RU196151U1 - RFID tag - Google Patents

Abstract

The utility model relates to the field of radio frequency identification, in particular to the design of radio frequency identification tags on integrated circuits. The technical result is to increase the reading range of the RFID tag at microwave frequencies (860-960 MHz). The radio frequency identification tag is arranged to be placed entirely on a metal surface and contains inlay on which the chip and antenna, and the dielectric core are placed. The antenna contains the first part and the second part. The dielectric core has an upper side, an end side and a lower side. The inlay is located on the dielectric core so that the first part of the antenna is located on the upper part of the dielectric core, the second part of the antenna is located on the lower part of the dielectric core, and the chip is located on the end side of the dielectric core. 6 c.p. f-ly, 11 ill.

Description

The invention relates to the field of radio frequency identification, in particular to the design of radio frequency identification tags on integrated circuits.

The following terms and abbreviations will be used hereinafter.

Radio frequency identification (abbreviated RFID, RFID - Radio Frequency IDentification) is a method of automatic identification of objects in which data stored in the so-called transponders or RFID tags are read or written using radio signals.

Inlay (Engl. Inlay) - the functional part of the RFID tag, which encoded the identification information and which consists of two components: an integrated circuit or chip connected to a metal antenna made of aluminum, copper or silver; The antenna and chip are located on the substrate.

Chip - an integrated (micro) circuit - a microelectronic device - an electronic circuit of arbitrary complexity (crystal) made on a semiconductor substrate (plate or film).

RFID reader (reader) - a device for reading information from an RFID tag.

PET (Polyethylene terephthalate) - a type of thermoplastics.

ABS (ABS) -plastic (acrylonitrile butadiene styrene) is an impact resistant technical thermoplastic resin based on a copolymer of acrylonitrile with butadiene and styrene (the name of the plastic is formed from the initial letters of the names of monomers).

Polypropylene (PP) is a thermoplastic polymer of propylene (propene).

Polyethylene - a thermoplastic polymer of ethylene, belongs to the class of polyolefins.

UHF (English Ultra high frequency) - decimeter waves (UHF) - a range of radio waves with a wavelength of 1 m to 10 cm, which corresponds to a frequency of 300 MHz to 3 GHz.

The closest analogue of the claimed utility model is a radio frequency identification tag, known from patent application US 2008122631 and containing a flexible inlay with an antenna, including a substrate and an antenna structure, a dielectric core with an inlay attached to it, a metallized substrate attached to a dielectric core to protect the inlay from external exposure, and a protective structure for accommodating and protecting inlay, dielectric core and metallized substrate.

However, this mark in the range of resonant frequencies does not provide a range of more than 26 feet, i.e. 7.8 m.

The technical problem to which the claimed utility model is directed is the insufficient reading range of RFID tags.

The technical result of the proposed utility model is to increase the reading range of the RFID tag.

The claimed technical result is achieved due to the fact that the radio frequency identification tag is made with the possibility of placement entirely on a metal surface and contains inlay on which the chip and antenna, and the dielectric core are placed; the antenna comprises a first portion and a second portion, and the dielectric core has an upper side, an end side and a lower side, the inlay being located on the dielectric core so that the first antenna portion is located on the upper part of the dielectric core, the second antenna portion is located on the lower part of the dielectric core , and the chip is located on the front side of the dielectric core.

In the RFID, the inlay and dielectric core can be housed in the housing.

In a radio frequency identification tag, the inlay may comprise a PET or polyamide substrate on which the antenna is placed.

In the radio frequency identification tag, the dielectric core may be in the form of a parallelepiped.

In the radio frequency identification tag, the metal surface can be made in the form of a metal plate on which the inlay and the dielectric core are fixed.

In the radio frequency identification tag, the inlay and dielectric core located on the metal plate may be located in the housing.

In the radio frequency identification tag, the dielectric core may be made of a polyolefin material with a dielectric constant of 1.9-2.5.

High range - not less than 10 meters and up to 54 meters - is achieved by placing RFID tags on a metal base, the size of which should be comparable with the dimensions of the RFID tags or more. RFID tags have a fairly wide amplitude-frequency characteristic with a working frequency band of about 30 MHz in terms of maximum amplitude and another about 30 MHz in terms of a drop in the reading range of the tag up to 2 times, which gives a margin for shifting the resonance frequency to the low and high frequencies. This means that the range of the RFID tag remains high when attached to various metal surfaces. Structurally, the RFID tag is designed in such a way as to be able to adjust the resonance frequency for placement on specific objects.

The utility model is illustrated using FIG. 1-11, which show:

FIG. 1 is a perspective view of a construction of a radio frequency identification tag in a housing;

FIG. 2 - scan antenna;

FIG. 3 - plot antenna for mounting the chip;

FIG. 4 is a general view of an RFID inlay wrapped around a core;

FIG. 5-7 - RFID tag embodiment for the operating frequency range up to 900 MHz;

FIG. 8-10 - an embodiment of an RFID tag for a range of operating frequencies up to 930 MHz;

FIG. 11 is a graph of the frequency range of reading RFID tags.

In FIG. 1-10 positions 1-12 are indicated:

1 - metal surface;

2 - substrate;

3 - dielectric core;

4 - the first section of the antenna located on top and facing the identification object;

5 - case;

6 - fold line;

7 - antenna;

8 - place for the chip;

9 - the second section of the antenna;

10 - end face of the core;

11 - the upper side of the dielectric core;

12 - bottom side of the dielectric core.

The radio frequency identification tag (RFID tag) contains an inlay with an antenna 7 and a chip (not shown) and a dielectric core 3. The inlay contains a flexible substrate on which an antenna 7 is placed, comprising a first portion 4 and a second portion 9.

In the particular case, the antenna 7 is made of aluminum and etched on PET material. Antenna 7 may also be copper or other suitable material. The flexible inlay substrate may be made of PET or polyamide.

The dimensions of the antenna 7 are selected in such a way as to compensate for the influence of the material of the dielectric core 3 and the housing 5. The tuning (tuning) options are shown in FIG. 5-10. There are other options for tuning the antenna 7, which can be both theoretically calculated and empirically selected for a particular task, indicating the requirements for the operating range at certain frequencies.

On inle, space 8 is provided for the placement of the chip. In the inventive device, two types of chips can be used: NXP UCODE7 and NXP UCOD8, as well as their modifications that differ from the indicated memory sizes, as well as with minor adjustments to the footprint, NXP UCODE DNA chips and modifications. A wide frequency response is also provided by the chip, which has an integrated cascade of connected capacities.

The dielectric core 3 has an upper side 11, an end side 10 and a lower side 12.

The inlay is located on the dielectric core 3 so that the first antenna portion 4 is located on the upper side 11 of the dielectric core 3, the second antenna portion 9 is located on the lower side 12 of the dielectric core 3, and the chip is located on the end side 10 of the dielectric core 3.

For the RFID tag to work correctly, the antenna 3 on the inle is bent around the dielectric core 3 along the fold lines 6. The lengths of sections 4 and 9 are selected for the material, taking into account the influence of the material of the dielectric core, body, glue (if any) and the inlay with the antenna itself.

To fix the inlay to the dielectric core 3, glue can be applied to the inlay.

The effect of the adhesive is offset by the methods described above. In the current design of the label, the method of attaching inlay to glue (self-adhesive inlay) is selected as the most technologically advanced option.

The dielectric core 3 is made of polyolefin materials with a dielectric constant of 1.9-2.5, such as high density polyethylene (HDPE), high pressure polyethylene, isotactic polypropylene (iso-PP), etc.

The inventive RFID tag is designed to work on metal. It is when attaching the RFID tag to a metal surface that it begins to work at such significant distances up to the RFID reader.

This effect is observed due to the re-reflection of the electromagnetic signal from the metal base on which the label is attached. The combination of RFID inlay, dielectric 3 and metal surface 1 acts as a signal amplifier, concentrating on the RFID tag that signal that does not directly irradiate the RFID tag, but falls on metal surface 1. This effect is observed for antennas based on microstrip communication lines, and described in detail in the literature on microwave antenna technology.

When using RFID tags on other materials or in the air, the distance of its operation is significantly reduced.

If you want to achieve an increase in range on other materials, you can provide the RFID tag with a metal layer between the tag and the mount.

The preferred metals for placing RFID tags on them are aluminum, copper and iron. In general, any conductive materials may be used.

