Slot array antenna with parasitic characteristics

Abstract

An illustrative example antenna device is disclosed, comprising a substrate. A plurality of conductive members in the substrate form a substrate-integrated waveguide. A plurality of first slots and second slots (5, 54) are located on the outer surface of a first portion of the substrate. Each second slot is associated with a corresponding first slot. The first and second slots are configured to establish a radiation pattern across a variation in the radiated beam emitted by the antenna device. A plurality of parasitic interference elements include slots located on the outer surface of a second portion of the substrate. The parasitic interference elements reduce ripple effects introduced by adjacent antennas.

Description

[0001] This application is a divisional application of the invention application filed by Aptiv Technology Co., Ltd. on March 5, 2020, with application number CN2202010146513.9 and title "Slot Array Antenna with Parasitic Features". Background Technology

[0002] More and more technologies are being incorporated into motor vehicles. Radar and lidar sensors provide the ability to detect objects near or in the path of a vehicle. Many of these devices include radiating antennas that emit radiation for object detection.

[0003] While different antenna types have proven useful, they are not without drawbacks or limitations. For example, some antennas used for short- or medium-range detection have the ability to cover a wide field of view, but suffer high losses when electromagnetic waves radiated from the antenna pass through a vehicle's dashboard. This high loss is often associated with the antenna's vertical polarization. One attempt to address this problem is to incorporate horizontal polarization. However, a difficulty associated with horizontal polarization is that the impedance bandwidth is often too narrow for production requirements. One way to increase the impedance bandwidth involves increasing the thickness of the antenna substrate material. The disadvantage associated with this method is that it increases cost.

[0004] Another challenge associated with some known radar antenna constructions is the presence of high-frequency ripples caused by radiation scattering from nearby antennas, vehicle electronics, and other metallic or dielectric materials adjacent to the antennas. Complicating matters further, the ripples in the radiation pattern of each antenna appear at different angles, affecting the uniformity of the radiation patterns of all antennas used in the radar. This non-uniform radiation pattern significantly reduces the angle-finding accuracy of the radar system. Summary of the Invention

[0005] An illustrative example antenna device includes a substrate. Multiple conductive members in the substrate form a substrate integrated waveguide (SIW). A first portion of the substrate is within the SIW, and a second portion of the substrate is outside the SIW. Multiple first slots are on the outer surface of the first portion of the substrate. Multiple second slots are also on the outer surface of the first portion of the substrate. Each second slot is associated with a corresponding first slot. The first and second slots are configured to create a radiation pattern that varies across a radiated beam emitted by the antenna device. Multiple parasitic interference elements (interruptions) include at least a first parasitic interference element located on a first side of the SIW and at least a second parasitic interference element located on a second, opposite side of the SIW.

[0006] In an exemplary embodiment of the antenna device having one or more features of the preceding paragraph, these parasitic interference elements each include: a slot along the outer surface of a second portion of the substrate, and at least one conductive connector that establishes a conductive connection between the outer surfaces of the second portion near the slot and a conductive layer near the opposite side of the substrate.

[0007] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, at least one conductive connector includes a plurality of conductive members.

[0008] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the parasitic interference slot has a depth corresponding to one-quarter of the wavelength being guided.

[0009] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the parasitic interference slot is lined with a conductive material.

[0010] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the conductive material comprises metal, and the conductive layer near the opposite side of the substrate comprises metal.

[0011] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the metal is copper.

[0012] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the radiation emitted by the first slot has a first feature, and the radiation emitted by the second slot has a second feature different from the first feature.

[0013] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the first feature and the second feature respectively include at least one of the power of the emitted radiation, the phase of the emitted radiation, or the gain of the emitted radiation.

[0014] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the first feature and the second feature cause the gain of the radiated beam to be biased toward one side of the radiation pattern.

[0015] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the first slot has a first length, the second slot has a second length, and the first feature and the second feature are based on the first length and the second length, respectively.

[0016] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the spacing between the associated first slot and second slot varies along the length of the substrate integrated waveguide.

[0017] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the spacing controls the intensity of radiation emitted through the associated first and second slots.

[0018] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the substrate includes a plurality of substrate integrated waveguides, at least one first parasitic interference element on a first side of each substrate integrated waveguide, and at least one second parasitic interference element on a second, opposite side of each substrate integrated waveguide.

[0019] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, each substrate-integrated waveguide includes an input port located between opposite ends of the substrate-integrated waveguide, at least some of the parasitic interference elements on one side of a corresponding one of the input ports, and at least some other parasitic interference elements on a different side of a corresponding one of the input ports.

[0020] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the substrate integrated waveguides are aligned parallel to each other, the parasitic interference elements are parallel to the substrate integrated waveguides, the input ports to at least one of the substrate integrated waveguides are located between adjacent substrate integrated waveguides, and at least some of the parasitic interference elements are located between adjacent substrate integrated waveguides.

