Antennas and antenna devices

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

Technical Field

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

Background Art

[0002] Patent Document 1 discloses an array antenna including an inverted-F antenna, a plurality of parasitic elements grounded to a ground plane and functioning as a reflector and a waveguide. Thereby, the array antenna of Patent Document 1 improves the directivity in the radiation direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The array antenna of Patent Document 1 radiates radio waves not only in the target radiation direction.

[0005] In contrast, an object of the present invention is to provide an antenna and an antenna device capable of suppressing unnecessary radiation and improving the directivity in the target radiation direction.

Means for Solving the Problems

[0006] The antenna of the present invention is characterized by comprising: a first radiating conductor having a first open end and a first feed point; a second radiating conductor having a second open end and a second feed point, wherein the second open end is positioned opposite the first open end; a planar ground conductor that overlaps the first and second radiating conductors in plan view; a shielding ground conductor positioned between the first and second open ends in plan view; an end ground conductor connected to the first and second radiating conductors in plan view; and a feed line that supplies power to the first and second radiating conductors, respectively, with a predetermined phase difference. [Effects of the Invention]

[0007] According to this invention, unwanted radiation can be suppressed and the directivity towards the desired radiation direction can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view of antenna 1. [Figure 2] This is a side cross-sectional view of antenna 1 at the position indicated by AA in Figure 1. [Figure 3] This is a side cross-sectional view illustrating the radiation from antenna 1. [Figure 4] This is a side cross-sectional view illustrating the radiation from antenna 1. [Figure 5] This is a side cross-sectional view illustrating the radiation from antenna 1. [Figure 6] This is a plan view of antenna 1. [Figure 7] This is a plan view of antenna 1. [Figure 8] This is a plan view of antenna 1A according to modified example 1. [Figure 9] This is a plan view of antenna 1B according to modified example 2. [Figure 10] This is a plan view of antenna 1C according to modified example 3. [Figure 11] This is a plan view of antenna 1D according to modified example 4. [Figure 12] This is a plan view of antenna 1E according to modified example 5. [Figure 13] This is a schematic side view of an antenna device comprising an antenna 1 and a flexible substrate 5 connected to the antenna 1. [Modes for carrying out the invention]

[0009] The following describes an antenna 1 according to an embodiment of the present invention. Figure 1 is a plan view of the antenna 1. Figure 2 is a side cross-sectional view of the antenna 1 at the position indicated by line AA in Figure 1.

[0010] Antenna 1 includes 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 when viewed from above. The shielding ground conductor 13 is positioned between the first open end 111A and the second open end 111B when viewed from above. 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 when viewed from above. This short-circuits the ends of the first radiating conductor 11A and the second radiating conductor 11B opposite to the first open end 111A and the second open end 111B, respectively.

[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 a plan view is the Y direction.

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

[0014] The length of the first radiation conductor 11A in the X direction is 1 / 4 wavelength of the radiated radio wave. The length of the second radiation conductor 11B in the X direction is also 1 / 4 wavelength of the radiated 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 power supply conductor 155 to the first power supply point 151A is different from the length from the power supply conductor 155 to the second power supply point 151B. Therefore, the power supply line 15 supplies 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 power supply conductor 155 to the first power supply point 151A is longer than the length from the power supply conductor 155 to the second power supply point 151B by half a wavelength. Therefore, the power supply line 15 supplies 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 direction toward the upper surface in the thickness direction of the base 10 is the Z direction. The base 10 is formed by laminating, for example, a plurality of thermoplastic resins. The thermoplastic resin is, for example, a liquid crystal polymer resin. The thermoplastic resin may be, for example, PEEK (polyether ether ketone), PEI (polyether imide), PPS ( Poly polyphenylene sulfide), PI (polyimide), etc. Also, the base 10 may be an insulator 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] The end ground conductor 14 is configured in a ring shape, when viewed from above, so as to surround the first radiating conductor 11A, the second radiating conductor 11B, and the shielding ground conductor 13. This allows the end ground conductor 14 to ground the first radiating conductor 11A and the second radiating conductor 11B, and to suppress unwanted radiation from the first radiating conductor 11A and the second radiating conductor 11B in the X and Y directions.

