+

WO2018106181A1 - Antenne intégrée dans du béton et procédé d'intégration d'antenne dans du béton - Google Patents

Antenne intégrée dans du béton et procédé d'intégration d'antenne dans du béton Download PDF

Info

Publication number
WO2018106181A1
WO2018106181A1 PCT/SG2017/050558 SG2017050558W WO2018106181A1 WO 2018106181 A1 WO2018106181 A1 WO 2018106181A1 SG 2017050558 W SG2017050558 W SG 2017050558W WO 2018106181 A1 WO2018106181 A1 WO 2018106181A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
concrete
particles
mold
antenna structure
Prior art date
Application number
PCT/SG2017/050558
Other languages
English (en)
Other versions
WO2018106181A8 (fr
Inventor
Yee Loon Sum
Vanessa RHEINHEIMER
Boon Hee Soong
Paulo J.M. Monteiro
Original Assignee
Nanyang Technological University
The Regents Of The University Of California
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nanyang Technological University, The Regents Of The University Of California filed Critical Nanyang Technological University
Publication of WO2018106181A1 publication Critical patent/WO2018106181A1/fr
Publication of WO2018106181A8 publication Critical patent/WO2018106181A8/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
    • C04B14/02—Granular materials, e.g. microballoons
    • C04B14/34—Metals, e.g. ferro-silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/40—Radiating elements coated with or embedded in protective material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/005—Patch antenna using one or more coplanar parasitic elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/42—Resonant antennas with feed to end of elongated active element, e.g. unipole with folded element, the folded parts being spaced apart a small fraction of the operating wavelength
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/90—Electrical properties
    • C04B2111/94—Electrically conducting materials

