JP6591906B2 - Antenna board - Google Patents

Description

  The present invention relates to an antenna substrate formed by laminating a dielectric layer and a conductor layer in multiple layers.

  Conventionally, an antenna substrate includes, for example, a dielectric substrate 11 in which a large number of dielectric layers 11a to 11e are stacked, and a grounding conductor for shielding, as shown in a cross-sectional view and a top view in FIGS. 6 (a) and 6 (b). The layer 12 includes a strip conductor 13 for inputting and outputting a high-frequency signal, and a patch conductor 14 for transmitting and receiving electromagnetic waves.

  The dielectric substrate 11 is formed, for example, by laminating five dielectric layers 11a to 11e vertically. The dielectric layers 11a to 11e are formed of, for example, a resin layer containing glass cloth or a resin layer not containing glass cloth.

  The ground conductor 12 is deposited on the entire lower surface of the lowermost dielectric layer 11a. The ground conductor 12 is made of, for example, copper.

  The strip conductor 13 faces the ground conductor 12 with the dielectric layer 11a interposed therebetween, and is disposed between the dielectric layers 11a and 11b. The strip conductor 13 is a thin strip-shaped conductor extending in one direction from the outer peripheral edge to the central portion of the inside of the dielectric substrate 11, and has a termination portion 13 a at the central portion of the dielectric substrate 11. The strip conductor 13 is made of, for example, copper.

  The patch conductor 14 includes a first patch conductor 14a, a second patch conductor 14b, and a third patch conductor 14c. These patch conductors 14a to 14c are rectangular. The patch conductors 14a to 14c are made of copper, for example.

  The first patch conductor 14 a is disposed between the dielectric layers 11 c and 11 d so as to cover the position of the terminal end portion 13 a of the strip conductor 13. The first patch conductor 14a is connected to the end portion 13a of the strip conductor 13 through a through conductor 15 that penetrates the dielectric layer 11c and a through conductor 16 that penetrates the dielectric layer 11b.

  The second patch conductor 14b is disposed between the dielectric layers 11d and 11e so as to cover the position where the first patch conductor 14a is formed. The second patch conductor 14b is electrically independent from the direct current.

  The third patch conductor 14c is disposed on the upper surface of the dielectric layer 11e so as to cover the position where the second patch conductor 14b is formed. The third patch conductor 14c is electrically independent in terms of direct current.

  In this antenna substrate, when a high-frequency signal is fed to the strip conductor 13, the signal is transmitted to the first patch conductor 14a via the through conductors 15 and 16, which are the first patch conductor 14a and the second patch conductor. 14b and the third patch conductor 14c are radiated to the outside as electromagnetic waves. By the way, such an antenna substrate includes the second patch conductor 14b and the third patch conductor 14c which are electrically independent in addition to the first patch conductor 14a. This is because the frequency band can be widened.

  However, for example, in a wireless personal area network, the frequency band to be used is different in each country, and it is necessary to cover a wide frequency band of 57 to 66 GHz so that one antenna substrate can be used all over the world. For this purpose, it is necessary to provide an antenna substrate having a wider frequency band than the conventional antenna substrate.

Therefore, the applicant of the present application has proposed another form of antenna substrate in order to solve the above problem in Japanese Patent Application No. 2014-174923 (Japanese Patent Laid-Open No. 2015-92653).
Such an antenna substrate will be described with reference to FIGS.

  For example, as shown in FIGS. 7A and 7B in a cross-sectional view and a top view, the antenna substrate of another form includes a dielectric substrate 21 in which a large number of dielectric layers 21a to 21e are stacked, and a shielding substrate. A ground conductor layer 22, a strip conductor 23 for inputting / outputting a high frequency signal, a patch conductor 24 for transmitting / receiving electromagnetic waves, and an auxiliary patch conductor 27 are provided.

  The dielectric substrate 21 is formed by, for example, laminating five dielectric layers 21a to 21e on the top and bottom. The dielectric layers 21a to 21e are formed of, for example, a resin layer containing glass cloth or a resin layer not containing glass cloth.

  The ground conductor 22 is deposited on the entire lower surface of the lowermost dielectric layer 21a. The ground conductor 22 is made of, for example, copper.

