KR20220155940A - antenna structure with beam tilt function - Google Patents

Abstract

The present invention provides an antenna structure capable of a beam tilt by using a single array antenna structure without using a divider which can be applied to radar for a vehicle. To achieve the purpose of the present invention, the antenna structure includes: a printed circuit board including an integrated circuit processing a radio frequency (RF) signal, a power supply line connected to the integrated circuit, and a power supply pad transmitting the RF signal by being connected to the power supply line; and a conductive upper layer connected to the power supply pad by a waveguide and including an antenna slot pattern radiating or receiving the RF signal by being opened in the vertical direction. The conductive upper layer also includes a protrusion rib installed on one side of the antenna slot pattern.

Description

Antenna structure with beam tilt function {antenna structure with beam tilt function}

The present invention relates to an antenna structure, and more particularly, to an antenna structure having a beam tilt function mounted on the left and right sides of a front and rear bumper of a vehicle so as to scan the front and rear directions of a vehicle as a corner radar for a vehicle.

The vehicle corner radar is mounted on the left and right sides of the front and rear bumpers of the vehicle, and for this reason, a beam tilt of a radiation pattern is required. This is to increase detection in a direction perpendicular to the vehicle.

Except for U.S. Patent No. 10,944,184 of Aptiv to provide such a beam tilt, it is necessary to provide a beam tilt by forming a phase difference using an additional divider, which results in a single array ), there was a problem in that many antennas had to be placed because the antennas could not be used.

The above-described information disclosed in the background art of the present invention is only for improving the understanding of the background of the present invention, and thus may include information that does not constitute prior art.

An object to be solved by the present invention is to solve the above problems, and the present invention is to provide an antenna structure capable of beam tilt using a single array antenna structure without using a divider applicable to a vehicle radar. .

An antenna structure having a beam tilt function according to an embodiment of the present invention includes an integrated circuit for processing a radio frequency (RF) signal, a feed line connected to the integrated circuit, and a feed pad connected to the feed line to transmit an RF signal. A printed circuit board comprising; and a conductive upper layer including an antenna slot pattern connected to the feed pad through a waveguide and opened in a vertical direction to radiate or receive an RF signal, wherein the conductive upper layer is provided on one side of the antenna slot pattern. further includes ribs,

The antenna structure is disposed between the printed circuit board and the conductive upper layer, and is provided in a region connected to a power feeding pad of the printed circuit board and is disposed on an upper surface of the printed circuit board while being connected to a feed hole opened in a vertical direction and connected to the feed hole. and a conductive lower layer that is in close contact between the printed circuit board and the conductive upper layer.

The antenna slot pattern of the conductive upper layer may include a linear slot array disposed above the waveguide of the conductive lower layer, and the protruding rib may be provided on a side of the first row slot array.

The protruding rib may be provided in a straight line shape equal to the length of the first row of slot arrays.

The antenna slot pattern of the conductive upper layer may include a zigzag-shaped two-column slot array disposed above the waveguide of the conductive lower layer, and the protruding rib may be provided on a side of each slot of the two-column slot array. have.

The protruding rib may be provided in a straight line shape similar to the entire length of the two-column slot array.

A cross-sectional shape of the protruding rib may include a triangular, quadrangular, trapezoidal, semicircular or semielliptical shape.

The conductive upper layer may further include a peripheral slot pattern having a plurality of slot arrays provided around the antenna slot pattern.

The peripheral slot pattern may have a depth of 1/4 of an RF signal wavelength.

The peripheral slot pattern may include a long hole-shaped slot penetrating in a vertical direction or a long hole-type groove dug in a vertical direction.

The peripheral slot pattern may include a plurality of slot arrays.

The waveguide of the conductive lower layer may include a bottom surface lower than the top surface, side surfaces connected from both ends of the bottom surface to the top surface, and protrusions protruding upward from a center of the bottom surface.

A total length along the cross section of the bottom surface and the protrusion may be equal to or greater than half a wavelength of an RF signal.

A height of the protrusion may be greater than a width of the protrusion and greater than half a depth of the side surface.

The printed circuit board, the conductive lower layer, and the conductive upper layer are coupled to each other in a guide protrusion and guide hole coupling method, and the printed circuit board, the conductive lower layer, and the conductive upper layer each include a rivet hole to which a rivet is coupled. Thus, they can be coupled to each other in a rivet manner.

The antenna slot pattern of the conductive upper layer includes at least two rows of slot arrays, and in the at least two rows of slot arrays, the slot lengths of the first row and the second row may be different from each other or the slots of each row may be arranged in a zigzag pattern.

According to the present invention, a single array antenna can be used or provided without an additional divider by tilting a beam by further forming a protrusion next to an antenna slot in a vehicle antenna.

