Antenna and antenna device

Abstract

This antenna is characterized by including: a first radiating conductor having a first open end and a first power feed point; a second radiating conductor which has a second open end and a second power feed point and which is disposed such that the second open end faces the first open end; a planar ground conductor overlapping the first radiating conductor and the second radiating conductor in a plan view; a shielding ground conductor disposed between the first open end and the second open end in a plan view; an end portion ground conductor connected to the first radiating conductor and the second radiating conductor in a plan view; and a power feed line for supplying power to the first radiating conductor and the second radiating conductor with a predetermined phase difference.

Description

Antennas and Antenna Devices

[0001] The present invention relates to an antenna and an antenna device.

[0002] Patent Document 1 discloses an array antenna including an inverted-F antenna and a plurality of parasitic elements that are grounded to a ground plate and function as reflectors and directors, thereby improving the directivity in the radiation direction of the array antenna.

[0003] JP 9-55621

[0004] The array antenna of Patent Document 1 radiates radio waves in directions other than the intended radiation direction.

[0005] In response to this, an object of the present invention is to provide an antenna and an antenna device that can suppress unnecessary radiation and improve directivity in a desired radiation direction.

[0006] The antenna of the present invention is characterized by comprising: a first radiating conductor having a first open end and a first feeding point; a second radiating conductor having a second open end and a second feeding point and arranged so that the second open end faces the first open end; a planar ground conductor overlapping the first radiating conductor and the second radiating conductor in a planar view; a shielding ground conductor arranged between the first open end and the second open end in a planar view; an end ground conductor connected to the first radiating conductor and the second radiating conductor in a planar view; and feeder lines supplying power to the first radiating conductor and the second radiating conductor with a predetermined phase difference, respectively.

[0007] According to the present invention, it is possible to suppress unnecessary radiation and improve the directivity in the desired radiation direction.

[0008] FIG. 1 is a plan view of antenna 1. FIG. 2 is a side cross-sectional view of antenna 1 at the position indicated by A-A in FIG. 1. FIG. 3 is a side cross-sectional view for explaining radiation of antenna 1. FIG. 4 is a side cross-sectional view for explaining radiation of antenna 1. FIG. 5 is a side cross-sectional view for explaining radiation of antenna 1. FIG. 6 is a plan view of antenna 1. FIG. 7 is a plan view of antenna 1. FIG. 8 is a plan view of antenna 1A according to modified example 1. FIG. 9 is a plan view of antenna 1B according to modified example 2. FIG. 10 is a plan view of antenna 1C according to modified example 3. FIG. 11 is a plan view of antenna 1D according to modified example 4. FIG. 12 is a plan view of antenna 1E according to modified example 5. FIG. 13 is a side schematic view of an antenna device including antenna 1 and a flexible substrate 5 connected to antenna 1.

[0009] An antenna 1 according to an embodiment of the present invention will now be described. Fig. 1 is a plan view of the antenna 1. Fig. 2 is a side cross-sectional view of the antenna 1 taken along line AA in Fig. 1.

[0010] The antenna 1 has a first radiating conductor 11A, a second radiating conductor 11B, a planar ground conductor 12, a shielding ground conductor 13, an end ground conductor 14, and a feed line 15. The first radiating conductor 11A has a first open end 111A and a first feed point 151A. The second radiating conductor 11B has a second open end 111B and a second feed point 151B. The first open end 111A and the second open end 111B are arranged opposite each other.

[0011] The planar ground conductor 12 overlaps the first radiating conductor 11A and the second radiating conductor 11B in plan view. The shielding ground conductor 13 is disposed between the first open end 111A and the second open end 111B in plan view. The end ground conductor 14 is connected to the first radiating conductor 11A and the second radiating conductor 11B at the first short-circuit end 112A and the second short-circuit end 112B in plan view. As a result, the ends of the first radiating conductor 11A and the second radiating conductor 11B opposite the first open end 111A and the second open end 111B, respectively, are short-circuited.

[0012] In this embodiment, the direction in which the first radiating conductor 11A, the shielding ground conductor 13, and the second radiating conductor 11B are aligned is the X direction, and the direction perpendicular to the X direction in plan view is the Y direction.