  The strip conductor 23 faces the ground conductor 22 with the dielectric layer 21a interposed therebetween, and is disposed between the dielectric layers 21a and 21b. The strip conductor 23 is a thin strip-shaped conductor extending in one direction (hereinafter referred to as a first direction) from the outer peripheral edge to the central portion of the inside of the dielectric substrate 21, and has a termination portion at the central portion of the dielectric substrate 21. 23a. The strip conductor 23 is made of, for example, copper.

  The patch conductor 24 includes a first patch conductor 24a, a second patch conductor 24b, and a third patch conductor 24c. These patch conductors 24a to 24c are rectangular. The patch conductors 24a to 24c are made of copper, for example.

  The first patch conductor 24a is disposed between the dielectric layers 21c and 21d so as to cover the position of the end portion 23a of the strip conductor 23. The first patch conductor 24a is connected to the end portion 23a of the strip conductor 23 via a through conductor 25 that penetrates the dielectric layer 21c and a through conductor 26 that penetrates the dielectric layer 21b.

The second patch conductor 24b is disposed between the dielectric layers 21d and 21e so that at least a portion thereof covers the position of the first patch conductor 24a. Furthermore, the second patch conductor 24b is arranged eccentrically in the first direction with respect to the first patch conductor 24a.
The second patch conductor 24b is electrically independent from the direct current.

The third patch conductor 24c is arranged on the upper surface of the dielectric layer 21e so that at least a part thereof covers the position of the second patch conductor 24b. Furthermore, the third patch conductor 24c is arranged eccentrically with respect to the second patch conductor 24b in the first direction.
The third patch conductor 24c is electrically independent in terms of direct current.

  The auxiliary patch conductor 27 is a position where the first patch conductor 24a and the second patch conductor 24b are formed on the upper surface of the dielectric layer 21e on both sides of the third patch conductor 24c in the direction orthogonal to the first direction. It is formed so as not to be covered.

As described above, the second patch conductor 24b is eccentrically disposed in the first direction with respect to the first patch conductor 24a, and the third patch conductor 24c is disposed with respect to the second patch conductor 24b. For example, when electromagnetic waves corresponding to high-frequency signals are radiated via the patch conductors 24a to 24c, the upper patch conductors 24b and 24c are arranged from the lower patch conductor 24a. Electromagnetic waves are radiated so as to spread sequentially along the outer peripheral edge, and complex resonance occurs due to eccentricity.
Further, further complex resonance occurs and is radiated between the third patch conductor 24 c and the auxiliary patch conductor 27 and through the end of the auxiliary patch conductor 27.
Thereby, the frequency band of the high frequency signal radiated | emitted via the 1st-3rd patch conductors 24a-24c and the auxiliary patch conductor 27 can be made still wider.

  However, although the frequency band of the high-frequency signal can be widened, the direction in which the electromagnetic wave corresponding to the high-frequency signal can be radiated is limited to the upper side from the third patch conductor 24c, and the radiation direction of the electromagnetic wave is small. There is a problem of lack of convenience.

JP-A-5-145327

  An object of the present invention is to provide a wide-band antenna substrate that is rich in direction of signal transmission and reception in, for example, a wide frequency band of 57 to 66 GHz.

  The antenna substrate of the present invention is arranged to have a first dielectric layer and a termination portion on the upper surface of the first dielectric layer, and extends in a first direction toward the termination portion. A strip conductor, a grounding conductor layer for shielding disposed on the lower surface side of the first dielectric layer, a second dielectric layer laminated on the upper surface side of the first dielectric layer and the strip conductor, A first patch conductor disposed on the upper surface of the second dielectric layer so as to cover the position of the terminal portion; and a through hole penetrating the second dielectric layer and connecting the terminal portion and the first patch conductor. A conductor, a third dielectric layer laminated on the second dielectric layer and the first patch conductor, and at least at a position where the first patch conductor is formed on the upper surface of the third dielectric layer. A part of the first patch conductor is arranged so as to cover the first patch conductor and is eccentric in the first direction. And the second patch conductor independent of DC, and in the first direction side region from the first and second patch conductors, the first, second and second Two rows are formed so that the upper and lower ground conductor layers facing each other with at least one of the three dielectric layers sandwiched from above and below and the dielectric layer between the upper and lower ground conductor layers are sandwiched from the left and right along the first direction. And a plurality of ground penetrating conductors arranged through the dielectric layer between the upper and lower ground conductor layers.

