JP2013016879A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna which is made compact while minimizing deterioration of performance.SOLUTION: The antenna 1 includes a substrate 11 and an element member 12. On the surface A of the substrate 11, a ground pattern 111 and a feed pattern 112 consisting of a conductor pattern are provided. The element member 12 consists of a bent sheet plate and is disposed on the substrate 11. The element member 12 includes a rising part 121, a parallel part 122, and a return part 123. The rising part 121 is rising from the feed pattern 112 for the substrate 11. The parallel part 122 is bent from the tip of the rising part 121, and extends in parallel with the surface A while facing the plate surface toward the surface of the substrate 11. The return part 123 is bent from the parallel part 122 and returns back to the surface A of the substrate 11. The substrate 11 is provided, on the surface A, with an extension pattern 113 consisting of a conductor pattern different from the ground pattern 111 and feed pattern 112 and extending furthermore in contact with the return part 123.

Description

  The present invention relates to an antenna.

  Some types of antennas are installed in electronic equipment. Such antennas are required to be small and thin. For example, Patent Document 1 discloses the principle of an antenna device having an upright element standing on a ground plane and a folding element. As a specific structure, for example, Patent Document 2 discloses an antenna device having a chip antenna. The chip antenna has a dielectric substrate and a radiation electrode disposed on the dielectric substrate. Patent Document 3 discloses an antenna made of a radiation plate formed by processing a plate-like metal.

JP 2008-244668 A International Publication No. 2006/134701 Pamphlet JP 2010-259048 A

  Antennas are required to be further miniaturized while suppressing deterioration of characteristics.

  An object of the present invention is to solve the above problems and to provide a miniaturized antenna while suppressing deterioration in performance.

The antenna of the present invention that achieves the above object includes a substrate provided with a ground pattern and a feeding pattern made of a conductor pattern on the surface,
An element member made of a bent sheet metal disposed on the substrate,
The element member is
A rising portion rising from the power supply pattern with respect to the substrate;
A parallel portion that is bent from the tip of the rising portion and extends in parallel to the surface with the plate surface facing the surface of the substrate;
A return part that bends from the parallel part and returns to the surface of the substrate,
The substrate is provided with an extension pattern on the surface, which is made of a conductor pattern different from the ground pattern and the power feeding pattern, which extends further from the return portion in contact with the return portion.

  In the antenna of the present invention, the antenna element connected to the feeding pattern is constituted by an extended pattern made of a conductor pattern on the substrate surface in addition to the rising portion, the parallel portion, and the return portion made of sheet metal of the element member. The deterioration of the radiation performance is suppressed by the three-dimensional structure of the element member, and the tip portion of the antenna element is formed by the conductor pattern on the substrate surface, so that the volume of the three-dimensional portion is reduced and the overall size is reduced.

  Here, in the antenna of the present invention, the element member includes a vertical plane parallel portion that is bent from the middle of the rising portion and extends in parallel with the surface by forming a plate surface substantially perpendicular to the parallel portion. Are preferred.

  The vertical plane parallel part functions as a second antenna element different from the antenna element including the rising part, the parallel part, the return part, and the extension pattern. The vertical plane parallel part is bent from the middle of the rising part and extends in the region between the parallel part and the substrate surface. For this reason, the space of this area | region is utilized effectively. Further, since the vertical plane parallel portion forms a substantially vertical plate surface with respect to the parallel portion, interference between the vertical plane parallel portion and the parallel portion can be suppressed.

  As described above, according to the present invention, a miniaturized antenna is realized while suppressing deterioration of characteristics.

It is a 1st perspective view which shows one Embodiment of the antenna of this invention. It is a 2nd perspective view which shows one Embodiment of the antenna of this invention. It is a 3rd perspective view which shows one Embodiment of the antenna of this invention. It is a 4th perspective view which shows one Embodiment of the antenna of this invention. It is a perspective view which shows the board | substrate of the antenna shown in FIGS. It is a 1st perspective view which shows the element member of the antenna shown in FIGS. It is a 2nd perspective view which shows the element member of the antenna shown in FIGS. It is a 3rd perspective view which shows the element member of the antenna shown in FIGS. It is a top view which shows the structure of an Example. 10 is a graph showing measurement results of the antenna shown in FIG. 9. 10 is a graph showing frequency characteristics of the antenna shown in FIG. 9.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 are perspective views showing an embodiment of the antenna of the present invention. 1-4, the external appearance which looked at the antenna 1 from the mutually different angle is shown.

