Antenna device

Abstract

The present invention relates to an antenna layer (1) having a rear surface (2) and a front surface (3), and a method for manufacturing the antenna layer (1). The antenna layer (1) comprises a plurality of waveguide channels (4) extending to the rear surface (2), each waveguide channel comprising a waveguide opening (5) located on the front surface (3) for transmitting and receiving signals. Each waveguide channel (4) comprises a radial opening (6), which is located in the antenna layer (1) and interconnected with the waveguide opening (5) in the radial channel (7). A dividing line (8) is located between the rear surface (2) and the front surface (3) in the radial channel (7), and the dividing line (8) is spaced a distance (D) from the radial opening (6) toward the waveguide opening (5) and extends circumferentially within the radial channel (7). Further disclosure relates to an antenna assembly (17) comprising the antenna layer (1), and an antenna device (23) comprising the antenna assembly (17).

Description

Technical Field

[0001] The present invention relates to an antenna layer for an antenna assembly used for automotive radar applications, and this antenna assembly includes a waveguide disposed therein.

Background Art

[0002] International Publication No. WO 2019 / 057965 published on March 28, 2019 under the name of Gapwaves AB relates to a phased array having a base layer. The base layer includes a substrate having a plurality of protruding posts for stopping the propagation of waves along the base layer, and a printed circuit board (PCB) disposed on the base layer. The PCB includes at least one phased array radio frequency (RF) integrated circuit (IC) on a first side of the PCB facing the base layer and the protruding posts. The PCB further includes a feeding portion for transmitting an RF signal from the phased array RFIC(s) to a second side opposite to the PCB. Also provided is a radiation layer having a plurality of radiation elements for transmitting and / or receiving an RF signal from the phased array antenna, together with a feeding layer for transmitting the RF signal disposed between the feeding portion of the PCB on the second side and the radiation elements of the radiation layer.

[0003] International Publication No. 2023 / 020668, published on February 23, 2023, under the name of Continental Autonomous Mobility Germany GmbH, relates to a radar system for detecting the surroundings. The radar system comprises a printed circuit board on which at least one high-frequency component is mounted and high-frequency signals are guided from the component to the printed circuit board via electrical connections, and a molded portion having one or more individual antennas on its upper side for transmitting and / or receiving radar signals. The electrical connection between the printed circuit board and at least one individual antenna on the upper side of the molded portion is realized at least partially by an internal waveguide. The molded portion is located on the same side of the printed circuit board as the at least one high-frequency component and is conductively connected at least partially to the high-frequency component, in particular by soldering and / or conductive adhesive bonding. At least one hollow waveguide is formed by a recess on the side of the molded portion facing the printed circuit board and the metallized surface of the printed circuit board. At least one waveguide is powered by a printed circuit board, and the molded portion may or may consist of a single layer of at least partially metallized plastic or a single layer of metal, and is preferably manufactured by die-casting, deep drawing, or bending techniques. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 057965 [Patent Document 2] International Publication No. 2023 / 020668 [Overview of the Initiative]

[0005] The use of millimeter-wave (MMW) frequencies in communications and automotive radar applications is continuously expanding. Antennas are critical components in all of these applications, requiring stringent requirements regarding performance, size, weight, and compliance with environmental standards. In terms of performance, antenna gain and efficiency are important parameters because they directly affect the overall system link budget (representing link distance and coverage for communications systems, and maximum detection range for automotive radar).

[0006] A key parameter in the design of the antenna layers of an antenna assembly with hollow waveguide channels is the arrangement of radial apertures, which are typically interconnected to waveguide apertures for signal transmission and / or reception. Antenna assemblies, particularly those for automotive radar applications, are typically made of at least two mounted antenna layers coupled along a plane. Typically, at least two waveguide channels extend into the antenna assembly. Each of the at least two waveguide channels extends from a feeding aperture to at least one waveguide aperture. Signals are typically fed through the feeding aperture to each waveguide channel of the antenna assembly and transmitted or received by the waveguide apertures. To enable the antenna assembly to actually transmit and / or receive signals, typically at least two waveguide channels each have at least one radial aperture. The precise arrangement of radial apertures relative to each waveguide channel significantly impacts the elevation pattern of the antenna assembly. Therefore, in addition to the design and wiring of at least two waveguide channels in the antenna assembly, the precise placement of at least one radial aperture for each waveguide channel is crucial. Placement significantly impacts the antenna layer's fabrication, and die tolerances in particular can have a significant effect on the antenna's transmit and / or receive characteristics.

[0007] Therefore, the object of this disclosure is to provide an antenna layer with improved transmission and / or reception characteristics.

[0008] The antenna layer according to this disclosure has a rear and a front surface. The antenna layer can be manufactured by a molding process, injection molding or die casting being preferable. Alternatively, the antenna layer can be manufactured by punching or cutting. Particularly in automotive applications, where large production volumes and light weight are required, the antenna layer is usually manufactured by injection molding from a thermoplastic material. In addition, the front and / or rear surface can be at least partially or completely metallized or coated. The rear and / or front surface is usually substantially planar and / or parabolic. To enable the manufacture of antenna assemblies with internal wiring in the antenna assembly, the antenna assembly usually comprises at least one antenna layer and a printed circuit board (PCB). The antenna assembly according to this disclosure comprises an antenna layer which may be in the front or middle of the antenna assembly, and optionally a second antenna layer which is usually in the rear of the antenna assembly. In the context of this disclosure, the rear and front surfaces are understood as follows: the rear surface of the antenna assembly is the feeding side, and the front surface is the side of the antenna assembly for transmitting and / or receiving signals.