According to the antenna substrate of the present invention, at least one of the first, second, and third dielectric layers is sandwiched from above and below in a region on the first direction side from the first and second patch conductors. Many opposing vertical ground conductor layers and dielectric layers between the upper and lower ground conductor layers are arranged through the dielectric layers between the upper and lower ground conductor layers in two rows so as to be sandwiched from the left and right along the first direction. And a ground through-conductor.
For this reason, a part of the electromagnetic wave corresponding to the high frequency signal radiated from the second patch conductor is radiated in the first direction through the waveguide.
As a result, it is possible to transmit and receive signals in the first direction in addition to the upward direction with respect to the second patch conductor. For example, a wideband antenna rich in signal transmission and reception directions in a wide frequency band of 57 to 66 GHz. A substrate can be provided.

FIGS. 1A to 1C are a cross-sectional view and a top view showing a first embodiment of an antenna substrate of the present invention. FIGS. 2A to 2C are a cross-sectional view and a top view showing a second embodiment of the antenna substrate of the present invention. 3A to 3C are a sectional view and a top view showing a third embodiment of the antenna substrate of the present invention. 4A to 4C are a cross-sectional view and a top view showing a fourth embodiment of the antenna substrate of the present invention. 5A and 5B are a sectional view and a top view showing a fifth embodiment of the antenna substrate of the present invention. 6A and 6B are a sectional view and a top view showing a conventional antenna substrate. 7A and 7B are a cross-sectional view and a top view showing another form of the conventional antenna substrate.

Next, an embodiment of the antenna substrate of the present invention will be described with reference to the accompanying drawings. 1A is a cross section passing through the line XX in FIG. 1C, and FIG. 1B is a cross section passing through the line YY in FIG. 1C.
The antenna substrate of this example includes a dielectric substrate 1 on which a large number of dielectric layers 1a to 1e are laminated, and a grounding conductor for shielding, as shown in cross-sectional and top views in FIGS. A layer 2, a strip conductor 3 for inputting and outputting a high-frequency signal, a patch conductor 4 for transmitting and receiving electromagnetic waves, an auxiliary patch conductor 7, and a waveguide D are provided.

  The dielectric layers 1a to 1e are made of, for example, a resin-based dielectric material in which a glass cloth is impregnated with a thermosetting resin such as an epoxy resin, a bismaleimide triazine resin, or an acrylic-modified polyphenylene ether resin. Each of the dielectric layers 1a to 1e has a thickness of about 30 to 100 μm. The relative permittivity of the dielectric layers 1a to 1e is about 3 to 5.

  The ground conductor 2 is deposited on the entire lower surface of the lowermost dielectric layer 1a. The ground conductor 2 functions as a shield. The thickness of the ground conductor 2 is about 5 to 20 μm. The ground conductor 2 is made of, for example, copper.

  The strip conductor 3 faces the ground conductor 2 with the dielectric layer 1a interposed therebetween, and is disposed between the dielectric layers 1a and 1b. The strip conductor 3 is a thin strip-shaped conductor having a termination portion 3a at the center of the dielectric substrate 1, and the inside of the dielectric substrate 1 faces in one direction (hereinafter referred to as a first direction) toward the termination portion 3a. It extends to. The strip conductor 3 functions as a transmission path for inputting and outputting a high-frequency signal in the antenna substrate of this example, and the high-frequency signal is transmitted to the strip conductor 3. The width of the strip conductor 3 is about 50 to 350 μm. The thickness of the strip conductor 3 is about 5 to 20 μm. The strip conductor 3 is made of, for example, copper.

