Circularly polarized anti-metal tag antenna

Abstract

The invention discloses a circularly polarized anti-metal tag antenna. The circularly polarized anti-metal tag antenna comprises a dielectric slab, and a circularly polarized radiation patch and a metal floor which are respectively etched at the top and the bottom of the dielectric slab through a light etching technology, wherein the circularly polarized radiation patch is a corner cutting rectangle micro strip patch, at least on cross-line-shaped groove which extends towards the center of the corner cutting rectangle micro strip patch is arranged on each edge of the corner cutting rectangle micro strip patch, at least one cross groove is formed in the surface of a portion surrounded by each two adjacent cross-line-shaped grooves and the corresponding edge of the circularly polarized radiation patch, a groove body is arranged at the center of the circularly polarized radiation patch, an impedance matching wire is arranged in the circularly polarized radiation patch, an impedance matching branch node is arranged at one end of each cross-line-shaped groove, close to the groove body, and the impedance matching wire is connected with the circularly polarized radiation patch through a chip, and connected with the metal floor through a metal short circuit pin. The circularly polarized anti-metal tag antenna has a good impedance characteristic and a circular polarization characteristic, is compact in structure, and simple and clear in design thought, and can be directly installed on an object of a metal structure for use.

Description

technical field [0001] The invention relates to the field of radio frequency identification, in particular to a circular polarization anti-metal tag antenna. Background technique [0002] Radio frequency identification (RFID) conducts non-contact two-way communication through electromagnetic or inductive coupling to realize automatic identification, and has the advantages of high precision and strong environmental adaptability. The development of RFID technology has promoted the advancement of antenna design and manufacturing technology, especially in the field of electronic tag antennas, which has formed a unique research field. The importance of the antenna as a device for sending and receiving carrier information in the RFID system is self-evident. [0003] In order to reduce costs, the tag antenna is directly connected to the tag chip without using matching circuits and other components between the chip and the antenna. The performance of the tag antenna and the power ...

AI Technical Summary

Problems solved by technology

In most RFID systems, the reader antenna uses a circularly polarized antenna. If the tag antenna uses a linearly polarized antenna, it will cause a polarization mismatch between the reader antenna and the tag antenna, thereby reducing the system reliability. Maximum read range achieved

It should be noted that if the reader antenna is in the form of a linearly polarized antenna, in order to ensure the maximum reading range, more stringent requirements will be placed on the placement and orientation of the linearly polarized tag antenna, which is obviously not convenient for system implementation and control

[0005] At present, there are many kinds of anti-metal tag antennas on the market, but there are relatively few circularly polarized anti-metal tag antennas. This is mainly because the design of circularly polarized anti-metal tag antennas is difficult.

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