JP4770497B2 - antenna - Google Patents

Description

  The present invention relates to an antenna in which an antenna element is not conspicuous.

  When a half-wave dipole antenna is considered as an antenna for wireless communication for transmitting and receiving radio waves in the VHF band (30 to 300 MHz) or UHF band (300 MHz to 3 GHz), as shown in FIG. A pair of conductor plates 73 connected to the section 72 and extending on both sides of the power feeding section 72 by a predetermined length is configured as an antenna element 74.

  In addition to the metal plate which is a rigid body, the conductor plate 73 may be configured by printing a conductive paste on a film-like substrate. The length L (hereinafter referred to as the antenna length; see FIGS. 7, 8, and 9) of the two conductor plates 73 on both sides of the power feeding unit 72 is various, but the antenna length L in the most fundamental antenna is different. Is ½ of the wavelength used. For example, when the frequency used is 500 MHz, the wavelength is 600 mm, so the antenna length L = 300 mm. In this case, the practical width W of the conductor plate is several mm or more. This is because, in order to reduce the resistance in order to achieve impedance matching with the power feeding unit, a width W of several mm is required even if a copper plate having a low resistivity is used.

  The shape of the conductor plate in the antenna that transmits and receives the UHF band includes the following.

  As shown in FIG. 8, in this antenna 81, the conductor plate 83 has a constant wide width W over the entire longitudinal direction. The width W is several mm or more as described above.

  As shown in FIG. 9, in this antenna 91, the conductor plate 93 has a wide width W at both ends in the longitudinal direction, and has almost no width at the central portion connected to the power feeding portion 72. That is, the two conductor plates 93 are each formed in a triangular shape, and each vertex is connected to the power feeding portion 72. The shape of the antenna element 91 is called a bow tie shape. The width W of the conductor plate 93 at both ends is several mm or more.

  As shown in FIG. 10, in this antenna 101, another conductor plate 105 is arranged in parallel with a distance from a pair of conductor plates 103 connected to the power feeding portion 72 as a power feeding antenna element 104, and this conductor The plate 105 is a parasitic antenna element 106. The width W of the feeding antenna element 104 is several mm or more.

JP-A-5-136617 JP 2000-59124 A JP 2000-174529 A JP-A-11-145717 JP 2001-242114 A

  In the conventional antenna shown in FIGS. 7 to 10, since the width W of the conductor plate constituting the antenna element is large, a person can easily see the antenna element. In addition, if an antenna is installed in the vehicle window, in the vehicle, or in the vicinity of the television receiver, it becomes a hindrance when the outside is viewed from inside the vehicle. In addition, the harmony of the design with other articles in the car and in the house is impaired. For example, in Patent Documents 1 and 2, a wire rod is attached to a window glass as an antenna element. However, the visual problem caused by the antenna element is not considered at all, and the above problem cannot be solved.

  Therefore, an object of the present invention is to solve the above-described problems and provide an antenna in which an antenna element is not conspicuous.

In order to achieve the above object, the present invention provides a plurality of flexible wires having a diameter of 0.04 mm or less arranged parallel to each other at intervals, and these wires are made of a transparent insulating material having flexibility. An antenna element composed of a long parallel line tape having both ends fixed to the film surface is sandwiched between two transparent insulating substrates, and the parallel line tape itself is folded back at an arbitrary position in the longitudinal direction. and a planar bend and any shape which turned pull by combining a linear portion.

  The wire may be fixed by adhering to the insulating film with a transparent adhesive.

  The wire may be fixed by being sandwiched between the two insulating films.

A planar bent portion may be formed by folding the parallel line tape.

  The parallel line tape may be used as a power supply antenna element by attaching a metal plate for power supply to the parallel line tape.

  Another parallel line tape may be arranged in parallel with the parallel line tape as the feeding antenna element at a distance, and this parallel line tape may be used as the parasitic antenna element.

  You may comprise the said wire with a silver plating copper alloy.

  It is good also considering the space | interval of the said wire as 10 times or more of the diameter of this wire.

  The present invention exhibits the following excellent effects.

(1) The antenna element becomes inconspicuous.
(2) A variety of antennas according to needs can be provided by the present invention, which can have a desired shape, size, number, and arrangement. Moreover, it can be easily produced at low cost.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a parallel wire tape 1 used for an antenna according to the present invention includes a plurality of flexible wire rods 2 having a diameter of 0.04 mm or less arranged in parallel with a distance from each other. It is formed by fixing the wire 2 to the surface of the transparent insulating film 3 having flexibility, and the parallel wire tape 1 itself thus formed is also flexible so that it can be bent into any shape. And can be folded. Although specific values of the diameter and interval of the wire 2 and the reason thereof will be described later, the wire 2 is sufficiently thin, and the interval is sufficiently wider than the diameter of the wire 2.