  The patch conductor 4 includes a first patch conductor 4a, a second patch conductor 4b, and a third patch conductor 4c. These patch conductors 4a to 4c are electrically independent from each other in terms of direct current. The patch conductors 4a to 4c have sides parallel to the first direction in which the strip conductor 3 extends (hereinafter referred to as vertical sides) and sides parallel to the direction perpendicular to the first direction (hereinafter referred to as horizontal sides). A square having a side). The length of each side of the patch conductors 4a to 4c is about 0.5 to 5 mm. Each of the patch conductors 4a to 4c has a thickness of about 5 to 20 μm. Each of the patch conductors 4a to 4c is made of copper, for example.

  The first patch conductor 4a is disposed between the dielectric layers 1c and 1d so as to cover the position of the end portion 3a of the strip conductor 3. Therefore, two dielectric layers 1b and 1c are interposed between the first patch conductor 4a and the strip conductor 3. The first patch conductor 4a is connected to the end portion 3a of the strip conductor 3 through a through conductor 5 that penetrates the dielectric layer 1c and a through conductor 6 that penetrates the dielectric layer 1b. The through conductor 5 has a cylindrical shape with a diameter of about 50 to 200 μm and a thickness of about 5 to 20 μm. The through conductor 6 has a columnar shape or a truncated cone shape with a diameter of about 30 to 100 μm. The through conductors 5 and 6 are made of copper, for example. The first patch conductor 4a receives the high frequency signal from the strip conductor 3 and radiates electromagnetic waves to the outside. Alternatively, a high frequency signal is generated in the strip conductor 3 by receiving an electromagnetic wave from the outside.

The second patch conductor 4b is disposed between the dielectric layers 1d and 1e so that at least a part thereof covers the position of the first patch conductor 4a. As a result, the second patch conductor 4b is capacitively coupled to the first patch conductor 4a with the dielectric layer 1d interposed therebetween.
Furthermore, the second patch conductor 4b is arranged eccentrically in the first direction with respect to the first patch conductor 4a. The eccentricity of the second patch conductor 4b is set to cover an area of 80% or more of the position where the first patch conductor 4a is formed.
The second patch conductor 4b receives the electromagnetic wave from the first patch conductor 4a and radiates the corresponding electromagnetic wave to the outside. Or the electromagnetic wave from the outside is received and the electromagnetic wave corresponding to it is supplied to the 1st patch conductor 4a. In addition, it is preferable that each side of the second patch conductor 4b is larger by about 0.05 to 0.5 mm than each side of the first patch conductor 4a.

The third patch conductor 4c is disposed on the upper surface of the uppermost dielectric layer 1e so that at least a part thereof covers the position of the second patch conductor 4b. As a result, the third patch conductor 4c is capacitively coupled to the second patch conductor 4b with the dielectric layer 1e interposed therebetween.
Further, the third patch conductor 4c is arranged eccentrically in the first direction with respect to the second patch conductor 4b. The eccentricity of the third patch conductor 4c is such that it covers an area of 80% or more of the position where the second patch conductor 4b is formed.
The third patch conductor 4c receives the electromagnetic wave from the second patch conductor 4b and radiates the corresponding electromagnetic wave to the outside. Alternatively, it receives an electromagnetic wave from the outside and supplies the corresponding electromagnetic wave to the second patch conductor 4b. In addition, it is preferable that each side of the third patch conductor 4c is larger by about 0.05 to 0.5 mm than each side of the second patch conductor 4b.

  The second patch conductor 4b is eccentric so as to cover an area of less than 80% of the position where the first patch conductor 4a is formed, or the third patch conductor 4c is the second patch conductor. When it is decentered so as to cover an area of less than 80% of the position where 4b is formed, the frequency band in the antenna substrate becomes narrow. Therefore, the second patch conductor 4b is preferably eccentric so as to cover an area of 80% or more of the position where the first patch conductor 4a is formed, and the third patch conductor 4c is the second patch conductor 4c. It is preferable to be eccentric so as to cover an area of 80% or more of the position where the conductor 4b is formed.

