CN205302816U - An anti-metal label based on EBG structure - Google Patents

Abstract

The utility model discloses an anti-metal label based on an EBG structure, which comprises a double-sided adhesive arranged on the first layer, an antenna arranged on the second layer, an antenna substrate arranged on the third layer, and an antenna substrate arranged on the fourth layer. EBG structure. In the utility model, an EBG structure is added between the tag and the metal, so that the signal of the antenna of the reader can be positively reflected on the surface of the EBG structure, thereby achieving the capability of enhancing the signal.

Description

An anti-metal label based on EBG structure

technical field

The utility model relates to an anti-metal label based on an EBG structure.

Background technique

Radio frequency identification, RFID (Radio Frequency Identification) technology, also known as radio frequency identification, is a communication technology that can identify specific targets through radio signals and read and write related data without the need for mechanical or optical contact between the identification system and specific targets.

An RFID tag consists of a tag chip and a tag antenna connected to the chip. In a considerable part of UHF radio frequency identification applications, labels need to be pasted on the surface of metal objects, such as: cars, containers, metal pallets and other objects made of metal.

Since the electromagnetic wave hits the metal surface, it will be reflected in reverse, so the signal at the metal surface is weakened. If the ordinary tag is placed in this area, the tag cannot obtain the energy to work, so the ordinary tag cannot work on the metal surface. Design a special label, this kind of label that can work on the metal surface, we call it an anti-metal label.

Ideal electrical conductors (PEC: perfect electronic conductors) and ideal magnetic conductors (PMC: perfect magnetic conductors) are two very important concepts in classical electromagnetic field theory. The tangential electric field of an ideal electric conductor is zero. It can be seen that when a plane wave is incident on its surface, there is a 180-degree phase difference between the reflected wave and the incident wave. This makes when the metal is used as the reflective surface of the antenna to enhance the half-space radiation, the distance between the antenna and the reflective surface must be about a quarter of a wavelength, otherwise the radiation capability of the antenna will be drastically reduced due to the phase inversion of the electric field of the reflected wave . The tangential magnetic field of an ideal magnetic conductor is zero, and when a plane wave is incident on an ideal magnetic conductor, the incident wave and the reflected wave are in phase. The in-phase signal can strengthen the signal strength, so that the label can obtain more energy signals on the surface of the ideal magnetic conductor than on the metal surface, achieving the effect of anti-metal. The EBG (ElectromagneticBandGap) structure is a microstrip structure that simulates the in-phase reflection characteristics of a plane wave similar to an ideal magnetic conductor. In this configuration the refracted and reflected waves of a plane wave are in phase.

Utility model content

The purpose of the utility model is to provide an anti-metal label based on the EBG structure in view of the defects existing in the prior art. The EBG structure is used as the substrate substrate so that the signal can be reflected in the same phase on the surface of the EBG structure, which can reduce the impact of the metal on the energy obtained by the label. influences.

In order to achieve the above object, the utility model adopts the following technical scheme: an anti-metal label based on EBG structure, including a double-sided adhesive disposed on the first layer, an antenna disposed on the second layer, and an antenna substrate disposed on the third layer , and the EBG structure set on the fourth layer.

Further, the material of the antenna is silver paste or copper, which is attached to the upper surface of the antenna substrate by sintering or electroplating.

Further, the EBG structure is composed of a periodic patch unit layer arranged on the top layer, a metal layer arranged on the bottom layer, and a dielectric layer arranged between the periodic patch unit layer and the metal layer; the period A plurality of patch units evenly distributed on the patch unit layer and the metal layer are correspondingly provided with metal via holes for forming electrical connections.

Further, the dielectric layer is made of non-conductive material, and its thickness is 3mm-12mm.

Further, the patch unit adopts a spiral structure layer made of metal.

Further, the spiral structure layer is composed of regular arcs or a plurality of rectangular lines.

The beneficial effects of the utility model:

1. When the EBG structure antenna is used in an anti-metal environment, the metal environment has little effect on the antenna's pattern, which greatly improves the performance of the antenna.

2. On the same area, because the size of the patch unit is reduced, the number of the patch unit is increased, and the anti-metal effect is more obvious, especially suitable for the application of small anti-metal labels.