  An antenna 1 shown in FIGS. 1 to 4 is a multiband antenna for transmitting and receiving radio waves in three frequency bands. The antenna 1 operates in a band including a first resonance frequency, a band including a second resonance frequency higher than the first resonance frequency, and a band including a third resonance frequency higher than the second resonance frequency. For example, assuming a wireless LAN, the first resonance frequency, the second resonance frequency, and the third resonance frequency are about 2.5 GHz, about 5.2 GHz, and about 5.8 GHz, respectively. The antenna 1 has a transmission / reception function in a wide band. For example, the second resonance frequency and the third resonance frequency cover the 5 GHz band in the wireless LAN.

  The antenna 1 includes a substrate 11 and an element member 12 disposed on the substrate 11.

  The substrate 11 includes a flat substrate body 110 and conductor patterns 111, 112, and 113 provided on the surface of the substrate body 110. The conductor patterns 111, 112, and 113 are a ground pattern 111, a power feeding pattern 112, and an extension pattern 113.

[substrate]
FIG. 5 is a perspective view showing a substrate of the antenna shown in FIGS. FIG. 5 shows a state in which the element member 12 is removed from the antenna 1 in the posture shown in FIG. The substrate 11 will be described with reference to FIG.

  The substrate body 110 is a plate-like member made of an insulating material (dielectric material). The substrate body 110 of this embodiment is rectangular. The ground pattern 111, the power feeding pattern 112, and the extension pattern 113 are provided on one surface A of the front and back surfaces of the substrate body 110. This one surface A corresponds to the surface referred to in the present invention. In the following description, this one surface A is referred to as the surface A.

  The ground pattern 111 has an area larger than that of the element member 12 in a plan view on the surface A side of the substrate body 110. The ground pattern 111 occupies more than half of the surface A of the substrate body 110. The power feeding pattern 112 is disposed in the vicinity of the ground pattern 111. A pair of electric wires from a transmission / reception device (not shown) is connected to a portion of the ground pattern 111 adjacent to the power supply pattern 112 and the power supply pattern 112 to be supplied with power. In addition, about the electric power feeding pattern 112, the structure extended for electric power supply is also employable.

  The extension pattern 113 is provided on the opposite side of the power supply pattern 112 with respect to the ground pattern 111. The extension pattern 113 has a rectangular frame shape.

  The ground pattern 111, the power feeding pattern 112, and the extension pattern 113 are formed integrally with the substrate body 110 by, for example, etching a metal layer formed on the surface of the substrate body 110.

  The element member 12 is solder-connected to the ground pattern 111, the power feeding pattern 112, and the extension pattern 113 on the substrate 11. However, the connection means is not limited to solder, and, for example, a conductive adhesive can also be used.

[Element member]
6 to 8 are perspective views showing element members of the antenna shown in FIGS. 6 to 8 show the external appearance of the element member 12 viewed from different angles. The board | substrate 11 is demonstrated with reference to FIGS. 1-4 and FIGS.

  The element member 12 is formed of a bent sheet metal. More specifically, the element member 12 is formed by punching and bending a conductive metal plate. The element member 12 has a substantially rectangular parallelepiped shape, and is provided so that each plate-like portion is along the surface of the rectangular parallelepiped.

  The element member 12 includes a rising portion 121, a parallel portion 122, a return portion 123, a vertical plane parallel portion 124, and a grounding portion 125. The rising part 121, the parallel part 122, the return part 123, the vertical plane parallel part 124, and the grounding part 125 are all plate-like and are continuous with each other.