The auxiliary patch conductor 7 is a position where the first patch conductor 4a and the second patch conductor 4b are formed on the upper surface of the dielectric layer 1e on both sides of the third patch conductor 4c in the direction orthogonal to the first direction. It is formed so as not to be covered.
The auxiliary patch conductors 7 are electrically independent from each other in terms of direct current. The auxiliary patch conductor 7 includes a side parallel to a first direction (hereinafter referred to as a vertical side) in which the strip conductor 3 extends and a side parallel to a direction perpendicular to the first direction (hereinafter referred to as a horizontal side). And a quadrangle having The length of each side of the auxiliary patch conductor 7 is about 0.5 to 5 mm. Each of the auxiliary patch conductors 7 has a thickness of about 5 to 20 μm. The auxiliary patch conductors 7 are each made of copper, for example.
The auxiliary patch conductors 7 are arranged at positions spaced from the vertical sides of the third patch conductors 4c by about 0.1 to 1 mm, respectively.

As described above, the second patch conductor 4b is eccentrically disposed in the first direction with respect to the first patch conductor 4a, and the third patch conductor 4c is disposed with respect to the second patch conductor 4b. For example, when electromagnetic waves corresponding to a high-frequency signal are radiated through the patch conductors 4a to 4c, the upper patch conductors 4b and 4c are arranged from the lower patch conductor 4a. Electromagnetic waves are radiated so as to spread sequentially along the outer peripheral edge, and complex resonance occurs due to eccentricity.
Further, further complex resonance occurs and is radiated between the third patch conductor 4 c and the auxiliary patch conductor 7 and through the end of the auxiliary patch conductor 7.
Thereby, the frequency band of the high frequency signal radiated | emitted via the 1st-3rd patch conductors 4a-4c and the auxiliary patch conductor 7 can be made wide.

  The waveguide D is composed of an upper and lower ground conductor layer D1 and a ground penetrating conductor D2 formed in a region closer to the first direction than the patch conductor 4.

  The upper and lower ground conductor layers D1 include, for example, a ground conductor 2 formed on the lower surface of the lowermost dielectric layer 1a and a ground conductor 2a formed on the upper surface of the dielectric layer 1d. Each of the upper and lower ground conductor layers D1 has a thickness of about 5 to 20 μm. The upper and lower ground conductor layers D1 are made of copper, for example.

The grounding through conductor D2 is composed of a plurality of through conductors 5a to 5d that coaxially penetrate the dielectric layers 1a to 1d interposed between the upper and lower grounding conductor layers D1. The through conductor 5a is connected to the ground conductor 2, and the through conductor 5d is connected to the ground conductor 2a.
The grounding through conductor D2 is arranged in two rows so as to sandwich the dielectric layers 1a to 1d from the left and right along the first direction.
The through conductors 5a, 5b, and 5d have a columnar shape or a truncated cone shape with a diameter of about 30 to 100 μm. The through conductor 5c has a cylindrical shape with a diameter of about 50 to 200 μm. Each of the ground through conductors D2 is made of copper, for example.
In addition, it is preferable that the two rows of the ground through conductors D2 are formed on the outer peripheral side of the left and right auxiliary patch conductors 7 at least on the patch conductor 4 side. If two rows of ground through conductors D2 are formed inside the left and right auxiliary patch conductors 7 on the patch conductor 4 side, the electromagnetic waves propagated from the patch conductor 4 and the auxiliary patch conductor 7 to the waveguide D are weak. turn into.

