Optimization Design Of RFID Antenna

Radio Frequency Identification (RFID) is a type of non-contact automatic identification technology using radio wave to uniquely identify an object. Bearing feature of great capacity, long term of service life, non-contact data reading and writing, high speed moving object recognition and multi-target recognition, RFID has become a hot research field of automatic identification, regard as one of ten major technologies in the 21st century. Nowadays UHF and microwave frequency band RFID technology develops rapidly. Since design and optimization of antenna is a key part of the system, so it's very important to do some research on them.In the paper, the RFID antenna which works in UHF is analyzed. First, some basic knowledge of RFID is introduced, the important of the RFID antenna design and works principle is simply present. And then the basic theory of micro-strip patch antenna is highlighted. Subsequently micro-strip patch antenna which works in UHF is designed.Second, the micro-strip patch antenna which works in UHF is researched. The impaction of antenna parameters on the resonant frequency of the antenna is analyzed. It include substrate material, dielectric constant, length and width of patch etc. after that a coaxial feed micro-strip antenna is designed, simulation result show that this antenna has excellent performance, return loss is about 10db, dielectric constant is about 915MHZ, bandwidth is about 12MHZ, gain is about 7.5db. The antenna structure is simple and easy manufacture, it's very suitable for UHF antenna.Third, for design of antenna is need fast and accurately, according to antenna structure parameters of the antenna performance. Using BP neural networks building model of antenna designing, There are two optimization GA (Genetic Algorithm) and PSO (Particle Swarm Optimization) to optimize the BP neural network, to find an appreciate optimization method.