[0021] In an exemplary embodiment having one or more features of the antenna device in any of the preceding paragraphs, the plurality of parasitic interference elements on the first side of the substrate integrated waveguide are different from the plurality of parasitic interference elements on the second side of the substrate integrated waveguide.

[0022] In an exemplary embodiment having one or more features of the antenna device described in any of the preceding paragraphs, the outer surface includes a metal layer.

[0023] An illustrative example of a method of fabricating an antenna device includes: forming a plurality of first slots on the outer surface of a first portion of a substrate, the substrate including a substrate integrated waveguide (SIW), the first portion of the substrate being within the SIW and a second portion of the substrate being outside the SIW; forming a plurality of second slots on the outer surface of the first portion of the substrate, each second slot being associated with a corresponding one of the first slots, the first and second slots being configured to establish a radiation pattern of radiation beam variation across a radiated beam emitted by the antenna device; and forming a plurality of parasitic interference elements, at least one first parasitic interference element being located on a first side of the SIW and at least one second parasitic interference element being located on an opposite second side of the SIW.

[0024] In an exemplary embodiment having one or more features of the method described in the preceding paragraph, the outer surface includes a first conductive layer. Establishing parasitic interference elements includes: forming a slot along the outer surface of a second portion of the substrate, lining the formed slot with a conductive material, and establishing a conductive connection between the outer surface of the second portion near the slot and a conductive layer near the opposite side of the substrate. Attached Figure Description

[0025] From the following detailed description, various features and advantages of at least one disclosed exemplary embodiment will become apparent to those skilled in the art. The accompanying drawings, accompanying the detailed embodiments, can be briefly described below.

[0026] Figure 1 An example embodiment of the antenna device is illustrated schematically.

[0027] Figure 2 It shows Figure 1 The selected features of the embodiments.

[0028] Figure 3 An exemplary radiation pattern emitted by an exemplary embodiment of the antenna device is shown graphically.

[0029] Figure 4 It is along Figure 1 The cross-sectional view taken by line 4-4 in the figure.

[0030] Figure 5 The graphic representation is shown by Figure 1 An exemplary radiation pattern emitted by an embodiment.

[0031] Figure 6 The following is a graphical representation of what would happen if it did not exist. Figure 1 The features of the embodiments may produce exemplary radiation patterns. Detailed Implementation

[0032] Figure 1 An example embodiment of the antenna device 20 is schematically illustrated. The substrate 22 includes a plurality of substrate integrated waveguides (SIWs). A first substrate integrated waveguide 24 is established between a plurality of conductive members 26, which in this example are conductive vias. A conductive member 28, also a conductive via in this example, establishes a first input port 30 of the first substrate integrated waveguide 24. A second substrate integrated waveguide 34 is established between a plurality of conductive members 36. The conductive member 38 establishes a second input port 40 in the second substrate integrated waveguide 34. In the illustrated example, a third SIW 44 is included, defined between a plurality of conductive members 46. The conductive member 48 establishes a third input port 50 in the third substrate integrated waveguide 44. In this example, all conductive members 36, 38, 46, and 48 are conductive vias.

[0033] The portions of substrate 22 within substrate integrated waveguides 24, 34, and 44 are all referred to as the first portion of substrate 22. The remaining portions of substrate 22 outside the substrate integrated waveguides are referred to as the second portion of substrate 22.

[0034] The outer surface 51 of substrate 22 includes a conductive material layer. In this example, the outer surface 51 includes a metal such as copper. The outer surface of a first portion of substrate 22 includes a plurality of first slots 52 and a plurality of second slots 54. The first slots 52 and the second slots 54 allow energy within the respective substrate integrated waveguides to radiate through the slots 52 and 54. Each substrate integrated waveguide having slots 52 and 54 serves as an antenna.

[0035] The radiation emitted through the first slot 52 has different characteristics than the radiation emitted through the second slot 54. These different characteristics can be any of the power, phase, or gain of the radiation. In the example shown, the different characteristics arise from the different dimensions of the first slot 52 compared to the second slot 54.

[0036] Each second slot 54 is associated with one of the first slots 52. Figure 2 An exemplary group of first slots 52 and associated second slots 54 is shown. The first length L1 of the first slot 52 is longer than the second length L2 of the second slot 54. In the illustrated example, all first slots 52 are longer than their associated second slots 54. The different lengths L1 and L2 provide a varying radiation pattern between the radiated beams emitted by each substrate-integrated waveguide antenna. The different lengths result in different phases of the radiation, and the arrangement of the first slots 52 along one side of the substrate-integrated waveguide and the second slots 54 along the other side of the substrate-integrated waveguide provides a phase tilt that causes the radiation gain from the substrate-integrated waveguide antenna gain towards a one-sided bias.