[0013] The feed line 15 supplies power input from the feed conductor 155 to the first radiation conductor 11A and the second radiation conductor 11B via the interlayer connection conductor 19. The feed line 15 feeds power to the first radiation conductor 11A at a first feed point 151A. The feed line 15 also feeds power to the second radiation conductor 11B at a second feed point 151B.

[0014] The length of the first radiation conductor 11A in the X direction is ¼ wavelength of the supplied radio wave. The length of the second radiation conductor 11B in the X direction is also ¼ wavelength of the supplied radio wave. Therefore, the first radiation conductor 11A and the second radiation conductor 11B each constitute an inverted-F antenna.

[0015] The length from the feed conductor 155 to the first feed point 151A is different from the length from the feed conductor 155 to the second feed point 151B. Therefore, the feed line 15 feeds power to the first radiation conductor 11A and the second radiation conductor 11B with a predetermined phase difference. In this embodiment, the length from the feed conductor 155 to the first feed point 151A is longer by half a wavelength than the length from the feed conductor 155 to the second feed point 151B. Therefore, the feed line 15 feeds power to the first radiation conductor 11A and the second radiation conductor 11B with opposite phases.

[0016] The antenna 1 is composed of a rectangular parallelepiped base 10. In this embodiment, the Z direction is the thickness direction of the base 10 toward the upper surface. The base 10 is formed by laminating multiple thermoplastic resins, for example. The thermoplastic resin is, for example, a liquid crystal polymer resin. The thermoplastic resin may be, for example, PEEK (polyether ether ketone), PEI (polyetherimide), PPS (polyphenylene sulfide), PI (polyimide), or the like. The base 10 may also be made of an insulating material other than resin, such as ceramic.

[0017] The first radiation conductor 11A, the second radiation conductor 11B, the shielding ground conductor 13, and the end ground conductor 14 are arranged on the upper surface of the base 10. The planar ground conductor 12 is arranged on the lower surface of the base 10.

[0018] In plan view, the end ground conductor 14 is configured in a ring shape to surround the first radiation conductor 11A, the second radiation conductor 11B, and the shielding ground conductor 13. This enables the end ground conductor 14 to ground the first radiation conductor 11A and the second radiation conductor 11B and to suppress unwanted radiation from the first radiation conductor 11A and the second radiation conductor 11B in the X and Y directions.

[0019] The first radiation conductor 11A and the second radiation conductor 11B have a rectangular shape that is longer in the X direction in plan view. The shielding ground conductor 13 has a rectangular shape that is longer in the Y direction in plan view. In this embodiment, the length of the shielding ground conductor 13 in the Y direction is longer than that of the first radiation conductor 11A and the second radiation conductor 11B.

[0020] The shielding ground conductor 13 is connected to the planar ground conductor 12 via a plurality of interlayer connection conductors 17. The end ground conductor 14 is also connected to the planar ground conductor 12 via a plurality of interlayer connection conductors 17.

[0021] The planar ground conductor 12 is disposed over substantially the entire surface of the antenna 1, excluding the power feeding conductor 155, in a planar view. This allows the planar ground conductor 12 to suppress unwanted radiation in the −Z direction from the first radiation conductor 11A and the second radiation conductor 11B.

[0022] Furthermore, the antenna 1 of this embodiment can enhance radiation in the Z direction while suppressing radiation in the X and Y directions.

[0023] 3, 4, and 5 are side cross-sectional views illustrating radiation from the antenna 1. Fig. 3 schematically shows the voltage distribution of radio waves radiated in the X direction from the first radiation conductor 11A. In this embodiment, a first distance D1 between the first open end 111A and a position of the shielding ground conductor 13 closest to the first radiation conductor 11A is longer than a second distance D2 between the first open end 111A and the first feed point 151A. Therefore, the radio waves radiated from the first radiation conductor 11A and the radio waves reflected by the shielding ground conductor 13 cancel each other out.

[0024] 4 schematically shows the voltage distribution of radio waves radiated in the X direction from the second radiation conductor 11B. In this embodiment, the first distance D1 between the second open end 111B and the position of the shielding ground conductor 13 closest to the second radiation conductor 11B is longer than the second distance D2 between the second open end 111B and the second feed point 151B. Therefore, the radio waves radiated from the second radiation conductor 11B and the radio waves reflected by the shielding ground conductor 13 cancel each other out.

