Antenna suitable to be integrated in a printed circuit board, printed circuit board provided with such an antenna

Abstract

Antenna suitable to be integrated in a printed circuit board, which is an electromagnetically coupled antenna that comprises: a body of dielectric material of a substantially planar design having a bottom side and top side; a bottom metallized layer on the bottom side of the body, which layer is provided with a slot; a top metallized layer on the top side of the body, which layer is provided with a T-shaped slot; wherein both the above slots, as well as the top and bottom metallized layer surrounding the slots, are provided on symmetrically opposite sides of the body; wherein electrically conductive strands are provided in the body, which strands extend substantially vertically from the bottom side to the top side, and electrically connect the bottom metallized layer with the top metallized layer; wherein the strands are disposed in such a way as to collectively form a row that delimits an inner volume of the body; wherein a feeding line of electrically conductive material is provided inside the body, the feeding line extending in a plane between the bottom side and the top side, wherein the feeding line has a distal section extending within the inner volume of the body delimited by the strands, which distal section has a curled shape in the plane in which it extends.

Claims

1. Antenna suitable to be integrated in a printed circuit board, which is an electromagnetically coupled antenna that comprises: a body of dielectric material of a substantially planar design having a bottom side and top side; a bottom metallized layer on the bottom side of the body, which layer is provided with a slot; a top metallized layer on the top side of the body, which layer is provided with a T-shaped slot; wherein both the above slots, as well as the top and bottom metallized layer surrounding the slots, are provided on symmetrically opposite sides of the body; wherein electrically conductive strands are provided in the body, which strands extend substantially vertically from the bottom side to the top side, and electrically connect the bottom metallized layer with the top metallized layer; wherein the strands are disposed in such a way as to collectively form a row that delimits an inner volume of the body; wherein a feeding line of electrically conductive material is provided inside the body, the feeding line extending in a plane between the bottom side and the top side, wherein the feeding line has a distal section extending within the inner volume of the body delimited by the strands, which distal section has a curled shape in the plane in which it extends.

2. Antenna according to claim 1, further provided with an additional body of dielectric material which covers the T-shaped slot in the top metallized layer.

3. Antenna according to claim 1 wherein the contour of the T-shaped slot in the top metallized layer is composed of two longitudinal slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot.

4. Antenna according to claim 1, wherein the distance between adjacent strands in a row is in the range of 1 up to 2 times the thickness of a single strand.

5. Antenna according to claim 1 which is suitable to be used in the frequency range between 4.9 and 6 GHz.

6. Antenna according to claim 5, wherein the bottom metallized layer is provided with a slot having a rectangular, preferably square shape.

7. Antenna according to claim 5, wherein the curled shape is an L-shape, so that the final part of the distal section of the feeding line is oriented substantially orthogonal to a proximal section of the feeding line.

8. Antenna according to claim 7, wherein the L-shape is of a rectangular design, which comprises two longitudinal sections having an orthogonal orientation.

9. Antenna according to claim 8, wherein the first longitudinal section comprises a proximal section of the feeding line, and the second longitudinal section comprises the end part of the distal section of the feeding line, wherein the length of the first longitudinal section (L1) is in the range of 2 to 4 times the length of the second longitudinal section (L2).

10. Antenna according to claim 5 wherein the T-shaped slot comprises a first, horizontally oriented slot having a cross-directional width halfway its length, denoted as Hw, in a range of 0.60 up to 0.90 mm.

11. Antenna according to claim 5 wherein the T-shaped slot comprises a second, vertically oriented slot having a cross-directional width halfway its length, denoted as Vw, in a range of 3.00 mm up to 4.00 mm.