[0019] The first radiating conductor 11A and the second radiating conductor 11B are rectangular in shape, elongated in the X direction when viewed from above. The shielding ground conductor 13 is rectangular in shape, elongated in the Y direction when viewed from above. In this embodiment, the length of the shielding ground conductor 13 in the Y direction is equal to the length of the first radiating conductor 11A and the second radiating conductor 11B Length in the Y direction It is longer than that.

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

[0021] The planar ground conductor 12 is positioned over almost the entire surface of the antenna 1, excluding the feed conductor 155, when viewed from above. This allows the planar ground conductor 12 to suppress unwanted radiation in the -Z direction from the first radiating conductor 11A and the second radiating 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] Figures 3, 4, and 5 are side cross-sectional views illustrating the radiation of antenna 1. Figure 3 schematically shows the voltage distribution of radio waves radiated in the X direction from the first radiating conductor 11A. In this embodiment, the length of the first distance D1 between the position of the shielding ground conductor 13 closest to the first radiating conductor 11A and the first open end 111A is longer than the second distance D2 between the first open end 111A and the first feed point 151A. Therefore, the radio waves radiated from the first radiating conductor 11A and the radio waves reflected by the shielding ground conductor 13 cancel each other out.

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

[0026] Figure 5 schematically shows the voltage distribution of radio waves radiated in the Z direction by the first radiating conductor 11A and the second radiating conductor 11B. The feed line 15 supplies power to the first radiating conductor 11A and the second radiating conductor 11B in opposite phases. Since the first radiating conductor 11A and the second radiating conductor 11B face each other, the radio waves radiated in the Z direction by the first radiating conductor 11A and the second radiating 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 emit radio waves with strong directivity in the Z direction, which is the desired direction.

[0028] As shown in Figure 6, in this embodiment, if the first straight line L1 is drawn from the first power supply point 151A so as to be perpendicular to the first region closest to the second radiating conductor 11B within the first radiating conductor 11A, and the second straight line L2 is drawn from the second power supply point 151B so as to be perpendicular to the second region closest to the first radiating conductor 11A within the second radiating conductor 11B, then the power supply line 15 does not intersect with the first straight line L1 and the second straight line L2.

[0029] As a result, the power supply line 15 is not located in areas with strong electric fields, thus suppressing unwanted coupling between the power supply line 15 and the first radiating conductor 11A and the second radiating conductor 11B.

[0030] Furthermore, as shown in Figure 7, in this embodiment, when the distance A1 is between the first open end 111A and the first feed point 151A, and the distance A2 is between the second open end 111B and the second feed point 151B, the distance P1 of each of the multiple interlayer connecting conductors 17 is less than or equal to twice the shorter of the two distances A1 or A2. In other words, it is preferable that the spacing between the multiple interlayer connecting conductors 17 is 1 / 2 wavelength or less. If the spacing between the multiple interlayer connecting conductors 17 is 1 / 2 wavelength or less, radio waves radiated from the first radiating conductor 11A and the second radiating conductor 11B can be reflected, and unwanted radiation in the X direction can be suppressed.

[0031] (Variation 1) Figure 8 is a plan view of antenna 1A according to modified example 1. The first radiating conductor 11A and the second radiating conductor 11B of antenna 1A have an elliptical shape when viewed from above. The other configurations are the same as those of antenna 1 shown in Figures 1 and 2.

[0032] In this case as well, the shielding ground conductor 13 is positioned between the first open end 111A and the second open end 111B when viewed from above. Therefore, the shielding ground conductor 13 of antenna 1A can also suppress unwanted radiation in the X direction from the first radiating conductor 11A and the second radiating conductor 11B.

[0033] (Modification 2) Figure 9 is a plan view of antenna 1B according to modified example 2. Antenna 1 B The first radiating conductor 11A and the second radiating conductor 11B, when viewed from above, have a pentagonal shape with tapered corners at the first open end 111A and the second open end 111B. The rest of the configuration is the same as that of antenna 1 shown in Figures 1 and 2.

[0034] In this case as well, the shielding ground conductor 13 is positioned between the first open end 111A and the second open end 111B when viewed from above. Therefore, antenna 1 B The shielding ground conductor 13 can also suppress unwanted radiation in the X direction from the first radiating conductor 11A and the second radiating conductor 11B.

[0035] As shown in Figures 8 and 9, the plan view shapes of the first radiating conductor 11A and the second radiating conductor 11B are not limited to rectangular shapes.

