Ultrahigh-frequency RF identification metal circular polarization preventing label antenna

Abstract

The invention discloses an ultrahigh-frequency RF identification metal circular polarization preventing label antenna which is mainly composed of four parts of a dielectric substrate upper surface antenna part, a dielectric substrate, metalized vias and metal ground. The antenna part is composed of a square ring structure and two centrosymmetric feed lines. A label chip is connected with the square ring structure through the two centrosymmetric feed lines. The metalized vias are communicated with the square ring structure and the metal ground. The two feed lines are composed of a stepped broken line, a 45-DEG broken line and a straight line. The ultrahigh-frequency RF identification metal circular polarization preventing label antenna is advantageous in that -10dB bandwidth of the ultrahigh-frequency RF identification metal circular polarization preventing label antenna is 533MHz (533-1066MHz) and can satisfy a frequency band requirement of each country to RFID application; secondly, when the frequency band is 840-845MHz in China, the axial ratio of the antenna is below 3dB and a circular polarization requirement is satisfied; and furthermore when the frequency band is 840-960MHz,the antenna gain range is -0.2-1.8dBi; and a defect of low gain of the metal circular polarization preventing label antenna in a metal environment is overcome; and furthermore the ultrahigh-frequencyRF identification metal circular polarization preventing label antenna has advantages of small size, simple structure, easy manufacture, and high suitability for various application scenes such as vehicle identification.

Description

technical field [0001] The patent of the present invention relates to a tag antenna, in particular to an ultra-high frequency radio frequency identification (UHF RFID) anti-metal circularly polarized tag antenna, which belongs to the technical field of RFID tag antennas. Background technique [0002] In radio frequency identification technology, the design of tag antenna is one of the key technologies. Because the tag has the characteristics of high data transmission rate, fast recognition speed and long reading and writing distance, the tag has been applied and developed in various industries in China. But at the same time, there are also great challenges and difficulties in the design of the tag antenna, such as: the impact of the application environment on the tag, the impedance matching of different tag IC circuits, and the widest possible working bandwidth. Therefore, overcoming these challenges and difficulties and strengthening the research on UHF RFID tag antennas a...

AI Technical Summary

Problems solved by technology

Therefore, there is a polarization mismatch between the reader antenna and the tag antenna, which will result in only half of the transmitted power being received by the linearly polarized tag

Images