12. Antenna according to claim 5, wherein the contour of the T-shaped slot in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot, wherein the contours of the first and second slot are each defined by the following formula: $r_{i} (φ) = {({.Math. \frac{1}{a_{i}} \cos \frac{m_{i}}{4} φ .Math.}^{n_{2_i}} + {.Math. \frac{1}{b_{i}} \sin \frac{m_{i}}{4} φ .Math.}^{n_{3_i}})}^{- 1 / n_{1_i}}$ wherein: the letter i is an indicator for the formula defining either a first slot (i=1) or a second slot (i=2), n1=n2 ρd(φ) is a curve located in the XY-plane, φ∈[0,2π) is the angular coordinate ai and bi are scaling factors determining the size of the shape.

13. Antenna according to claim 12, wherein the following parameters are applied: for i=1 m1=6 n1_1=38 n2_1=19 for i=2 m2=6 n1_2=24 n2_2=47.5 with L2=3.15 mm Hw=0.84 Vw=3.38 ai=1 bi=1.

14. Antenna according to claim 12, wherein the following parameters are applied: for i=1 m1=6 n1_1=38 n2_1=79 for i=2 m2=6 n1_2=24 n2_2=47.5 with L2=3.15 mm Hw=0.84 Vw=3.38 ai=1 bi=1.

15. Antenna according to claim 1 which is suitable to be used in the frequency range between 2.4 and 2.5 GHz.

16. Antenna according to claim 15, wherein the bottom metallized layer is provided with a T-shaped slot, which preferably is identical to the slot in the top metallized layer.

17. Antenna according to claim 15, wherein the curled shape of the feeding line is a G-shape, preferably a rectangular G-shape which comprises four or five longitudinal sections of which consecutive sections have an orthogonal orientation.

18. Antenna according to claim 15, wherein the feeding line comprises four or five longitudinal sections of which consecutive sections have an orthogonal orientation, wherein the first longitudinal section comprises a proximal section of the feeding line, and the fourth or fifth longitudinal section constitutes the end part of the distal section of the feeding line, wherein the length of the first longitudinal section (L1) is in the range of 2 to 4 times the length of the second longitudinal section (L2).

19. Antenna according to claim 15 wherein the feeding line has a width in the range of 0.25 to 2.0 mm.

20. Antenna according to claim 15, wherein the T-shaped slot comprises a first, horizontally oriented slot having a cross-directional width halfway its length, denoted as Hw, in a range of 1.20 to 1.40 mm.

21. Antenna according to claim 15, wherein the T-shaped slot comprises a second, vertically oriented slot having a cross-directional width halfway its length, denoted as Vw, in a range of 2.5-3.0 mm.

22. Antenna according to claim 1, wherein the contour of the T-shaped slot in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot, wherein the contours of the first and second slot are each defined by the following formula: $r_{i} (φ) = {({.Math. \frac{1}{a_{i}} \cos \frac{m_{i}}{4} φ .Math.}^{n_{2_i}} + {.Math. \frac{1}{b_{i}} \sin \frac{m_{i}}{4} φ .Math.}^{n_{3_i}})}^{- 1 / n_{1_i}}$ wherein: the letter i is an indicator for the formula defining either a first slot (i=1) or a second slot (i=2), ρd(φ) is a curve located in the XY-plane, φ∈[0,2π) is the angular coordinate, ai and bi are scaling factors determining the size of the shape.

23. Antenna according to claim 22, wherein the following parameters are applied: for i=1 a1=0.5 b1=4.1 m1=4 n1_1=103 n2_1=33 n3_1=59 for i=2 a2 7.3 b2 3.7 m2=4 n1_2=33 n2_2=48 n3_2=49 with Hw=1.23 Vw=2.76.

24. Antenna according to claim 22, wherein the following parameters are applied: for i=1 a1=7.6 b1=3.8 m1=4 n1_1=89.8 n2_1=87 n3_1=88 for i=2 a2=7.7 b2=7.8 m2=4 n1_2=81.9 n2_2=82 n3_2=91 with Hw=1.38 Vw=2.76.

