KR102304450B1 - Antenna - Google Patents

Abstract

An antenna according to an embodiment of the present invention includes a first dielectric substrate; and a second dielectric substrate disposed under the first dielectric substrate and having an air layer formed therein, wherein the first dielectric substrate includes a dielectric layer, a ground disposed on the dielectric layer, and at least one radiation slot formed therein; an upper layer including a feeding part, a lower layer disposed under the dielectric layer and in contact with the second dielectric substrate, the radiation slot passing through the first dielectric substrate and the second dielectric substrate and disposed in the upper layer; and a plurality of vias surrounding the air layer formed in the second dielectric substrate.

Description

antenna {ANTENNA}

An embodiment according to the present invention relates to an antenna, and more particularly, to an SIW (Surface Imntegrate Waveguide) antenna having a waveguide having an air layer structure.

In general, a slot antenna is an antenna in which a radio wave is radiated from a wide metal plate (waveguide) by drilling a thin and long space, that is, a hole (slit) on the side parallel to the electric field plane, and excitation of it, This is called a slot or slit antenna.

This slot antenna can use a parallel two-wire type or a coaxial feed line, and radio waves are radiated from the slot when traversing the waveguide to interfere with the tube wall current. When feeding with a coaxial feeder, feed from a point moved a little from the center to the end in order to match. It is a magnetic dipole and vertically polarized waves are radiated in horizontal slots and horizontally polarized waves are radiated in vertical slots. The directivity characteristic is the same as the complementary dipole, but it is maximized in the direction perpendicular to the conductor tube, and if a shielding cavity is installed at the rear, it becomes unidirectional.

In addition, a slot array antenna is an antenna which drills a half-wavelength resonance slot obliquely to the side parallel to the electric field plane of a waveguide, arranges this as a slot antenna row, and obtains the required directivity and gain. Power is supplied from the center or one end of the antenna. It is covered with a dielectric radome for waterproofing, prevention, prevention of salt damage, and reinforcement of strength.

On the other hand, the SIW (Surface Integrate Waveguide) antenna has the advantage of being able to transmit a millimeter wave (mm-wave) signal with low loss in the form of an existing metal waveguide structure implemented on a printed circuit board. This is a combination of the low loss characteristics of the existing waveguide structure and the advantage of easy signal processing due to the integration of the printed circuit board.

However, the conventional SIW antenna structure is a waveguide structure including a dielectric layer filled with Teflon, which has a disadvantage in that a Teflon material having a predetermined thickness or more must be used to make the waveguide structure. In addition, the occurrence of millimeter wave loss due to Teflon raw materials is inevitable, and the constraint of using an expensive, low-loss material due to the characteristics of raw materials is equally generated.

In an embodiment according to the present invention, an antenna capable of minimizing the transmission loss of millimeter wave while remarkably reducing the thickness of the dielectric layer by using an air layer is provided.

In addition, in an embodiment according to the present invention, an antenna capable of transmitting a signal by an effective permittivity in which a dielectric constant of a dielectric layer such as Teflon and a dielectric constant of an air layer are combined with each other is provided.

In addition, in an embodiment according to the present invention, an antenna including a transmission line for signal transmission capable of minimizing signal loss is provided.

The technical problems to be achieved in the proposed embodiment are not limited to the technical problems mentioned above, and other technical problems not mentioned are clear to those of ordinary skill in the art to which the proposed embodiment belongs from the description below. will be able to be understood

An antenna according to an embodiment of the present invention includes a first dielectric substrate; and a second dielectric substrate disposed under the first dielectric substrate and having an air layer formed therein, wherein the first dielectric substrate includes a dielectric layer, a ground disposed on the dielectric layer, and at least one radiation slot formed therein; an upper layer including a feeding part, a lower layer disposed under the dielectric layer and in contact with the second dielectric substrate, the radiation slot passing through the first dielectric substrate and the second dielectric substrate and disposed in the upper layer; and a plurality of vias surrounding the air layer formed in the second dielectric substrate.

In addition, the dielectric layer contains Teflon.

In addition, the air layer is vertically overlapped with the at least one radiation slot formed in the ground of the upper layer.

In addition, the second dielectric substrate includes a first insulating layer, a first metal layer disposed on the first insulating layer, a first adhesive layer disposed on the first metal layer, and a second metal layer disposed on the first adhesive layer. and a second insulating layer disposed on the second metal layer, a third metal layer disposed on the second insulating layer, and a second adhesive layer disposed on the third metal layer.

In addition, the first insulating layer and the second insulating layer include FR4, and the first adhesive layer and the second adhesive layer include a prepreg.

In addition, the air layer passes through the first adhesive layer, the second metal layer, the second insulating layer, the third metal layer, and the second adhesive layer.