Definitions

  • Embodiments relate generally to an antenna structure and a method for forming an antenna structure.
  • Antennas have the ability of converting radio frequency (RF) signals into electrical signals and vice versa.
  • Most antennas are electrically large between 0.25 ⁇ to 1 ⁇ , where ⁇ is the wavelength, which has excellent Sn of less than -20 dB and a percentage bandwidth of up to 180%. As the size of antenna reduces to less than 0.25 ⁇ , the Sn increases and the bandwidth narrows. This limits the capability of the antenna.
  • a method of improving this is to perform impedance matching where the impedance of the antenna can be adjusted to a desired value such as 50 ohms to maximize power transfer.
  • This method introduces losses as the non-ideal matching components have inherent resistance. This is especially so when the antennas are electrically small and the frequency increases.
  • Magnetic and metallic particles application in concrete is still very limited and focuses only in the need for disposing the industry residues (environmental aspect).
  • Existing studies in this composite material are restricted to concrete performance and durability, thus far not applying the use of metallic and/or magnetic particles in concrete for enhancing the electromagnetic shielding, or energy harvesting abilities of the concrete structure.
  • the use of conductive concrete for the electromagnetic shielding has been explored before, but up until now not using magnetic/metallic particles to improve the properties of concrete.
  • Wireless communications are essential in buildings for many Internet of things (IOT) applications.
  • materials used in buildings do not allow good propagation of wireless signals within, and in and out of the buildings. This is especially so for embedded antennas in building materials.
  • RFID radio -frequency identification
  • EM electromagnetic
  • common building materials such as concrete, gypsum and plaster have high shielding effectiveness due to their nature.
  • Direct measurements, and analysis using finite-difference time-domain (FDTD), and method of moments (MOM) techniques show that building materials have more than 80 dB to 100 dB of shielding effectiveness.
  • the antenna may be configured to send and/or configured to receive an electromagnetic signal.
  • Various embodiments may further include the antenna being embedded in a concrete.
  • the concrete may include at least a cement.
  • the concrete may further include additions in the form of particles.
  • the particles may include a magnetic and/or a metallic material.
  • the method for forming the antenna structure may include providing an antenna.
  • the antenna may be configured to send and/or configured to receive an electromagnetic signal.
  • the method may further include providing a concrete composition.
  • the concrete composition may include at least a cement.
  • the concrete composition may further additions in the form of particles.
  • the particles may include a magnetic and/or a metallic material.
  • the method may further include providing a mold for pouring the concrete composition in.
  • the method may further include pouring the concrete composition into the mold. After arranging the antenna in the mold and after pouring the concrete into the mold, the antenna may be at least partially surrounded by the concrete.
  • the antenna may be arranged in the mold before the pouring of the concrete composition into the mold.
  • the antenna may be arranged in the mold after the pouring of the concrete composition into the mold.
  • Fig. 1 shows a schematic illustration of an antenna structure 10 according to the invention, including an antenna 20, able to receive an electromagnetic signal 12, embedded in a concrete 30;
  • Fig. 2 shows a Sii plot over a frequency of 2 to 3 GHz of an electrically small antenna designed for wireless LAN of 2.4 GHz, with the solid line 200 representing the plot as measured and the dotted line 201 representing the plot as simulated;
  • Fig. 3 shows a Sii plot over a frequency (f) of 2 to 3 GHz, with the antenna in air for comparison (solid line 301), an antenna structure according to the invention (long dashed line 302), and a comparative example wherein an antenna is embedded into concrete only (short dashed line 303);
  • Fig. 4 shows a flowchart illustrating a method for forming an antenna structure according to various embodiments.
  • Fig. 5 shows the geometry of an exemplary antenna used for the experiments, in front view (left) and back view (right).
  • Fig. 6 shows a schematic representation of the exemplary antenna used for the experiments (a) and of the antenna arranged in concrete (b).
  • Fig. 6 (c) to (e) show the geometry of a second, a third, and a fourth antenna structure according to various embodiments.
  • Fig. 7 (a) is a schematic representation of antenna structures as prepared according to the invention.
  • Fig. 7 (b) and Fig. 7 (c) illustrate the experimental setup for measuring of Sn (Fig. 7 (b)) and S21 or S12 (Fig. 7 (c)).
  • Fig. 8 shows six Si 1 plots over a frequency (f) of 2 to 3 GHz, for a comparative example wherein an antenna is embedded into concrete only (solid line 801), the antenna in air (small spaced dotted line 802), and according to the invention for micro-sized iron (III) oxide (long dashed line 803), nano-sized iron (III) oxide (large spaced dotted line 804), micro-sized magnetite (short dashed line 805), and nano-sized magnetite (dash-dot line 806);
  • Fig. 9 shows six S21 plots over a frequency (f) of 2 to 3 GHz, for a comparative example wherein an antenna is embedded into concrete only (solid line 901), the antenna in air (small spaced dotted line 902), and according to the invention for micro-sized iron (III) oxide (long dashed line 903), nano-sized iron (III) oxide (large spaced dotted line 904), micro-sized magnetite (short dashed line 905), and nano-sized magnetite (dash-dot line 906); Fig.
  • the short dashed line 1001 corresponds to the antenna before embedding into concrete with lweight% of micro-sized iron oxide particles
  • the long dashed line 1002 corresponds to the antenna before embedding into concrete with 2weight% of micro-sized iron oxide particles
  • the solid line 1003 is for the antenna of the comparative example wherein an antenna is embedded into concrete only;
  • Fig. 11 shows a S21 plot, corresponding to the plots in Fig. 10, over a frequency of 2 to 3 GHz of antennas in air before embedding into concrete
  • the short dashed line 1101 corresponds to the antenna before embedding into concrete with lweight% of micro-sized iron oxide particles
  • the long dashed line 1102 corresponds to the antenna before embedding into concrete with 2weight% of micro-sized iron oxide particles
  • the solid line 1103 is for the antenna of the comparative example wherein an antenna is embedded into concrete only;
  • Fig. 12 shows a Sn plot over a frequency of 2 to 3 GHz of an antenna structure according to the invention for lweight% of micro-sized iron oxide particles (short dashed line 1201) and 2weight% of micro-sized iron oxide particles (long dashed line 1202), and further a comparative example wherein an antenna is embedded into concrete only (solid line 1203);