[0037] Figure 3 A graph showing the gain across the radiation pattern of an exemplary radiating beam. The gain is higher at 62 than at 64 and is biased to one side of the radiating beam. Such a radiation pattern makes the exemplary embodiment usable, for example, with a medium-range radar, and provides a narrow elevation angle and a wide azimuth range at significant distances. Figure 3 As in the example, biasing the gain to one side allows, for example, the strategic placement of multiple antenna devices 20 on the vehicle to achieve a desired sensing or detection radiation pattern around the vehicle perimeter.

[0038] The associated first and second slots 52 and 54 are spaced apart by a distance S. The distance S varies along the length of the corresponding substrate-integrated waveguide. The distance S near the input portion and the end portion of the substrate-integrated waveguide is smaller compared to the distances between the other associated first and second slots 52 and 54. The different distances between the associated first and second slots 52 and 54 correspond to different distances between the respective slots 52 and 54 and the conductive members 26, 36, or 46 that establish the boundary of the substrate-integrated waveguide. Figure 2 The distance shown at point D affects the radiation intensity from the corresponding slot. A smaller distance D provides stronger radiation. Varying the spacing S and distance D along the length of the substrate-integrated waveguide achieves the desired taper of the radiated beam. In the example shown, the radiated beam tapers near the edge of the beam.

[0039] Figure 1 Example embodiments include multiple parasitic interference elements 70 to minimize or eliminate interference or connections between substrate-integrated waveguide antennas. The parasitic interference elements 70 also reduce interference caused by other devices near the antenna assembly 20. The parasitic interference elements 70 include a slot 72 on the outer surface 51 of a second portion of the substrate outside the substrate-integrated waveguide. The depth of the slot 72 corresponds to one-quarter of the guided wavelength. The parasitic interference elements 70 also include multiple conductive connectors 74 located on opposite sides of the slot 72.

[0040] like Figure 4 As shown, slot 72 has a conductive coating or liner 80. In this example, the conductive liner 80 comprises a metal layer such as copper. A conductive connector 74 establishes a conductive connection between outer layer 51 and another conductive layer 82 on the opposite side near substrate 22. In this example, conductive layer 82 establishes or defines the outer surface of the opposite side of substrate 22 and serves as a ground layer.

[0041] In this example, the conductive connector 74 is a conductive via. The conductive connector 74 establishes a conductive barrier that forms or establishes the side of a choke, which includes a slot 72 located between two rows of conductive connectors 74. Some of these slots have a conductive connector 74 on one side of the slot 72, while having a conductive member 26, 36, or 46 on the other side of the slot 72 adjacent to the side of the integrated waveguide on the substrate. Figure 4 The example shown includes the left side of the integrated waveguide 24 on the substrate (according to...). Figure 1 The two slots 72, and the conductive member 26 also serves as a conductive connector to establish or define Figure 4One side of one of the chokes shown. Some example chokes of the parasitic interference element 70 include conductive members 28, 38, 48, which respectively establish input ports 30, 40, and 50 as at least some conductive connectors on one side of one of the slots 72. The slot 72 and the conductive connectors 74 (and in some cases conductive members 26, 28, 36, 38, 46, or 48) establish a choke with a generally U-shaped metal surface cross-section that reduces antenna coupling between the substrate-integrated waveguide antenna. The choke interrupts the flow of electrical energy or current along the outer surface 51.

[0042] like Figure 1 As shown, based on the number of slots 72 on each side, there are different numbers of parasitic interference elements 70 on both sides of the substrate integrated waveguide. Considering the bias gain of the exemplary substrate integrated waveguide antenna, different numbers of slots are placed to address the way in which energy may propagate along the outer surface 51 and cause coupling between the substrate integrated waveguide antennas.

[0043] The parasitic interference component 70 ensures the desired profile or smoothness of the radiation pattern of each antenna in the antenna assembly 20. Figure 5 The desired radiation pattern is shown for three beams spanning the output beams corresponding to the radiation from each of the substrate-integrated waveguide antennas. If parasitic interference is absent, coupling will exist between the substrate-integrated waveguide antennas, and the resulting radiation pattern will resemble... Figure 6 As shown at 94. As shown at 96, this coupling has the effect of causing a dip in the radiation pattern, which is undesirable. The parasitic jammer 70 prevents this dip. In addition, the parasitic jammer 70 allows more antenna units 20 to be placed close to each other to provide wider radiation beam coverage from each antenna, which allows for a more comprehensive and consistent scanning or detection around the perimeter or exterior of the vehicle.

[0044] The foregoing description is illustrative in nature and not restrictive. Variations and modifications of the disclosed exemplary embodiments will become apparent to those skilled in the art without departing from the spirit of the invention. The scope of legal protection provided for this invention can only be determined by studying the following claims.