In addition, the thickness of the air layer is thicker than the thickness of the dielectric layer.

In addition, at one end of the ground, a depression is formed into which a first region of the signal transmission line of the power feeding unit is inserted, and a width of the depression is greater than a width of the first region of the signal transmission line, and the signal transmission line The first region of the line is not in contact with the ground.

In addition, the lower layer is formed in a first slot formed in an area vertically overlapping with the air layer, spaced apart from the first slot by a predetermined interval, and formed in an area vertically overlapping with the first area of the signal transmission line and a second slot.

In addition, the second slot includes a first portion formed in a region overlapping the first region in a vertical direction, and a second portion formed by being vertically bent from one end of the first portion toward the first slot; , and a third portion formed by being vertically bent from the other end of the first portion toward the first slot.

In addition, the first region of the signal transmission line protrudes from the first part of the second slot in the vertical direction, and at least a part is disposed between the second part and the third part.

In addition, an end of the first region is disposed between one end and the other end of each of the second part and the three parts in the vertical direction.

According to the embodiment according to the present invention, in a form in which the characteristics of the air layer waveguide and the dielectric constant characteristics are mutually combined, the signal loss due to the transmission of millimeter waves through the air layer having a relatively high thickness compared to the low thickness Teflon can be minimized, and Teflon is used. By implementing a pattern (other than the slot type), it is possible to improve the easiness of manufacturing the millimeter wave antenna.

In addition, according to an embodiment of the present invention, by including an air layer capable of minimizing transmission loss as well as a structure that can implement SIW using Teflon of a low thickness, product reliability can be improved.

In addition, according to the embodiment of the present invention, the signal is transmitted by the effective dielectric constant in which the dielectric constant (Er) of Teflon and the dielectric constant (Er=1) of the air layer are mutually combined, thereby improving the degree of freedom in structural design can do it

In addition, according to the embodiment according to the present invention, since the signal is transmitted in the waveguide mode (Transverse Electric 10), the energy loss due to the air layer is relatively low loss compared to the loss factor (Df) of the medium of Teflon. can have

In addition, according to the embodiment according to the present invention, by implementing the pattern using the upper layer of Teflon, it is possible to overcome the disadvantages of the antenna design of the structure including only the air layer, and thus the difficulty of manufacturing the slot pattern can be reduced. have.

In addition, in the present invention, by designing a transmission line for the connection between the upper layer of Teflon and the communication device, it is possible to minimize the insertion loss (Insertion Loss).

1 is a view showing the structure of an antenna according to a first embodiment of the present invention, FIG. 2 is a plan view of the upper layer 120 of the first dielectric substrate 100 of FIG. 1, and FIG. 1 is a plan view of the lower layer 130 of the dielectric substrate 100, and FIG. 4 is an enlarged view of a region in which the second slot of FIG. 3 is formed.
5 is a view showing a comparative structure with an embodiment of the present invention.
6 is a graph showing the insertion loss of the structure of the embodiment of the present invention and the comparative structure.
7 is a diagram showing signal characteristics according to an embodiment of the present invention.
8 is a view showing radiation characteristics of an antenna according to an embodiment of the present invention.
9 is a diagram illustrating signal loss in an antenna according to an embodiment of the present invention.
10 is a diagram showing signal loss in comparison with the antenna of the present invention.
11 to 15 are diagrams illustrating various implementation examples of slots according to an embodiment of the present invention.
16 is a diagram showing the structure of an antenna according to a second embodiment of the present invention.

Hereinafter, the configuration and operation according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same components are given the same reference, regardless of the reference numerals, and redundant description thereof will be omitted. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

Hereinafter, the embodiments will be clearly revealed through the accompanying drawings and the description of the embodiments. In the description of embodiments, each layer (film), region, pattern or structure is formed “on” or “under” the substrate, each layer (film), region, pad or pattern. When described as being, “on” and “under” include both “directly” or “indirectly” formed through another layer. In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not fully reflect the actual size. Hereinafter, embodiments will be described with reference to the accompanying drawings.

Meanwhile, in the following description, for the purpose of helping the understanding of the present invention and for convenience of description by the applicant, the antenna according to the present invention is for a millimeter wave as an example. In addition, the millimeter wave antenna according to the present invention may be configured as a substrate integrated waveguide (SIW) series slot array antenna. However, the scope of the present invention is not limited only to the illustrated serial slot array antenna, and various types of antennas, for example, a parallel slot array antenna or a serial/parallel array antenna, may be implemented in the same or similar manner. Various types of antennas implemented in this way may also fall within the scope of the present invention.

