This study presents a report of our research work on the design, construction and testing of a cell phone detector. It has become obvious that blocking or jamming of cell phone signals is difficult, expensive, and/or illegal in many... more
This study presents a report of our research work on the design, construction and testing of a cell phone detector. It has become obvious that blocking or jamming of cell phone signals is difficult, expensive, and/or illegal in many situations. A more practical means of controlling cell phones involves detecting their RF signals, followed by confiscation or other intervention. With this, a cell phone detector is a device designed to detect the presence of a cell phone within a certain range of vicinity (from a distance of one and-a-half metres.). Our aim is to design a cell phone detector that can be used to prevent the use of mobile phones in examination halls, confidential rooms, banks, petrol filling stations, military intelligent gathering etc. We made use of two signal detectors each with a dipole antenna, choke, and diode. Each dipole antenna is tuned to 900MHz. When the antennas resonate at 900 MHz a charge is induced in the inductor. A diode then demodulates the signal, which is amplified by an op-amp and passed along to a 3.5mm headphone jack. The results of our experiment shows that the technique used in this design can detect Global System for Mobile Communication (GSM) signals at 900MHz. The realised cell phone detector has been tested and found working and is detecting the cell phones as desired within the design range.
