Improved coverage of phased array antennas used for RFID applications

This paper presents new study and design of microstrip phased array antennas used for extending the coverage area of RFID applications (ISO 18000-4 for 2.45GHz). The main idea is to modifying the antenna radiation pattern in order to extend the coverage area. The principle element achieving this operation is a distributed phase shifter. We have designed a patch antenna working at 2.45GHz and used it to build an antenna array. The antenna beam steering was achieved by implementing RF distributed phase shifter to excite the radiating elements of the antenna array. Distributed phase shifters are designed to provide the required phase shift to change the array pattern without disturbing the system performances.