1 is a diagram showing the structure of an antenna according to a first embodiment of the present invention, FIG. 2 is a plan view of the upper layer 120 of the first dielectric substrate 100 of FIG. 1, and FIG. 1 is a plan view of the lower layer 130 of the dielectric substrate 100, and FIG. 4 is an enlarged view of an area in which the second slot of FIG. 3 is formed.

1 to 4 , the antenna includes a first dielectric substrate 100 and a second dielectric substrate 200 disposed under the first dielectric substrate 100 .

Here, the first dielectric substrate 100 is made of a non-conductive material having a predetermined dielectric constant Er and a thickness h.

The first dielectric substrate 100 includes a dielectric layer 110 , an upper layer 120 disposed on the dielectric layer 110 , and a lower layer 130 disposed under the dielectric layer 110 .

The dielectric layer 110 may be made of Teflon.

The upper layer 120 is a metal layer disposed on the dielectric layer 110 . In addition, the lower layer 130 is a metal layer disposed under the dielectric layer 110 .

In other words, the first dielectric substrate 100 including the dielectric layer 110 , the upper layer 120 , and the lower layer 130 may be a Teflon substrate.

The upper layer 120 includes a ground 122 including a plurality of slots and a power feeding unit 121 for feeding power. The ground 122 and the power feeding unit 121 may be manufactured by using a metal film etching method for the upper layer 120 . Preferably, the ground 122 may be a ground including a slot 1221 . In this case, the upper layer 120 may further include a plurality of vias 1222 disposed to surround the slot 1221 formed in the ground 122 .

The via 1222 is disposed through the upper layer 120 . Preferably, the via 1222 is disposed through the first dielectric substrate 100 and the second dielectric substrate 200 including the upper layer 120 as well as the upper layer 120 . Accordingly, one surface of the via 1222 is exposed through the upper surface of the first dielectric substrate 100 (the upper surface of the upper layer 120), and the other surface of the via 1222 is the second dielectric substrate ( 200) is exposed through the lower surface.

The via 1222 is a passage for an interlayer electrical connection between the first dielectric substrate 100 and the second dielectric substrate 200, and is a via hole (not shown) by drilling an electrically disconnected layer. ) and filling the formed via-holes with a conductive material or plating with a conductive material.

The metal material for forming the via 1222 may be any one material selected from Cu, Ag, Sn, Au, Ni, and Pd, and the filling of the metal material is performed by electroless plating, electrolytic plating, or screen printing (Screen printing). Printing), sputtering, evaporation, inkjetting, and dispensing, or a combination thereof may be used.

In this case, the via hole may be formed by any one processing method among mechanical, laser, and chemical processing.

When the via hole is formed by machining, methods such as milling, drilling, and routing can be used, and when the via hole is formed by laser processing, a UV or Co2 laser method can be used. In the case of being formed by chemical processing, the first dielectric substrate 100 and the second dielectric substrate 200 may be opened using chemicals including aminosilane, ketones, and the like.

On the other hand, the processing by the laser is a cutting method in which a part of the material is melted and evaporated by concentrating optical energy on the surface to take a desired shape, and complex formation by a computer program can be easily processed, and in other methods, cutting Even difficult composite materials can be machined.

In addition, the processing by the laser can have a cutting diameter of at least 0.005mm, and has a wide advantage in a range of possible thicknesses. As the laser processing drill, it is preferable to use a YAG (Yttrium Aluminum Garnet) laser, a CO2 laser, or an ultraviolet (UV) laser. The YAG laser is a laser that can process both the copper foil layer and the insulating layer, and the CO2 laser is a laser that can process only the insulating layer.

The via 1222 may have a predetermined diameter, and a plurality of vias 1222 may be spaced apart from each other by a predetermined distance. In this case, the diameter of each of the plurality of vias 1222 may be 300 μm, and the separation distance between the plurality of vias 1222 may be 300 μm.

Meanwhile, the ground 122 may not be disposed over the entire area of the upper surface of the dielectric layer 110 , but may be disposed only on a partial area. That is, the ground 122 may have a longitudinal shape of the size a*b on the upper surface of the dielectric layer 110 . In this case, the size of the ground 122 is smaller than the size of the top surface of the dielectric layer 110 .

In addition, a power feeding unit 121 is disposed on the dielectric layer 110 . Like the ground 122 , the power feeding part 121 may be formed using the upper layer 120 . The power feeding unit 121 connects a communication device (not shown) and the ground 122 of the upper layer 120 . Preferably, the power feeding unit 121 transmits a signal transmitted through the communication device to the ground 122 .

To this end, the power feeding unit 121 may include a signal transmission line 1211 having a generally used micro-strip line structure.

In this case, a depression 1223 is formed at one end of the ground 122 in an inward direction of the ground 122 , and the first region of the power feeding part 121 is the depression of the ground 122 . 1223 is inserted.

