED & IC CA3130 on the breadboard.
 Connect Base of transistor with 2.2M ohm resistor & connect other end of
resistor with pin 2 of IC.
 Connect 1k resistor with emitter of transistor & other end of resistor with positive
end of voltage source.
 Connect positive end of LED with collector of transistor & negative end of LED
with negative end of voltage source.
Implementation

8.  Connect 100k resistor with pin3 of IC & with negative end of voltage source.
 Connect 0.22uF capacitor with pin2 & pin3 of IC. Then connect 47pF capacitor
with pin1 & pin8 of IC.
 Connect positive end of 100uF capacitor with 2.2M resistor & connect that end with
pin3 of IC. Then connect negative end of capacitor with negative end of voltage
source & connect other end of resistor with positive end of voltage source.
 Connect pin6 of IC to base of transistor.
 Connect pin7 & pin4 with positive & negative end of voltage source respectively.

9.  Mobile phone uses RF with wavelength of 30cm at 0.9 to 3
GHz. That is the signal with high frequency and
wavelength.
 To detect mobile signal, the sensor part should be like an
aerial, so the capacitor 0.22uF is arranged like a mini-
loop(like a TV antenna).
 In short with this arrangement, the capacitor works like an
air core coil with ability to oscillate and discharge current.
How the circuit works!

10.  When the mobile phone radiates high energy pulsations,
capacitor oscillates and releases energy in the inputs of IC.
 This oscillation is indicated by flashing of the LED.
 In short, capacitor carries energy and is in an electromagnetic
field.
 So, a slight change in field caused by the RF from phone will
disturb the field and forces the capacitor to release energy
which helps in blipping of the LED.

11. Timeline
 1st week : Bought the equipments needed & checked if those are okay.
 2nd week : Started assembly of the circuit.
 3rd week : Completed the circuit implementation & made sure it
worked.
 4th week : Tried to find out if there were any errors and modified the
project.

12. Screenshot of the Project

13.  There were some problems in finding the IC CA3130.
 The capacitor 0.22uF we brought at first wasn’t working.
 Our LED was burning out too often.
Problems We Faced

14. Applications:
 This circuit can be used at examination halls, meetings to
detect presence of mobile phones and prevent the use of
cell phones.
 It can be used for detecting mobile phones used for
spying and unauthorized transmission of audio and video.
 It can be used to detect stolen mobile phones.

15.  We will try to improve our detection range.
 Our circuit only works when a call is going on or a
message is being sent or received, so we want to
implement a circuit which can detect whenever an active
mobile phone is found within our range.
Future Works

16. Thank you!