Özet:
The aim of this work is to design, implement and verify a low cost microcontroller based electronic article surveillance (EAS) system prototype and is accomplished in great success. An EAS system is basically used for preventing the shoplifters. The system basically consists of three parts, namely, the tag, the transceiver and the antenna. The tag is a series LC circuit that consists of a wire wound coil and a capacitor. The transceiver circuit is responsible for detecting the presence of the tag in the environment and finally the antenna is basically a large coil that is used for energizing the tag in the environment. Our study basically consists of two parts, namely the simulation results based on acquired data and the hardware implementation. The physical data is captured via a commercially available EAS system from Checkpoint Company. The transceiver circuit and the antenna is used to energize the tag in the environment. A separate loop antenna that is tuned for 8.2 MHz is used for capturing data. This loop antenna is called “sniffer” throughout the rest of this work. The captured data is saved via Tektronix DPO4104 oscilloscope as “csv” files. MATLAB is used for processing the captured data and for developing the algorithm. The hardware implementation part is the practical realization of our work. There are mainly five blocks used in a typical EAS system which are frequency synthesizer, amplifier, receiver, power unit and the processing unit. Each of them are carefully designed and tested as they will be explained in great detail within the relevant chapter.