  • Fig. 13 shows a S21 plot, corresponding to the plots in Fig. 12, over a frequency of 2 to 3 GHz of antenna structure according to the invention for lweight% of micro-sized iron oxide particles (short dashed line 1301) and 2weight% of micro-sized iron oxide particles (long dashed line 1302), and further a comparative example wherein an antenna is embedded into concrete only (solid line 1303);
  • Fig. 14 shows a S n plot over a frequency of 2 to 3 GHz of antennas in air, before embedding into concrete, the short dashed line 1401 corresponds to the antenna before embedding into concrete with 3weight% of micro-sized iron oxide particles, the long dashed line 1402 corresponds to the antenna before embedding into concrete with 4weight% of micro-sized iron oxide particles, and the solid line 1404 is for the antenna of the comparative example wherein an antenna is embedded into concrete only;
  • Fig. 15 shows a S21 plot, corresponding to the plots in Fig. 14, over a frequency of 2 to 3 GHz of antennas in air, before embedding into concrete
  • the short dashed line 1501 corresponds to the antenna before embedding into concrete with 3weight% of micro- sized iron oxide particles
  • the long dashed line 1502 corresponds to the antenna before embedding into concrete with 4weight% of micro-sized iron oxide particles
  • the solid line 1503 is for the antenna of the comparative example wherein an antenna is embedded into concrete only;
  • Fig. 16 shows a Sn plot over a frequency of 2 to 3 GHz of an antenna structure according to the invention for 3weight% of micro- sized iron oxide particles (short dashed line 1601) and 4weight% of micro-sized iron oxide particles (long dashed line 1602), and further a comparative example wherein an antenna is embedded into concrete only (solid line 1603);
  • Fig. 17 shows a S21 plot, corresponding to the plots in Fig. 12, over a frequency of 2 to 3 GHz of an antenna structure according to the invention for 3weight% of micro- sized iron oxide particles (short dashed line 1701) and 4weight% of micro-sized iron oxide particles (long dashed line 1702), and further a comparative example wherein an antenna is embedded into concrete only (solid line 1703);
  • Fig. 18 shows the improvement in transmission, in relation to the comparative example, with the increase of the concentration of the additions.
  • Various embodiments provide an antenna structure and a method for forming an antenna structure.
  • a magnetic and/or metallic material may mean a metallic material, a magnetizable material, or a metallic magnetizable material.
  • the antenna may be an electrical small antenna.
  • the antenna may also be a metamaterial resonator or an array of resonators.
  • Antennas are considered electrically small if the diameter of the sphere containing the antenna is small compared to the wavelength of operating frequency.
  • the definition of electrically small is generally taken as any maximum length smaller than ⁇ . ⁇ . As such, there is a range of values that an antenna can take to be considered electrically small. In summary, if the antenna maximum dimension is less than ⁇ . ⁇ to 0.0795 ⁇ , it is considered small.
  • the antenna structure may be configured such that the antenna is able to receive an electromagnetic signal.
  • the antenna structure may be configured such that the antenna is able to send electromagnetic signal.
  • the antenna structure may be configured such that the antenna is able to receive and send electromagnetic signal.
  • the antenna structure may be configured to operate in the frequency range above 1 GHz, for example between 2 GHz and 60 GHz, or 2 GHz to 6 GHz.
  • the antenna in the antenna structure may include an operational frequency within this range.
  • To "operate” as in “operational frequency” may mean that the antenna structure is configured to send and/or configured to receive the electromagnetic signal.
  • An operational frequency may mean the frequency for which the transmission coefficient is close of a maximum, for example is a maximum.
  • the antenna structure may be configured to operate in a wireless LAN frequency range, thus configured to send and receive wireless LAN data
  • wireless LAN frequency range may refer to the frequency ranges including the frequencies used by the IEEE 802.11 protocols, for example the IEEE 802.11-2016 protocols variants a/b/g/n/ac/ad.
  • IEEE 802.11-2016 protocols variants a/b/g/n/ac/ad.
  • LAN stands for local area network.
  • the antenna is embedded in a concrete, mortar or cementitious materials.
  • the term "embedded” may mean to be firmly fixed in the concrete, wherein the concrete surrounds the antenna.
  • the antenna may be completely embedded into the concrete, for example completely surrounded by concrete, so that no part of the antenna is accessible (as in direct physical contact).
  • no part of the antenna may be accessible without breaking the concrete.
  • the concrete surrounding the antenna may include a thickness of at least 1cm.
  • An electrical connection may be envisaged, which allow for transmission of electrical signal from and/or to the antenna, for example via a coaxial cable. Such electrical connection may itself be at least partially embedded into the concrete.
  • Such electrical connection may include at least a part which is not embedded into concrete, thus enabling external electrical connection, for example to a radio equipment.
  • An example of a radio equipment is a wireless LAN router.
  • concrete may mean a building composite including a building composite material.
  • concrete is formed by an aggregate, for example a silica aggregate, and a cement that, when fluid, hardens over time.
  • aggregate for example a silica aggregate
  • cement that, when fluid, hardens over time.
  • Example of such concrete are mortar, gypsum plaster.
  • the concrete may include at least a cement.
  • the cement may be any hydraulic material, for example any hydraulic inorganic material. Any material with cementing properties when in contact with water may be used as hydraulic inorganic material. For example, all types of Portland cement, alumina cement, water glass cement, magnesia cement, gypsum, either alone or in combination.
  • One exemplary cement is of the type ordinarily called Portland cement (which does not necessarily need to come from Portland).
  • the concrete may further include additions.
  • the additions may be in the form of particles.
  • the concrete may further include at least an additive.
  • the additive may be liquid.
  • the concrete may further include a superplasticizer.
  • Superplaticizers are high range water reducers widely used in concrete to improve the workability and reduce the water consumption in the mixture (by reducing the water in the mixture the concrete strength increases).
  • Superplasticizers are chemical admixtures which may be used where well-dispersed particle suspension is required in concrete.
  • the particles may include a magnetic and/or a metallic material.