[0025] In this way, the shielding ground conductor 13 can suppress unnecessary radiation in the X direction from the first radiation conductor 11A and the second radiation conductor 11B.

[0026] 5 schematically shows the voltage distribution of radio waves radiated in the Z direction from the first radiation conductor 11A and the second radiation conductor 11B. The feed line 15 feeds power in opposite phases to the first radiation conductor 11A and the second radiation conductor 11B. Because the first radiation conductor 11A and the second radiation conductor 11B face each other, the radio waves radiated in the Z direction from the first radiation conductor 11A and the second radiation conductor 11B are in phase and reinforce each other.

[0027] As a result, the antenna 1 of this embodiment can suppress radiation in directions other than the Z direction and can radiate radio waves with strong directivity in the Z direction, which is the desired direction.

[0028] As shown in FIG. 6 , in this embodiment, when a straight line drawn from the first feed point 151A so as to be perpendicular to a first region in the first radiating conductor 11A that is closest to the second radiating conductor 11B is defined as a first straight line L1, and a straight line drawn from the second feed point 151B so as to be perpendicular to a second region in the second radiating conductor 11B that is closest to the first radiating conductor 11A is defined as a second straight line L2, the feed line 15 does not intersect with the first straight line L1 or the second straight line L2.

[0029] As a result, the feed line 15 is not disposed in a location where the electric field is strong, and therefore unnecessary coupling between the feed line 15 and the first radiation conductor 11A and the second radiation conductor 11B can be suppressed.

[0030] 7 , in this embodiment, when the distance A1 between the first open end 111A and the first feed point 151A and the distance A2 between the second open end 111B and the second feed point 151B are defined as follows: the distance P1 between each of the plurality of interlayer connection conductors 17 is equal to or less than twice the shorter of the distance A1 or the distance A2. In other words, the spacing between the plurality of interlayer connection conductors 17 is preferably equal to or less than half the wavelength. If the spacing between the plurality of interlayer connection conductors 17 is equal to or less than half the wavelength, radio waves radiated from the first radiation conductor 11A and the second radiation conductor 11B can be reflected, and unwanted radiation in the X direction can be suppressed.

[0031] (Modification 1) Fig. 8 is a plan view of an antenna 1A according to Modification 1. The first radiation conductor 11A and the second radiation conductor 11B of the antenna 1A have an elliptical shape when viewed in plan. The rest of the configuration is the same as that of the antenna 1 shown in Figs. 1 and 2.

[0032] In this case, the shielding ground conductor 13 is also disposed between the first open end 111A and the second open end 111B in plan view. Therefore, the shielding ground conductor 13 of the antenna 1A can also suppress unwanted radiation in the X direction from the first radiation conductor 11A and the second radiation conductor 11B.

[0033] (Variation 2) Fig. 9 is a plan view of an antenna 1B according to Variation 2. The first radiating conductor 11A and the second radiating conductor 11B of the antenna 1A have a pentagonal shape in plan view, with the corners of the first open end 111A and the second open end 111B tapered. The rest of the configuration is the same as that of the antenna 1 shown in Figs. 1 and 2.

[0034] In this case, the shielding ground conductor 13 is also disposed between the first open end 111A and the second open end 111B in plan view. Therefore, the shielding ground conductor 13 of the antenna 1A can also suppress unwanted radiation in the X direction from the first radiation conductor 11A and the second radiation conductor 11B.

[0035] As shown in FIGS. 8 and 9, the shape of the first radiating conductor 11A and the second radiating conductor 11B in plan view is not limited to a rectangular shape.

[0036] 10 is a plan view of an antenna 1C according to Modification 3. The antenna 1C is divided into multiple (three in FIG. 10 ) shielded ground conductors 13. The multiple shielded ground conductors 13 are each connected to the planar ground conductor 12 via an interlayer connection conductor 17.

[0037] As such, there is no need to have only one shielding ground conductor 13. The spacing between the multiple shielding ground conductors 13 is preferably equal to or less than half the wavelength. If the spacing between the multiple shielding ground conductors 13 is equal to or less than half the wavelength, the radio waves radiated from the first radiating conductor 11A and the second radiating conductor 11B can be reflected.