25. A printed circuit board which is provided with an antenna according to claim 1, wherein a part of the board, and preferably a part of the circumferential edge of the board, constitutes the body of dielectric material of the antenna.

Description

(1) The invention will be further elucidated by the appended figures in which:

(2) FIG. 1 shows an exploded view of constituting parts of a first preferred type of an antenna according to the invention;

(3) FIG. 2 shows an exploded view of constituting parts of a second preferred type of an antenna according to the invention;

(4) FIG. 3 shows schematically a cross-sectional view of the antenna, which is applicable to both preferred types of the antenna;

(5) FIG. 4 shows a transparent top view of the first preferred type;

(6) FIGS. 5 and 6 show two preferred T-shaped slots applicable to the first preferred type.

(7) FIG. 7 shows how a preferred T-shaped slot is composed from two combined longitudinal slots.

(8) FIG. 8 shows a transparent top view of the second preferred type;

(9) FIGS. 9, 10 and 11 show three preferred T-shaped slots applicable to the second preferred type;

(10) FIG. 12 shows how a preferred T-shaped slot is composed from two combined longitudinal slots.

(11) FIG. 13 shows a perspective view of a PCB board provided with an antenna according to the invention.

(12) FIG. 1 shows the following elements of a first preferred type of the antenna: An additional body in the form of a thin block or dielectric chip 1, a T-shaped slot 3 to be provided on the top metallized layer, strands of electro conductive material 5 that are positioned in rows that delimit an internal space, and a feeding line 7A of an L-shape of which the distal section extends within the internal space. Further, a rectangular slot 9 to be provided on the bottom metallized layer is shown.

(13) This first preferred type of the antenna, is suitable to be used in the frequency range between 4.9 and 6.0 GHz, and may be referred to as 5G antenna.

(14) FIG. 2 shows a second preferred type of the antenna, having similar elements as described for the first preferred type, which elements are indicated by the same numerals.

(15) The second preferred type differs from the first, in that a slot to be provided on the bottom metallized layer is not shown, but is actually identical to the T-shaped slot 3. Further, the strands are positioned in a more intricate pattern, and the feeding line 7B is of a G-shape. The chosen dimensions of the second type antenna are also different over the first type.

(16) This second preferred type of the antenna, is suitable to be used in the frequency range between 2.4 and 2.5 GHz, and may be referred to as 2G antenna.

(17) FIG. 3 shows in cross-section the general constitution that applies to both preferred types of the antenna, with a body 34 of dielectric material of a substantially planar design having a bottom side and top side; a bottom metallized layer 32 on the bottom side of the body, which layer is provided with a slot; a top metallized layer 31 on the top side of the body, which layer is provided with a T-shaped slot; wherein both the above slots, as well as the top and bottom metallized layer surrounding the slots, are provided on symmetrically opposite sides of the body; a feeding line 7A, 7B of electrically conductive material provided inside the body, the feeding line extending in a plane between the bottom side and the top side.

(18) The whole assembly 36 constitutes an antenna according to the invention, which is complemented with an additional body 1 on the top side to further enhance the antenna characteristics.

(19) In FIG. 3 the electrically conductive strands have been omitted to simplify the overview.

(20) FIG. 4 shows a transparent top view of an antenna 36A of the first type, with a special modified T-shaped slot 3 on the top side metallized layer, and of a rectangular slot 9 on the bottom side metallized layer. The contours of both slots are indicated by 3c resp. 9c. The strands 5 are disposed in rows, delimiting an inner volume of the body 34 in which the feeding line 7A extends with its distal section that comprises the distal part of first longitudinal section s1A (depicted as the left side) and the second longitudinal section s2A. The proximal section of 7A (right side) is connectable to a not shown radio element (RF chain).

(21) FIG. 5 shows a preferred T-shaped slot 3 delimited by a contour 3c and provided on the top metallized layer 31. This slot is suitable for the first preferred type, and is referred to as having an optimal impedance matching (OIM) configuration.