[0009] An antenna layer typically comprises at least two waveguide channels, each extending from the rear of the antenna layer and interconnected to at least one waveguide opening located at the front of the antenna layer for transmitting and / or receiving signals. Waveguide channels may be located on the rear of the antenna layer and / or in front of a second antenna layer. Each waveguide channel typically interconnects a feeding opening located at the rear of the antenna assembly with a waveguide opening located at the front of the antenna assembly. The feeding openings are interconnectable to electronic components, and signals are typically supplied to the waveguide channels through their respective feeding openings. To enable the transmission and / or reception of signals, each waveguide channel is located in the antenna layer and comprises at least one radial opening interconnected to the waveguide opening by at least one radial channel.

[0010] The power supply opening can be directly coupled to the coupling element of the PCB, or it can be coupled to a hole in the PCB that transmits electromagnetic waves. The hole in the PCB can be a plated through-hole, which is suitable for propagating the basic mode TE10 (i.e., a short waveguide).

[0011] By placing deflection elements such as protrusions or pins immediately after the power supply opening, where the signal enters the waveguide channel, the following can be achieved: a) Rotate the basic mode TE10 by 90°. The electric field of the waveguide channel is perpendicular to the front of the antenna. Such an arrangement is suitable for waveguide channels, or better waveguides having a rectangular cross-section with long extensions parallel to the antenna plane (i.e., parallel to the front of the antenna). Or, b) The propagation direction of the fundamental mode TE10 is changed while the waveguide channel's electric field remains parallel to the antenna front. Additional deflection elements are subsequently placed to rotate the fundamental mode TE10 by an angle from 0° to 90°, keeping the waveguide channel's electric field parallel to the antenna front. Such a configuration is suitable for waveguide channels, or better waveguide channels having a rectangular cross-section with a short extension parallel to the antenna surface (i.e., parallel to the antenna front 3).

[0012] Waveguide channels have a predetermined length. To avoid phase differences between waveguide channels due to temperature changes, the difference in length between channels should be maintained similarly. Due to the thermal expansion coefficient of the materials, channels with significantly different lengths may behave very differently over a wide temperature range, such as from -40° to +125°. The so-called waveguide wavelength is the distance that needs to be added for a waveguide channel to have the same phase as another channel. This can be calculated as 2π / beta, where beta is the propagation constant for the fundamental mode TE10.

[0013] In this application, it is advantageous that the difference in length between at least two waveguide channels of the same type (all receivers or all transmitters) does not differ by more than 10 waveguide wavelengths. In a modified example, it is also advantageous that the associated phase difference is a multiple of (180° ± 20°).

[0014] In a modified version, the rear surface of the antenna layer is positioned in front of the second antenna layer. The waveguide channel may extend in the antenna assembly at least partially in front of the second antenna layer. The rear surface of the antenna layer and the front of the second antenna layer can be in full contact with each other. By making the antenna layer and the second antenna layer each substantially rectangular plates, a cost-effective antenna assembly can be obtained. The antenna assembly is typically part of an antenna device. Antenna devices according to this disclosure, particularly antenna devices for automotive radar applications, typically comprise an antenna assembly and an electronic component. The electronic component is typically a radar chip, which is located on a printed circuit board or interconnected to a printed circuit board. The electronic component is electrically interconnected to a feeding aperture of the antenna assembly. Signals are supplied from the electronic component to the antenna assembly or, conversely, received signals are transmitted to the electronic component through the feeding aperture.

[0015] The antenna layer may have a number of radial apertures arranged in an array of apertures. It is advantageous that the number of radial apertures in the array be energized by a common waveguide channel interconnected to electronic components via a feeding aperture. Depending on the design, the radial apertures in the array are configured to radiate and / or receive signals. Including multiple parallel radial apertures narrows the radiated beam emitted by the antenna layer. This can be beneficial for long-range radar. For very short-range radar, having a single aperture may be beneficial. Good results can be achieved when the radial apertures are designed as slots. Depending on the field of application, the radial apertures may have different shapes, which will become apparent from the variations illustrated in more detail below. Each waveguide channel has a cross section of a group or combination thereof, typically rectangular, rhombic, elliptical, or circular, and the main extension direction of the cross section is substantially parallel to the feeding aperture and waveguide aperture. The feeding aperture and waveguide aperture can be offset laterally from each other. This offset allows for optimization of the wiring of each waveguide channel, enabling impedance matching and low-loss transmission of RF signals, maintaining specified phase relationships between different antenna elements, and facilitating proper manufacturing processes.