[0038] (Modification 4) Fig. 11 is a plan view of an antenna 1D according to Modification 4. The shapes of the first radiating conductor 11A and the second radiating conductor 11B of the antenna 1D in plan view are the same as those of the antenna 1 shown in Fig. 1 and Fig. 2. However, the length of the first radiating conductor 11A in the Y direction is longer than the length of the second radiating conductor 11B in the Y direction.

[0039] In this case, the shielding ground conductor 13 is also disposed between the first open end 111A and the second open end 111B in plan view. The length of the shielding ground conductor 13 in the Y direction is the same as the length of the first radiation conductor 11A in the Y direction and is longer than the length of the second radiation conductor 11B in the Y direction.

[0040] That is, the length of the shielding ground conductor 13 in the Y direction is equal to or greater than the length of the longest portion of the first radiation conductor 11A or the second radiation conductor 11B in the Y direction.

[0041] In this case, the shielding ground conductor 13 of the antenna 1A can also suppress unwanted radiation in the X direction from the first radiation conductor 11A and the second radiation conductor 11B.

[0042] 12 is a plan view of an antenna 1E according to Modification 5. The end ground conductor 14 of the antenna 1E is not annular, but is arranged only at the end in the X direction. The length of the end ground conductor 14 in the Y direction is longer than the lengths of the first radiation conductor 11A and the second radiation conductor 11B in the Y direction.

[0043] Even in this case, the end ground conductor 14 can suppress unwanted radiation in the X direction.

[0044] 13 is a schematic side view of an antenna device including an antenna 1 and a flexible substrate 5 connected to the antenna 1. The lower surface of the antenna 1 is joined to the upper surface of the flexible substrate 5.

[0045] The flexible substrate 5 is made of a flexible material such as liquid crystal polymer resin, PEEK (polyether ether ketone), PEI (polyetherimide), PPS (polyphenylene sulfide), or PI (polyimide).

[0046] The flexible substrate 5 has flexibility and can be bent at any position, so that the radiation direction of the antenna 1 of the antenna device shown in FIG.

[0047] The description of the present embodiment should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above-described embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope of the claims.

[0048] The present invention has the following configuration.

[0049] <1> An antenna comprising: a first radiating conductor having a first open end and a first feeding point; a second radiating conductor having a second open end and a second feeding point, the second open end being arranged so as to face the first open end; a planar ground conductor overlapping the first radiating conductor and the second radiating conductor in a planar view; a shielding ground conductor arranged between the first open end and the second open end in a planar view; an end ground conductor connected to the first radiating conductor and the second radiating conductor in a planar view; and a feeding line feeding the first radiating conductor and the second radiating conductor with a predetermined phase difference, respectively.

[0050] <2> The antenna according to <1>, wherein the edge ground conductor is configured to surround the first radiation conductor, the second radiation conductor, and the shielding ground conductor in a plan view of the antenna.

[0051] <3> The antenna according to <1> or <2>, wherein the feed line feeds power to the first radiation conductor and the second radiation conductor in opposite phases.

[0052] <4> The antenna according to any one of <1> to <3>, wherein the direction in which the first radiation conductor, the shielding ground conductor, and the second radiation conductor are aligned is defined as an X direction, and the direction perpendicular to the X direction in a planar view is defined as a Y direction, and the length of the shielding ground conductor in the Y direction is equal to or longer than the length of a portion of the first radiation conductor or the second radiation conductor that has the longest length in the Y direction.

[0053] <5> The antenna according to any one of <1> to <4>, wherein a first distance D1 between a position of the shielding ground conductor closest to the first radiation conductor or the second radiation conductor and the first feed point or the second feed point is longer than a second distance D2 between the first open end or the second open end and the first feed point or the second feed point.

[0054] <6> The antenna according to any one of <1> to <5>, wherein a first line is a line drawn from a first feed point so as to be perpendicular to a first region in a first radiation conductor that is closest to the second radiation conductor, and a second line is a line drawn from a second feed point so as to be perpendicular to a second region in a second radiation conductor that is closest to the first radiation conductor, and the feed line does not intersect the first line or the second line.

