KR20090095085A - RFID [Radio Frequency Identification] Antenna for Tag and Reader using Cement Composite - Google Patents

Abstract

The present invention relates to a ceramic antenna for a tag and a reader of a radio frequency identification system (RFID). The present invention relates to a ceramic material used for a tag and a reader in a radio frequency identification system consisting of a tag and a reader antenna. It is to design a system that can be used for buildings, tunnels, bridges, etc. using composite materials for cement, aluminate, and portland cement. The frequency band used in the radio frequency identification system is 915MHz, and the composition of the tag antenna generally uses a high frequency dielectric. The high frequency dielectric composition used for the high frequency dielectric uses a phase dielectric material having a stable temperature coefficient. In general, high-frequency dielectric materials have a strength of 100 MPa, causing damage when exposed to harsh environments. Therefore, high strength, high toughness, high hardness ceramics are required to be applied to various environments. Cement composites have high strength, excellent chemical resistance, and are environmentally friendly materials that can be applied in various fields such as buildings, railways, bridges and tunnels. History management of buildings, tunnels, bridges, etc. by using cement composite materials (water, cement, sand, gravel) as a composition of ceramic antennas for tags and readers in radio frequency identification systems with high strength, high toughness and high hardness Cement composites employing an allite-based (3CaO.SiO2.Al203.MgO) ballite, aluminate, and portland system that can be used with RFID tags and readers are coated with cement paste and then coated with silver paste. , Copper foil or aluminum foil is attached to form the ground and top electrodes, and then coated with poly-coated to prevent corrosion of the electrodes.

Description

Antenna for tag and reader using cement composite material of building radio frequency identification system {RFID [Radio Frequency Identification] Antenna for Tag and Reader using Cement Composite}

Radio frequency identification system is automatic recognition technology through radio frequency recognition and consists of reader, tag and host computer. The principle of operation is that the radio goes out through the reader antenna and the tag antenna receives the radio wave. At this time, the ID and data are transmitted to the IC built in the tag antenna, and the antenna converts the ID transmitted from the tag into a data signal and the computer is stored in advance. It uses the principle of providing a service compared to a database. The advantage of RFID is that the recognition method is non-contact, the recognition distance is long and the recognition speed is very fast, 0.01 ~ 0.1 seconds. The recognition rate is 99.9% or more, and radio waves can be transmitted except for metal. Its service life is 100,000 times (60 years) and it is semi-permanent. Data storage is more than 64K bytes, so there is little card damage rate and the price of tag is low. Security is not duplicated and can be recycled. When comparing the RFID characteristics by frequency, the sensing distance is 0.5-1m in the band 125 ~ 135KHz, about 1m in 13.56MHz, and the sensing distance is about 3m in the 860 ~ 960MHz band which is UHF band. great. Application of RFID is used for distribution logistics supply chain management, automobile toll collection, and the tag of 900MHz band has the advantage of fast recognition speed. Other uses of RFID tags include electronics, (laptops, PDAs, refrigerators, TVs), the automotive industry, gold bullion, asset management, vehicle access control, anti-theft, inventory management, records management, casinos, PCB board management, There are various applications such as steel companies (steel management, rolling rolls, cold rolled coils, steelmaking cranes), and curing concrete structures at construction sites. Common RFID tags and readers include ABS plastic, FR4, Teflon, Polyimide, urethane, styrofoam, and synthetic resin. The dielectric constant of this polymer material is generally 2 ~ 5, which has the disadvantage of large tag and reader size.

. Ceramic materials in the 900MHz band, which have good high frequency characteristics, are environmentally friendly and have a short wavelength, which makes the tag compact and solves omnidirectional recognition and directional problems. Another advantage of the ceramic tag is that it is excellent in waterproof, environmental resistance and moisture resistance, and can be applied to harsh environments, can be attached to a minimum area, and can be applied to various environments due to its high temperature characteristics. In general, the strength of the composition of the building composite material is weak to 100MPa when exposed to the outside environment is not applicable to various environments. Therefore, in the present invention, the development of a building cement composite material that can be applied to various environments has developed a ceramic material for RFID ceramic tag and reader antenna having high frequency characteristics and excellent mechanical properties.

The present invention is applied for RFID after cement paste is applied to concrete tile of cement composite material (water, cement, sand, gravel) as a composition of ceramic antenna for tag and reader in radio frequency identification system with high strength, high toughness and high hardness. By using it as a tag and reader antenna, history management of buildings, tunnels, bridges, etc. is possible. For example, in older aging apartments, it is convenient to reconstruct if there is a history and design drawings of the building materials used in the apartment during remodeling. Maintenance is also easy if the history of materials, construction methods, designs, etc. used during maintenance of buildings, bridges, tunnels, etc. is maintained. When using Allite (3CaO.SiO2.Al203.MgO), Bellite, Aluminate, and Portland cement composites as RFID tags and reader antennas, the installation cost of the antenna can be further reduced and the construction is simple. It is economical.

[Composition of the Invention] Cement composite materials in the broad sense refers to materials and materials adhering materials, but generally refers to inorganic bond hardeners for civil engineering and construction. Among them, what is commonly referred to as cement today is the main components of Portland cement, such as lime, silica, alumina and iron oxide. This cement mixes the raw material containing these in a suitable ratio sufficiently, and part of it melts. Powder is made by adding an appropriate amount of gypsum to a fired clinker. Cement is the main construction material. Cement products are commonly seen in everyday life such as concrete piles, fume pipes, bricks, etc. for secondary products based on concrete or cement. In the present invention, when manufacturing a concrete tile using a cement composite material (water, cement, sand, gravel) as a main raw material, if the RFID tag and the antenna for the reader are manufactured, the construction is simple and economical, and the history management of the future building is easy. There is a merit that it is easy to recover in case of occurrence. History management of buildings, tunnels, bridges, etc. by using cement composite materials (water, cement, sand, gravel) as a composition of ceramic antennas for tags and readers in radio frequency identification systems with high strength, high toughness and high hardness Cement composites employing an allite-based (3CaO.SiO2.Al203.MgO) ballite-based and aluminate-based cement composites with RFID tags and readers. After attaching aluminum foil to form ground and top electrodes, it is intended to be used as RFID tags and reader antennas for buildings, etc. after coating with Pima to prevent corrosion of the electrodes.

In general, the frequency range used in the RFID tag and reader is 915MHz band, and the dielectric composition uses a temperature compensation phase dielectric with stable temperature coefficient. The strength of the dielectric ceramic composition is about 100 MPa, which is vulnerable to RFID tags and readers for applications in steel, automotive, shipbuilding, and construction. Therefore, in the present invention, the dielectric constant has a value of 5 to 10, the mechanical properties (strength, toughness, hardness) are good and the electrical and mechanical properties of the RFID tag and reader antenna having excellent Q values to reduce circular polarization loss. The purpose is to develop the composition. The cement composite was composed of CaOSiO2, Al2O3, MgO, and water, cement, sand, gravel, etc., to prepare concrete tiles. The cement composite material for RFID by these compositions has good mechanical properties (high strength, high toughness, high hardness) and has a dielectric constant of 5 to 10, which can be used as a material for RFID tags and readers. The characteristics and manufacturing process of the cement composite material having high strength, high toughness, and high hardness of the present invention will be described in detail by examples. Figure 1 shows the electrical and mechanical characteristics of the RFID tag and reader antenna of the Allite composition system. The dielectric constant was 7.5 when W / C (water / cement ratio) = 0.5 and 9.8 when 0.8. Compressive strength was W / C = 0.5 and showed 477MPa when cured for 90 days. In Figures 2 and 3, the cement paste is applied on the cement tile, cured and then inlayed. In the case of 60mm in width, 20mm in length, and 3mm in thickness, the recognition distance was 2m when the IC was attached to the front side, whereas the difference was more than doubled by 4m when the IC was attached to the side. When the IC is attached to the side, the polarization loss is reduced and the recognition distance is increased.

In the present invention, since an allite cement composite material having a strength of 400 MPa is used as a composition of an RFID ceramic tag antenna and a reader antenna having high strength and mechanical properties as a cement composite material, the ceramic composition for RFID is generally 100 MPa in strength. Compressive strength can be extended to ~ 470MPa, and furthermore, it is a cement composite material for RFID tags and readers with good toughness and hardness. It has excellent mechanical properties, excellent chemical resistance, seawater resistance, and environmentally friendly cement composite composition This is possible.

Example 1

The composition of the cement composite was based on CaOSiO2 and Al2O3 and MgO were added. After weighing, concrete tiles were prepared using water (7 wt%), sand (30 wt%), and gravel (44 wt%). As a mixed material, fly ash or pozzolane was added. The mixed slurry was cured at room temperature in a diameter of 10 mm, a thickness of 7 mm, and a disc mold. The dielectric constant was measured by Hakki-Coleman method using TE11 resonance mode between two plates. Instron was also used to measure the mechanical strength of the specimen. The specimen size was 15Cm in diameter and 30Cm in height.

Example 2

As in Example 1, cement is used as a tag and reader antenna for manufacturing concrete tiles by using cement such as bellite, aluminate, and portland.

1 Electrical and Mechanical Characteristics of RFID Tag and Reader Antenna of Allite Composition System

Fig. 2 Inlay of IC after cement paste is applied on cement tile and cured

Fig. 3 A diagram in which the cement paste is applied on a cement tile, cured, and then the IC is inlaid on the side

Claims (5)

High-strength, high toughness It is possible to manage history of buildings, tunnels, bridges, etc. by using cement composite materials (water, cement, sand, gravel) as a composition of ceramic antennas for tags and readers in radio frequency identification systems with high mechanical properties. Cement composite material employing allite-based (3CaO.SiO2.Al203.MgO) ballite and aluminate-based antennas using RFID tags and readers. Formed as top electrode and used as RFID tag and reader antenna for buildings such as buildings after coating with Pima to prevent electrode corrosion The composition of the cement composite was based on CaOSiO2 and Al2O3 and MgO were added. These cement composite materials for RFID have good mechanical properties (high strength, high toughness, high hardness) and dielectric constant of 5 ~ 10, and have high strength, high toughness, and high hardness properties that can be used for RFID tags and readers. Cement composite materials Antenna material for tag and reader of radio frequency recognition system using Portland cement composed of SiO2 20.8 ~ 25.9, Al2O3 3.0 ~ 5.0, Fe2O3 2.8 ~ 4.4, CaO 63.0 ~ 65.0, MgO 1.0 ~ 1.6 Cement paste is applied on a concrete concrete tile composed of water, cement, sand, and gravel, and then cured. After forming an electrode with silver coating, copper foil or aluminum foil, attaching IC and attaching IC to prevent oxidation of the electrode upon contact with air. Used as a tag and reader antenna material for radio frequency identification system after polymera coating How to attach IC to the side to reduce polarization loss when inlaying RFID tag antenna of RFID

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