The case can be made of polyethylene, polypropylene, ABS plastic. Antennas 7 are tuned for each of the materials. In the given examples of implementation, the housing is made of polypropylene.

The recommended recommended values are taken as the dimensions of technological platforms and clearances for chip seating, but they can be changed by the company that manufactures the antenna based on its internal requirements for observing technological clearances and the size of contact pads.

In FIG. 4 shows a general view of the construction of an RFID tag. A feature of the claimed RFID tag is the ability to configure it for a specific region, because frequencies in different countries vary, which is regulated by the legislation of the country in which the label will be used. This feature is reflected in the form of two performance variations (Fig. 5-10), which differ from each other by the antenna configuration.

The device is made as follows.

An antenna 7 is made on a flexible inlay substrate by electrochemical etching. Then a flexible inlay substrate with an antenna 7 is wrapped around the dielectric core 3, bending the inlay substrate along lines 6. The inlay is glued and bent, observing gaps and distances. A deviation of even 0.5 mm significantly affects the tuning of the antenna 7, and, consequently, the range. Sticking and bending can occur both manually and on a specialized device. The gap accuracy should be within 0.1 mm.

Then, a chip is mounted on the pads of place 8. After that, the RFID tags are tuned to the required operating frequency range by cutting the inlay from one or both sides of the antenna 7.

The resulting RFID tag in a particular case is placed in the housing 5.

The following are particular cases of RFID tag execution.

Option 1.

For the operating frequency range up to 900 MHz, the following RFID tags were selected:

- a dielectric core measuring 100 × 15 × 10 mm made of high pressure polyethylene;

- an aluminum antenna on a PET substrate 205.64 mm ± 0.2 mm long, the upper part to the fold line 95.76 mm ± 0.2 mm, the lower part 99.78 mm ± 0.2 mm.

Option 2

For the operating frequency range up to 930 MHz, the following RFID tags were selected:

- a dielectric core measuring 100 × 15 × 10 mm made of high pressure polyethylene;

- an aluminum antenna on a PET substrate 187.17 mm ± 0.2 mm long, the upper part to the bend line 92.91 mm ± 0.2 mm, the lower part 94.26 mm ± 0.2 mm.

The device is used as follows.

A fabricated RFID tag is placed on an identifiable entity. Identification is carried out using an RFID reader.

RFID reader (reader) must work with RFID tags EPC Class1 Generation2. To achieve high range performance, the reader should have a power of about 1 watt. To achieve maximum reading ranges, an RFID reader, an RFID antenna, and a coaxial cable of the reader antenna are chosen so that the effective radiated power of such a system is about 2 watts.

The range of stable operation of the claimed RFID tags during testing is 42 meters. For testing, we used the system: an RFID reader, an antenna, and a cable tuned to 2 watts of effective radiated power. According to the results of tests in an anechoic chamber at a specialized Voyantic RFID stand, the range is from 27 to 30 meters for a batch of 100 tags (Fig. 11).

The value of this development in its electronic filling and in the selection of materials. The combination of the electronic part and the materials used made it possible to achieve a high working range.

Claims (7)

1. Radio-frequency identification tag, characterized in that it is made with the possibility of placement entirely on a metal surface and contains inlay on which the chip and antenna are placed, and the dielectric core; the antenna comprises a first portion and a second portion, and the dielectric core has an upper side, an end side and a lower side, the inlay being located on the dielectric core so that the first antenna portion is located on the upper part of the dielectric core, the second antenna portion is located on the lower part of the dielectric core , and the chip is located on the front side of the dielectric core. 2. The radio frequency identification tag according to claim 1, characterized in that the inlay and dielectric core are housed in a housing. 3. The radio frequency identification tag according to claim 1, characterized in that the inlay contains a substrate of PET or polyamide on which the antenna is placed. 4. The radio frequency identification tag according to claim 1, characterized in that the dielectric core is made in the form of a parallelepiped. 5. The radio frequency identification tag according to claim 1, characterized in that the metal surface is made in the form of a metal plate on which the inlay and the dielectric core are fixed. 6. The radio frequency identification tag according to claim 5, characterized in that the inlay and dielectric core located on the metal plate are located in the housing. 7. The radio frequency identification tag according to claim 1, characterized in that the dielectric core is made of a polyolefin material with a dielectric constant of 1.9-2.5.

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