[0055] <7> The antenna according to any one of <1> to <6>, further comprising a plurality of interlayer connection conductors connecting the planar ground conductor with the end ground conductor and the shielding ground conductor, wherein, when a distance A1 between the first open end and the first feed point and a distance A2 between the second open end and the second feed point are defined as a distance P1 between the plurality of interlayer connection conductors is equal to or less than twice the shorter of the distance A1 or the distance A2.

[0056] <8> An antenna device comprising: the antenna according to any one of <1> to <7>; and a flexible substrate connected to the antenna.

[0057] 1: Antenna 1A: Antenna 1B: Antenna 1C: Antenna 1D: Antenna 1E: Antenna 5: Flexible substrate 10: Base 11A: First radiation conductor 11B: Second radiation conductor 12: Planar ground conductor 13: Shielding ground conductor 14: End ground conductor 15: Feed line 17: Interlayer connection conductor 19: Interlayer connection conductor 111A: First open end 111B: Second open end 112A: First short-circuit end 112B: Second short-circuit end 151A: First feed point 151B: Second feed point 155: Feed conductor A1: Distance A2: Distance D1: First distance D2: Second distance L1: First straight line L2: Second straight line P1 :distance

Claims

1. a first radiating conductor having a first open end and a first feed point; a second radiation conductor having a second open end and a second feeding point, the second open end being disposed opposite the first open end; a planar ground conductor overlapping the first radiation conductor and the second radiation conductor in a plan view; a shielded ground conductor disposed between the first open end and the second open end in a plan view; an end ground conductor connected to the first radiation conductor and the second radiation conductor in a plan view; a feed line that feeds power to the first feed point and the second feed point with a predetermined phase difference; An antenna with.

2. A first radiation conductor having a first open end and a first feeding point; a second radiation conductor having a second open end and a second feeding point, the second open end being disposed opposite the first open end; a planar ground conductor overlapping the first radiation conductor and the second radiation conductor in a plan view; a shielded ground conductor disposed between the first open end and the second open end in a plan view; an end ground conductor connected to the first radiation conductor and the second radiation conductor in a plan view; a feed line that feeds power to the first feed point and the second feed point, respectively; Equipped with In the power supply line, a length from a position where power is input to the power supply line to the first power supply point is different from a length from the position to the second power supply point. antenna.

3. the feed line feeds power to the first feed point and the second feed point in opposite phases, 10. The antenna of claim 1.

4. The length of the power supply line from the position to the first power supply point is longer than the length from the position to the second power supply point by half the wavelength of the radio wave to be supplied.

3. The antenna of claim 2.

5. the end ground conductor is configured to surround the first radiation conductor, the second radiation conductor, and the shielding ground conductor in a plan view of the antenna.

5. The antenna according to claim 1.

6. a direction in which the first radiation conductor, the shielding ground conductor, and the second radiation conductor are arranged is defined as an X direction, and a direction orthogonal to the X direction in a plan view is defined as a Y direction; a length of the shielded ground conductor in the Y direction is equal to or greater than a length of a portion of the first radiation conductor or the second radiation conductor that has the longest length in the Y direction; 5. The antenna according to claim 1.

7. a first distance D1 between a position of the shielding ground conductor closest to the first radiation conductor or the second radiation conductor and the first open end or the second open end is longer than a second distance D2 between the first open end or the second open end and the first feed point or the second feed point; 5. The antenna according to claim 1.

8. a first line is a line drawn from the first feed point so as to be perpendicular to a first region in the first radiation conductor that is closest to the second radiation conductor; When a line drawn from the second feed point so as to be perpendicular to a second region closest to the first radiation conductor in the second radiation conductor is defined as a second line, the power supply line does not intersect with the first straight line and the second straight line; 5. The antenna according to claim 1.

9. a plurality of interlayer connection conductors connecting the planar ground conductor to the edge ground conductor and the shielding ground conductor; When the distance between the first open end and the first feed point is A1 and the distance between the second open end and the second feed point is A2, a distance P1 between each of the plurality of interlayer connection conductors is equal to or less than twice the shorter of the distance A1 or the distance A2; 5. The antenna according to claim 1.

10. An antenna according to any one of claims 1 to 4; a flexible substrate connected to the antenna; An antenna device comprising: