A Rearch On A Universal UHF RFID Reader Module And Its Flexible Interface

Currently the UHF RF modules generally have large size, support single protocol standard and few communication interfaces. They work within short range and have difficulty being used by both PC and embedded products transplantation. Also they seldom consider the security and software based on those modules is hard to develop. They lead to the hard promotion of UHF RFID technology. In other words, it doesn’t effectively exploit the advantage of UHF RFID technology whose is efficient automated intelligent recognition. Considering the current problems, the paper will design a UHF RFID reader module which can work fast and can be conveniently transplanted to the fixed and hand-held devices.The reader will use RF chip AS3992, and has excellent compatibility and portability. It will also support for multiple standards, have efficient reading rate and long-term recognition distance. This module can also be linked to PC or embedded devices with detailed communication protocol. This paper will talk about the design of hardware circuit design, software application development. In the end the thesis will test the module and analyze the result. The main work of this paper is as follows:(1) The construction of electronic circuit composed of power control part, RF peripheral circuit section and main control circuit part. Especially it will talk about the Loop filter part, the difference signal balance transformer part, power amplification, filtering and directional coupler section in detail. In order to improve the module performance, the matching impedance of the module is calculated.(2) Definition of the transmitting and receiving data format between the module and other devices. The designing and development of the reader module software program as well as the host computer software program of the serial communication.(3) Using a variety of test equipment to analyze the performance of the module. By test and analysis, the UHF module designed meets the initial expectations, is in accordance with the standard protocol, can rapidly identify the tags within long recognition fields and can be easily connected to PC and embedded products.