  The rising portion 121 is a wall-shaped portion that rises substantially perpendicularly to the substrate 11 from the power supply pattern 112.

  The parallel part 122 is a part that bends substantially vertically from the tip of the rising part 121 and extends. The parallel portion 122 extends parallel to the surface A with the plate surface facing the surface A of the substrate 11. The parallel portion 122 includes a first extending portion 122a following the rising portion 121 and a second extending from the tip of the first extending portion 122a so as to bend substantially perpendicularly with the plate surface facing the surface A of the substrate 11. And an extending portion 122b.

  The return portion 123 is a portion that is bent substantially vertically from the vicinity of the tip of the parallel portion 122 extending from the rising portion 121 and returns to the surface A of the substrate 11. More specifically, the return portion 123 is a wall-like portion that bends and extends from the vicinity of the tip of the second extending portion 122b. The extension pattern 113 of the substrate 11 is provided at a position in contact with the substrate 11 of the return portion 123. More specifically, the return portion 123 contacts a portion of the frame-like extension pattern 113 that is farthest from the ground pattern 111. That is, the extension pattern 113 further extends from the return portion 123 toward the ground pattern 111.

  The vertical plane parallel part 124 is bent from the middle of the rising part 121 and extends in parallel with the surface A, forming a plate surface substantially perpendicular to the parallel part 122. The vertical plane parallel part 124 is disposed in a region between the parallel part 122 and the surface A of the substrate 11. More specifically, the vertical plane parallel part 124 is parallel to the edge of the parallel part 122. The front end portion of the vertical plane parallel portion 124 is bent substantially vertically along a shape in which the second extending portion 122b of the parallel portion 122 bends vertically from the tip of the first extending portion 122a.

  The grounding portion 125 is branched and extends from the vicinity of the boundary between the parallel portion 122 and the rising portion 121. The grounding portion 125 has a U-shaped portion 125a that extends in a U-shape with the plate surface facing the surface A of the substrate 11, and a grounding that is bent substantially vertically from the tip of the U-shaped portion 125a and returns to the surface A of the substrate 11. And a return part 125b. The parallel part 122 and the U-shaped part 125 a of the grounding part 125 are at the same height from the surface A of the substrate 11. The first extending portion 122a and the second extending portion 122b of the parallel portion 122 form a right angle. The U-shaped portion 125a of the grounding portion 125 is disposed inside the corner formed by the first extending portion 122a and the second extending portion 122b.

  A lower end portion of the rising portion 121, that is, a portion in contact with the substrate 11 is bent substantially perpendicularly, and a connection fixing portion 121 c is provided with the plate surface facing the substrate 11. The lower end portion of the return portion 123 is also provided with a connection fixing portion 123c that is bent substantially vertically and has a plate surface facing the substrate 11. In addition, a connection fixing portion 125 c that is bent substantially vertically and has a plate surface facing the substrate 11 is also provided at the lower end portion of the ground return portion 125 a of the ground portion 125. These three connection fixing portions 121c, 123c, and 125c are respectively solder-connected to the power feeding pattern 112, the extension pattern 113, and the ground pattern 111 of the substrate 11, whereby the element member 12 is firmly fixed to the substrate 11. Since the element member 12 is fixed to the substrate 11 at three points, the mechanical strength is high.

[Antenna function]
In the antenna 1 shown in FIGS. 1 to 4, from the ground pattern 111, the ground portion 125, the parallel portion 122, and the return portion 123, the tip of the extension pattern 113 of the substrate 11 (the return portion 123 in the frame-like extension pattern 113 The distance to the opposite point) has a length that is ¼ of the wavelength of the first resonance frequency of the antenna 1. Therefore, in the antenna 1, an inverted F-type antenna is formed with the ground portion 125, the parallel portion 122, the return portion 123, and the extension pattern 113 as the element body and the rising portion 121 as the feeding element with respect to the first resonance frequency. The

  Further, the distance from the ground pattern 111 through the grounding portion 125 and the rising portion 121 to the tip of the vertical plane parallel portion 124 has a length that is ¼ of the wavelength of the second resonance frequency of the antenna 1. Therefore, in the antenna 1, an inverted F-type antenna is formed in which the grounding portion 125, the rising portion 121, and the vertical plane parallel portion 124 are element bodies and a part of the rising portion 121 is a feeding element for the second resonance frequency. Is done.