  • the particles may include or essentially consist of magnetic and/or metallic material, for example the particle may include or essentially consist of a material which can be magnetized.
  • the particle may be magnetized, for example by exposing the particle to a magnetic field.
  • the magnetic material, and the magnetic particle may be from "hard” magnetic materials or from "soft” magnetic materials. "Hard" magnetic metals tend to stay magnetized over a long period while “soft” magnetic metals can be magnetized but lose their magnetism quickly.
  • a composition of a particle of the particles may be at least 40% of metallic material.
  • a metallic material which is also a magnetic material is iron (III) oxide.
  • One example of a magnetic material is magnetite.
  • the term "particles” may refer to granular material, wherein each particle (or also named each grain) may include a plurality of atoms.
  • the plural "particles", according to the invention may include an average size from about 10 nm and up to about 5 micrometers.
  • the average size may be calculated over the size of the particles that are according to the invention, for example, only considering the particles including metallic and/or magnetic materials.
  • the size of each particle may be determined as the largest diameter of each particle.
  • a concrete composition may be used for forming the concrete.
  • the concrete composition may include the cement and the additions.
  • the concrete composition may further include an aggregate, for example a mixture of materials selected from at least one of: coarse gravel, crushed rocks, granite, sand, and a mixture thereof.
  • water for example in liquid form, is mixed to the concrete composition to form a slurry, which, after hardening, forms the concrete.
  • the additions may be included in a weight percentage to the total sum of dry concrete compositions, depending on the type of additions. This ensures that a sufficient workability and strength are achieved in the concrete.
  • a metal steel frame may be part of a building structure, and may be surrounded by concrete, however the metal steel frame is neither part of the concrete composition nor part of the definition of "a concrete” or "the concrete” in accordance with the invention.
  • the method for forming an antenna structure may include providing a mold.
  • a mold is a structural concrete mold, such as used for building construction.
  • the mold may be a cavity in a building structure in which the antenna structure may be formed. This allows for example, for establishing of a telecommunications infrastructure, after a building structure is formed.
  • the antenna may be arranged into the mold before pouring the concrete composition into the mold. Arranging the antenna into the mold before the pouring of the concrete composition may facilitate an exact positioning of the antenna, since it can be fixed in relation to the mold, and thus be fixed in relation to the concrete, once the antenna structure is formed. Alternatively, in other embodiments, the antenna is arranged in the mold, after the pouring of the concrete. At this stage of "pouring", the concrete composition is still in a non-set stage, for example mixed with water in the form of a slurry. Arranging the antenna into the mold with concrete may have the advantage of not requiring to fix the antenna to the mold, thus saving time and fixing material, as the antenna may be secured in place by the slurry.
  • the antenna could also be arranged into the mold after the concrete composition is partially poured into the mold, wherein after arranging the antenna, the concrete composition is further poured, thus completing the process.
  • the antenna may be arranged over the concrete composition on a certain height of the mold, which can then be further filled.
  • the antenna is at least partially surrounded by the concrete. At least partially surrounded means embedded into concrete, as explained above.
  • the antenna may also be completely surrounded by the concrete, meaning that it is fully embedded into the concrete.
  • the antenna may be arranged in the mold keeping a distance of at least 1 cm to a closest mold wall.
  • An improvement of Sn refers to an improve of the reflection coefficient.
  • improvement may refer to less reflection than a comparative case.
  • An improvement of S21 or S 12 refers to an improve of the transmission coefficient.
  • improvement may refer to a stronger transmission coefficient than a comparative case.
  • S21 and S 12 can be used interchangeably.
  • the particles including a magnetic and/or a metallic material is comprised in an amount of at least 0.5 weight% of the concrete, for example in an amount of from 0.5 weight% to 4 weight%.
  • the weight percentage may refer to the percentage of particles according to the invention in relation to the total sum of the dry concrete composition.
  • the particles may be of a non-uniform shape.
  • a nonuniform shape may refer to random shape, for example sand grain shaped.
  • a non-uniform shape may also refer to grinded material. The grinded material may be filtered material, for providing a certain particle size of the particles.
  • the particles' average size may be from about 5 nm to about 5 micrometers. In various embodiments, the particles' average size may be from about 100 nm to about 5 micrometers. The size of a single particle may be the largest diameter of the particle.
  • the particles used in various embodiments may be obtained from commercial sources.
  • micro sized iron oxide particles are commercially available.
  • the particles may be homogeneously distributed in the concrete.
  • the concrete composition may be mixed, for example before and/or after the addition of water.
  • the particles may be dispersed in water, for example with ultra- sound, before mixing the dispersion with cement.
  • the invention further relates to use of antenna embedded or in the surface of conductive building elements for either cloaking/transparency or shielding/attenuation to certain wavelengths, focusing on several different usages.
  • Electromagnetic shielding is necessary in certain structures such as for medical, defense, databases, or scientific applications, normally through a Faraday cage.
  • some structures require electromagnetic transparency to enhance the transmission of certain wavelengths through walls for example, such as office space, underground structures, etc.
  • the present conductive composite material for building applications used with antenna permits adjusting the properties of the material in order to attain these benefits depending on the usage.
  • Fig. 1 shows a schematic illustration of an antenna structure 10 according to the invention, including an antenna 20, configured to send and/or receive an electromagnetic signal 12, wherein the antenna is embedded in a concrete 30, the concrete comprising at least a cement.
  • the concrete further comprises additions in the form of particles, wherein the particles comprise a magnetic and/or a metallic material.