1 is an exemplary view of an antenna structure according to an embodiment of the present invention.
2A and 2B are a plan view and a bottom view illustrating a conductive lower layer in an antenna structure according to an embodiment of the present invention.
3A and 3B are a plan view and a bottom view illustrating a conductive upper layer in an antenna structure according to an embodiment of the present invention.
4A and 4B are a plan view and a bottom view illustrating a conductive sublayer in an antenna structure according to an embodiment of the present invention.
5 is a partial perspective view illustrating a mutual relationship between a printed circuit board and a conductive lower layer in an antenna structure according to an embodiment of the present invention.
6 is a graph showing the bandwidth of the antenna shown in FIG. 1;
7 is a graph showing a radiation pattern of the antenna shown in FIG. 1;
8A and 8B are exemplary diagrams of protrusion waveguides in the antenna structure shown in FIG. 1 .
9 is an exemplary view comparing the spacing between antennas when a hollow waveguide VS a protrusion waveguide is applied.
10 is a cross-sectional view of FIG. 8B.
11A is a diagram showing an antenna structure of a vehicle radar as a comparative example of the present invention, and FIG. 11B is a diagram showing a signal waveform including an angle error according to the antenna structure of FIG. 11A.
12A is a diagram showing an overlapping shape of an antenna structure according to an embodiment of the present invention, and FIG. 12B is a diagram showing a signal waveform including an angle error according to the shape of the antenna of FIG. 12A.
13A is a diagram showing a TX1/3 radiation pattern before applying a peripheral slot pattern, and FIG. 13B is a diagram showing a TX1/3 radiation pattern after applying a peripheral slot pattern.
14A is a diagram illustrating an RX 1/2/3/4 radiation pattern before applying a peripheral slot pattern, and FIG. 14B is a diagram illustrating an RX 1/2/3/4 radiation pattern after applying a peripheral slot pattern.
15 is a diagram illustrating a pattern referred to in designing a peripheral slot pattern.
16 is an enlarged view of an antenna structure and a partial area thereof according to an embodiment of the present invention.
17 is a diagram comparing the magnitudes of electric fields on the upper surface of an antenna shape according to an embodiment of the present invention.
18 and 19 are plan and cross-sectional views illustrating structures of a single array antenna and a slot having a beam tilt structure according to an embodiment of the present invention.
20 and 21 are graphs illustrating radiation patterns of a beam tilt antenna structure according to an embodiment of the present invention.
22 is a diagram showing an electric field distribution of a beam tilt antenna structure according to an embodiment of the present invention.
23 and 24 are plan and cross-sectional views illustrating a beam tilt antenna structure according to an embodiment of the present invention.
25 is a graph showing a radiation pattern for a beam tilt antenna structure according to an embodiment of the present invention.
26 is a diagram illustrating an application example of a beam tilt antenna according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of explanation, and the same reference numerals refer to the same elements in the drawings. As used herein, the term "and/or" includes any one and all combinations of one or more of the listed items. In addition, the meaning of "connected" in the present specification means not only when member A and member B are directly connected, but also when member A and member B are indirectly connected by interposing member C between member A and member B. do.

Terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, when used herein, “comprise, include” and/or “comprising, including” refers to a referenced form, number, step, operation, member, element, and/or group thereof. presence, but does not preclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

In this specification, terms such as first and second are used to describe various members, components, regions, layers and/or portions, but these members, components, regions, layers and/or portions are limited by these terms. It is self-evident that These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described in detail below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

Space-related terms such as “beneath,” “below,” “lower,” “above,” and “upper” are associated with an element or feature shown in a drawing. It can be used for easy understanding of other elements or features. Terminology related to this space is for easy understanding of the present invention according to various process conditions or use conditions of the present invention, and is not intended to limit the present invention. For example, if an element or feature in a figure is turned over, an element or feature described as "lower" or "below" becomes "above" or "above." Accordingly, "below" is a concept encompassing "upper" or "below".

1 is an exemplary diagram of an antenna structure 100 according to an embodiment of the present invention. As shown in FIG. 1, the antenna structure 100 according to an embodiment of the present invention includes a printed circuit board 110 and a conductive upper layer 130, and may further include a conductive lower layer 120. have. In some examples, the antenna structure 100 according to an embodiment of the present invention may further include a conductive sublayer 140 .

The antenna structure 100 according to the present invention can be implemented with the printed circuit board 110 and the conductive upper layer 130, and the conductive lower layer 120 between the printed circuit board 110 and the conductive upper layer 130 The antenna structure 100 according to the present invention may be implemented by including. In addition, the antenna structure 100 according to the present invention may be implemented by including the printed circuit board 110, the conductive lower layer 120, the conductive upper layer 130, and the conductive sub-layer 140.

When the antenna structure 100 according to the present invention is implemented with the printed circuit board 110 and the conductive upper layer 130, the conductive upper layer 130 passes through a propagation path to the power supply pad 113 of the printed circuit board 100. ) and includes an antenna slot pattern 131 that is open in the vertical direction and radiates or receives an RF signal. The antenna slot pattern 131 of the conductive upper layer 130 may transmit an RF signal by being connected to the feed pad 113 of the printed circuit board 110 through various propagation passages such as a waveguide and/or a feed hole.

The printed circuit board 110 has a substantially flat plate shape, and an integrated circuit 111 for processing an RF signal may be mounted on the surface. In addition, the printed circuit board 110 may include a power supply line 112 electrically connected to the integrated circuit 111 and a power supply pad 113 electrically connected to the power supply line 112 to transmit or receive an RF signal. have. In some examples, the entire outer area of the integrated circuit 111 , the power supply line 112 , and the power supply pad 113 of the printed circuit board 110 may be coated with metal. In some examples, a region of the printed circuit board 110 facing the conductive sub-layer 120 and/or the conductive sub-layer 140 may be coated with a metal to prevent transmission/reception loss of electromagnetic waves. In some examples, the printed circuit board 110 may further include a plurality of rivet holes 119 for riveted coupling. In some examples, printed circuit board 110 may include or be referred to as a radar board.

The conductive lower layer 120 has a substantially flat plate shape and is provided in an area connected to the power supply pad 113 of the printed circuit board 110 (transmission and reception of electromagnetic waves is possible) and includes a power supply hole 121 and a power supply hole opened in a vertical direction. It may include a protrusion waveguide 122 disposed on the upper surface while being connected to (121). In some examples, the protrusion waveguide 122 may further include a bottom surface 1221 , a side surface 1222 and a protrusion 1223 , which are described again below. In some examples, the feed hole 121 may have a rectangular shape, a rectangular shape with rounded corners, or an elliptical shape, and the waveguide 122 may have a shape of a long straight line or a wired line. In some examples, the conductive lower layer 120 may be adhered to and fixed to the printed circuit board 110 using a rivet method, and may further include a plurality of rivet holes 129 for this purpose. In some examples, the conductive lower layer 120 may include or be referred to as an antenna feed layer.

The conductive upper layer 130 has a substantially flat plate shape and is provided in an area corresponding to the waveguide 122 of the conductive lower layer 120 and is vertically open to form a plurality of antenna slot patterns 131 for radiating or receiving RF signals. can include In some examples, the antenna slot pattern 131 may include slots and/or slot arrays 132 arranged in a single row or multiple rows and having a shape of a rectangle, a rectangle with rounded corners, or an ellipse. In some examples, the antenna slot pattern 131, the antenna slot array 132, and the antenna slot may be used interchangeably, but all of them are for describing a form penetrating the conductive upper layer 130 in a vertical direction.

In some examples, the conductive upper layer 130 may further include a peripheral slot pattern 133 having a vertically open or grooved shape at one side of the slot array 132 . In some examples, the peripheral slot pattern 133 may include or be referred to as a corrugation structure that may improve ripple and angle error. Such a corrugation structure can, for example, improve angle errors for improving angular resolution in vehicle radars that are used for accident prevention and autonomous driving by detecting the distance, speed, angle, etc. of objects around a vehicle equipped with vehicle radars. can In other words, the corrugation structure can improve the angle error of the sensing object by improving the angle error for improving the angular resolution.

In some examples, the conductive upper layer 130 may be riveted to and fixed to the conductive lower layer 120 and/or the printed circuit board 110, and for this purpose, a plurality of rivet holes 139 may be further included. can In some examples, the conductive upper layer 130 may include or be referred to as an antenna slot layer or an antenna radiating portion.

The optional conductive sub-layer 140 has a substantially flat plate shape and may be interposed between the printed circuit board 110 and the conductive sub-layer 120 as a structure for transitioning electromagnetic waves. In some examples, the conductive sub-layer 140 is also an RF signal path provided between the feed pad 113 of the printed circuit board 110 and the feed hole 121 of the conductive lower layer 120, that is, the feed hole 141 can include The RF signal path may also have a rectangular shape or a rectangular shape with rounded corners or an oval shape when viewed from a plan view. In some examples, the conductive upper layer 130 is riveted together to the conductive lower layer 120, the conductive upper layer 130, and the printed circuit board 110 to provide a plurality of rivet holes 149 so that they can be closely attached and fixed. can include more. In some examples, the conductive sub-layer 140 may include or be referred to as an antenna feed layer or a printed circuit board connection.

In some examples, the conductive lower layer 120, the conductive upper layer 130, and the conductive sub-layer 140 may include an insulating body (not shown) molded or molded by a plastic injection method and a conductive layer coated on the surface of the insulating body, respectively. (not shown). The insulating body may be a conventional thermosetting or thermoplastic resin, and the conductive layer may include at least one of common copper, gold, platinum, silver, aluminum, and nickel, or an alloy thereof. In some examples, the conductive layer may include a top surface, a bottom surface, a side surface, a waveguide, a feed hole, and/or a rivet hole, which may be provided on the conductive lower layer 120, the upper conductive layer 130, and the conductive sub layer 140, respectively. It can be provided on any surface in contact with the outside air.

In this way, according to an embodiment of the present invention, an angular error of a sensing object can be improved by providing an angle error improvement structure to which a gain deviation improvement structure for each antenna port is applied for improving angular resolution. In addition, the antenna structure 100 according to an embodiment of the present invention can simultaneously implement wideband/wide angle characteristics suitable for a corner radar for a next-generation vehicle.

2A and 2B are a plan view and a bottom view illustrating a conductive lower layer 120 of an antenna structure 100 according to an embodiment of the present invention.

As shown in FIGS. 2A and 2B, the conductive lower layer 120 of the antenna structure 100 according to an embodiment of the present invention has a substantially flat upper surface and a substantially flat lower surface, and the upper and lower surfaces have waveguides 122 and 122, respectively. B) may be provided. Of course, the waveguide 122 on the upper surface and the waveguide 122B on the lower surface may be connected to each other through the feed hole 121 . In some examples, the waveguide 122 provided on the top surface of the conductive lower layer 120 includes a bottom surface 1221 lower than the top surface, side surfaces 1222 connected from both ends of the bottom surface 1221 to the top surface, and bottom surface 1221 ) may include a protrusion 1223 protruding upward from the center. In some examples, the waveguide 122B provided on the lower surface of the conductive lower layer 120 may not include the protrusion 1223 .

In some examples, two transmission waveguides 122 are provided in an approximately upper region of the upper surface of the conductive lower layer 120, one transmission waveguide 122 is provided in an approximately central region, and four transmission waveguides 122 are provided in an approximately lower region. A receiving waveguide 122 may be provided. As described above, all of the three transmission waveguides 122 and the four reception waveguides 122 may be protrusion waveguides 122, and may have a predetermined length in a straight or streamlined shape.

In some examples, three transmission waveguides 122B may be provided in an approximately upper region of the lower surface of the conductive lower layer 120 and four reception waveguides 122B may be provided in approximately a central region and a side region.

As described above, the waveguide 122 on the upper surface and the waveguide 122B on the lower surface may be connected to each other through the feed hole 121 .

In some examples, the conductive lower layer 120 may include a plurality of rivet holes 129 penetrating upper and lower surfaces. In some examples, the conductive lower layer 120 may include a plurality of guide protrusions 128T provided on an upper surface and a plurality of guide holes 128B penetrating the upper and lower surfaces. In some examples, the conductive lower layer 120 may further include a guide groove 129T provided around the rivet hole 129 on the upper surface. The diameter of the guide groove 129T may be greater than the diameter of the rivet hole 129 .

The guide protrusion 148T of the conductive sub-layer 140 may be coupled to the guide hole 128B of the conductive lower layer 120, and the guide protrusion 128T of the conductive lower layer 120 may be coupled to the guide protrusion 128T of the conductive upper layer 130. ) may be coupled to the guide hole 138B, and the guide protrusion 148T of the conductive upper layer 130 may be coupled to the guide groove 129T of the conductive lower layer 120.

3A and 3B are a plan view and a bottom view illustrating the conductive upper layer 130 of the antenna structure 100 according to an embodiment of the present invention.

As shown in FIGS. 3A and 3B , the conductive upper layer 130 of the antenna structure 100 according to an embodiment of the present invention has a substantially flat upper surface and a substantially flat lower surface, and penetrates the upper and lower surfaces in a vertical direction. may include a plurality of antenna slot patterns 131 and/or a plurality of antenna slot arrays 132.

In some examples, the antenna slot pattern 131 includes two slot arrays 132 arrayed in two rows at approximately the upper region of the conductive upper layer 130 and one slot array 132 arrayed in one row at approximately the central region. can include In some examples, the two slot arrays 132 and the one slot array 132 may be provided in regions corresponding to the protrusion waveguides 122 provided on the conductive lower layer 120 , respectively.

In some examples, the conductive upper layer 130 may further include perforated or grooved peripheral slot patterns 133 in a vertical direction between and outside the two slot arrays 132, respectively. . In some examples, the peripheral slot pattern 133 may include or be referred to as a corrugation structure, which may improve ripple and angle error. In some examples, the conductive upper layer 130 may further include a peripheral slot pattern 133 provided in a zigzag type and a groove shape at the outer side of one zigzag type slot array 132 on the lower surface (see FIG. 3B ). ).

In some examples, the length of each slot in the two-column slot array 132 may be different. In other words, the length of each slot constituting the first column and the length of each slot constituting the second column may be different from each other. For example, the slot length of the first column may be greater than the slot length of the second column.

In this way, by setting the length of each slot differently in the two-column slot array 132, the beam tilt performance can be improved.

In some examples, the antenna slot pattern 131 may further include a plurality of slot arrays 132 arranged in multiple rows at approximately a lower region of the conductive upper layer 130 .

In some examples, the plurality of slot arrays 132 may be provided in regions corresponding to the protrusion waveguides 122 provided on the conductive lower layer 120 .

In some examples, multiple slot arrays 132 arranged in multiple rows may be arranged in a staggered fashion. At this time, it is preferable that the length of each slot arrayed in a zigzag manner is the same.

In some examples, the conductive top layer 130 may further include perforated or grooved peripheral slot patterns 133 in a vertical direction capable of improving ripple and angle errors on either side of the multiplicity of slot arrays 132 . can

In some examples, the thickness of the conductive upper layer 130 may be thinner than the thickness of the conductive lower layer 120 . Accordingly, the conductive upper layer 130 may be provided in a cover form substantially covering the conductive lower layer 120 .

In addition, the conductive upper layer 130 includes a plurality of rivet holes 139, and the guide hole 138B to which the guide protrusion 128T of the conductive lower layer 120 is coupled and the guide groove of the conductive lower layer 120 A guide protrusion 139B coupled to 129T may be further included.

4A and 4B are a plan view and a bottom view illustrating the conductive sublayer 140 of the antenna structure 100 according to an embodiment of the present invention.

4A and 4B, the conductive sublayer 140 of the antenna structure 100 according to an embodiment of the present invention has a substantially flat upper surface and a substantially flat lower surface, and the waveguide 142 provided on the upper surface And it may include a passage (142B) provided on the lower surface.

In some examples, the waveguide 142 on the upper surface and the passage 142B on the lower surface may be connected with a plurality of power supply holes 141 or RF signal passages penetrating the upper and lower surfaces.

In some examples, an area accommodating the RF integrated circuit 111 provided on the printed circuit board 110, an area accommodating the power supply line 112, and a power supply pad 113 are accommodated on the lower surface of the conductive sub-layer 140. In this case, the receiving area of the feeding line 112 and the receiving area of the feeding pad 113 may be referred to as a passage 142B for convenience of description.

In some examples, the feed hole 141 of the conductive sub-layer 140 may be provided in a region corresponding to the feed pad 113 of the printed circuit board 110 .

In some examples, the conductive sub-layer 140 may include a plurality of rivet holes 149, and further include a guide protrusion 148T coupled to a guide hole 128B provided in the conductive sub-layer 120. can do.

In this way, the conductive sub-layer 140, the conductive lower layer 120, and the conductive upper layer 130 mutually form guide protrusions 148T, 128T, 139B, guide holes 128B, 138B, and guide grooves ( 129T), and furthermore, the rivets 150 may be coupled to each other through the rivet holes 149, 139, 129, and 119. Moreover, the printed circuit board 110 may also be rivet-joined to this structure.

5 is a partial perspective view illustrating a mutual relationship between a printed circuit board 110 and a conductive lower layer 120 of the antenna structure 100 according to an embodiment of the present invention.

In some examples, conductive sublayer 120 may be conductive sublayer 140 . As shown in FIG. 5 , the lengths of the power supply lines 112 and the power supply pads 113 of the printed circuit board 110 may be relatively long or extended in the longitudinal direction.

In some examples, the length of the feed hole 121 provided in the conductive lower layer 120 (or the conductive sub layer 140) is also relatively long in the longitudinal direction similar to the feed line 112 and the feed pad 113 Or it may be in an extended form.

Of course, the waveguide 122 (or passage 142B) provided in the conductive lower layer 120 (or the conductive sub-layer 140) and the feed hole 121 (or the feed hole 141) are the printed circuit board 110 ) may be provided at positions corresponding to the feed line 112 and the feed pad 113. In some examples, this structure may include or be referred to as a transition structure or adapter.

6 is a graph showing a bandwidth of the antenna structure 100 shown in FIG. 1, and FIG. 7 is a graph showing a radiation pattern of the antenna structure 100 shown in FIG.

As shown in FIGS. 6 and 7, the antenna structure 100 according to an embodiment of the present invention operates in a bandwidth of about 76 GHz to about 81 GHz, that is, about 5 GHz, and the beam width of the antenna is about 150 degrees or more. It can be seen that the structure can be applied to the corner radar for vehicles since the wide-angle characteristics can be implemented at the same time.

8A and 8B are exemplary diagrams of the protruding waveguide 122 of the antenna structure 100 shown in FIG. 1, FIG. 9 is an exemplary diagram comparing the spacing between antennas when the hollow waveguide VS the protruding waveguide is applied, and FIG. 10 is It is a cross-sectional view of FIG. 8B.

As shown in FIG. 8A, the protrusion waveguide 122 provided on the top surface of the conductive lower layer 120 has a bottom surface 1221 lower than the top surface, and side surfaces 1222 connected from both ends of the bottom surface 1221 to the top surface, respectively. and a protrusion 1223 protruding upward from the center of the bottom surface 1221 . In some examples, protrusion 1223 may include or be referred to as a protrusion or protrusion.

In some examples, the upper end (cross-sectional shape) of the protrusion 1223 may include a substantially round (or round) shape, a square shape, or a triangular shape.

In some examples, the total length A along the cross section of the bottom surface 1221 and the protrusion 1223 may be half the wavelength of the RF signal, i.e., half a wavelength or more.

In some examples, the height B of the protrusion 1223 may be greater than the width C of the protrusion 1223 and greater than half the depth E of the side surface 1222 . Reference numeral D in the drawing indicates the width of the shortest straight line distance of the waveguide 122.

In some examples, the distance between the antennas of the transmitter and/or receiver of the vehicle radar may be provided as a half-wavelength based on a center frequency of an operating frequency. In the case of requiring a band of approximately 5 GHz, such as a corner radar for a vehicle, the transmitter and/or receiver antennas may be disposed at intervals of approximately 1.91 mm, which is a half-wavelength of 78.5 GHz, which is a center frequency of approximately 76 GHz to approximately 81 GHz.

In this case, it can be seen that a slot array antenna using a general hollow waveguide (refer to the left drawing of FIGS. 8B, 9, and 10) cannot be applied because the width of the waveguide is approximately 2.54 mm and is larger than half a wavelength. However, in the present invention, this problem can be solved by using a slot array antenna to which the protrusion waveguide 122 is applied.

In some examples, since the protrusion waveguide 122 can reduce the width of the waveguide to approximately 1.4 mm (see the right side view of FIG. 13B), a distance of approximately 1.91 mm between the antennas of the transmitter and/or receiver required by the radar can be applied. It can be (refer to the right drawing of FIG. 9).

The protrusion waveguide 122 has a structure in which the protrusion 1223 is placed inside the hollow waveguide to lower the cutoff frequency of the waveguide so that it can be used in the same band as the hollow waveguide even with a smaller waveguide width.

Referring to FIGS. 8B, 9, and 10, a hollow waveguide on the left side and a protrusion waveguide 122 on the right side are shown. For example, even when the inner width of the waveguide is as small as about 1.4 mm, it is shown on the left side of FIG. It is possible to operate in the band of about 70 GHz in the same way as the hollow waveguide. If a hollow waveguide having a width of about 1.4 mm is used, the cut-off frequency of the waveguide of this structure is about 107 GHz, which is out of the band of about 76 GHz to about 81 GHz, which is the operating frequency range of vehicle radar.

The protrusion waveguide 122 can change the impedance of the waveguide 122 by adjusting the height and width of the internal protrusion 1223. The smallest size was achieved.

Hereinafter, comparative examples and embodiments of the present invention will be described based on an overlapping state of the conductive lower layer 120 having the waveguide 122 and the conductive upper layer 130 having the antenna slot pattern 131.

11A is a diagram showing an antenna structure of a vehicle radar as a comparative example of the present invention, and FIG. 11B is a diagram showing a signal waveform including an angle error according to the antenna structure of FIG. 11A.

As shown in FIGS. 11A and 11B, in the case of an antenna structure without a peripheral slot pattern (or corrugation structure) proposed in the present invention, the difference in angle error (refer to the red square box in FIG. 11B) is approximately 45 degrees When comparing the blue line between ~ about 75 degrees, it can be confirmed that about 5 degrees or more occur. Therefore, it can be seen that when the antenna structure according to the comparative example is applied to a vehicle radar, the detection accuracy for the position (angle) of the object is significantly reduced.

12A is a diagram showing an overlapping shape of the antenna structure 100 according to an embodiment of the present invention, and FIG. 12B is a diagram showing a signal waveform including an angle error according to the shape of the antenna of FIG. 12A.

As shown in FIG. 12A, the antenna structure 100 according to the embodiment of the present invention is between two slot patterns 131 (or slot arrays) and two slot patterns 131 ( Alternatively, a peripheral slot pattern 133 (or a corrugated structure) may be further included on the outer side of the slot array) each of which is vertically penetrated or grooved.

In some examples, the peripheral slot pattern 133 may include a peripheral slot array configured by arranging 5 slots of 3 slots in 3 rows. In some examples, the two slot patterns 131 (or slot array) provided in the approximately upper region of the conductive upper layer 130 include a first transmit port (or TX 1 ) and a third transmit port (or TX 3 ). or may be referred to as

In some examples, the antenna structure 100 is provided on both sides of one slot pattern 131 (or slot array) provided in an approximately central region of the conductive upper layer 130, and peripheral slot patterns in the form of long hole-shaped grooves that are not penetrated, respectively. (133) (or a corrugation structure) may be further included (see FIG. 3B). These peripheral slot patterns 133 may be arranged in a substantially zigzag shape. In addition, one slot pattern 131 (or slot array) provided in an approximately central region of the conductive upper layer 130 may include or be referred to as a second transmission port (or TX 2 ).

In some examples, the antenna structure 100 includes peripheral slot patterns 133 (perforated or grooved) on both sides of four slot patterns 131 (or slot arrays) provided in approximately a lower region of the conductive upper layer 130, respectively. or a corrugation structure) may be further included. In some examples, the peripheral slot pattern 133 may consist of an array of five elongated slots. In some examples, the four slot patterns 131 (or slot arrays) provided at approximately the lower area of the conductive upper layer 130 are the first, second, third, and fourth receive ports (or RX 1, RX 2, RX 3, RX 4) may include or be referred to as.

In some examples, the peripheral slot pattern 133 (or corrugation structure) may also include or be referred to as a soft surface structure, which is a port-specific (TX 1/3, RX 1/2/3/4) of an antenna. An angle error may be improved by improving a radiation pattern gain deviation.

In the antenna structure 100 according to the embodiment of the present invention configured as described above, as shown in FIG. 12B, when looking at the angle error difference (red box part) between about 45 degrees and about 75 degrees, in particular, the blue line In comparison, it can be seen that the value of the angle error is almost all within about 3 degrees (more than 5 degrees in the case of the comparative example).

13A is a diagram showing a TX 1/3 radiation pattern before applying the peripheral slot pattern 133, and FIG. 13B is a diagram showing a TX 1/3 radiation pattern after applying the peripheral slot pattern 133.

Referring to FIGS. 13A and 13B, as a result, the radiation pattern of the transmission port TX 1/3 before application of the peripheral slot pattern 133 has a greater difference in the gain of the radiation pattern between the antennas, and the beam shape itself is distorted. , In the case of the transmission port TX 1, it can be seen that the ripple is more severe, but it can be seen that the ripple, distortion, and difference of the radiation pattern are reduced after the peripheral slot pattern 133 is applied.

In addition, the peripheral slot pattern 133 applied to the receiving port RX has the same effect and blocks the lateral wave (surface wave) flowing to the ground surface of the antenna of the receiving port RX 1/RX 4, thereby reducing the radiation of the antenna. Since the pattern is prevented from being tilted in the ground direction, it can be seen that the reception port RX 1/2/3/4 has a similar radiation pattern of the antenna after application of the peripheral slot pattern 133 compared to before application.

14A is a diagram showing the RX 1/2/3/4 radiation pattern before applying the peripheral slot pattern 133, and FIG. 14B is a diagram showing the RX 1/2/3/4 radiation pattern after applying the peripheral slot pattern 133. is a drawing showing

Looking at the above results, it can be seen that the gain deviation between the receiving port RX 1/2/3/4 radiation patterns marked with a red circle is significantly reduced. In addition, it can be seen that the maximum deviation is approximately 7.4 dB before application of the peripheral slot pattern 133, whereas the maximum deviation is improved to approximately 2.3 dB after application.

The peripheral slot pattern 133 or the corrugation structure may have the following design formula, which is as follows.

15 is a diagram showing a pattern referred to in designing the peripheral slot pattern 133.

As shown in FIG. 15, according to the formula, the height (or depth of the slot) of the peripheral slot pattern 133 or the corrugation structure may be set to be similar to 1/4 wavelength of the center frequency of the operating frequency λ, , the sum of the widths and periods of the adjacent slots must be much smaller than the half-wavelength of the center frequency. The structure of FIG. 15 is expressed as Equation 1 below.

If this is calculated based on the frequency of 78.5 GHz, the calculated value: W + V << 1.91 mm, d = 0.955 mm is calculated.

In the case of the structure applied in the embodiment of the present invention, W = 0.5mm / V = 0.5mm / d = 1.2mm, which are the minimum dimensions that can be manufactured, and the smaller the dimensions, the higher the stable operation of the peripheral slot pattern 133 this can be guaranteed.

In addition, the length of the peripheral slot pattern 133 does not affect the angle error, etc., and can be applied with a minimum dimension-based manufacturable length (approximately 3.5 mm).

16 is an enlarged view of an antenna structure 100 and a partial area thereof according to an embodiment of the present invention, and FIG. 17 is a view comparing the magnitude of an electric field on the upper surface of an antenna shape according to an embodiment of the present invention. .

As shown in FIGS. 16 and 17, when the peripheral slot pattern 133 is applied, the size of the electric field at the upper surface of the antenna is reduced (see the left photo of FIG. 17), while the antenna when the peripheral slot pattern 133 is not applied. It can be seen that the magnitude of the electric field at the upper surface is not reduced (meaning that the magnitude of the electric field increases as the color goes to red).

In this way, according to the present invention, by further providing an additional peripheral slot pattern (in the form of a through hole or groove) or a corrugation structure around the antenna slot pattern or slot array, improvement in gain deviation per antenna port for improving angular resolution It is possible to provide an antenna structure 100 capable of providing a structure, thereby providing an angle error improvement structure, and eventually improving an angle error of a sensing object.

18 and 19 are plan and cross-sectional views illustrating structures of a single array antenna and a slot having a beam tilt structure according to an embodiment of the present invention. In particular, FIGS. 18 and 19 are plan and cross-sectional views illustrating the conductive upper layer 130 of the antenna structure 100 according to the embodiment of the present invention.

As shown in FIGS. 18 and 19, the antenna slot pattern 131 of the upper conductive layer 130 is a linear slot array (1 row) disposed on the protrusion waveguide 122 of the lower conductive layer 120. 132) may be included. That is, a plurality of slots may be arranged in one row in a substantially straight line with a predetermined pitch to form the slot array 132 .

In some examples, the conductive upper layer 130 may further include protruding ribs 134 provided on the side of the row of slot arrays 132 on the top surface. In some examples, the protruding ribs 134 may be provided in a straight line at the side of the row of slot arrays 132 to approximate the entire length of the slot array. In practice, the length of the protruding rib 134 may be equal to, shorter, or longer than the entire length of the row of slot arrays 132 .

Meanwhile, as will be described later, the protruding ribs 134 may be provided independently for each slot of the slot array 132 .

In some examples, the protruding rib 134 may protrude from the upper surface of the conductive upper layer 130 toward the upper direction by a predetermined height. In some examples, the protruding rib 134 may include a triangular, square, trapezoidal, semicircular, or semi-elliptical shape in cross-section.

In this way, the protruding rib 134 tilts the beam, thereby providing a single array antenna structure without an additional divider.

20 and 21 are graphs illustrating radiation patterns of a beam tilt antenna structure according to an embodiment of the present invention.

Referring to FIGS. 20 and 21 , it can be seen from the result of the radiation pattern that the beam is tilted when the protruding rib 134 is applied in the beam tilt antenna structure of the present invention. As an example, it can be seen that the beam is tilted in the range of approximately 25 degrees to approximately 60 degrees (see red circles in FIGS. 20 and 21 ).

22 is a diagram showing an electric field distribution of a beam tilt antenna structure according to an embodiment of the present invention.

Referring to FIG. 22, the electric field distribution radiated from the antenna in the beam tilt antenna structure according to an embodiment of the present invention is shown. Due to the protruding ribs indicated by the red circles in FIG. formation can be observed. In FIG. 22, the intensity of the electric field increases as it becomes red.

23 and 24 are plan and cross-sectional views illustrating a beam tilt antenna structure according to an embodiment of the present invention.

23 and 24, the antenna slot pattern 131 of the upper conductive layer 130 is a two-column slot array ( 132) may be included. That is, a plurality of slots may be arranged in two rows in a zigzag shape to form the slot array 132 . In other words, the slot array 132 of one column and the slot array 132 of another column adjacent to it may not overlap each other in the horizontal direction.

In some examples, the protruding rib 134A may be provided on each side of each slot of the zigzag two-column slot array 132 . In other words, the protruding rib 134A may be provided independently for each slot constituting the slot array.

In some examples, the protruding rib 134A may be provided in a straight line shape similar to or equal to the length of each slot of the zigzag two-column slot array 132 . In practice, the length of the protruding rib 134A may be equal to, shorter, or longer than the length of each slot.

In some examples, the protruding rib 134A may protrude from the upper surface of the conductive upper layer 130 toward the upper direction by a predetermined height, and may have a cross-sectional shape (cross-sectional shape in the width direction or cross-sectional shape in the longitudinal direction) of the protruding rib 134. ) may include a triangular, quadrangular, trapezoidal, semi-circular or semi-elliptical shape. In the case of triangular, square or trapezoidal cross-sections, the corners may be rounded.

In this way, the protruding rib 134A tilts the beam, thereby providing a single array antenna structure without an additional divider, and also eliminating the grating lobe phenomenon.

25 is a graph showing radiation patterns for beam tilt antenna structures according to an embodiment of the present invention.

When the antenna structure according to the present invention (see FIGS. 23 and 24) is applied, there is an advantage in that a grating lobe is not generated while beam tilt is also performed.

Referring to FIG. 25, looking at the radiation pattern for the antenna structure (see FIGS. 23 and 24) according to an embodiment of the present invention, it can be seen that the beam tilt is the same as before, and the grating lobe in the vertical beam pattern It can be confirmed that neither occurs.

In some examples, it can be seen that the radiation pattern deviation for each frequency in the radiation pattern in the horizontal direction becomes more severe than that of the primary shape, and this difference in the radiation pattern for each frequency tends to become more severe as the height of the protruding rib increases.

In some examples, the protruding rib in the antenna structure (see FIGS. 23 and 24) according to an embodiment of the present invention is a relation between the height, the degree of radiation pattern beam tilt, and the radiation pattern deviation for each frequency. The higher the height of the protruding rib, the more radiation There is a trend toward +45 degree directional gain increase by patterned beam tilt.

In addition, the higher the height of the protruding rib, the more severe the radiation pattern deviation for each frequency, and the lower the height of the protruding rib, the weaker the degree of beam tilt of the radiation pattern.

26 is a diagram illustrating an application example of a beam tilt antenna according to an embodiment of the present invention.

As shown in FIG. 26, the antenna having a beam tilt function according to an embodiment of the present invention is applied to a corner radar for a vehicle and can improve detection capability in a direction generally perpendicular to the vehicle. For example, it is possible to detect another vehicle behind through the -45 degree beam and also detect two other vehicles behind through the +45 degree beam (tilted beam).

The foregoing may be modified and modified by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100; Multi-layer antenna structure according to the present invention
110; Printed circuit board 111; integrated circuit
112; feed line 113; feeding pad
119; rivet hole
120; conductive lower layer 121; feeding hall
122; Projection waveguide 122B: waveguide
1221; bottom surface 1222; side
1223; Projection 128T: guide projection
128B: guide hole 129; rivet hole
129T; guide home
130; conductive upper layer 131; antenna slot pattern
132; slot array 133; perimeter slot pattern
134; Protruding rib 138B: guide hole
139B: guide projection 139; rivet hole
140; conductive sub-layer 141; feeding hall
142; waveguide 142B; Passage
148T; guide protrusion 149; rivet hole

Claims (2)

A printed circuit board including an integrated circuit for processing a radio frequency (RF) signal, a power supply line connected to the integrated circuit, and a power supply pad connected to the power supply line to transmit an RF signal; and
A conductive upper layer including an antenna slot pattern connected to the feed pad through a waveguide and open in a vertical direction to radiate or receive an RF signal;
The antenna structure having a beam tilt function, wherein the conductive upper layer further comprises a protruding rib provided on one side of the antenna slot pattern. The method of claim 1 , disposed between the printed circuit board and the conductive upper layer, provided in a region connected to a feed pad of the printed circuit board, and a feed hole opened in a vertical direction and connected to the feed hole on an upper surface of the printed circuit board. An antenna structure having a beam tilt function, further comprising a conductive lower layer including a disposed waveguide and being in close contact between the printed circuit board and the conductive upper layer.

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