  Further, the distance from the power feeding pattern 112 to the ground pattern 111 through the rising portion 121 and the ground portion 125 has a length that is ¼ of the wavelength of the third resonance frequency of the antenna 1. Therefore, in the antenna 1, a folded monopole antenna is formed with the rising portion 121 and the grounding portion 125 as the element body with respect to the third resonance frequency.

  Therefore, the antenna 1 functions as a multiband antenna for transmitting and receiving radio waves in three frequency bands including a band including the first resonance frequency, a band including the second resonance frequency, and a band including the third resonance frequency.

  The antenna 1 of the present embodiment includes a portion that rises substantially perpendicular to the substrate 11, that is, a rising portion 121, a return portion 123, and a ground return portion 125 b of the ground portion 125. The parallel part 122, the vertical plane parallel part 124, and the grounding part 125 are arranged in a state of floating from the substrate 11. For this reason, compared with the case where all the element bodies are arranged on a common plane, the direction of polarization of the radiated radio wave is dispersed. In the space around the antenna 1, radiation is performed in a wide range including the space on the opposite side of the element member 12 with the substrate 11 interposed therebetween.

  In the antenna 1 of the present embodiment, the ground portion 125, the rising portion 121, the parallel portion 122, and the return portion 123 are made of sheet metal among the portions that function as the element main body with respect to the first resonance frequency, and the extension pattern 113. Consists of a conductor pattern provided on the surface A of the substrate 11. For this reason, compared with the case where all the parts functioning as the element body are formed of sheet metal, the length of the part extending away (floating) from the substrate 11 is short. Therefore, the overall volume of the antenna 1 is small. In addition, the extension pattern 113 extends from the position in contact with the return portion 123 toward the ground pattern 111. For this reason, in the area of the surface A of the substrate 11, the area directly below the parallel part 122 and the grounding part 125 floating from the substrate 11 is effectively used. Therefore, the antenna 1 is reduced in size.

  Further, in the antenna 1 of this embodiment, the vertical plane parallel part 124 is arranged in a region between the parallel part 122 and the substrate 11. Therefore, an antenna element corresponding to the second resonance frequency is added without increasing the overall volume or area of the antenna 1. Further, since the vertical plane parallel part 124 forms a substantially vertical plate surface with the parallel part 122, interference between the vertical plane parallel part 124 and the parallel part 122 is suppressed.

  In the antenna 1 of this embodiment, the extension pattern 113 is formed in a rectangular frame shape. For this reason, the thickness of the side extending close to the vertical plane parallel portion 124 and the thickness of the portion corresponding to the opposite side can be easily adjusted at the design stage. Therefore, it is easy to adjust the influence of electromagnetic induction on the extension pattern 113 due to the current of the second resonance frequency flowing in the vertical plane parallel part 124 to the minimum by design.

[Example]
An antenna based on the embodiment described above was created and the characteristics were measured. The dimensions of each element of the antenna 1 were such that the first resonance frequency, the second resonance frequency, and the third resonance frequency were about 2.5 GHz, about 5.2 GHz, and about 5.8 GHz, respectively. The created antenna 1 was mounted on the back surface of a metal plate assuming a liquid crystal panel of a liquid crystal television as an example of an electronic device.

  In addition, as a comparative example, a planar antenna in which elements having the same dimensions as the antenna 1 were formed only with the conductor pattern of the substrate was prepared. The antenna of the comparative example was also mounted on the back surface of the metal plate in the same manner as the antenna 1 of the example.

  FIG. 9 is a plan view showing the configuration of the embodiment. FIG. 9 shows an arrangement of the liquid crystal television viewed from above when a liquid crystal television panel is assumed. Part (A) of FIG. 9 shows a state in which the antenna 1 of the present embodiment having the substrate 11 and the element member 12 is attached to the metal plate 3 via an insulating spacer 4. Part (B) shows a state in which the planar antenna 5 as a comparative example is attached to the metal plate 3 via the spacer 6.