[0016] The placement of at least one radial aperture relative to each waveguide channel negatively impacts antenna performance, particularly the radiation pattern. Variations in the patterns between radial apertures relative to each other, especially those relative to the waveguide channels, significantly affect beamforming and can lead to false target detection or inability to detect in angular directions. Therefore, to ensure proper function of the antenna assembly, electrical parameters must remain stable, but in reality, in addition to design parameters, there are also manufacturing tolerances that affect accuracy. While tolerances in areas formed on one part of an injection mold can be well reproduced, tolerances along the mold's dividing line vary and depend on the precision of tool manufacturing, process parameters, and tool wear. In conventional designs, when manufacturing the antenna layer by injection molding or die casting, the dividing surface of the two mold halves is positioned between the waveguide channel and the waveguide aperture, thereby typically defining the narrowest aperture / cross-section of the aperture. Radial apertures are usually precisely positioned on the dividing surface. Waveguide channels are typically located on the rear surface of the antenna layer and formed by a first mold half, while interconnected waveguide openings are located on the front surface and formed by a second mold half. Consequently, the accuracy of the placement of radial openings in known designs, which are positioned between the waveguide channels and waveguide openings, depends heavily on the tolerances of the mold.

[0017] To improve accuracy, radial channels can be placed between radial apertures and waveguide apertures, and at least one radial aperture can be interconnected with the waveguide aperture. The antenna layer according to this disclosure is typically manufactured by a conventional mold having two mold halves. To improve the accuracy of the antenna layer, the parting surface of the mold is displaced. Instead of placing the parting surface between radial apertures and waveguide apertures as is known, the parting surface is placed between radial channels and waveguide apertures, and therefore at a certain distance from the radial apertures. The parting surface of the mold is typically in the form of a burr, leading to a parting line of the product. The parting line is typically located in at least one radial channel between the rear and front surfaces. The parting line is spaced at a certain distance from at least one radial aperture toward at least one waveguide aperture. It is advantageous for the parting line to extend circumferentially through at least one radial channel. As a result, the tolerance in the transition between radial openings and radial channels is reduced to the machining tolerance of one mold half, rather than the closing accuracy of two mold halves.

[0018] Considering the mold division lines and layer separation, high-precision plastic injection molding, and, if necessary, metallization processes or metal die casting techniques, are selected. When the two antenna layers are coupled together, high-precision mold division lines are required to minimize the impact on electromagnetic signal propagation (i.e., to minimize losses and mismatches). Depending on the design of the radial channels and the apertures connected to them, the division lines can be located somewhere in at least one radial channel, or at the very edge of the distal end of the radial channels. Thus, the division lines can coincide with the transition between the radial channels and the apertures. Subsequently, the cross-section of the waveguide aperture fits perfectly into the cross-section of the radial channels, and there is no step between the radial channels and the waveguide apertures. In some other variations, the radial channels can merge into the apertures in the form of a step. The division lines can coincide with the edge of the step.

[0019] At least one radial aperture can merge into a radial channel by a rounded or chamfered transition region. Theoretically, abrupt transitions in the form of sharp edges would be advantageous for signal propagation between the radial aperture and the radial channel. Nevertheless, for manufacturing purposes, a mold removal bevel is required so that the mold can be removed from the antenna layer. Therefore, a chamfered or rounded edge is necessary. A good compromise between efficient signal propagation and mold removal behavior can be achieved by making the ratio of the radius of the transition region to the distance between the radial aperture and the dividing line less than 1, preferably less than 0.8, and most favorably less than 0.6.

[0020] Each waveguide channel can be interconnected to a splitter via its primary port, and the splitter is configured to split the transmitted signal into a first waveguide channel branch, typically interconnected to the splitter's first secondary port, and a second waveguide channel branch, typically interconnected to the splitter's second secondary port. In an advantageous modification, the waveguide channels are located at the distal end, interconnected to the waveguide splitter by its primary port with respect to their respective feeding openings. The splitter is configured to split the signal into two parts and adjust the orientation of the signal parts, for example, by rotating the polarization from horizontal to vertical and / or vice versa, as needed. Each splitter sends the first part of the signal power to the first waveguide channel branch interconnected to the splitter's first secondary port, and the second part of the signal power to the second waveguide channel branch interconnected to the splitter's second secondary port. The length of at least one waveguide channel is usually longer than the sum of the lengths of the first waveguide channel branch and the second waveguide channel branch.

[0021] The primary and secondary ports of the splitter are not necessarily visible externally, as they can be fully integrated into the waveguide channel and the structure of each waveguide channel branch. In a modified configuration, the splitter can be configured to rotate a portion of the signal power clockwise and the other portion counterclockwise. In an advantageous modification of the antenna assembly, the electric field, upon reaching the waveguide primary port, is twisted horizontally (substantially in the plane of the antenna assembly) and vertically (substantially perpendicular to the front of the antenna assembly) as it exits the splitter at the waveguide secondary port. The first and second waveguide channel branches typically each have at least one radial opening, which can be collinear with respect to the centerline. At least one waveguide opening of the first waveguide channel branch and at least one waveguide opening of the second waveguide channel branch are optionally interconnected.

