STRUCTURE OF A CIRCULARL POLARIZED ANTENNA FOR UHF BAND RFID READER

摘要

The present invention relates to a circularly polarized antenna structure for UHF RFID reader. Improvement of the present invention includes a signal generator for generating an original signal by separating into two signals having 90 phase difference, and the radiation patch to implement an embedded stripline is circularly polarized when supplied the generated signal, and the radiation efficiency plate is provided with radiation having a predetermined spacing with the radiating patch 2, which is installed to the feed point. In addition, the signal generating unit is further connected to a matching impedance consists of a microstrip transmission line for compatibility with other RFID systems, the signal generating unit, a hybrid coupler or Valium is used having a predetermined electrical properties. In accordance with the present invention having such a configuration the antenna radiation efficiency is maximized, the number of tags at the same time the advantage that it can be accurately recognized without error at a distance.