  • Fig. 2 shows a Sn plot over a frequency of 2 to 3 GHz of an electrically small antenna designed for wireless Lan of 2.4 GHz, with the solid line 200 representing the plot as measured and the dotted line 201 representing the plot as simulated.
  • the simulated and measured results vary slightly due to fabrication limitations. From the graph, it can be seen that both simulated and measured results have a bandwidth just wide enough to cover the wireless LAN spectrum from 2.412 GHz to 2.472 GHz.
  • the center frequency of 2.442 GHz is the lowest point of the graph, which is also the resonant frequency.
  • the two main disadvantages of this is that firstly, although through simulations, the simulated resonant frequency has a Sn of less than -25 dB, the measured value was much lesser at -16 dB. Although any value below -16 dB is considered very good, this antenna is easily affected by the surrounding environment such as the presence of humans or metallic objects. Secondly, the bandwidth of the antenna is very narrow. This is a typical issue with electrically small antennas. With a narrow bandwidth, the extreme wireless LAN channels will encounter a greater loss than the center resonant frequency.
  • Fig. 3 shows a Sn plot over a frequency (f) of 2 to 3 GHz, with the antenna in air for comparison (solid line 301), an antenna structure according to the invention (long dashed line 302), and a comparative example (short dashed line 303).
  • the plots of Fig. 3 are results of test cases created to show the effects of embedding antenna in concrete, for example cement paste, enhanced with metallic and/or magnetic particles.
  • Fig. 4 shows a flowchart illustrating a method 400 for forming an antenna structure according to various embodiments.
  • the method 400 may include providing (410) an antenna configured to send and/or receive an electromagnetic signal.
  • the method may include providing (420) a concrete composition; wherein the concrete composition comprises a cement and additions in the form of particles, wherein the particles comprise a magnetic and/or a metallic material.
  • the method may include providing (430) a mold for pouring the concrete composition in.
  • the method may further include (440) arranging the antenna in the mold; and pouring the concrete composition into the mold.
  • the method may also be characterized by after arranging the antenna in the mold and after pouring the concrete composition into the mold, the antenna being at least partially surrounded by the concrete (450).
  • the concrete composition was mixed in water to form a paste, the paste was poured into a mold with inner volume of 8cm x 8cm x 8cm.
  • Ordinary Portland cement was used with water/cement volume ratio 0.35 and including additions as articles in weight% to the total dry weight.
  • Superplasticizer was used at 260 ml per lOOKg cement to improve the workability.
  • the antenna in the present example an antenna array was arranged at the center of the samples, which were demolded from the mold after hardening and kept in a closed container. The antenna array was also measured in air and in a control sample without the particles added.
  • the experimental setup comprised a network analyzer connected to a sample via a coaxial cable, for the present examples, a N5242A PNA-X network analyzer was used.
  • the data plot of the Sn is captured and various frequency ranges are displayed. From this plot, the resonant frequency can be seen, together with the bandwidth and Sn values at the various frequencies.
  • a reference antenna was connected to another port to measure the S21 parameter.
  • FIG. 5 shows the structure of an exemplary antenna used for the experiments, in front view 501 (left) and back view 502 (right).
  • the antenna used for the examples includes seven metamaterial split ring resonators 100, arranged adjacent to each other in an array 550.
  • Each metamaterial split ring resonator includes a first split ring including a first split at a first edge of the first split ring and a second split at a second edge of the first split ring. The first edge is opposite to the second edge.
  • Each metamaterial split ring resonator may further include a second split ring inside the first split ring and concentric with the first split ring, wherein the second split ring includes a third split at a first edge of the second split ring adjacent to the first edge of the first split ring.
  • the first split ring includes a first pair of stubs extending inwardly from the first split
  • the second split ring includes a second pair of stubs extending inwardly from the third split.
  • Fig. 5 shows an embodiment wherein the metamaterial split ring resonator array includes six resonators surrounding one resonator located in the center, it is understood that the metamaterial split ring resonator array 550 may include any suitable number of resonators arranged in any suitable form of array in various embodiments.
  • the plurality of metamaterial split ring resonators may be arranged in a one-dimensional array, or in a two-dimensional array (e.g. in rows and columns).
  • Fig. 5(left) shows a top view 510 of a fabricated metamaterial split ring resonator array 550.
  • the array 550 may be fabricated as a planar array on a top surface of a substrate.
  • the top side of the substrate has seven metaresonators 100, which are linked to a bottom layer of the substrate via two through hole vias 530 of each metaresonator 100.
  • Fig. 5(right) shows a bottom view 520 of the fabricated metamaterial split ring resonator array 550 according to various embodiments.
  • each metaresonator is connected via DC lines 540, as the current can be treated as uniform.
  • Fig. 6 (a) shows a schematic illustration of the exemplary antenna 610 including a metaresonator array 100 on a substrate 612 used for the experiments.
  • a cable 650 with a connector 652 and tag 654 is shown connected to the antenna 610.
  • Fig. 6 (b) shows an exemplary mold structure 660 comprising 3 molds 670.
  • the two right molds include each an antenna embedded in concrete and a cable 650 connected to the antenna. Only the cables can be seen, marked with ".2" and “.3", each arranged in concrete in a corresponding mold.
  • the right mold comprises concrete without an antenna for forming an antenna-free block may be used for other comparative experiments.
  • the fabricated metaresonator is formed on a substrate, for example, a front surface of the substrate.
  • the fabricated metaresonator includes through hole vias at the front surface of the substrate.
  • the width of the metaresonator in this exemplary embodiment is about 1.2cm, and the width of the substrate in this exemplary embodiment is about 1.3cm.
  • standard PCB processes and FR-4 as a substrate are used.
  • PCB technologies there are four classes of printed boards according to the IPC standards. In most cases, Class 2 has a good balance between cost and standard.
  • the trace width of the split ring required in an exemplary embodiment is about 0.127mm with a trace separation of about 0.0889mm, and accordingly Class 2 was selected.
  • the exemplary values of parameters of the fabricated metaresonator are listed in Table 1.
