JP5863111B2 - 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, as an antenna substrate, as shown in a schematic cross-sectional view in FIG. 4 and an exploded perspective view in FIG. 5, a first dielectric layer 11 and a lower surface of the first dielectric layer 11 in a first direction A strip-shaped strip conductor 14 extending and terminating, and a ground conductor layer 15 deposited on the upper surface of the first dielectric layer 11 with a slot 15a extending in a second direction perpendicular to the strip conductor 14; The second dielectric layer 12 laminated on the first dielectric layer 11 and the ground conductor layer 15, and the slot 15 a is formed on the upper surface of the second dielectric layer 12. The deposited first patch conductor 16, the third dielectric layer 13 stacked on the second dielectric layer 12 and the first patch conductor 16, and the upper surface of the third dielectric layer 13 So as to cover the position where the first patch conductor 16 is formed. Antenna substrate is known in which a second patch conductor 17.

  In this antenna substrate, when a high-frequency signal is supplied to the strip conductor 14, the signal is transmitted to the first and second patch conductors 16 and 17 through the slot 15a by electromagnetic coupling, and the first and second patch conductors 16 and 17 are transmitted. High-frequency signals are radiated as electromagnetic waves through the patch conductors 16 and 17. By the way, such an antenna substrate includes the first and second two-layer patch conductors 16 and 17 so as to overlap each other, by providing the two-layer patch conductors 16 and 17 so as to overlap each other. This is because the frequency band of the antenna 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.

JP 7-212125 A

  An object of the present invention is to provide a broadband antenna substrate capable of transmitting and receiving a good signal even in a wide frequency band of, for example, 57 to 66 GHz.

The antenna substrate of the present invention includes a first dielectric layer, and only one strip-shaped strip conductor disposed on the lower surface of the first dielectric layer and extending in the first direction and terminating. A ground conductor layer disposed on an upper surface of the first dielectric layer and having a slot extending in a second direction perpendicular to the strip conductor; and on the first dielectric layer and the ground conductor layer An antenna substrate comprising: a second dielectric layer stacked on the first dielectric layer; and a first patch conductor disposed on the upper surface of the second dielectric layer so as to cover the position where the slot is formed. The slot has a protruding portion where the width in the first direction in the slot is partially larger than the width of the portion not overlapping the strip conductor at a position overlapping the strip conductor. The second direction rather than the width of And it is characterized in that it is formed by 0~150μm small dimensions.

According to the antenna substrate of the present invention, so as to overlap with the strip conductors of the slot, near exit portion to be the first width is partly larger than the width of the region that does not overlap with the strip conductors in slots of the strip conductors Since it is formed with a dimension smaller by 0 to 150 μm in the second direction than the width , a complex resonance occurs satisfactorily by the slot provided with the protruding portion, and therefore, a good signal transmission / reception is possible in a wide frequency band. It is possible to do.

FIG. 1 is a schematic cross-sectional view for explaining an example of an embodiment of an antenna substrate of the present invention. FIG. 2 is an exploded perspective view of the antenna substrate shown in FIG. FIG. 3 is a plan view of the main part of the antenna substrate shown in FIGS. 1 and 2. FIG. 4 is a cross-sectional view showing a conventional antenna substrate. FIG. 5 is an exploded perspective view of the antenna substrate shown in FIG.

  Next, an embodiment of the antenna substrate of the present invention will be described with reference to the accompanying drawings. The antenna substrate of this example is shown in a schematic cross-sectional view in FIG. 1 and in an exploded perspective view in FIG. 2, in a first direction on the lower surface of the first dielectric layer 1 and the first dielectric layer 1. A strip-shaped strip conductor 5 extending to the end of the first dielectric layer 1 and a ground conductor layer 6 deposited on the upper surface of the first dielectric layer 1 with a slot 6a extending in a second direction perpendicular to the strip conductor 5. And the second dielectric layer 2 laminated on the first dielectric layer 1 and the ground conductor layer 6, and the slot 6 a formed on the upper surface of the second dielectric layer 2. A first patch conductor 7 deposited on the second dielectric layer 2, a third dielectric layer 3 laminated on the second dielectric layer 2 and the first patch conductor 7, and a third dielectric layer 3 A second patch conductor 8 deposited so as to cover the position where the first patch conductor 7 is formed on the upper surface; and a third dielectric layer And the fourth dielectric layer 4 laminated on the second patch conductor 8, and the second dielectric layer 4 is deposited so as to cover the position where the second patch conductor 8 is formed on the upper surface of the fourth dielectric layer 4. The third patch conductor 9 is provided.

  The dielectric layers 1 to 4 are, for example, an insulating sheet obtained by impregnating a glass cloth with a thermosetting resin such as an epoxy resin, a bismaleimide triazine resin, or an allyl-modified polyphenylene ether resin, an epoxy resin, a bismaleimide triazine resin, or an allyl-modified polyphenylene ether. An insulating sheet in which an inorganic insulating filler such as silica powder is dispersed in a resin is cured. These insulating layers 1 to 4 preferably have a relative dielectric constant of 4 or less, and preferably have a thickness of about 50 to 200 μm. Each of the strip conductor 5, the ground conductor layer 6, and the patch conductors 7 to 9 is made of a highly conductive conductive material such as a copper foil or a copper plating layer having a thickness of 5 to 20 μm.

  The strip conductor 5 disposed on the lower surface of the first dielectric layer 1 is a strip-shaped conductor having a width of about 50 to 350 μm. The strip conductor 5 extends in the first direction on the lower surface of the first dielectric layer 1 and ends at the lower surface of the first dielectric layer. The strip conductor 5 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 5.