As described above, according to the antenna substrate of the present invention, the upper and lower ground conductors facing each other with the dielectric layers 1a to 1d sandwiched from above and below in the region on the first direction side with respect to the patch conductor 4 and the auxiliary patch conductor 7. Dielectric layers 1a to 1d between the upper and lower ground conductor layers D1 in two rows so that the dielectric layers 1a to 1d between the layer D1 and the upper and lower ground conductor layers D1 are sandwiched from the left and right along the first direction. A waveguide D is formed which includes a large number of grounding through conductors D2 arranged so as to pass through.
For this reason, a part of the electromagnetic wave corresponding to the high-frequency signal radiated from the third patch conductor 4 c and the auxiliary patch conductor 7 is also radiated in the first direction via the waveguide D.
As a result, it is possible to transmit and receive signals in the first direction in addition to the third patch conductor 4 and the auxiliary patch conductor 7, for example, in the wide frequency band of 57 to 66 GHz. A wide-band antenna substrate rich in direction can be provided.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, up and down The ground conductor layer D1 is formed on the dielectric layer 1a and the dielectric layer 1d. For example, as shown in FIGS. 2A to 2C, the surfaces of the dielectric layer 1a, the dielectric layer 1c, and the dielectric layer 1d You may form in.
Further, for example, in the example of the above-described embodiment, the two rows of the ground through conductors D2 are arranged linearly along the first direction from the patch conductor 4 side to the outer peripheral side. For example, FIG. As shown to (a)-(c), you may make the space | interval of the row | line | columns of an outer peripheral side smaller than the space | interval of the row | line | columns by the side of a patch conductor.
Further, as shown in FIGS. 4A to 4C, the interval between the rows on the outer peripheral side may be larger than the interval between the rows on the patch conductor side.
Thus, by arranging and forming the upper and lower ground conductor layers D1 and the ground through conductors D2, it is possible to provide an antenna substrate that can efficiently transmit and receive signals according to the frequency of the high-frequency signal.

Further, for example, in the example of the embodiment described above, the first patch conductor 4a and the terminal end portion 3a of the strip conductor 3 are connected by a pair of through conductors 5 and 6 connected in series. As shown in FIG. 4, the two through conductors 5, 6 and 15, 16 may be connected to each other along the first direction. Thus, by arranging two sets of through conductors 5, 6 and 15, 16 so as to be adjacent to each other and providing a capacity between them, a complex resonance can be generated. As a result, the frequency band of the high-frequency signal can be further expanded.
In addition, it is preferable that an adjacent space | interval is 1/2 or less of the wavelength of the high frequency signal transmitted to the strip conductor 3. FIG. When the adjacent interval exceeds ½, sufficient capacity cannot be provided, so that complex resonance cannot be generated, and the effect of expanding the frequency band of the high-frequency signal is reduced.

1a to 1e Dielectric layer 2 Ground conductor 3 Strip conductor 3a End portion of strip conductor 4 Patch conductor 4a First patch conductor 4b Second patch conductor 4c Third patch conductor 5, 6 Through conductor D Waveguide D1 Up and down Ground conductor layer D2 Ground through conductor

Claims (5)

  A first dielectric layer, and a strip-shaped strip conductor disposed on the upper surface of the first dielectric layer so as to have a termination portion and extending in the first direction toward the termination portion; A grounding conductor layer for shielding disposed on the lower surface side of the first dielectric layer; a second dielectric layer laminated on the upper surface side of the first dielectric layer and the strip conductor; A first patch conductor disposed on the top surface of the second dielectric layer so as to cover the position of the termination portion, and the termination portion and the first patch conductor penetrating the second dielectric layer. The through conductor to be connected, the third dielectric layer laminated on the second dielectric layer and the first patch conductor, and the first patch conductor on the upper surface of the third dielectric layer The first patch conductor is disposed so that at least a part of the formed position is covered. An antenna substrate that is eccentrically disposed in the first direction and is DC-independently provided with a second patch conductor, the first direction side with respect to the first and second patch conductors. The upper and lower ground conductor layers facing each other with at least one of the first, second and third dielectric layers sandwiched from above and below, and the dielectric layer between the upper and lower ground conductor layers, And a plurality of grounding through conductors arranged in rows through the dielectric layer between the upper and lower grounding conductor layers so as to be sandwiched from right and left along the direction of A characteristic antenna substrate.   The antenna substrate according to claim 1, wherein the second patch conductor is disposed so as to cover an area of 80% or more of a position where the first patch conductor is formed.   The upper surface of the third dielectric layer is disposed so as not to cover the position where the first patch conductor is formed on both sides of the second patch conductor in the direction orthogonal to the first direction. The antenna substrate according to claim 1, further comprising an auxiliary patch conductor that is DC independent.   4. The device according to claim 1, wherein the terminal portion and the first patch conductor are connected by a plurality of the through conductors disposed adjacent to each other along the first direction. The antenna substrate according to 1.   The antenna substrate according to claim 4, wherein an interval between the through conductors is ½ or less of a high frequency signal wavelength transmitted to the strip conductor.

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