  • the parameters of the metaresonator according to various embodiments of this specification may be in any other suitable values or range of values depending on the design need.
  • Fig. 6 (c) to (e) show the geometry of a second, a third, and a fourth antenna structure according to various embodiments.
  • Fig. 6 (c) shows a patch antenna 670, comprising a microstrip patch 672 on a first side of a substrate 673, and a ground layer 674 on a second side of the substrate 673.
  • the exemplary values of parameters of the fabricated antenna 670 are listed in Table 2.
  • Fig. 6 (d) shows a quarter wavelength monopole antenna 680 comprising a microstrip 682 on a first side of a substrate 683, and a ground layer 684 on a second side of the substrate 683.
  • the exemplary values of parameters of the fabricated antenna 680 are listed in Table 3. Parameter Property Units
  • Fig. 6 (e) shows a meander line antenna 690 comprising a microstrip 692 on a first side of a substrate 693, and a ground layer 694 on a second side of the substrate 693.
  • the exemplary values of parameters of the fabricated antenna 690 are listed in Table 4.
  • Any other antenna structure may be used.
  • an omnidirectional antenna may be used in the present invention.
  • FIG. 7 (a) shows a schematic illustration 700 of demolded antenna structures according to the invention.
  • Each concrete block 710 of an antenna structure 720 is marked by writing the code on the concrete block.
  • Each antenna is marked before embedding with a tag 754 secured to the coaxial cable 750.
  • the marking of the antennas is represented in Fig. 7 (a) as with a ".” followed by a number, for illustrative purposes only.
  • the cable 750 may include a connector 752. Concrete blocks used as reference are also prepared in a similar manner, for example, the block 730 does not include an embedded antenna.
  • Fig. 7 (b) and Fig. 7 (c) illustrate the experimental setup for measuring of S n (Fig.
  • the measurement setup 760 for measuring Sn is schematically demonstrated, the device under test 768 (e.g. antenna structure) is connected to the port 1 762 of the network analyzer 761.
  • the measurement setup 770 for measuring S21 (or S12) is schematically demonstrated, the device under test 778 (e.g. antenna structure) is connected to the port 2 776 of the network analyzer 771, a reference antenna 774 (in air) is connected to port 1 772 of the network analyzer 771.
  • the performance of the antenna improves at least in terms of S n and bandwidth, thus the performance of the antenna structure is improved in comparison with a comparative example.
  • the hypothesis is that by changing the surrounding dielectric from air to other composites that are more conductive and magnetic, at least two properties of Sn and bandwidth of the antenna can be improved.
  • the mixture includes any hydraulic inorganic material and metallic and/or magnetic particles, at different contents.
  • Magnetite, cementite, carbon-coated nickel, cobalt, iron, or any other kind of magnetic particles in any size may be used as the material for the particles.
  • cobalt oxide particles, and nickel oxide particles may be used.
  • the material for the particles provide for permittivity to the building material, alone or in combination, and at different ratios, always assuring that the mechanical and durability properties of the structural element are not compromised.
  • Changing the medium surrounding an antenna changes its behavior due to the different characteristic impedances.
  • the material of the antenna form capacitors and/or inductors which are coupled to its surrounding medium. Any metallic, magnetic, and/or dielectric material in the near field affects these inductive and capacitive values.
  • the quality factor is important, as they typically have a small bandwidth, BW.
  • the quality factor provided by the Chu- limit is given as
  • ⁇ is the angular frequency
  • W is the average stored energy
  • rad is the radiated power. It is beneficial that Q is small as BW is inversely proportional to Q, by having as little energy stored in the antenna, and increasing the power radiated.
  • One way to decrease the Q and improve the BW is to analyze the antenna using series and parallel resonance transmission lines (TLs).
  • the quality factor can be written as
  • the electrical permittivity and permeability may be changed in a way that can positively impact the performance of the antenna. Having the particles, the aim is to increase the bandwidth by lowering the overall reflection coefficient.
  • the experiments support the hypothesis of improvement of an antenna structure by using magnetic and/or metallic particles included in the concrete with the antenna embedded.
  • Fig. 8 shows six Sn plots over a frequency range of 2 to 3 GHz, for a comparative example (solid line), the antenna in air (small spaced dotted line), and according to the invention for micro-sized iron (III) oxide (long dashed line), nano-sized iron (III) oxide (large spaced dotted line), micro-sized magnetite (short dashed line), and nano-sized magnetite (dash-dot line).
  • FIG 8 shows the measured reflection coefficient, Sn of several examples.
  • the solid line 801 represents the measured Sn of the comparative example with an antenna in concrete only.
  • the Sn of one sample antenna measured in air medium small spaced dotted line 802 is shown as a reference.
  • the frequency range between the two vertical dashed lines represents the intended wireless LAN spectrum.
  • the Sn is changed significantly.
  • the Sn is changed to -13 dB.
  • micro-sized particles enhanced concrete were able to lower the Sn of the embedded antenna to be even better than the sample reference antenna measured in air. This shows that when the sample antennas are embedded into micro-sized magnetic iron-based particles enhanced concrete, the Sn is significantly better than just the antenna in air. Nano-sized magnetic iron based enhanced concrete could also lower the Sn of the antenna, although less than for iron oxide. In all samples, the Sn is reduced to less than - 10 dB within the intended wireless LAN bandwidth. A reading of -10 dB or less indicates a sufficient performance of the antenna where at least 90% of the input power is delivered to the antenna, and 10% is reflected.
  • iron (III) oxide shifted the resonance frequency more than magnetite, with micro- sized iron (III) oxide particle enhanced concrete shifting the most towards higher frequency. A small shift in frequency shows that the material has little detuning effect on the antenna.
  • micro-sized particles enhanced concrete maintain the general shape of the Sn curves with a single distinct resonance frequency that can be noted.
  • the nano-sized particles enhanced concrete exhibit two resonance frequencies, altering the single resonance frequency shape of the antenna.
  • both micro-sized particles enhanced concrete increased the bandwidth, with magnetite particles enhanced concrete having the bigger effect than iron (III) oxide enhanced concrete.
  • the double dip shape also has an increased bandwidth when compared to the bandwidth of the reference antenna in air.