The ground conductor layer 6 disposed on the upper surface of the first dielectric layer 1 is disposed so as to cover most of the upper surface of the first dielectric layer, and the second direction crosses the strip conductor 5 at a right angle. A substantially rectangular slot 6a extending in the direction is provided. As shown in FIG. 3, the slot 6a has a width W1 parallel to the first direction of about 0.1 to 1 mm and a length L1 parallel to the second direction of about 0.5 to 150 mm. In the position overlapping 5, an extended portion E in which the width W <b> 2 in the first direction in the slot 6 a is partially increased is formed. The width W2 in the protruding portion E is about 0.1 to 0.8 mm larger than the width W1 of other portions. In addition, the dimension L2 of the 2nd direction in the protrusion part E is 50-350 micrometers , and the dimension smaller by 0-150 micrometers than the width | variety of the strip conductor 5 is preferable. The slot 6 a is provided so that the end side of the protruding portion E on the end side of the strip conductor 5 is located at a distance of 0.2 to 8 mm from one end where the strip conductor 5 ends. The ground conductor layer 6 supplies a high frequency signal transmitted through the strip conductor 5 as an electromagnetic wave to the patch conductors 7 to 9 via the slot 6a, or receives an electromagnetic wave of the high frequency signal received by the patch conductors 7 to 9 in the slot 6a. The function to transmit to the strip conductor 5 is achieved.

  The first patch conductor 7 disposed on the upper surface of the second dielectric layer 2 has a short side parallel to the first direction in which the strip conductor 5 extends and a second direction in which the slot 6a extends. A quadrilateral having a long side. The patch conductor 7 functions to radiate an electromagnetic wave of a high-frequency signal from the slot 6a to the outside and transmit the electromagnetic wave to the second, third, and fourth patch conductors 8 and 9.

  Similarly, the second patch conductor 8 disposed on the upper surface of the third dielectric layer 3 also has a short side parallel to the first direction in which the strip conductor 5 extends and a second direction in which the slot 6a extends. It is a quadrilateral having parallel long sides. The patch conductor 8 functions to radiate an electromagnetic wave of a high-frequency signal from the first patch conductor 7 to the outside and to transmit the electromagnetic wave to the third patch conductor 9.

  Similarly, the third patch conductor 9 disposed on the upper surface of the fourth dielectric layer 4 also has a short side parallel to the first direction in which the strip conductor 5 extends and a second direction in which the slot 6a extends. It is a quadrilateral having parallel long sides. The patch conductor 9 functions to radiate electromagnetic waves of high-frequency signals from the first and second patch conductors 7 and 8 to the outside.

  In addition, the length of the short side and the long side in the 1st-3rd patch conductors 7-9 is 0.5-5 mm, respectively. Here, for convenience, they are expressed as short sides and long sides, and the lengths of both may be the same, or the lengths of both may be reversed.

  In this example, as described above, the protruding portion E in which the width W2 in the first direction of the slot 6a partially increases is formed at the position overlapping the strip conductor 5 of the slot 6a. is important. Since complex resonance occurs due to the presence of the protruding portion E, the frequency band of the high-frequency signal radiated through the first to third patch conductors 7 to 9 becomes wide.

  Here, in the antenna substrate shown in FIG. 2 by the present inventor, the relative dielectric constant of the insulating layers 1 to 4 is 3.7, the thickness of the insulating layers 1 and 2 is 100 μm, and the thickness of the insulating layers 3 and 4 is The thickness of the strip conductor 5 is 15 μm, the width is 200 μm, the thickness of the ground conductor layer 6 and the patch conductors 7 to 11 is 11 μm, the width W1 of the slot 6a is 0.2 mm, the length L1 is 1 mm, and W2 is 0. .4 mm, L2 is 50 μm, the distance from the end of the protruding portion E to the end of the strip conductor 5 is 0.75 mm, and these dimensions are made common, and the short side dimension of the first patch conductor 7 Is 0.6 mm, the long side dimension is 0.7 mm, the short side dimension of the second patch conductor 8 is 0.6 mm, the long side dimension is 0.9 mm, and the short side of the third patch conductor 9 is The size of the long side is 0.8mm, the long side is 1.0mm The first model corresponding to the present invention and the second model corresponding to the outside of the scope of the present invention having the same configuration as the first model except that the side-by-side portion E is not provided are represented by an electromagnetic field simulator. As a result of comparison by simulation, in the second model corresponding to the outside of the scope of the present invention, the band having a reflection loss of −10 dB or less was 55 to 73 GHz, whereas in the first model corresponding to the present invention, It was confirmed that the band having a reflection loss of −10 dB or less was as wide as 54 to 74 GHz. This indicates that a good signal can be transmitted and received with a sufficient margin even in a wide frequency band of, for example, 57 to 66 GHz.

DESCRIPTION OF SYMBOLS 1 1st dielectric material layer 2 2nd dielectric material layer 5 Strip conductor 6 Grounding conductor layer 6a Slot 7 1st patch conductor E Side part

Claims (1)

A first dielectric layer, a single strip-shaped strip conductor disposed on the lower surface of the first dielectric layer, extending in a first direction and terminating, and the first dielectric A ground conductor layer disposed on a top surface of the layer and having a slot extending in a second direction perpendicular to the strip conductor; and a second dielectric layer laminated on the first dielectric layer and the ground conductor layer. An antenna substrate comprising: a dielectric layer; and a first patch conductor disposed so as to cover a position where the slot is formed on the upper surface of the second dielectric layer, wherein the slot is In the position overlapping the strip conductor, a protruding portion where the width in the first direction in the slot is partially larger than the width of the portion not overlapping the strip conductor is the second width than the width of the strip conductor. 0 to 150 μm smaller in the direction of Antenna substrate, characterized in that in is formed.