A flexible anti-metal label

Abstract

The invention discloses a flexible anti-metal label, which comprises a dielectric substrate layer (2), a radiation patch layer (1) fixed above the dielectric substrate layer (2), and a floor layer ( 12); the radiation patch layer (1) includes a radiation area (3) and a feeding area, and the feeding area includes a chip (4), a first microstrip line (5) and a second microstrip line (6 ); one end of the first microstrip line (5) and one end of the second microstrip line (6) are respectively connected to the two ends of the chip (4); the other end of the first microstrip line (5) is connected to the second microstrip line The other ends of (6) are connected together as the common end of two microstrip lines to the radiation area (3), so that the feeding area and the radiation area (3) form a whole. The invention combines the feeding area and the radiation area into a whole to form a coplanar integral special microstrip antenna, which reduces the size of the tag and reduces the cost of the tag.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to a flexible anti-metal label. Background technique [0002] In the application of various tags, it is often necessary to mark metal objects, such as automobiles, steel cylinders, containers, weapons and equipment, etc.; when ordinary UHF tags are placed on metal surfaces, the reading distance of tags will be shortened rapidly , cannot even be read. [0003] When an ordinary UHF tag is attached to a metal surface, the main factor leading to the deterioration of the tag performance is that the metal boundary condition makes the reflected wave of the interrogation signal of the reader and the phase of the incident wave opposite, resulting in energy being canceled out, and it is difficult for the tag to obtain sufficient energy. Energy activated tag chip. When the incident wave is perpendicular to the metal surface, because the difference between the reflected wave and the inci...

AI Technical Summary

Problems solved by technology

[0002] In the application of various tags, it is often necessary to mark metal objects, such as automobiles, steel cylinders, containers, weapons and equipment, etc.; when ordinary UHF tags are placed on metal surfaces, the reading distance of tags will be shortened rapidly , cannot even be read

[0003] When an ordinary UHF tag is attached to a metal surface, the main factor leading to the deterioration of the tag performance is that the metal boundary condition makes the reflected wave of the interrogation signal of the reader and the phase of the incident wave opposite, resulting in energy being canceled out, and it is difficult for the tag to obtain sufficient energy. Energy Activated Tag Chip

When the incident wave is perpendicular to the metal surface, because the difference between the reflected wave and the incident wave is exactly 180°, the electric field component is distributed as a standing wave on the metal surface. In other words, when the label is directly attached to the metal surface, the energy that can be obtained is almost zero, and when placed at a distance from the metal surface, the energy that can be obtained is the largest; therefore, when the tag antenna is directly attached to the metal surface, the radiation efficiency of the tag antenna is seriously attenuated due to the influence of boundary conditions

[0004] In addition to the impact on the radiation efficiency of the tag antenna, the impedance matching of the tag antenna will also become poor, resulting in a decrease in the power transfer coefficient between the antenna and the chip; the change in antenna impedance is due to the decrease of the antenna radiation resistance on the one hand, and the Because the metal surface will have an inductive effect on the antenna; the reduction in radiation efficiency caused by the metal boundary condition can be overcome to some extent by using absorbing materials, but the inductive effect of the metal surface on the antenna cannot be eliminated

[0005] In response to this situation, some domestic and foreign manufacturers have specially designed some anti-metal tags that can be used on metal surfaces. These tags often use microstrip antennas, which requires drilling and grounding of the dielectric substrate, or open-circuit microstrip antennas. Generally extended at the rear, there are disadvantages of large volume, poor performance, complicated processing, and high cost, and it is difficult to meet the needs of practical applications.

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