[0036] (Variation 3) Figure 10 is a plan view of antenna 1C according to modified example 3. Antenna 1C is divided into multiple (three in Figure 10) shielding ground conductors 13. Each of the multiple shielding ground conductors 13 is connected to a planar ground conductor 12 via an interlayer connecting conductor 17.

[0037] Thus, there does not need to be only one shielding ground conductor 13. Furthermore, it is preferable that the spacing between multiple shielding ground conductors 13 be 1 / 2 wavelength or less. If the spacing between multiple shielding ground conductors 13 is 1 / 2 wavelength or less, radio waves radiated from the first radiating conductor 11A and the second radiating conductor 11B can be reflected.

[0038] (Modification 4) Figure 11 is a plan view of antenna 1D according to modified example 4. The plan view of the first radiating conductor 11A and the second radiating conductor 11B of antenna 1D is the same as that of antenna 1 shown in Figures 1 and 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 as well, the shielding ground conductor 13 is positioned between the first open end 111A and the second open end 111B when viewed from above. Furthermore, the length of the shielding ground conductor 13 in the Y direction is the same as the length of the first radiating conductor 11A in the Y direction, and longer than the length of the second radiating conductor 11B in the Y direction.

[0040] In other words, the length of the shielding ground conductor 13 in the Y direction is equal to or greater than the length of the longest point in the Y direction among the first radiating conductor 11A or the second radiating conductor 11B.

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

[0042] (Variation 5) Figure 12 is a plan view of antenna 1E according to modified example 5. The end ground conductor 14 of antenna 1E is not ring-shaped, but is located only at the end in the X direction. In addition, the length of the end ground conductor 14 in the Y direction is longer than the length of the first radiating conductor 11A and the second radiating 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] (Other examples) Figure 13 is a schematic side view of an antenna device comprising 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, for example, liquid crystal polymer resin, PEEK (polyether ether ketone), PEI (polyether imide), PPS ( Poly It is made of a flexible material such as phenylene sulfide or PI (polyimide).

[0046] Because the flexible substrate 5 is flexible, it can be bent at any position. The antenna device shown in Figure 13, therefore, allows the radiation direction of the antenna 1 to be adjusted to any direction.

[0047] The description of this embodiment should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, rather than by the embodiments described above. Furthermore, the scope of the invention is intended to include all modifications within the meaning and scope of equivalence to the claims.

[0048] The present invention has the following configuration.

[0049] <1> A first radiating conductor having a first open end and a first feed point, A second radiating conductor having a second open end and a second feed point, wherein the second open end is positioned opposite the first open end, Viewed from above, a planar ground conductor overlapping the first radiating conductor and the second radiating conductor, Viewed from above, a shielding ground conductor is positioned between the first open end and the second open end, Viewed from above, the end ground conductor connected to the first radiating conductor and the second radiating conductor, A power supply line that supplies power to the first radiating conductor and the second radiating conductor, respectively, with a predetermined phase difference, An antenna.

[0050] <2> The end ground conductor is configured to surround the first radiating conductor, the second radiating conductor, and the shielding ground conductor when the antenna is viewed in plan. <1> The antenna described above.

[0051] <3> The power supply line supplies power to the first radiating conductor and the second radiating conductor in opposite phases. <1> or <2> The antenna described above.

[0052] <4> The direction in which the first radiating conductor, the shielding ground conductor, and the second radiating conductor are aligned is defined as the X direction, and the direction perpendicular to the X direction in a plan view is defined as the Y direction. The length of the shielding ground conductor in the Y direction is equal to or greater than the length of the longest point in the Y direction among the first radiating conductor or the second radiating conductor. <1> ~ <3> The antenna described in any of the following.

[0053] <5> The position of the shielding ground conductor closest to the first radiating conductor or the second radiating conductor and the first open end or the second open end The first distance D1 is longer than the second distance D2 between the first open end or the second open end and the first power supply point or the second power supply point. <1> ~ <4> The antenna described in any of the following.

[0054] <6> The first straight line is defined as a straight line drawn from the first power supply point so as to be perpendicular to the first region closest to the second radiating conductor within the first radiating conductor. If we define the second straight line as the straight line drawn from the second power supply point so as to be perpendicular to the second region closest to the first radiating conductor within the second radiating conductor, The aforementioned power supply line does not intersect the first straight line and the second straight line. <1> ~ <5> The antenna described in any of the following.