  The parallel line tape 1 is long and has an appropriate width, and is cut or bent to an appropriate length or width according to the characteristics of radio waves to be transmitted / received and the space of the installation location, thereby providing an antenna element. It can be. Further, by folding back the parallel line tape 1 at an arbitrary broken line, a planar bent portion bent at an arbitrary angle is formed, and a planar figure is drawn by combining the bent portion and the linear portion, and an arbitrary shape is formed. The antenna element can be created.

  In this parallel wire tape 1, since the wire 2 is fixed to the insulating film 3 at a predetermined interval, the wires 2 are not short-circuited even if they are bent. Moreover, if the parallel wire tape 1 is folded back so that the insulating film 3 is inside, the wires 2 are not short-circuited. When the wire 2 is sandwiched between the two insulating films 3, the wires 2 are not short-circuited regardless of which of the parallel wire tape 1 is folded.

  The parallel wire tape 1 shown in FIG. 1 is formed by sandwiching a wire 2 arranged in parallel between two insulating films 3 each having a transparent adhesive layer 4 on one side, whereby the wire 2 is attached to the insulating film 3. It is fixed. In addition, the wire 2 arranged in parallel may be sandwiched between two transparent insulating films 3 and fixed by thermocompression bonding (lamination) or roll bonding, or one wire 2 arranged in parallel may be fixed. Even if it adheres and fixes to the transparent insulating film 3 of this with a transparent adhesive agent, it can comprise.

As shown in FIG. 2, the antenna 21 according to the present invention is such that the parallel wire tape 1 is an antenna element 22. In this embodiment, three parallel line tapes 1 are used in combination. The first parallel-line tape 1 extends upward from a power supply portion 23 located below the drawing, and is bent at a 45 ° fold to form a bent portion 24 bent 90 ° to the left, and extends leftward. The second parallel-line tape 1 extends upward from the power feeding portion 23 located below the drawing, and is bent at a 45 ° fold to form a bent portion 24 that is bent 90 ° to the right and extends rightward. A pair of antenna elements 22 of a dipole antenna are formed from the first and second bent portions 24 of the parallel wire tape 1. The antenna length L, which is the length from the left end to the right end of the antenna element 22 constituting the dipole antenna, is determined corresponding to the frequency used.

  In order to fix the flexible parallel line tape 1 in a state of being formed into a desired shape as shown in FIG. 2, the parallel line tape 1 is sandwiched between two transparent insulating substrates 25. As a result, the parallel line tape 1 is covered with the insulating substrate 25 except for the downward portion toward the power supply unit 23, so that the parallel line tape 1 can maintain the illustrated shape. In addition, since the parallel-line tape 1 is sandwiched and fixed between the insulating substrates 25, an isolated member that is not connected from the outside, such as a parasitic antenna element 28 described later, can also be fixed.

  The insulating substrate 25 can fix the parallel line tape 1 firmly in the shape shown in FIG. 2 by using a material having rigidity. However, even if a material having flexibility without having rigidity is used, the parallel line tape 1 can be used. The shape of the tape 1 being folded or routed and the positional relationship between the plurality of parallel line tapes 1 can be maintained.

  In the power feeding unit 23, a power feeding metal plate 26 is attached to the parallel wire tape 1. Specifically, as shown in FIG. 3, a metal plate 26 is affixed to a parallel wire tape 31 in which the wire 2 is fixed to one surface of a single insulating film 3. The metal plate 26 is a copper plate, for example. Since the metal plate 26 is in contact with each wire 2, power can be supplied from the metal plate 26 to each wire 2 in the parallel wire tape 31.

  The metal plate 26 may be attached to the surface of the insulating film 3. In this case, the metal plate 26 and each wire 2 are electrostatically coupled via the insulating film 3, and power can be supplied from the metal plate 26 to each wire 2.

  By attaching the power feeding metal plate 26 to the parallel line tape 1 in this way, the parallel line tape 1 becomes a power feeding antenna element 27 as shown in FIG.

  The antenna 21 in FIG. 2 has a third parallel line tape 1. That is, another parallel line tape 1 is arranged in parallel with the first and second parallel line tapes 1 as the feeding antenna elements 27 with a space therebetween. The third parallel wire tape 1 becomes a parasitic antenna element 28. In this embodiment, the parallel line tape 1 as the parasitic antenna element 28 has the same width W as the parallel line tape 1 as the feed antenna element 27 and is shorter than the antenna length L.

  Next, the operation of the antenna 21 shown in FIG. 2 will be described. When a radio wave is received by the antenna 21, a current is induced for each of the wires 2 included in the parallel wire tape 1 constituting the antenna element 22, and a receiver (not shown) is passed through the power feeding unit 23 made of the metal plate 26. Received power can be obtained. Since the plurality of wires 2 have the same length, the power feeding unit 23 combines the received power from each wire 2 in the same phase. Therefore, even if the received power from one wire 2 is small, the combined received power is large.

  Here, since one wire 2 has a small diameter, it has a high resistance value. However, for the above-described reason, if a plurality of wires 2 form a parallel circuit and the number N is sufficiently large, the combined resistance value is 1 / N. Thereby, the resistance value of the antenna element 22 can be made sufficiently low to reduce the resistance loss. Therefore, impedance matching with the outside in the power feeding unit 23 is possible. That is, by having a plurality of parallel wires 2, the parallel wire tape 1 functions sufficiently as the feeding antenna element 27. Needless to say, the parallel-line tape 1 functions sufficiently as the parasitic antenna element 28.

For example, a silver plated copper alloy wire having a resistance value of 1.5 × 10 ⁻⁸ Ω having a diameter of 0.02 mm is used as the wire 2. When a dipole antenna for 500 MHz (wavelength 600 mm) is created, the antenna length L is 300 mm. At this time, the high-frequency resistance value from the left end to the right end of the antenna element 22 in one wire 2 is about 150Ω. Since the radiation resistance value of the antenna 21 is 73.13Ω, if only one wire 2 is used, the resistance value becomes much larger than the radiation resistance value, so that the heat loss increases. However, if the number N of the wires 2 is 50, the combined resistance value is about 3Ω, which is sufficiently smaller than the radiation resistance value, so that heat loss can be ignored. That is, the antenna 21 has sufficient radio wave transmission / reception performance.

  By the way, if the interval of the wire 2 is 0.2 mm which is 10 times the diameter of the wire 2 at this time, the width occupied by the 50 wires 2 is about 10 mm. That is, the width W of the parallel line tape 1 is about 10 mm. A width W of about 10 mm is a width W of a general antenna.

  When quantifying the visual ability with general naked eyes or glasses, an object having a diameter of about 0.04 mm can be visually recognized with a fractional visual acuity of 2.0, which is an index of visual acuity, when the object is viewed at a distance of 250 mm. It is a limit. Therefore, when the object is the wire 2 and the diameter of the wire 2 is 0.04 mm or less, the wire 2 cannot be visually recognized from a distance of 250 mm. When the diameter is 0.02 mm or less, it is difficult to visually recognize the wire 2 with a fractional visual acuity of 2.0 even from a short distance.

  Since the parallel wire tape 1 is obtained by fixing the wire 2 to the transparent insulating film 3, if the wire 2 is difficult to visually recognize, the parallel wire tape 1 is also difficult to visually recognize.

  However, the parallel wire tape 1 has a plurality of wires 2 arranged in parallel. Therefore, considering the spacing between the wires 2, if the distance between the wires 2 is not less than 10 times the diameter of the wires 2, the region where the transmitted light is blocked by the wires 2 when the visual field is covered with the parallel wire tape 1 Is 10% or less of the entire area. If the blocking ratio is 10% or less, the visibility with respect to the background seen through the parallel line tape 1 is sufficiently good. From this point of view, the distance between the wires 2 is preferably 10 times or more the diameter of the wires 2.

  The material of the surface of the wire 2 is more preferably a light and matte material such as tin or silver than a dark and glossy material such as copper or brass.

  As described above, the parallel line tape 1 of the present invention has the wires 2 that are difficult to visually recognize as a single unit arranged at appropriate intervals and fixed to the transparent insulating film 3, so that it is difficult to visually recognize the parallel line tape 1. .

  In the antenna 21 of the present invention, since the parallel wire tape 1 is used as the antenna element 22, it is difficult to visually recognize the antenna element 22, and the background of the antenna element 22 is easily visible. That is, the antenna element 22 becomes inconspicuous.

  Furthermore, the parallel line tape 1 is formed in a long and appropriate width and is not only cut into an appropriate length and width, but also has flexibility. By folding back at, it is possible to form a planar bent portion bent at an arbitrary angle and draw a planar figure by combining the bent portion and the straight portion, thereby creating an antenna element having an arbitrary shape.

  In the antenna 21 of the present invention, the parallel line tape 1 formed in a desired shape as an antenna element is sandwiched between two transparent insulating substrates 25, so that the antenna 21 is difficult to see and the parallel line tape 1 is routed. The shape as it was done can be maintained.

  In addition, the diameter of the wire 2 is not limited to the said example, What is necessary is just a thickness of the grade which is difficult to visually recognize. The material of the conductor and plating used for the wire 2 is not limited to the above example, and other materials may be used as long as the visual recognition is difficult and sufficient power can be supplied. The number of the wires 2 is not limited to the above example, and may be greater than or less than the above example as long as sufficient power can be supplied. The intervals between the wire rods 2 are not limited to equal intervals, and may be different intervals.

  Examples of the material of the insulating film 3 or the insulating substrate 25 include polyvinyl chloride polyamide, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, and cellulose acetate. Examples of the material of the adhesive 4 include materials mainly composed of polyethylene terephthalate and polybutylene terephthalate, and other polyester materials. The thickness of the insulating film 3 and the adhesive 4 is not limited. The temperature at the time of rolling or bonding is not limited.

  The metal plate 26 may be linear instead of the plate shape as in the above example. The metal type, thickness, and dimensions of the metal plate 26 are not limited.

  As shown in FIG. 4, the antenna 41 according to the present invention is such that the parallel wire tape 1 is an antenna element 42. In this embodiment, two parallel line tapes 1 are used in combination. The first parallel-line tape 1 extends upward from the power feeding portion 23 located at the lower left of the drawing, and is folded at a 45 ° crease, thereby forming a bent portion 24 bent 90 ° to the left and extended leftward. Is bent at a 45 ° fold to form a bent portion 24 bent 90 ° upward and extended upward, and further bent at a 45 ° fold to form a bent portion 24 bent 90 ° to the right. A rectangular loop which is not closed is formed so as to extend rightward, and is returned to the power feeding unit 23 located at the lower right of the drawing. The rectangular loop antenna element 42 serves as a feeding antenna element.

  The second parallel line tape 1 is arranged parallel to the parallel line tape 1 that is the upper side of the rectangular loop-shaped power supply antenna element 42 with a gap therebetween, and forms a parasitic antenna element 43.

  As shown in FIG. 5, the antenna 51 according to the present invention is obtained by adding a parasitic antenna element made of the parallel line tape 1 to the antenna 21 of FIG. 2.

  In the present invention, the shape, size, number, and arrangement of the feeding antenna element and the parasitic antenna element are not limited to those of the embodiment, and a desired shape, dimension, number, and arrangement can be used. Therefore, a wide variety of antennas according to needs are provided by the present invention. Further, the antenna of the present invention can be easily produced at low cost.

  Although the parallel wire tape 1 of the present invention is used for an antenna element, this technique can also be applied to an electromagnetic wave shielding member. That is, not only a plurality of wires 2 are arranged parallel to each other at intervals, but also a plurality of other wires 2 are arranged so as to intersect with the plurality of wires 2 to form a transparent insulating film. By fixing to the surface, a film with a lattice-like or mesh-like wire rod is formed. Since this film with a wire rod is difficult to visually recognize the wire rod 2 and does not impair the visibility of the background, it should be affixed to the window glass or CRT surface of a house, or a transparent cover that protects the face. This can block electromagnetic waves without disturbing the field of view.

Example 1
50 non-glossy silver-plated copper alloy wires 2 having a diameter of 0.02 mm are arranged in parallel at equal intervals of 0.2 mm, and these wires 2 are transparent insulating films (polyethylene terephthalate or polycarbonate) having a thickness of 0.015 mm. 3 was bonded by an adhesive layer 4 having a thickness of 0.01 mm to form a parallel line tape 1 having a cross-sectional structure as shown in FIG. The parallel line tape 1 is cut to create two parallel line tapes 1 of the same length, and each parallel line tape 1 is folded at a 45 ° fold to form a 90 ° planar bent portion 24. In order to form a dipole antenna having an antenna length L = 300 mm with these two parallel wire tapes 1, as shown in FIG. The arrangement extended in parallel.

  Further, a parasitic antenna element 28 having a length of 160 mm shorter than the antenna length L of the feeding antenna element 27 is formed by using one parallel wire tape 1, and the parasitic antenna element 28 is parallel to the feeding antenna element 27. And sandwiched between two insulating substrates with an adhesive layer provided with a 0.01 mm thick adhesive layer on a transparent insulating substrate (polyethylene terephthalate or polycarbonate) 25 having a thickness of 0.015 mm. Roll bonding was performed at 150 ° C. The power feeding unit 23 is taken out of the insulating substrate 25. A copper plate having a thickness of 0.1 mm was attached on the insulating film 3 of the parallel wire tape 1 as the metal plate 26 to the power feeding unit 23.