  • FIG. 9 shows six S21 plots over the frequency (f) of 2 to 3 GHz, for a comparative example (solid line 901), the antenna in air (small spaced dotted line 902), and according to the invention for micro-sized iron (III) oxide (long dashed line 903), nano-sized iron (III) oxide (large spaced dotted line 904), micro-sized magnetite (short dashed line 905), and nano-sized magnetite (dash-dot line 906).
  • the frequencies between two vertical dotted lines indicates the wireless LAN 802.11 b/g/n spectrum.
  • a reference measurement of the sample antenna used (small spaced dotted line) is shown to indicate the in air performance of the antenna.
  • the S21 has a range of between -30 dB to -37 dB.
  • the S21 reduces by about 16 to 20 dB. This shows that the amount of electromagnetic radiation that can pass through into the concrete is significantly reduced.
  • the antenna When the antenna is embedded in iron-based magnetic particles enhanced concrete, most of the S21, within frequencies of from 2.412 GHz to 2.472 GHz, are improved except for the micro-sized magnetite particles, for which the improvement is shifted to higher frequencies.
  • the antenna may be adjusted such that, when embedded in concrete, the improvement peak corresponds to the required frequency.
  • a set of antennas was selected, having similar Sn values, in air and before embedding in concrete.
  • the Sn and the S12 of the antennas was firstly measured in air, so that properties could be better compared to the antenna structure in concrete and to the control sample embedded in concrete without particles.
  • the plots are shown in sets of 3 for ease of comparison.
  • the antennas were embedded in concrete using the method as described herein.
  • One sample was prepared as control sample, wherein the antenna was embedded into concrete without magnetic and/or metallic particles (sample 1).
  • Another sample was prepared according to the invention, wherein the antenna was embedded into concrete including micro-sized iron oxide particles in a concentration of 1 weight% (sample 2).
  • a third sample was prepared according to the invention, wherein the antenna was embedded into concrete including micro-sized iron oxide particles in a concentration of 2 weight% (sample 3).
  • a fourth sample was prepared according to the invention, wherein the antenna was embedded into concrete including micro-sized iron oxide particles in a concentration of 3 weight% (sample 4).
  • a fifth sample was prepared according to the invention, wherein the antenna was embedded into concrete including micro-sized iron oxide particles in a concentration of 4 weight% (sample 5).
  • Fig. 10 shows the respective Sn of antennas for samples 1 to 3 before embedding in concrete
  • Fig. 11 shows the respective S12 of the antennas for samples 1 to 3 before embedding in concrete. It is shown that the antennas have comparable Sn and S12 properties.
  • the solid lines 1003 and 1103 correspond to the antenna for sample 1, before it is embedded in concrete alone.
  • the short dashed lines 1001 and 1101 correspond to the antenna for sample 2 before it is embedded in concrete comprising micro- sized iron oxide particles in a concentration of 1 weight%.
  • the long dashed lines 1002 and 1102 correspond to the antenna for sample 3 before it is embedded in concrete comprising micro-sized iron oxide particles in a concentration of 2 weight%.
  • Fig. 10 shows the respective Sn of antennas for samples 1 to 3 before embedding in concrete
  • Fig. 11 shows the respective S12 of the antennas for samples 1 to 3 before embedding in concrete. It is shown that the antennas have comparable Sn and S12 properties.
  • Fig. 12 shows the S n of the prepared samples 1 to 3
  • Fig. 13 shows the S12 of the prepared samples 1 to 3.
  • the Sn and S12 of sample 1 are represented by solid lines 1203 and 1303 respectively
  • the S n and S12 of sample 2 are represented by the short dashed lines 1201 and 1301 respectively
  • the Sn and S12 of sample 3 is represented by the long dashed lines 1202 and 1302 respectively.
  • sample 3 allows more electromagnetic signal to be transmitted through it. Above 2.9 GHz, sample 3 acts more like a shield while sample 2 allows more electromagnetic signal to be transmitted through from 2.7 GHz to 2.9 GHz, and acting like a shield for frequencies above 2.9 GHz. At the range of the frequencies from 2.37 GHz to 2.6 GHz which includes the wireless LAN range of frequencies, sample 3 allows for more transmission of electromagnetic signal (6dB).
  • Fig. 14 shows the respective Sn of the antennas for samples 1, 4 and 5 before embedding in concrete
  • Fig. 15 shows the respective S12 of the antennas for samples 1,
  • the Sn and S 12 of the control antenna for sample 1 is represented by solid lines 1403 and 1503 respectively, for ease of comparison. It is shown that the other antennas for samples 4 and 5 and the control antenna have comparable S n and S12 properties.
  • the short dashed lines 1401 and 1501 correspond to the antenna for sample 4 before it is embedded in concrete comprising micro-sized iron oxide particles in a concentration of 3 weight%.
  • the long dashed lines 1402 and 1502 correspond to the antenna for sample 5 before it is embedded in concrete comprising micro- sized iron oxide particles in a concentration of 4 weight%.
  • Fig. 16 shows the Sn of the prepared samples 1, 4 and 5
  • Fig. 17 shows the S12 of the prepared samples 1, 4 and 5.
  • the Sn and S12 of sample 1 is represented by solid lines 1603 and 1703 respectively
  • the Sn and S12 of sample 4 is represented by short dashed lines 1601 and 1701 respectively
  • Fig. 16 is represented by long dashed lines 1602 and 1702 respectively.
  • the Su are generally decreased which shows better matching, and the frequencies are shifted towards the higher frequency after the antennas are embedded into the respective concrete samples.
  • Fig. 16 also shows that the matching is greatly improved for sample 5 with the Su at -44 dB with a shift in the frequency to 2.84 GHz.
  • Fig. 17 shows the S12 of the antennas after embedding.
  • the enhanced concrete increases the transmission of electromagnetic signal.
  • sample 5 allows more electromagnetic signal to pass through the sample. Beyond 2.6 GHZ, samples 4 and 5 act more like shield compared to concrete alone.
  • Fig. 18 summarizes the results of the improvement in transmission. It can be seen that the transmission is improved, in relation to the comparative example, with the increase of the concentration of the additions.
  • concentration of the additions There is an increasing trend of increasing transmission of electromagnetic signal with increase in the concentration of iron oxide in building materials. The most significant increase is when 4% iron oxide is added to building materials, the transmission coefficient increases by 5.5 dB, which translates to about 1.9 times more transmission compared to concrete alone.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Civil Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Details Of Aerials (AREA)
  • Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)