Here, the width of the recessed portion 1223 is greater than the line width of the signal transmission line 1211 . Accordingly, the first region of the signal transmission line 1211 is inserted into the depression 1223 without contacting the ground 122 .

In other words, between the ground 122 and the first region of the signal transmission line 1211 , the upper surface of the lower dielectric layer 110 is exposed by the depression 1223 . That is, the dielectric layer 110 may be disposed around the lower portion of the first region of the signal transmission line 1211 .

That is, in the present invention, the dielectric layer 110 is disposed to surround the lower portion of the periphery of the first region of the signal transmission line 1211, thereby reducing the loss of the signal transmitted through the periphery of the first region. to be minimized.

The lower layer 130 is disposed on the lower surface of the dielectric layer 110 .

The lower layer 130 is electrically connected to the upper layer 120 through the via 1222 . Preferably, the lower layer 130 is electrically connected to the ground 122 of the upper layer 120 through the via 1222 .

A plurality of slots are formed in the lower layer 130 . In this case, the plurality of slots are formed in the overlapping region R1 vertically overlapping with the ground 122 disposed on the dielectric layer 110 of the lower layer 130 .

That is, in the overlapping region R1 of the lower layer 130 , a first slot 131 and a second slot 132 spaced apart from the first slot 131 are formed.

The first slot 131 exposes at least a portion of a lower surface of the dielectric layer 110 vertically overlapping with the ground 122 . In this case, the first slot 131 vertically overlaps the air layer C formed on the second dielectric substrate 200 . The air layer (C) may be referred to as a void, and is a passage through which the signal is transmitted. Clearly, the air layer (C) may be referred to as an air cavity.

Accordingly, the lower surface of the dielectric layer 110 exposed through the first slot 131 is disposed in the air layer C of the second dielectric substrate 200 .

Meanwhile, the first slot 131 may have a '□' shape, and may have a size smaller than the size of the air layer C formed on the second dielectric substrate 200 .

The second slot 132 is formed on the lower layer 130 at a position spaced apart from the first slot 131 by a predetermined interval. The second slot 132 is disposed in the overlapping area.

Preferably, at least a portion of the second slot 132 is formed in a region that vertically overlaps with the first region of the signal transmission line 1211 .

In other words, the second slot 132 includes a first portion 1321 having a straight shape, and a second portion ( 132 , and a third part 1323 formed at the other end of the first part 132 in a direction perpendicular to the first part 132 and parallel to the second part 132 .

That is, the combination shape of the first part 1321 , the second part 1322 , and the third part 1323 of the second slot 132 has a U-shape.

The second slot 132 has a U-shape as described above, and is formed to at least partially overlap the signal transmission line 1211 in the vertical direction. Accordingly, in the present invention, in the signal waveguide structure having the air layer C, it is possible to connect the power supply unit 121 and the upper layer 120 of the first dielectric substrate 100 without an insertion loss.

Meanwhile, a relationship between the second slot and the signal transmission line 1211 will be described in more detail with reference to FIG. 4 .

In the second slot 132 , the first portion 1321 vertically overlaps the first area of the signal transmission line 1211 . Preferably, at least a portion of the first portion 1321 of the second slot 132 is positioned in an area overlapping the first area in a vertical direction. In this case, the left and right widths of the first portion 1321 are greater than the left and right widths of the first region of the signal transmission line 1211 .

Accordingly, the first portion 1321 includes a portion overlapping the first area of the signal transmission line 1211 and a portion not overlapping the signal transmission line 1211 in the vertical direction, respectively.

In addition, the second part 1322 is vertically bent at one end of the first part 1321 . Preferably, the second part 1322 is vertically bent from one end of the first part 1321 in a direction in which the first slot 131 is formed.

In addition, the third portion 1323 is vertically bent at the other end of the first portion 1321 . Preferably, the third portion 1323 is vertically bent from the other end of the first portion 1321 in a direction in which the first slot 131 is formed.

On the other hand, the first area of the signal transmission line 1211 includes an area overlapping with the first portion 1321 of the second slot 132 in the vertical direction, and in addition to the overlapping area, It is disposed to protrude to an area between the second part 1322 and the third part 1323 in the vertical direction.

In this case, the end of the first region of the signal transmission line 1211 is disposed in the region between the second part 1322 and the third part 1323 in the vertical direction. That is, there is a large difference in the insertion loss according to the positional relationship between the second slot 132 and the signal transmission line 1211 in the vertical direction.

5 is a view showing a comparative structure with an embodiment of the present invention.

As described above, in the present invention, the end of the first region of the signal transmission line 1211 is disposed in the region between the second part 1322 and the third part 1323 in the vertical direction.

Alternatively, as shown in FIG. 5A , the end of the first region of the signal transmission line 1211 is in the region between the second part 1322 and the third part 1323 in the vertical direction. It is not disposed, and may be disposed only on the first part 1311 . This means that the length of the first region of the signal transmission line 1211 is shorter than that of the embodiment of the present invention.

Alternatively, as shown in FIG. 5B , the end of the first region of the signal transmission line 1211 is a region between the second part 1322 and the third part 1323 in the vertical direction. In addition to being disposed within, it may extend to a position outside the region between the second part 1322 and the third part 1323 . This means that the length of the first region of the signal transmission line 1211 is longer than that of the embodiment of the present invention.

6 is a graph showing the insertion loss of the structure of the embodiment of the present invention and the comparative structure.

In the graph of FIG. 6, A shows the insertion loss caused by the structure of FIG. 5 (A), B shows the insertion loss caused by the structure of FIG. 5 (B), and C is the view according to FIG. The insertion loss caused by the structure of the embodiment of the invention is shown.

As shown in FIG. 6 , in the 76.5 GHz frequency domain, it was confirmed that the A structure exhibited an insertion loss of 0.91 dB, and the B structure exhibited an insertion loss of 0.84 dB. It was confirmed that the structure exhibits an insertion loss of 0.13 dB, which is clearly distinguished from the A and B structures.

Meanwhile, a second dielectric substrate 200 is disposed under the first dielectric substrate 100 . The second dielectric substrate 200 is a waveguide that transmits a millimeter wave signal transmitted from the first dielectric substrate 100 .

In other words, the second dielectric substrate 200 receives the signal from the first dielectric substrate 100 and transmits the signal through the internal air layer (C). At this time, the signal is the air layer (C) by an effective permittivity in which the dielectric constant of Teflon of the dielectric layer 110 and the dielectric constant (Er=1) of the air layer C of the second dielectric substrate 200 are mutually combined. ) is transmitted through

To this end, the second dielectric substrate 200 includes a first insulating layer 210 , a first metal layer 220 disposed on the first insulating layer 210 , and a first metal layer 220 disposed on the first metal layer 220 . A first adhesive layer 230 , a second metal layer 240 disposed on the first adhesive layer 230 , a second insulating layer 250 disposed on the second metal layer 240 , and the second insulating layer A third metal layer 260 disposed on the 250 , and a second adhesive layer 270 disposed on the third metal layer 260 .

The first adhesive layer 230 may be a prepreg, the first insulating layer 210 having the first metal layer 220 disposed on the upper surface, and the second insulating layer 210 having the second metal layer 240 disposed on the lower surface. It provides adhesion between the layers 220 so that they can be bonded together.

The second adhesive layer 270 provides an adhesive force between the second insulating layer 250 on which the third metal layer 260 is disposed and the first dielectric substrate 100 so that they can be coupled to each other.

The first insulating layer 210 and the second insulating layer 250 are formed to secure the air layer C having a predetermined thickness. At this time, if the thickness of the air layer (C) can be secured with one insulating layer, the insulating layer may be formed with one layer instead of two layers as in the present invention. In addition, the insulating layer may be formed of three or more layers instead of two as in the present invention.

The first insulating layer 210 and the second insulating layer 250 may be made of epoxy, duroid, bakelite, high-resistance silicon, glass, alumina, LTCC, and air form. However, it is preferable to use FR-4, which is relatively inexpensive.

The first metal layer 220 , the second metal layer 240 , and the third metal layer 260 include a circuit pattern serving as a wiring between the respective layers.

Meanwhile, the second adhesive layer 270 , the third metal layer 260 , the second insulating layer 250 , the second metal layer 240 and the first adhesive layer 230 are formed in the second dielectric substrate 200 . A penetrating air layer (C) is formed.

The air layer C is disposed in a region that vertically overlaps with the ground 122 formed on the first dielectric substrate 100 . Preferably, the position of the air layer C may be determined by the position of the via 1222 constituting the ground 122 .

The air layer C is formed at a position vertically overlapping with the inner region surrounded by the via 1222 . Accordingly, the via 1222 is disposed to pass through the second dielectric substrate 200, and since the air layer C is disposed in the inner region of the via 1222, the via 1222 and the air layer ( C) are spaced apart from each other by a predetermined interval in the second dielectric substrate 200 .

Meanwhile, the thickness of the air layer (C) is preferably thicker than the thickness of the first dielectric substrate 100 , preferably, the thickness of the dielectric layer 110 .

According to the embodiment according to the present invention, in a form in which the characteristics of the air layer waveguide and the dielectric constant characteristics are mutually combined, the signal loss due to the transmission of millimeter waves through the air layer having a relatively high thickness compared to the low thickness Teflon can be minimized, and Teflon is used. By implementing a pattern (other than the slot type), it is possible to improve the easiness of manufacturing the millimeter wave antenna.

In addition, according to an embodiment of the present invention, product reliability can be improved by including an air layer that can minimize transmission loss as well as a structure that can implement SIW using Teflon of a low thickness.

In addition, according to the embodiment of the present invention, the signal is transmitted by the effective dielectric constant in which the dielectric constant (Er) of Teflon and the dielectric constant (Er=1) of the air layer are mutually combined, thereby improving the degree of freedom in structural design can do it

In addition, according to the embodiment according to the present invention, since the signal is transmitted in the waveguide mode (Transverse Electric 10), the energy loss due to the air layer is relatively low loss compared to the loss factor (Df) of the medium of Teflon. can have

In addition, according to the embodiment according to the present invention, by implementing the pattern using the upper layer of Teflon, it is possible to overcome the disadvantages of the antenna design of the structure including only the air layer, and thus the difficulty of manufacturing the slot pattern can be reduced. have.

In addition, in the present invention, by designing a transmission line for the connection between the upper layer of Teflon and the communication device, it is possible to minimize the insertion loss (Insertion Loss).

7 is a diagram showing signal characteristics according to an embodiment of the present invention.

Referring to FIG. 7 , the ratio of the input signal and the reflected signal according to the embodiment of the present invention was -21.47 dB at a frequency of 76.50 GHz, and thus it was confirmed that the signal loss was minimized.

8 is a view showing radiation characteristics of an antenna according to an embodiment of the present invention.

As shown in FIG. 8 , it was confirmed that the maximum signal gain of 13.2925 dB was formed at the 76.5 GHz frequency based on the 0 degree curve, and the maximum signal gain of 12.4109 dB was formed at the 76.5 GHz frequency based on the 90 degree curve. was able to confirm that

9 is a diagram illustrating signal loss in an antenna according to an embodiment of the present invention.

As shown in FIG. 9 , it was confirmed that the signal loss of the antenna structure including the air layer (C) in the present invention at a frequency of 76.5 GHz was 0.17 dB.

10 is a diagram showing signal loss in comparison with the antenna of the present invention.

FIG. 10A shows a signal loss that occurs when an SIW antenna is implemented using only a typical Teflon layer, and FIG. 10B shows a signal loss that occurs on a conventional micro-strip line.

As shown in A of FIG. 10, when the SIW antenna is implemented using only a general Teflon layer, a signal loss of 0.72 dB occurred, and as shown in FIG. could be seen to appear.

11 to 15 are diagrams illustrating various implementation examples of slots according to an embodiment of the present invention.

11 is a typical and popularly used waveguide array antenna structure, exemplified by a slot array antenna equivalent to a parallel connection.

Here, all of the radiation slots 301 to 404 have a length and an offset corresponding to resonance, and have various parallel susceptances according to an offset distance away from the center of the waveguide.

In addition, each radiation slot is disposed at a distance of half a wavelength (λg/2) of the waveguide wavelength (guide wavelength), so that the phase of the electric field vector induced in each radiation slot is the same, and high-purity linearly polarized waves are radiated can do.

12 is a diagram illustrating a structure of a serial slot array antenna having a cross rotation angle in relation to the present invention.

The single radiating slot of FIG. 12 has a length corresponding to resonance and has various series resistance according to a rotation angle.

Here, each of the radiation slots 401 - 404 are spaced apart by a half wavelength distance of the waveguide guide wavelength.

13 is a diagram illustrating a structure of a serial slot array antenna having the same rotation angle in relation to the present invention.

The single radiating slot of FIG. 13 has a length corresponding to resonance and has a variable series resistance according to a rotation angle.

Here, each of the radiation slots 501 to 502 is spaced apart by one wavelength distance of the wavelength within the waveguide, and all radiation slots have the same electric field phase information.

Therefore, the direction of the electric field vector induced in each of the radiation slots 501 to 502 is the same, so that it is possible to generate a high-purity linear polarization wave.

14 is a diagram illustrating a structure of a traveling-wave serial slot array antenna in relation to the present invention.

The traveling wave series slot array antenna of FIG. 14 has a structure in which the spacing between the radiating slots is not constant but different from each other.

Further, the traveling wave array antennas 601 to 604 of FIG. 14 are terminated with the characteristic impedance load of the waveguide at the last slot 404, that is, at the end of the slot array.

15 is a diagram illustrating a structure of a slot pair serial slot array antenna in relation to the present invention.

The radar antenna of FIG. 15 has an antenna structure in which two radiation slots form a pair and are arranged in series.

Here, in the radar antenna as shown in FIG. 15, the spacing between the radiation slots 701 to 702 and 703 to 704 is very narrow, so mutual coupling impedance must be considered, and only design through repeated calculation is possible. Its design is very difficult.

16 is a diagram showing the structure of an antenna according to a second embodiment of the present invention.

Referring to FIG. 16 , the antenna includes a first dielectric substrate 100 and a second dielectric substrate 200 disposed under the first dielectric substrate 100 .

Here, the first dielectric substrate 100 is made of a non-conductive material having a predetermined dielectric constant Er and a thickness h. The first dielectric substrate 100 includes a dielectric layer 110 , an upper layer 120 disposed on the dielectric layer 110 , and a lower layer 130 disposed under the dielectric layer 110 .

The dielectric layer 110 may be made of Teflon. The upper layer 120 is a metal layer disposed on the dielectric layer 110 . In addition, the lower layer 130 is a metal layer disposed under the dielectric layer 110 .

In other words, the first dielectric substrate 100 including the dielectric layer 110 , the upper layer 120 , and the lower layer 130 may be a Teflon substrate.

The via 1222 is disposed through the upper layer 120 . Preferably, the via 1222 is disposed through the first dielectric substrate 100 and the second dielectric substrate 200 including the upper layer 120 as well as the upper layer 120 . Accordingly, one surface of the via 1222 is exposed through the upper surface of the first dielectric substrate 100 (the upper surface of the upper layer 120), and the other surface of the via 1222 is the second dielectric substrate ( 200) is exposed through the lower surface.

The via 1222 is a passage for an interlayer electrical connection between the first dielectric substrate 100 and the second dielectric substrate 200, and is a via hole (not shown) by drilling an electrically disconnected layer. ) and filling the formed via-holes with a conductive material or plating with a conductive material.

The metal material for forming the via 1222 may be any one material selected from Cu, Ag, Sn, Au, Ni, and Pd, and the filling of the metal material is performed by electroless plating, electrolytic plating, or screen printing (Screen printing). Printing), sputtering, evaporation, inkjetting, and dispensing, or a combination thereof may be used.

Meanwhile, the ground 122 may not be disposed over the entire area of the upper surface of the dielectric layer 110 , but may be disposed only on a partial area. That is, the ground 122 may have a longitudinal shape of the size a*b on the upper surface of the dielectric layer 110 . In this case, the size of the ground 122 is smaller than the size of the top surface of the dielectric layer 110 .

A second dielectric substrate 200 is disposed under the first dielectric substrate 100 . The second dielectric substrate 200 is a waveguide that transmits a millimeter wave signal transmitted from the first dielectric substrate 100 .

In other words, the second dielectric substrate 200 receives the signal from the first dielectric substrate 100 and transmits the signal through the internal air layer (C). At this time, the signal is the air layer (C) by an effective permittivity in which the dielectric constant of Teflon of the dielectric layer 110 and the dielectric constant (Er=1) of the air layer C of the second dielectric substrate 200 are mutually combined. ) is transmitted through

To this end, the second dielectric substrate 200 includes a first insulating layer 210 , a first metal layer 220 disposed on the first insulating layer 210 , and a first metal layer 220 disposed on the first metal layer 220 . A first adhesive layer 230 , a second metal layer 240 disposed on the first adhesive layer 230 , a second insulating layer 250 disposed on the second metal layer 240 , and the second insulating layer A third metal layer 260 disposed on the 250 , and a second adhesive layer 270 disposed on the third metal layer 260 .

The first adhesive layer 230 may be a prepreg, the first insulating layer 210 having the first metal layer 220 disposed on the upper surface, and the second insulating layer 210 having the second metal layer 240 disposed on the lower surface. It provides adhesion between the layers 220 so that they can be bonded together.

The second adhesive layer 270 provides an adhesive force between the second insulating layer 250 on which the third metal layer 260 is disposed and the first dielectric substrate 100 so that they can be coupled to each other.

The first insulating layer 210 and the second insulating layer 250 are formed to secure the air layer C having a predetermined thickness. At this time, if the thickness of the air layer (C) can be secured with one insulating layer, the insulating layer may be formed with one layer instead of two layers as in the present invention. In addition, the insulating layer may be formed of three or more layers instead of two as in the present invention.

The first insulating layer 210 and the second insulating layer 250 may be made of epoxy, duroid, bakelite, high-resistance silicon, glass, alumina, LTCC, and air form. However, it is preferable to use FR-4, which is relatively inexpensive.

The first metal layer 220 , the second metal layer 240 , and the third metal layer 260 include a circuit pattern serving as a wiring between the respective layers.

Meanwhile, the second adhesive layer 270 , the third metal layer 260 , the second insulating layer 250 , the second metal layer 240 and the first adhesive layer 230 are formed in the second dielectric substrate 200 . A penetrating air layer (C) is formed.