(22) The contour of the T-shaped slot 3 in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot, wherein the contours of the first and second slot are each defined by the superformula according to appended claim 12 with the parameters of appended claim 13.

(23) FIG. 6 shows an alternative, preferred T-shaped slot 3 delimited by a contour 3c and provided on the top metallized layer 31. Such a type of slot is referred to as having an ultra-wideband (UWB) configuration.

(24) The contour of the T-shaped slot 3 in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot, wherein the contours of the first and second slot are each defined by the superformula according to appended claim 12 with the parameters of appended claim 14.

(25) FIG. 7 shows how the preferred T-shaped slot depicted in FIG. 6, is composed from two combined longitudinal slots 70 and 72, of which the first is horizontally oriented, and the second is vertically oriented. The vertical slot 72 is a truncated form of a complete longitudinal slot as defined by the formula and shown in the picture, and the lower half 78 (indicated by hatched lines) is not used. Arrows 74 indicate the first slot 70 having a cross-directional width halfway its length, denoted as Hw. Arrows 76 indicate the second slot 72 having a cross-directional width halfway its length (i.e. halfway the complete length without truncation), denoted as Vw.

(26) FIG. 8 shows a transparent top view of an antenna 36B of the second type, with a special T-shaped slot 3 on the top side metallized layer, of which the contour is indicated by 3c. The strands are omitted from this view, but their position correspond to FIG. 2. The feeding line 7B has a distal section (left side of picture) that curls into a G-shape, consisting of five consecutive longitudinal sections s1B, s2B, s3B, s4B and 25B, of which consecutive sections have an orthogonal orientation. The proximal section of 7B (right side) is connectable to a not shown radio element (RF chain).

(27) FIG. 9 shows a preferred T-shaped slot 3 delimited by a contour 3c and provided on the top metallized layer 31. This slot is suitable for the second preferred type, and is referred to as having an optimal impedance matching (OIM) configuration.

(28) The contour of the T-shaped slot 3 in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot,

(29) wherein the contours of the first and second slot are each defined by the superformula according to appended claim 22 with the parameters of appended claim 23.

(30) FIG. 10 shows an alternative, preferred T-shaped slot 3 delimited by a contour 3c and provided on the top metallized layer 31. Such a type of slot is referred to as having a broad-band (BB) configuration.

(31) The contour of the T-shaped slot 3 in the top metallized layer is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot,

(32) wherein the contours of the first and second slot are each defined by the superformula according to appended claim 22 with the parameters of appended claim 24.

(33) FIG. 11 shows another alternative T-shaped slot 3 delimited by a contour 3c and provided on the top metallized layer 31.

(34) The contour of the T-shaped slot 3 in the top metallized layer has the form of a classical capital T, and is composed of two slots of which a first slot forms a horizontally oriented slot of which the middle part is connected to the top end of a second slot which forms a vertically oriented slot,

(35) wherein the contours of the first and second slot are each defined by the superformula according to claim 22,

(36) and by the additional conditions: m1=m2=4 n1_i, n2_i, n3_i.fwdarw.∞

(37) FIG. 12 shows how the preferred T-shaped slot depicted in FIG. 9, is composed from two combined longitudinal slots 120 and 122, of which the first is horizontally oriented, and the second is vertically oriented. The vertical slot 122 is a truncated form of a complete longitudinal slot as defined by the formula and shown in the picture, and the upper half 124 is not used. The first slot 120 has a cross-directional width halfway its length, denoted as Hw. The second slot 122 has a cross-directional width halfway its length (i.e. halfway the complete length without truncation), denoted as Vw.

(38) FIG. 13 shows a perspective view of a PCB board 130 provided at its circumferential side, with an antenna 36 according to the invention. Most of the antenna is not visible as it is fully covered by the block 36 which is provided on the top side of the antenna.