[0055] <7> The planar ground conductor has a plurality of interlayer connecting conductors that connect the end ground conductor and the shielding ground conductor, When the distance between the first open end and the first power supply point is A1, and the distance between the second open end and the second power supply point is A2, The distance P1 of each of the aforementioned multiple interlayer connecting conductors is no more than twice the shorter of the two distances A1 or A2. <1> ~ <6> The antenna described in any of the following.

[0056] <8> <1> ~ <7> An antenna as described in any of the following, A flexible circuit board connected to the aforementioned antenna, An antenna device equipped with the following features. [Explanation of Symbols]

[0057] 1: Antenna 1A: Antenna 1B: Antenna 1C: Antenna 1D: Antenna 1E: Antenna 5: Flexible circuit board 10: Base 11A: First radiating conductor 11B: Second radiating conductor 12: Planar ground conductor 13: Shielding ground conductor 14: End ground conductor 15: Power supply line 17: Interlayer connecting conductor 19: Interlayer connecting conductor 111A: 1st open end 111B: 2nd open end 112A: First short-circuit terminal 112B: Second short-circuit terminal 151A: First power supply point 151B: Second power supply point 155: Power supply conductor A1: Distance A2 :Distance D1: First distance D2: 2nd distance L1: 1st straight line L2: 2nd straight line P1 :Distance

Claims

1. A first radiating conductor having a first open end and a first feed point, A second radiating conductor having a second open end and a second power supply point, wherein the second open end is positioned opposite the first open end, Viewed from above, a planar ground conductor overlapping the first radiating conductor and the second radiating conductor, Viewed from above, a shielding ground conductor is positioned between the first open end and the second open end, Viewed from above, the end ground conductor connected to the first radiating conductor and the second radiating conductor, A power supply line that supplies power to the first power supply point and the second power supply point with a predetermined phase difference, An antenna.

2. A first radiating conductor having a first open end and a first feed point, A second radiating conductor having a second open end and a second power supply point, wherein the second open end is positioned opposite the first open end, Viewed from above, a planar ground conductor overlapping the first radiating conductor and the second radiating conductor, Viewed from above, a shielding ground conductor is positioned between the first open end and the second open end, Viewed from above, the end ground conductor connected to the first radiating conductor and the second radiating conductor, A power supply line that supplies power to the first power supply point and the second power supply point, Equipped with, In the aforementioned power supply line, the length from the point where power is input to the power supply line to the first power supply point is different from the length from that point to the second power supply point. antenna.

3. The aforementioned power supply line supplies power to the first power supply point and the second power supply point in opposite phases. The antenna according to 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 a wavelength of the radio waves being supplied. The antenna according to claim 2.

5. The end ground conductor is configured to surround the first radiating conductor, the second radiating conductor, and the shielding ground conductor when the antenna is viewed in plan. The antenna according to any one of claims 1 to 4.

6. The direction in which the first radiating conductor, the shielding ground conductor, and the second radiating conductor are aligned is defined as the X direction, and the direction perpendicular to the X direction in a plan view is defined as the Y direction. The length of the shielding ground conductor in the Y direction is equal to or greater than the length of the longest point in the Y direction among the first radiating conductor or the second radiating conductor. The antenna according to any one of claims 1 to 4.

7. The first distance D1 between the position of the shielding ground conductor closest to the first radiating conductor or the second radiating conductor and the first open end or the second open end is longer than the second distance D2 between the first open end or the second open end and the first feed point or the second feed point. The antenna according to any one of claims 1 to 4.

8. The first straight line is defined as a straight line drawn from the first power supply point so as to be perpendicular to the first region closest to the second radiating conductor within the first radiating conductor. If the second straight line is defined as the straight line drawn from the second power supply point so as to be perpendicular to the second region closest to the first radiating conductor within the second radiating conductor, The aforementioned power supply line does not intersect the first straight line and the second straight line. The antenna according to any one of claims 1 to 4.

9. The planar ground conductor has a plurality of interlayer connecting conductors that connect the end ground conductor and the shielding ground conductor, When the distance between the first open end and the first power supply point is A1, and the distance between the second open end and the second power supply point is A2, The distance P1 of each of the aforementioned multiple interlayer connecting conductors is no more than twice the shorter of the distances A1 or A2. The antenna according to any one of claims 1 to 4.

10. An antenna according to any one of claims 1 to 4, A flexible circuit board connected to the aforementioned antenna, An antenna device equipped with the following features.

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