  Here, for example, when assuming a liquid crystal television, the antennas 1 and 5 are disposed on the back surface of the liquid crystal panel. An arrow F represents the front of the liquid crystal television, that is, the electronic device. The metal plate 3 has a thickness of 13 mm assuming a liquid crystal panel. Further, assuming that the antennas 1 and 5 are arranged in the casing of the electronic device, both the example and the comparative example are arranged in a space from the metal plate 3 to 8.2 mm. In order to make the radiation characteristics as good as possible under these arrangement conditions, the spacers 4 and 6 are formed so that the antennas 1 and 5 are separated from the metal plate 3 as much as possible.

  For the two antennas 1 and 5 shown in FIG. 9, the electric field strength was measured in each direction on the horizontal plane including the antennas 1 and 5.

  FIG. 10 is a graph showing the measurement results of the antenna shown in FIG. Part (A) of FIG. 10 shows the measurement results of the example shown in part (A) of FIG. Part (B) of FIG. 10 shows the measurement results of the comparative example shown in part (B) of FIG.

  The measurement result is the electric field strength (unit: [dB]) in each direction on the horizontal plane including the antennas 1 and 5 (see FIG. 9). The frequency is 2.5 GHz. 10 also corresponds to FIG. 9 and shows an arrow F representing the front. The graph shows three electric field intensities: horizontal polarization component H, vertical polarization component V, and the sum of horizontal polarization component H and vertical polarization component V (H + V).

  For example, when the electric field of the sum (H + V) of the horizontal polarization component H and the vertical polarization component V is compared, the electric field of the embodiment shown in Part (A) is the same as that of the embodiment shown in Part (B) in all directions. It is larger than the electric field. In particular, it is larger than 5 [dB] in the front area indicated by the arrow F, that is, in many areas on the opposite side of the antenna 1 with the metal plate 3 interposed therebetween.

  FIG. 11 is a graph showing the frequency characteristics of the antenna shown in FIG. FIG. 11 shows the frequency characteristics of both the antenna 1 of the embodiment shown in FIG. 9 and the antenna 5 of the comparative example. As shown in the graph of FIG. 11, the characteristics of the antenna 1 of the example are better than those of the antenna 5 of the comparative example in all communication regions including the 2.5 GHz region.

  In the above-described embodiment, the antenna 1 having three resonance frequencies is shown as an example of the antenna according to the present invention. However, the present invention is not limited to this. For example, the antenna according to the present invention may have one or two resonance frequencies, and may have four or more resonance frequencies. There may be.

  The resonant frequency of the antenna may be a frequency different from about 2.5 GHz, about 5.2 GHz, and about 5.8 GHz.

DESCRIPTION OF SYMBOLS 1 Antenna 11 Board | substrate 111 Grounding pattern 112 Feeding pattern 113 Extension pattern 12 Element member 121 Rising part 122 Parallel part 123 Return part 124 Vertical surface parallel part 125 Grounding part

Claims (2)

A substrate provided with a grounding pattern and a feeding pattern made of a conductor pattern on the surface;
An element member made of a bent sheet metal disposed on the substrate,
The element member is
A rising portion rising from the power supply pattern with respect to the substrate;
A parallel portion that is bent from the tip of the rising portion and extends parallel to the surface with the plate surface facing the surface of the substrate;
A return part that bends from the parallel part and returns to the surface of the substrate,
The antenna according to claim 1, wherein the substrate includes an extension pattern on the surface, the extension pattern being in contact with the return portion and extending from the return portion, the conductor pattern being different from the ground pattern and the power feeding pattern.   The said element member was equipped with the perpendicular | vertical surface parallel part which bent from the middle of the said rising part, and made the board | substrate surface substantially perpendicular | vertical to the said parallel part, and extended in parallel with the said surface. Antenna.

Images