[0022] A waveguide splitter may typically include at least one deflection element, positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from horizontal to vertical. Alternatively or additionally, at least one deflection element may be positioned adjacent to the first and second secondary ports and configured to twist the polarization again from vertical to horizontal. Deflection elements positioned in the splitter or waveguide channel are typically configured to rotate the electric field by 90 degrees. The horizontally polarized electric field in the splitter and / or waveguide channel is twisted so that the electric field at the waveguide channel branch is vertically polarized. When an input signal is received, the polarization is twisted in the opposite direction. The polarization twist can also be achieved by a series of deflection elements positioned along the centerline of the waveguide channel branch and gradually changing and rotating the electric field. It is advantageous for the deflection elements to be configured as impedance matching elements. At least one deflection element can be configured to twist the polarization of the electric field so that the polarizations of the first waveguide channel splitter and the second waveguide channel splitter are equally polarized. Alternatively, the deflection element can be configured so that the polarizations of the electric field at the first waveguide channel splitter and the second waveguide channel splitter are inverted relative to each other. As described above, at least one deflection element can be configured to twist the polarization of the electric field, resulting in the electric field being twisted substantially 90 degrees from horizontal to vertical, providing impedance matching where appropriate. Alternatively or additionally, the deflection elements can be positioned asymmetrically with respect to the splitter to achieve an asymmetric power / phase distribution between the first and second waveguide channel splitters. This is useful for applications where it is necessary to point at an angle different from the aiming point.

[0023] In another modification, at least one deflecting element arranged inside and / or outside the waveguide channel and / or the splitter comprises at least one of the group consisting of a step, a recess, a channel, a bump, an indented corner, or a combination thereof, which typically protrude inside and / or outside the cross-section of the waveguide channel and / or the splitter, forming a local reduction of the cross-section. Good results can be achieved if the waveguide channel has two indented corners arranged opposite to each other in the region of the primary port of the splitter and designed as deflecting elements of the electric field. In an advantageous modification of the antenna device according to the present disclosure, the length of the waveguide channel of at least one antenna element is longer than the sum of the lengths of the first waveguide channel branch and the second waveguide channel branch.

[0024] Alternatively or additionally, ridges and / or neckings configured to introduce an electrical delay of the propagation mode can also be arranged in the first and / or second waveguide channel branches. The electrical delay further reduces the phase error and a higher directivity value is obtained. When the signal power is split into a first part and a second part, the splitter may comprise a necking, for example in the form of an inward-facing protrusion or in the form of a partition wall, arranged at the center of the splitter between the first branch and the second branch, which are the first and second secondary ports respectively. The necking is configured to assist in splitting the signal between the first and second waveguide channel branches. Depending on the distribution achieved, the necking can be arranged at the center between the first secondary port and the second secondary port, and the signal is evenly split between the first and second waveguide channel branches. If appropriate, the necking is arranged offset to one side between the first secondary port and the second secondary port with respect to the center point between the first secondary port and the second secondary port, and the signal, respectively its power, is unevenly split between the first waveguide channel branch and the second waveguide channel branch. Due to the performance advantages of the arrangements described herein, the power split is substantially lossless. The power lost during splitting is very small.

[0025] The first and second waveguide channel branches can be designed in a staggered configuration so that the radial apertures are collinear with respect to the centerline of at least one waveguide channel, with respect to the centerline of at least one waveguide channel. The electric fields of at least one radial aperture of the first waveguide channel branch and at least one radial aperture of the second waveguide channel branch are modified so that they are collinear with respect to each other. As is known from the prior art, one drawback of a standard array of apertures is the offset position of the apertures relative to the centerline. In particular, this offset produces asymmetric illumination of the effective antenna apertures, resulting in asymmetry in the radiation pattern outside the main radiating planes (i.e., the azimuthal and elevation planes). These asymmetries typically result in higher radiation levels at certain undesirable angles, consequently degrading the overall system performance. In an advantageous modification, the first and second waveguide channel branches of individual antenna elements can be designed in a staggered configuration so that the electric fields are modified. The electric field is advantageously modified so that at least one radial aperture of the first waveguide channel branch and at least one radial aperture of the second waveguide channel branch are collinear with respect to each other. The staggered arrangement design is configured to avoid asymmetric illumination when the apertures are arranged in a line. The arrangement has the advantage of less beam tilt tendency and providing a wider bandwidth than designs known from the prior art. However, MIMO antennas based on a standard centrally fed array require more than two layers of stacking because feeding must be done through the bottom of the horizontal waveguide. This results in increased manufacturing costs and complexity.

[0026] Waveguide apertures typically merge into a waveguide channel or its branch via radial channels. Therefore, radial channels interconnect radial apertures with waveguide apertures. It is advantageous for radial channels to have a funnel-shaped design in the vertical direction, with a cross-section that narrows inward. At least one radial aperture of a first waveguide channel branch and at least one radial aperture of a second waveguide channel branch may also be interconnected into at least one funnel, which merges into a common waveguide aperture. This modification allows for an expansion of the radiating surface of at least one radial aperture. In an advantageous modification, the funnel can be positioned asymmetrically with respect to the aperture. At least one funnel can be interconnected into a laterally displaced waveguide aperture to achieve an asymmetric radiation pattern. The asymmetrically displaced funnel adds a gradient to the radiation characteristics of the antenna device. The effect of the lateral displacement can result in local maximums in the antenna's directivity. These local maximums may help concentrate the antenna's energy in a specific region. Slope patterns can help extend the range of a specific area of ​​radar. Because slope patterns allow for wider coverage locally, they can achieve good results in applications such as automotive.

[0027] The radial openings can have a varying cross-section in order to tilt the radiation pattern. Each of the first and second waveguide channel branches can comprise two arrays of radial openings. Advantageously, the arrays are arranged substantially parallel to each other. In an advantageous variant, the two arrays are interconnected by at least one common funnel. Depending on the desired radiation characteristics, the common funnel can be arranged offset laterally with respect to the two rows of radial openings. Alternatively or additionally, the two rows of radial openings can have a varying cross-section in order to further tilt the radiation pattern. Due to the difference in the cross-sections of the openings, a phase difference occurs between the radiations of each opening. The phase difference causes a tilt in the radiation of the pattern. In an advantageous variant, the two arrays of openings are arranged parallel to each other. The cross-section of the openings of the first array is smaller and / or larger than the cross-section of the openings of the second array. This configuration causes a tilt in the radiation pattern. Alternatively, the cross-sections of the adjacent openings of one array can be different, and the openings with a smaller cross-section can be arranged adjacent to the openings with a larger cross-section. Good results can be achieved by arranging the openings with a small cross-section and the openings with a large cross-section alternately in a row. Thereby, the radiation pattern is compensated and radiates linearly.

[0028] At least one radial opening can have a rectangular cross-section. At least one radial opening can be oriented longitudinally with respect to the corresponding waveguide channel. Usually, the radial openings have a substantially rectangular, particularly rectangular cross-section. However, other shapes are possible, such as polygonal or C-shaped. The orientation of the radial openings defines the polarization of the radiation transmitted by the antenna layer.

[0029] In a further embodiment, the radial openings can be oriented at a specific angle between 0° and 90° with respect to the longitudinal direction of the corresponding waveguide channel. In a variant of this embodiment, all the radial openings of the antenna layer can be rotated by the same angle in order to rotate the polarization.

[0030] The waveguide can be formed at least partially by one of at least two waveguide channels extending to the rear surface of the antenna layer. The waveguide may have a rectangular cross-section with long and short extensions perpendicular to each other. At least one radial opening can be located in a portion of the waveguide wall substantially parallel to the long extension.

[0031] The electric field of the fundamental mode TE10 of a waveguide is generally oriented perpendicular to the long extension of the cross-section. By positioning radial openings in the waveguide wall portion substantially parallel to the long extension, the waveguide current can be interrupted by the radial openings, and an electric field perpendicular to the electric field of the fundamental mode TE10 of the waveguide can be generated at the radial openings. This makes it possible to couple only a portion of the waveguide's radiated energy through the radial openings. Therefore, a series of radial openings can be positioned in a given waveguide or waveguide branch.

[0032] In such a configuration, the arrangement of the dividing lines of the radial channel according to the present invention, i.e., the arrangement where they are spaced a certain distance apart from the radial aperture toward the waveguide aperture, is particularly beneficial. Changes in the relative position between the center of the radial aperture and the center of the waveguide have a significant impact on performance due to the fact that the two electric fields are orthogonal to each other. Therefore, if the shapes of the radial aperture and radial channel are not appropriately selected, higher-order modes with multiple orientations may be excited. In a waveguide antenna, it is necessary to avoid this because only the fundamental mode TE10 needs to be excited.

[0033] The longer extensions of the waveguide cross-section must be larger than the critical cutoff dimension, and the shorter extensions must be smaller than the critical cutoff dimension. The critical cutoff dimension corresponds to half the operating wavelength of the waveguide.

[0034] Waveguides can have cross-sections selected from the group consisting of rectangles, trapezoids, triangles, ellipses, semi-ellipses, and polygons. Waveguides with a rectangular cross-section with rounded edges are advantageous. Such shapes are suitable for production by injection molding.

[0035] The cross-sectional area of ​​at least one radial aperture can be smaller than the cross-sectional area of ​​the waveguide, and is usually smaller.

[0036] Typically, the length of a radial aperture ranges from one-quarter to two-thirds of the waveguide's operating wavelength. The radial aperture then generates appropriate excitations. The larger the aperture, the more it behaves like the end of a waveguide.

[0037] Alternatively or additionally, the waveguide channel can be at least partially replaced by a series of pillars based on gap waveguide techniques. In such an antenna assembly, it is advantageous that the front and / or rear may at least partially comprise pillars that at least partially form the outer contours of the waveguide channel and / or splitter and / or first and second waveguide channel branches. The pillars are configured to guide signals through the waveguide channel. The pillars can be positioned to allow a bandgap structure configured to compensate for potential manufacturing and assembly tolerances between the front and rear, since direct ohmic contact between the front and rear is not necessarily required. This can reduce leakage between antenna layers. The electromagnetic bandgap (EBG) structure is positioned substantially around the hollow waveguide channel. The electromagnetic bandgap structure can act as a conductive wall and block electromagnetic waves in a specific frequency range without requiring direct and / or ohmic contact between the antenna layer and the second antenna layer. The pillars can be arranged in a periodic pattern and can optionally be arranged as a mushroom shape in PCB technology or a pillar shape in waveguide technology.

[0038] In advantageous embodiments, the waveguide may be defined by front and / or rear grooves, and the lateral walls may be replaced by electromagnetic bandgap (EBG) structures such as a periodic structure of pillars. These pillars may be formed from the front or the rear only. Alternatively, the pillars may be formed from both parts, for example, alternating along the front and rear waveguides. Or, the pillars may be formed at half the height of both parts.

[0039] Another possibility is to implement a hard / soft structure defined by creating an elongated metal pillar along one axis of the lowest layer, and then creating a similar structure in which a second elongated pillar rotates at an angle of 45° to 90° relative to the first elongated pillar.

[0040] The method for manufacturing an antenna layer according to this disclosure includes manufacturing the antenna layer by injection molding or die casting. From a cost-effective manufacturing viewpoint, one goal is to achieve designs and techniques for implementing MIMO antenna arrays that can be manufactured using only the minimum number of laminates (components). The disclosure described herein provides the possibility of designing an antenna assembly comprising at least two laminates, for example, a rear and a front. An advantageous structure can be achieved if the waveguide channel extends at least partially to the rear surface of the antenna layer and partially to the front surface of the second antenna layer. The same applies to splitters and / or waveguide channel branches interconnected thereto. The rear surface of the antenna layer and the front surface of the second antenna layer do not need to be substantially flat. Where appropriate, the antenna layer and / or the second antenna layer can be skeletonized to reduce the contact area. This is advantageous because minimizing the contact area increases the surface pressure of the contact area, resulting in more precise alignment of the antenna layer and the second antenna layer in the waveguide channel and / or splitter and / or first and second waveguide channel branching regions.

[0041] The antenna layer can be fabricated by injection molding a plastic material and then metallizing the surface. The antenna layer and / or a second antenna layer can be fabricated by injection molding of at least one plastic material. Alternatively or additionally, the antenna layer and / or the second antenna layer can be made of metal and / or metallized plastic and / or any other material whose surface is conductive. In a variation, the antenna layer and / or the second antenna layer are made of metal and / or metallized plastic and / or other material whose surface is conductive. The design of the waveguide components and antenna layer may be optimized to be compatible with various bonding techniques.

[0042] It should be understood that the present invention is by no means limited to hollow waveguides and may be embodied in other types of waveguides, such as ridge waveguides.

[0043] It should be understood that both the general description above and the detailed description below present embodiments and are intended to provide an overview or framework for understanding the nature and features of this disclosure. The accompanying drawings are included to provide further understanding and are incorporated herein and constitute part thereof. The drawings illustrate various embodiments and, together with the description, help to illustrate the principles and operation of the disclosed concepts.

[0044] The invention described herein will be better understood from the following detailed description and accompanying drawings, but should not be considered as limiting the invention described in the accompanying claims. The drawings are as follows: [Brief explanation of the drawing]

[0045] [Figure 1] Front and top perspective views of a first modified example of the antenna device. [Figure 2] Figure 1 shows rear and top perspective views of a first modified example of the antenna device. [Figure 3]Figure 1 is a front view of a first modified example of the antenna device, showing the internal wiring of the waveguide channel. [Figure 4] This is a front and top perspective view of a first modified antenna assembly, showing the internal wiring of the waveguide channel. [Figure 5] This is a front and top perspective view of a second modified antenna assembly in an unfolded state, showing the internal wiring of the waveguide channel. [Figure 6] This is a front view of a second modified example of the antenna device, showing the internal wiring of the waveguide channel. [Figure 7] Figure 6 shows front and top perspective views of a second modified antenna device, illustrating the internal wiring of the waveguide channel. [Figure 8] As is known from prior art, this is a cross-sectional view of a waveguide channel interconnected to a waveguide opening via a splitter. [Figure 9] Figure 8 is a graph illustrating the propagation characteristics of a conventional design. [Figure 10] This is a cross-sectional view of a first modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 11] Figure 10 is a graph illustrating the propagation characteristics of the design. [Figure 12] Front and top perspective views of a second modification of the waveguide channel according to the present disclosure, interconnected to a waveguide opening via a splitter. [Figure 13] This is a cross-sectional view of a second modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 14] Front and top perspective views of a third modification of the waveguide channel according to this disclosure, interconnected to a waveguide opening via a splitter. [Figure 15] This is a cross-sectional view of a third modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 16]This is a front and top perspective view of a fourth modification of the waveguide channel according to the present disclosure, interconnected to a waveguide opening via a splitter. [Figure 17] This is a cross-sectional view of a fourth modification of a waveguide channel interconnected to a splitter according to the present disclosure, which is interconnected to a waveguide opening via a splitter. [Figure 18] This is a front and top perspective view of a fifth modification of the waveguide channel according to the present disclosure, interconnected to a waveguide opening via a splitter. [Figure 19] This is a cross-sectional view of a fifth modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 20] This is a front and top perspective view of a sixth modification of the waveguide channel according to the present disclosure, interconnected to a waveguide opening via a splitter. [Figure 21] This is a cross-sectional view of a sixth modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 22] This is a front and top perspective view of a seventh modification of the waveguide channel according to the present disclosure, interconnected to a waveguide opening via a splitter. [Figure 23] This is a cross-sectional view of a seventh modification of the waveguide channel according to the present disclosure, interconnected to waveguide openings via a splitter. [Figure 24] This is a front and top perspective view of the eighth modified waveguide channel according to the present disclosure. [Figure 25] This is a cross-sectional view of an eighth modified example of the waveguide channel according to the present disclosure. [Figure 26] This is a front and top perspective view of a ninth modified example of the waveguide channel according to the present disclosure. [Figure 27] This is a cross-sectional view of a ninth modified example of the waveguide channel according to the present disclosure. [Figure 28] These are front and top perspective views of a third variant of the antenna assembly according to this disclosure. [Figure 29]This is a front and top perspective view of a third modified antenna assembly according to the present disclosure in an unfolded state. [Figure 30] This is a cross-sectional view of a third modified example of the antenna assembly according to this disclosure. [Modes for carrying out the invention]

[0046] Herein, specific embodiments are referred to in detail, examples of which are illustrated in the accompanying drawings, which do not show all features, but only some features. In fact, the embodiments disclosed herein may be embodied in many different forms and should not be construed as being limited to the embodiments described herein, but rather these embodiments are provided so as to satisfy the applicable legal requirements of this disclosure. Wherever possible, similar reference numerals are used to refer to similar parts or components.