Claims

1. An antenna device (20), comprising: Substrate (22), the substrate having a first outer layer and a second outer layer, the first outer layer forming a first conductive surface and the second outer layer forming a second conductive surface; Multiple conductive components (26, 36, 46) are present in the substrate, and the multiple conductive components form a substrate integrated waveguide (24, 34, 44), a first portion of the substrate is within the substrate integrated waveguide, and a second portion of the substrate is outside the substrate integrated waveguide; A plurality of first slots (52) are provided on the outer surface (51) of a first portion of the substrate (22), the plurality of first slots including a first length; A plurality of second slots (54) are provided on the outer surface of the first portion of the substrate (22), each of the plurality of second slots being associated with a corresponding one of the first slots, the plurality of second slots having a second length, the first length (L1) being longer than the second length (L2), the plurality of first slots and the plurality of second slots being configured to establish a radiation pattern that varies across a radiation beam emitted by the antenna device; as well as A plurality of parasitic interference elements (70), wherein at least a first parasitic interference element is located on a first side of the substrate integrated waveguide (24, 34, 44), and at least a second parasitic interference element is located on an opposite second side of the substrate integrated waveguide, wherein the first parasitic interference element has a first set of slots, and the second parasitic interference element has a second set of slots, the parasitic interference elements (70) are parallel to the substrate integrated waveguide, and include at least one of the following: The number of slots in the first group differs from the number of slots in the second group; or The length of the slots in the first group is different from the length of the slots in the second group.

2. The antenna device according to claim 1, characterized in that, Each of the plurality of first slots (52) on the outer surface (51) of the first portion of the substrate includes a spacing from the plurality of conductive members (26, 36, 46) of the substrate, the spacing varying along the integrated waveguide (24, 34, 44) of the substrate, such that smaller spacing results in stronger radiation and larger spacing results in weaker radiation.

3. The antenna device according to claim 2, characterized in that, The change in the interval causes the radiation beam emitted by the antenna device (20) to gradually shrink.

4. The antenna device according to claim 1, characterized in that, The parasitic interference components include: At least one conductive connector (74) establishes a conductive connection between the outer surface (51) of the second portion near both sides of the groove of the first parasitic interference member and the conductive layer (82) near the opposite side of the substrate (22).

5. The antenna device according to claim 1, characterized in that, The radiation emitted by the first slot (52) has a first characteristic; and The radiation emitted by the second slot (54) has a second feature different from the first feature, and the first and second features cause the gain of the radiation beam to be biased toward one side of the radiation pattern.

6. The antenna device according to claim 5, characterized in that, The first feature and the second feature are based on the first length and the second length, respectively.

7. The antenna device according to claim 1, characterized in that, The substrate includes multiple substrate integrated waveguides (24, 34, 44).

8. The antenna device according to claim 7, characterized in that, Each substrate integrated waveguide (24, 34, 44) includes an input port (30, 40, 50) located between opposite ends of the substrate integrated waveguide. At least some of the parasitic interference elements (70) are located on one side of a corresponding one of the input ports (30, 40, 50); and At least some of the other parasitic interference devices (70) are located on different sides of the corresponding one of the input ports (30, 40, 50).

9. The antenna device according to claim 7, characterized in that, The substrate-integrated waveguides (24, 34, 44) are aligned to be parallel to each other; The parasitic interference element (70) is parallel to the substrate integrated waveguide (24, 34, 44); An input port (30, 40, 50) of at least one of the substrate integrated waveguides (24, 34, 44) is located between adjacent substrate integrated waveguides (24, 34, 44); and At least some of the parasitic interference elements (70) are located between adjacent substrate integrated waveguides (24, 34, 44).

10. The antenna device according to claim 1, characterized in that, Each of the plurality of first slots (52) on the outer surface (51) of the first portion of the substrate (22) is longer than each of the plurality of second slots (54) on the outer surface of the first portion.

11. The antenna device as claimed in claim 1, characterized in that, Each of the plurality of first slots (52) on the outer surface (51) of the first portion of the substrate (22) is associated with one of the plurality of second slots (54) on the outer surface of the first portion, the plurality of first slots (52) and the plurality of second slots (54) having a spacing between each respective associated slot, at least two of the spacings being variable.

12. The antenna device as claimed in claim 11, characterized in that, The spacing is smaller at the end of the waveguide compared to the spacing between the other associated first slot (52) and second slot (54).

13. The antenna device as claimed in claim 1, characterized in that, One or more slots in the first group or one or more slots in the second group have a depth corresponding to one-quarter of the wavelength being guided.

14. The antenna device as claimed in claim 1, characterized in that, The plurality of first parasitic interference elements include a conductive liner electrically connected to a selected conductive element among the plurality of conductive elements.

Images