EXAMPLES

(39) Radiation properties of several antennas within the realm of the invention were measured. The antennas measured cover both the first and second types, with various T-shaped slots on the metallized layer.

(40) Group 1; “5G Antenna”

(41) Of the first preferred type of the antenna of the general design given in FIG. 1, which is suitable to be used in the frequency range between 4.9 and 6.0 GHz, three variants were composed, which are also referred to as 5G antennas.

(42) Type 5G.1 “optimal impedance matching configuration”

(43) The general design of FIG. 1 was used, provided with the preferred T-shaped slot according to FIG. 5.

(44) Type 5G.2 “ultra wide band configuration”

(45) The general design of FIG. 1 was used, provided with the preferred T-shaped slot according to FIG. 6.

(46) Type 5G.3 “classical T-shape”

(47) The general design of FIG. 1 was used, provided with a classical T-shaped slot analogous to the one shown in FIG. 11.

(48) The table below shows the radiation properties for the three 5G antenna types.

(49) TABLE-US-00001 Property 5G.1 5G.2 5G.3 Bandwidth (GHz) 2.09 2.52 1.67 Fractional BW (%) 37.5 47.4 30 Input reflection coefficient 0.1163 0.169 0.1863 Peak realized gain (dBi) @5.5 GHz 3.4 3.3 3.3 Total efficiency @5.5 GHz 90.5 88.8 88.5 Average gain (dBi) @5.5 GHz −0.4 −0.5 −0.5 Peak directivity (dBi) @5.5 GHz 3.8 3.7 3.8 OF value (FBW/IRC) 322 280 161

(50) All the above three 5G antenna types have attractive properties in terms of their radiation properties, and OF value (the ratio of FBW divided by IRC).

(51) Within this group of 5G antennas, the supershaped T-shaped slots of the 5G.1 and 5G.2 configurations are most attractive in terms of OF value.

(52) Group 2, “2G antenna”

(53) Of the second preferred type of the antenna of the general design given in FIG. 2, which is suitable to be used in the frequency range between 2.4 and 2.5 GHz (“2G antennas”), three variants were composed.

(54) Type 2G.1 “optimal impedance matching configuration”

(55) The general design of FIG. 2 was used, provided with the preferred T-shaped slot according to FIG. 9.

(56) Type 2G.2 “broadband configuration”

(57) The general design of FIG. 2 was used, provided with the preferred T-shaped slot according to FIG. 10.

(58) Type 2G.3 “classical T-shape”

(59) The general design of FIG. 2 was used, provided with a classical T-shaped slot according to FIG. 11.

(60) The table below shows the radiation properties for the three 2G antenna types.

(61) TABLE-US-00002 Property 2G.1 2G.2 2G.3 Bandwidth (GHz) 0.207 0.24 0.202 Fractional BW (%) 8.5 9.8 8.3 Input reflection coefficient 0.0175 0.03 0.0192 Peak realized gain (dBi) @2.45 GHz 2.1 2.1 2.1 Total efficiency @2.45 GHz 88 86 85 Average gain (dBi) @2.45 GHz −0.7 −0.7 −0.7 Peak directivity (dBi) @2.45 GHz 2.7 2.7 2.72 OF value (FBW/IRC) 486 326 432

(62) All the above three 2G antenna types have attractive properties in terms of their radiation properties, and OF value (the ratio of FBW divided by IRC).

(63) Within this group of 2G antennas, the supershaped T-shaped slot of the 2G.1 configuration is most attractive in terms of OF value.

Antenna suitable to be integrated in a printed circuit board, printed circuit board provided with such an antenna

Assignee

Inventors

Cpc classification

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H01Q13/106

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H01Q13/16

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H01Q13/10

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H01Q13/18

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H01Q5/357

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H01Q13/085

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H01Q13/10

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H01Q5/10

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H01Q13/18

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H01Q13/08

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H01Q13/16

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H01Q5/357

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Abstract

Claims

Description