[0047] Figures 1 to 3 illustrate a first modified example of the antenna device 23, with Figure 1 being a perspective view from the front and above, Figure 2 being a perspective view from the rear and above, and Figure 3 being a front view showing the internal wiring of the waveguide channel 4. The illustrated antenna device 23 for automotive radar applications comprises an antenna assembly 17 and an electronic component 24. The illustrated electronic component 24 is a radar chip 25, which is located on a printed circuit board 26. The electronic component 24 is interconnected to a feed opening 28 of the antenna assembly 17. Signals are supplied from the electronic component 24 to the antenna assembly 17, or conversely, received signals are transmitted to the electronic component 24, through the feed opening 28. In the illustrated modified example, the illustrated antenna assembly 17 includes an antenna layer 1 as the front part 18 of the antenna assembly 17. The illustrated second antenna layer 21 is the rear part 20 of the antenna assembly 17. The illustrated antenna layer 1 is manufactured by injection molding.

[0048] Figure 4 is a front and top perspective view of a first modified antenna assembly 17 illustrating the internal wiring of the waveguide channel 4. The illustrated waveguide channel 4 interconnects a feeding opening 28 located on the rear surface of the antenna assembly 17 to a waveguide opening 5 located on the front surface of the antenna assembly 17, which is also the front surface 3 of the antenna layer 1. The illustrated waveguide channel 4 is partially located on the rear surface of the antenna layer 1 and partially located on the front surface of the second antenna layer 21. The feeding opening 28 is interconnectable to electronic components, and signals are supplied to the waveguide channel 4 via the feeding opening 28.

[0049] The waveguide channel 4, or better waveguide 31, has a rectangular cross-section with a long extension a and a short extension b (not shown in Figure 4). The short extension is parallel to the antenna plane (i.e., parallel to the front 3, for example). Upon entering the waveguide 31 through the feeding opening 28, the propagation direction of the fundamental mode TE10 changes, and the electric fields of the feeding opening 28 and waveguide 31 become parallel to the upper front 3 of the antenna.

[0050] In another embodiment, a deflection element can be placed after the feed opening 28 to rotate the electric field of the waveguide 31 at an angle of 0° to 90° in the antenna plane. In both cases, the electric field remains parallel to the front surface 3.

[0051] Each waveguide channel 4 is interconnected via its primary port to a splitter 10 that divides the transmitted signal into its respective first waveguide channel branch 12 and its respective second waveguide channel branch 14. The splitter 10 is configured to divide the signal into two parts and adjust the orientation of the signal parts by, if necessary, rotating the polarization, for example, from horizontal to vertical and / or vice versa. The splitter 10 wires the first part of the signal power to the first waveguide channel branch 12 interconnected to the splitter's first secondary port, and the second part of the signal power to the second waveguide channel branch 14 interconnected to the splitter's second secondary port. The length of each waveguide channel 4 is longer than the sum of the lengths of each first waveguide channel branch 12 and each second waveguide channel branch 14. The waveguide opening 5 shown in the diagram is aligned in a straight line with respect to the centerlines (L) of the first waveguide channel branch 12 and the second waveguide channel branch 14.

[0052] Figure 5 is a front and top perspective view of a second modification of the antenna assembly 17 illustrating the internal wiring of the waveguide channel 4. The illustrated antenna assembly 17 comprises two laminates. Antenna layer 1 is the front portion 18 of the antenna assembly 17, and the second antenna layer 21 is the rear portion 20 of the antenna assembly 17. The waveguide channel 4 extends at least partially into antenna layer 1 and partially into the second antenna layer 21. The illustrated antenna layer 1 and second antenna layer 21 are skeletonized to reduce the contact area. This is advantageous because minimizing the contact area increases the surface pressure of the contact area, resulting in more precise alignment of antenna layer 1 and second antenna layer 21 in the region of the waveguide channel 4 and / or splitter 10 and / or first waveguide channel branch 12 and second waveguide channel branch 14.

[0053] Figures 6 and 7 illustrate a second modification of the antenna device 23, illustrating the internal wiring of the waveguide channel 4. The illustrated antenna device 23 for automotive radar applications comprises only a single antenna layer 1 with its rear surface 2 mounted on a printed circuit board 26. The waveguide channel 4 is interconnected to an electronic component 24, which is a radar chip 25 located on the printed circuit board 26. The electronic component 24 is interconnected to a feeding aperture 28 of the antenna layer 1. Through the feeding aperture 28, signals are supplied from the electronic component 24 to the antenna assembly 17, or conversely, received signals are transmitted to the electronic component 24. The illustrated antenna assembly 17 comprises the antenna layer 1 as the front portion 18 of the antenna assembly 17 in the illustrated modification. The waveguide channel 4 is formed by a recess between the rear surface of the antenna layer 1 and the front surface of the printed circuit board 26.