(Example 2)
50 non-glossy silver-plated copper alloy wires 2 having a diameter of 0.02 mm are arranged in parallel at equal intervals of 0.2 mm, and these wires 2 are transparent insulating films (polyethylene terephthalate or polycarbonate) having a thickness of 0.015 mm. 3 was bonded by an adhesive layer 4 having a thickness of 0.01 mm to form a parallel line tape 1 having a cross-sectional structure as shown in FIG. The parallel line tape 1 is cut into an appropriate length, and the parallel line tape 1 is repeated so as to form a rectangular feeding antenna element 27 having a long side length of 300 mm and a short side length of 50 mm as shown in FIG. Then, both ends of the parallel line tape 1 which are folded back and aligned in parallel are used as the power feeding portion 23.

  Furthermore, a parasitic antenna element 28 having a length shorter than the long side of the feeding antenna element 27 is formed using one parallel line tape 1, and the parasitic antenna element 28 is arranged in parallel with the feeding antenna element 27. A transparent insulating substrate (polyethylene terephthalate or polycarbonate) 25 having a thickness of 0.015 mm is sandwiched between two insulating substrates with an adhesive layer having a thickness of 0.01 mm, and the temperature is 150 ° C. Rolled and bonded. The power feeding unit 23 is taken out of the insulating substrate 25. A copper plate having a thickness of 0.1 mm was attached on the insulating film 3 of the parallel wire tape 1 as the metal plate 26 to the power feeding unit 23.

  In the antennas of Examples 1 and 2, it was proved that the parallel line tape 1 as an antenna element is not conspicuous and does not become an obstacle to see through the background.

  FIG. 6 shows an antenna characteristic (return loss characteristic) α of the antenna of the first embodiment and an antenna characteristic (return loss characteristic) β of the antenna obtained by removing the feeding antenna element 27 from the antenna of the first embodiment. In the antenna characteristic α, the frequency range in which the return loss is equal to or lower than a predetermined level is wide, and in the antenna characteristic β, the frequency range in which the return loss is equal to or lower than the above level is narrow. As described above, the antenna characteristics of the present invention can be designed in the same manner as an antenna using a conventional conductor plate.

It is sectional drawing orthogonal to the longitudinal direction of the parallel wire tape which shows one Embodiment of this invention. It is a top view of the antenna which shows one Embodiment of this invention. It is an expansion perspective view of the electric power feeding part in the antenna of FIG. It is a top view of the antenna which shows other embodiment of this invention. It is a top view of the antenna which shows other embodiment of this invention. It is an antenna characteristic view in the antenna of this invention. It is a top view of the conventional antenna. It is a top view of the conventional antenna. It is a top view of the conventional antenna. It is a top view of the conventional antenna.

DESCRIPTION OF SYMBOLS 1 Parallel wire tape 2 Wire material 3 Insulating film 4 Adhesive layer 21 Antenna 22 Antenna element 23 Feeding part 24 Bending part 25 Insulating substrate 26 Metal plate 27 Feeding antenna element 28 Parasitic antenna element

Claims (7)

A plurality of flexible wire rods having a diameter of 0.04 mm or less are arranged in parallel with a distance from each other, and these wires are fixed to the surface of a flexible transparent insulating film. An antenna element made of a parallel line tape is sandwiched between two transparent insulating substrates, and a plane bent part and a straight line part are formed by folding the parallel line tape itself at an arbitrary position in the longitudinal direction. antenna, characterized in that an arbitrary shape turned pull combination.   2. The antenna according to claim 1, wherein the wire is fixed to the insulating film by bonding with a transparent adhesive.   The antenna according to claim 1, wherein the wire is fixed by being sandwiched between two insulating films. The antenna according to any one of claims 1 to 3, wherein the parallel line tape is used as a power supply antenna element by attaching a metal plate for power supply to the parallel line tape. 5. The antenna according to claim 4 , wherein another parallel line tape is arranged in parallel with the parallel line tape as the feeding antenna element at a distance, and the parallel line tape is used as a parasitic antenna element. The antenna according to any one of claims 1 to 5, wherein the wire is made of a silver-plated copper alloy. Antenna according to any one of claims 1-6, characterized in that the distance between the wire and at least 10 times the diameter of該線material.

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