Abtract to Detect Mobile
PORTABLE HANDY MOBILE DETECTION DEVICE USING MICROCONTROLLER
ABSTRACT
Cell-phone use has grown astronomically over the past decade. The Cellular Telecommunications and Internet Association estimates that there are more than 135 million cell-phone subscribers in the United States alone; other estimates have placed worldwide users at more than a billion. Along with the convenience of instant communications, cell phones have brought plenty of controversy. Opponents cite privacy, security, safety, and even tranquility issues in their call for regulations and electronic technology to limit cell-phone use in certain situations or locations. This handy cell phone detector, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cell phone from a distance of one and-a-half meters. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorized video transmission. The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases. An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug. Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency. The disk capacitor along with the leads acts as a small gigahertz loop antenna to
ABSTRACT
Cell-phone use has grown astronomically over the past decade. The Cellular Telecommunications and Internet Association estimates that there are more than 135 million cell-phone subscribers in the United States alone; other estimates have placed worldwide users at more than a billion. Along with the convenience of instant communications, cell phones have brought plenty of controversy. Opponents cite privacy, security, safety, and even tranquility issues in their call for regulations and electronic technology to limit cell-phone use in certain situations or locations. This handy cell phone detector, pocket-size mobile transmission detector or sniffer can sense the presence of an activated mobile cell phone from a distance of one and-a-half meters. So it can be used to prevent use of mobile phones in examination halls, confidential rooms, etc. It is also useful for detecting the use of mobile phone for spying and unauthorized video transmission. The circuit can detect the incoming and outgoing calls, SMS and video transmission even if the mobile phone is kept in the silent mode. The moment the bug detects RF transmission signal from an activated mobile phone, it starts sounding a beep alarm and the LED blinks. The alarm continues until the signal transmission ceases. An ordinary RF detector using tuned LC circuits is not suitable for detecting signals in the GHz frequency band used in mobile phones. The transmission frequency of mobile phones ranges from 0.9 to 3 GHz with a wavelength of 3.3 to 10 cm. So a circuit detecting gigahertz signals is required for a mobile bug. Here the circuit uses a 0.22μF disk capacitor (C3) to capture the RF signals from the mobile phone. The lead length of the capacitor is fixed as 18 mm with a spacing of 8 mm between the leads to get the desired frequency. The disk capacitor along with the leads acts as a small gigahertz loop antenna to