The air layer C is disposed in a region that vertically overlaps with the ground 122 formed on the first dielectric substrate 100 . Preferably, the position of the air layer C may be determined by the position of the via 1222 constituting the ground 122 .

The air layer C is formed at a position vertically overlapping with the inner region surrounded by the via 1222 . Accordingly, the via 1222 is disposed to pass through the second dielectric substrate 200, and since the air layer C is disposed in the inner region of the via 1222, the via 1222 and the air layer ( C) are spaced apart from each other by a predetermined interval in the second dielectric substrate 200 .

In addition, in the antenna of the second embodiment, a blocking layer 290 is further formed in the air layer (C). The blocking layer 290 is formed on the inner wall and bottom surface of the air layer (C), thereby blocking signal loss to the outside of the air layer (C).

According to the embodiment according to the present invention, in a form in which the characteristics of the air layer waveguide and the dielectric constant characteristics are mutually combined, the signal loss due to the transmission of millimeter waves through the air layer having a relatively high thickness compared to the low thickness Teflon can be minimized, and Teflon is used. By implementing a pattern (other than the slot type), it is possible to improve the easiness of manufacturing the millimeter wave antenna.

In addition, according to an embodiment of the present invention, by including an air layer capable of minimizing transmission loss as well as a structure that can implement SIW using Teflon of a low thickness, product reliability can be improved.

In addition, according to the embodiment of the present invention, the signal is transmitted by the effective dielectric constant in which the dielectric constant (Er) of Teflon and the dielectric constant (Er=1) of the air layer are mutually combined, thereby improving the degree of freedom in structural design can do it

In addition, according to the embodiment according to the present invention, since the signal is transmitted in the waveguide mode (Transverse Electric 10), the energy loss due to the air layer is relatively low loss compared to the loss factor (Df) of the medium of Teflon. can have

In addition, according to the embodiment according to the present invention, by implementing the pattern using the upper layer of Teflon, it is possible to overcome the disadvantages of the antenna design of the structure including only the air layer, and thus the difficulty of manufacturing the slot pattern can be reduced. have.

In addition, in the present invention, by designing a transmission line for the connection between the upper layer of Teflon and the communication device, it is possible to minimize the insertion loss (Insertion Loss).

Claims (12)

a first dielectric substrate; and
a second dielectric substrate disposed under the first dielectric substrate and having an air layer formed therein;
The first dielectric substrate,
a dielectric layer having a thickness smaller than that of the air layer;
an upper layer disposed over the dielectric layer and comprising a ground and a feed portion having at least one radiation slot formed therein;
a lower layer disposed under the dielectric layer and in contact with the second dielectric substrate;
a plurality of vias passing through the first dielectric substrate and the second dielectric substrate and surrounding the radiating slot disposed in the upper layer and the air layer formed in the second dielectric substrate;
At one end of the ground, a depression into which the first region of the signal transmission line of the power feeding unit is inserted is formed;
a width of the depression is greater than a width of the first region of the signal transmission line;
The first region of the signal transmission line is in contact with the ground.
antenna. The method of claim 1,
The lower layer is
a first slot formed in an area vertically overlapping with the air layer;
and a second slot spaced apart from the first slot by a predetermined interval and formed in an area vertically overlapping with the first area of the signal transmission line.
antenna. The method of claim 1,
The air layer is
The at least one radiation slot formed in the ground of the upper layer overlaps in a vertical direction.
antenna. The method of claim 1,
The second dielectric substrate,
a first insulating layer;
a first metal layer disposed on the first insulating layer;
a first adhesive layer disposed on the first metal layer;
a second metal layer disposed on the first adhesive layer;
a second insulating layer disposed on the second metal layer;
a third metal layer disposed on the second insulating layer;
a second adhesive layer disposed on the third metal layer;
The first insulating layer and the second insulating layer include FR4,
The first adhesive layer and the second adhesive layer include a prepreg
antenna. 5. The method of claim 4,
The air layer is
penetrating the first adhesive layer, the second metal layer, the second insulating layer, the third metal layer, and the second adhesive layer
antenna. 3. The method of claim 2,
The second slot is
a first portion formed in a region overlapping the first region in a vertical direction;
a second portion formed by being vertically bent from one end of the first portion toward the first slot;
and a third part formed by being vertically bent from the other end of the first part toward the first slot.
antenna. 7. The method of claim 6,
The first area of the signal transmission line,
at least a portion protruding from the first portion of the second slot in the vertical direction is disposed between the second portion and the third portion,
The end of the first region,
disposed between one end and the other end of each of the second part and the three parts in the vertical direction
antenna. delete delete delete delete delete

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