3. The application of the frequency selective surface can suppress the propagation of the surface wave, increase the gain of the antenna, and reduce the back lobe.

4. The EBG structure is applied to the antenna reflection surface of the dipole antenna. Through in-phase reflection, the energy of the signal can be enhanced and the antenna's ability to receive signals can be improved.

Description of drawings

Fig. 1 is a schematic diagram of the decomposition structure of the utility model.

Fig. 2 is a three-dimensional schematic diagram of the EBG structure of the present invention.

Fig. 3 is a schematic top view of the EBG structure of the present invention.

detailed description

As shown in Figure 1, it is an anti-metal label based on an EBG structure, including a double-sided adhesive 1 arranged on the first layer, an antenna 2 arranged on the second layer, an antenna substrate 3 arranged on the third layer, and Set the EBG structure 4 on the fourth floor.

Wherein, the material of the antenna 2 is silver paste or copper, which is attached to the upper surface of the antenna substrate 3 by sintering or electroplating. The antenna substrate 3 and the EBG structure 4 are closely combined. The provided double-sided adhesive tape 1 plays the role of installation, which can make the label firmly installed on the surface of other objects for use.

Figure 2 is a schematic perspective view of the EBG structure. It can be seen from the figure that the EBG structure 4 is composed of a periodic patch unit layer 6 arranged on the top layer, a metal layer 7 arranged on the bottom layer, and a metal layer arranged between the periodic patch unit layer 6 and the metal layer 7. The dielectric layer 8 is composed of a plurality of patch units 61 evenly distributed on the periodic patch unit layer 6 and the metal layer 7 are correspondingly provided with metal via holes 9 for forming electrical connections. Among them, the periodic patch unit layer 6 constitutes the frequency selective surface of the tag; and the metal layer 7 provided can shield the signal on the back of the tag.

In addition, the provided dielectric layer 8 is used to fill the space between the periodic chip unit layer 6 and the metal layer 7, and can be made of air, FR4 and other non-conductive materials with a thickness of 3 mm to 12 mm.

As shown in Figure 3, it is a schematic top view of the EBG structure. It can be seen from the figure that the patch unit 61 adopts a spiral structure made of metal such as copper and silver, and its function is to increase the distance from the center of the patch unit to the edge of the patch unit. The helical structure is arranged in order to reduce the size of the patch unit 61, increasing the distance from the center of the patch unit 61 to the edge of the patch unit 61, which can reduce the size of the patch unit 61, and the spiral structure can be regular Arcs can also be composed of multiple rectangular lines. Generally, the size of the patch unit 61 can be reduced by increasing the length of the helical structure, so that the number of patch units 61 increases on the same area, and the anti-metal effect is more obvious. In this design, more than six patch units 61 are usually selected to form a frequency selective surface.

In the utility model, an EBG structure is added between the tag and the metal, so that the antenna signal of the reader can be positively reflected on the surface of the EBG structure, thereby achieving the capability of enhancing the signal.

The above are only preferred embodiments of the utility model, and are not intended to limit the utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the utility model shall be included in the utility model. within the scope of protection.

Claims (6)

1. the anti-metal tag based on EBG structure, it is characterised in that include the double faced adhesive tape being arranged on ground floor, be arranged on the antenna of the second layer, is arranged on the antenna substrate of third layer, and is arranged on the EBG structure of the 4th layer.

2. anti-metal tag as claimed in claim 1, it is characterised in that the material of described antenna is silver slurry or copper, and it is attached on the upper surface of described antenna substrate by the mode sintering or electroplating.

3. anti-metal tag as claimed in claim 1, it is characterised in that described EBG structure, by the cycle chip unit layer being arranged on top layer, is arranged on the metal level of bottom, and is arranged on the dielectric layer composition between described cycle chip unit layer and described metal level; Described cycle chip unit layer is correspondingly arranged between equally distributed multiple chip units and described metal level the metallic vias for forming electrical connection.

4. anti-metal tag as claimed in claim 3, it is characterised in that described dielectric layer adopts non-conductive material to make, and its thickness is 3mm��12mm.

5. the anti-metal tag as described in claim 3 or 4, it is characterised in that described chip unit is metal helical structure layer.

6. anti-metal tag as claimed in claim 5, it is characterised in that described helical structure layer adopts the camber line of rule or multiple rectangle lines composition.