Abstract

Divers modes de réalisation concernent une structure d'antenne, comprenant une antenne configurée pour envoyer et/ou recevoir un signal électromagnétique. L'antenne est intégrée dans un béton comprenant au moins un ciment. Le béton comprend en outre des additions sous la forme de particules, et les particules comprennent un matériau magnétique et/ou métallique. Divers modes de réalisation concernent également un procédé de formation d'une structure d'antenne.
PCT/SG2017/050558 2016-12-05 2017-11-07 Antenne intégrée dans du béton et procédé d'intégration d'antenne dans du béton WO2018106181A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201662430172P 2016-12-05 2016-12-05
US62/430,172 2016-12-05

Publications (2)

Publication Number Publication Date
WO2018106181A1 true WO2018106181A1 (fr) 2018-06-14
WO2018106181A8 WO2018106181A8 (fr) 2018-12-13

Family

ID=62491293

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SG2017/050558 WO2018106181A1 (fr) 2016-12-05 2017-11-07 Antenne intégrée dans du béton et procédé d'intégration d'antenne dans du béton

Country Status (1)

Country Link
WO (1) WO2018106181A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021116008A1 (fr) 2019-12-09 2021-06-17 Repsol, S.A. Ciment comprenant des nanoparticules magnétiques et procédé de durcissement d'une suspension de ce dernier
AT526407A1 (de) * 2022-08-08 2024-02-15 Univ Innsbruck Pixelierte antennen

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040189528A1 (en) * 2003-03-31 2004-09-30 Killen William D. Arangements of microstrip antennas having dielectric substrates including meta-materials
US20060214855A1 (en) * 2005-03-22 2006-09-28 Koichi Harada Antenna device and method for manufacturing antenna device
US20090289765A1 (en) * 2008-05-21 2009-11-26 Mitomo Corporation Wireless identification tag

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040189528A1 (en) * 2003-03-31 2004-09-30 Killen William D. Arangements of microstrip antennas having dielectric substrates including meta-materials
US20060214855A1 (en) * 2005-03-22 2006-09-28 Koichi Harada Antenna device and method for manufacturing antenna device
US20090289765A1 (en) * 2008-05-21 2009-11-26 Mitomo Corporation Wireless identification tag

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JIN X. ET AL.: "EMBEDDED ANTENNAS IN DRY AND SATURATED CONCRETE FOR APPLICATION IN WIRELESS SENSORS", PROGRESS IN ELECTROMAGNETICS RESEARCH, PIER, vol. 1 02, 2010, pages 197 - 211, XP055491842, [retrieved on 20180108] *
SALAMA R. ET AL.: "An embeddable microwave patch antenna module for civil engineering applications", IEEE INTERNATIONAL INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE (I2MTC, 9 May 2013 (2013-05-09), XP055491841, [retrieved on 20180108] *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021116008A1 (fr) 2019-12-09 2021-06-17 Repsol, S.A. Ciment comprenant des nanoparticules magnétiques et procédé de durcissement d'une suspension de ce dernier
US20230028768A1 (en) * 2019-12-09 2023-01-26 Repsol, S.A. Cement comprising magnetic nanoparticles and method of setting a slurry thereof
US12024672B2 (en) 2019-12-09 2024-07-02 Repsol, S.A. Cement comprising magnetic nanoparticles and method of setting a slurry thereof
AT526407A1 (de) * 2022-08-08 2024-02-15 Univ Innsbruck Pixelierte antennen
WO2024031116A1 (fr) * 2022-08-08 2024-02-15 Universität Innsbruck Antennes pixellisées

Also Published As

Publication number Publication date
WO2018106181A8 (fr) 2018-12-13

Similar Documents

Publication Publication Date Title
Sun et al. Electromagnetic absorption of copper fiber oriented composite using 3D printing
Ozturk et al. Mechanical and electromagnetic performance of cement based composites containing different replacement levels of ground granulated blast furnace slag, fly ash, silica fume and rice husk ash
Deng et al. Ultrathin broadband absorber using frequency-selective surface and frequency-dispersive magnetic materials
Verma et al. Microwave permittivity and permeability of ferrite–polymer thick films
Sun et al. Tunable negative permittivity with fano-like resonance and magnetic property in percolative silver/yittrium iron garnet nanocomposites
Wang et al. Optimization of electromagnetic wave absorption bandwidth of cement-based composites with doped expanded perlite
Liu et al. Fabrication of core–multishell MWCNT/Fe 3 O 4/PANI/Au hybrid nanotubes with high-performance electromagnetic absorption
Khan Dual polarized dielectric resonator antennas
Dinh et al. Dielectric material characterization of concrete in GHz range in dependence on pore volume and water content
Chen et al. Influence of SiO2 fillers on microwave absorption properties of carbonyl iron/carbon black double-layer coatings
Darwish et al. Can hexaferrite composites be used as a new artificial material for antenna applications?
WO2018106181A1 (fr) Antenne intégrée dans du béton et procédé d'intégration d'antenne dans du béton
Chen et al. Cold‐sintered Na2WO4‐Ni0. 2Cu0. 2Zn0. 6Fe2O4 ceramics with matched permittivity and permeability for miniaturized antenna
Quintana et al. Design and operation of a real-scale electromagnetic shielding evaluation system for reinforced composite construction materials
Zhang et al. A novel design approach for dual-band electromagnetic band-gap structure
Hao et al. Optimisation of metamaterials by Q factor
Wu et al. Effective broadband electromagnetic wave absorption performance of nano-Fe3O4 magnetic fluid-modified resin geopolymer by metamaterial with a novel patterned structure
Wu et al. Effects of layered and metasurface structures on the electromagnetic wave absorption performance of cementitious materials
Lathiya et al. Enhancement in magnetic permeability of Ni‐Co‐Zn ferrites using CuO doping for RF and microwave devices
WO2017075847A1 (fr) Dispositif d'adaptation d'impédance sans blocage de signal radio
Yang et al. Roles of carbon black or carbon fibre on improving mechanical and electromagnetic properties of ultra-high performance concrete in K-band frequency range
Chua et al. Structural and microwave attenuation characteristics of ZnCuY barium ferrites synthesized by a sol–gel auto combustion method
CN110086001A (zh) 高效率宽带双极化腔体阵列天线
JP4726395B2 (ja) 電気的物性値測定法
Aydin et al. Experimental and numerical analyses of the resonances of split ring resonators

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17878780

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17878780

Country of ref document: EP

Kind code of ref document: A1

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载