RFID Reader And Antenna Analysis And Design

In recent years, with the continuous development of networking technology, radio fre-quency identification technology(RFID) has been widely used in various areas. This paper has firstly introduced RFID systems in detail, and then discussed its basic structure, key technolo-gies and its future development direction. Following these, the RFID's working principles, the structure of the various parts of the system have also been discussed.Within these parts constructing the system, RFID reader is an especially important com-ponent. It roles as a bridge between the upper databases and the electronic tags. In kinds of applications, the reader's appearance is various, while their basic structure is similar. So it is meaningful to discuss the common structure of a RFID reader in this paper and design a hand-held reader. In spite of the common requirements of other readers, such as reading and writing reliability, stability, and EMC, the design of hand-held readers also need to consider low-power consumption, which is all the hand-held products need to be taken great care.Accordance with the guiding principle of low-power consumption, we must take the power supply module into account firstly, and the module should be conversion efficiency. Because of this, selecting a proper power module for the reader plays a vital role. This paper has also dis-cussed the rest modules of the hardware sufficiently, including the processor module, memory expansion, interfaces, keyboard inputs, and LCD display module. One another important factor which affects the reader power consumption, read and write distance, stability is the reader loop antenna and its impedance matching. In this paper, after having completed the reader hardware construction, I have also discussed the reader's loop antenna design in depth. It involves the theory of the loop antenna, for example, field strength, coil inductance calculation, and the resonant circuits. Then according to the simulation and actual experiments, we can optimize the size of the antenna, and thus achieve the lowest power consumption while read and write distance keeps the same.