[0054] The waveguide channel 4 has a rectangular cross-section with a long extension a and a short extension b (not shown in Figures 6 and 7). The long extension is parallel to the antenna plane (i.e., parallel to the front 3, for example). When the fundamental mode TE10 enters the waveguide channel 4 through the feeding opening 28, it rotates by 90°, and the electric fields in the feeding opening 28 and the waveguide channel 4 are orthogonal to each other. Therefore, the electric field at the feeding opening 28 is parallel to the antenna plane (i.e., parallel to the front 3, for example). The electric field in the waveguide channel 4 is perpendicular to its longitudinal direction a, i.e., perpendicular to the antenna front 3.

[0055] Figure 8 shows a side view of a waveguide channel 4 known from the prior art. The waveguide channel 4 is interconnected to a splitter 10, which splits the signal into a first waveguide channel branch 12 and a second waveguide channel branch. The illustrated waveguide channel branch includes radial apertures 6, which are located in the antenna layer 1 and interconnected to waveguide apertures 5. The radial apertures 6 are arranged in an array of apertures and energized by a common waveguide channel 4 via feeding apertures interconnected to each electronic component on the rear surface of the antenna assembly 17. The radial apertures 6 of the array are designed as slots. The illustrated waveguide channel 4 extends partially to the front surface 22 of the second antenna layer 21 and partially to the rear surface 2 of the antenna layer 1. The illustrated waveguide channel 4 has a substantially rectangular cross-section. In the illustrated modification, the rear surface 2 of the antenna layer 1 and the front surface 22 of the second antenna layer 21 are in full contact. Waveguide channel 4 merges into a waveguide branch via splitter 10. Radial channels 7 interconnect each radial aperture 6 with its respective waveguide aperture 5. The illustrated antenna layer 1 is manufactured by a conventional mold having two mold halves. The dividing surface P of the mold half is located between the radial apertures 6 and the radial channels 7. As a result, the dividing line 8 is also located between the radial apertures 6 and the radial channels 7.

[0056] Figure 9 illustrates the propagation characteristics of the design according to Figure 6, specifically an array of curves. The graph shown in Figure 7 illustrates the antenna directivity and spread of directivity due to the lateral displacement of the radial aperture relative to the waveguide channel branch. As noted and explained above, the position of the radial aperture relative to the waveguide channel negatively affects antenna performance, particularly the radiation pattern. Since the dividing plane between the two mold halves is precisely positioned at the transition between the radial aperture and the radial channel, the position of the radial aperture is affected not only by the manufacturing tolerance of the mold but also by the reduction in mold precision. The spread between individual plots and the occurrence of zeros are caused by undesirable lateral displacement of the radial aperture relative to the waveguide channel.

[0057] Figure 10 shows a side view of a waveguide channel 4 interconnected to a splitter 10 that, in accordance with the present disclosure, splits a transmitted signal into a first waveguide channel branch 12 and a second waveguide channel branch. Similar to the modified example shown in Figure 6, the illustrated waveguide channel 4 is located in the antenna layer 1 and includes radial apertures 6 connected to waveguide apertures 5 via radial channels 7. The radial apertures 6 are arranged in an array of apertures and energized via feeding apertures by a common waveguide channel 4 interconnected to each radiating element at the rear of the antenna assembly 17. The radial apertures 6 of the array are designed as slots. The illustrated waveguide channel 4 partially extends to the front 22 of the second antenna layer 21 and partially extends to the rear 2 of the antenna layer 1. The illustrated waveguide channel 4 has a substantially rectangular cross-section. In the illustrated modified example, the rear 2 of the antenna layer 1 and the front 22 of the second antenna layer 21 are in full contact with each other.

[0058] The difference from the modified example illustrated in Figure 8 lies in the design of the radial channels 7. The illustrated radial channels 7 interconnect the radial apertures 6 with the waveguide apertures 5. As shown in Figure 10, the radial channels 6 have a rounded transition region 9. The illustrated antenna layer 1 is also manufactured by a mold with two mold halves. Nevertheless, the dividing plane P of the mold halves is spaced a distance D from the radial apertures 6 toward the waveguide apertures 5. Displacing the dividing plane P toward the radial channels 7 improves the precision of the antenna layer 1. A dividing line 8 is positioned in each radial channel 7 between the rear surface 2 and the front surface 3. The dividing line 8 is spaced a distance D from at least one radial aperture 6 toward at least one waveguide aperture 5 and extends circumferentially through at least one radial channel 7. The ratio of the radius of the transition region 9 to the distance between the radial aperture 6 and the dividing line 8 is substantially 0.4 in the illustrated modified example.

[0059] Figure 11 illustrates a graph, specifically an array of curves, showing the propagation characteristics of the design according to Figure 8. The graph shown in Figure 9, similar to the graph in Figure 7, illustrates the antenna directivity and directivity spread. The dividing plane between the two mold halves is positioned a certain distance away from the transition region between the radial aperture and radial channel toward the front of the antenna plate. Therefore, the position of the radial aperture depends only on the manufacturing tolerance of the mold and not on the sealing accuracy of the mold. The spread between individual plots is significantly smaller compared to the spread in Figure 7. The occurrence of zeros is also reduced.

[0060] Figures 12 and 13 illustrate a second modification of waveguide channel 4 interconnected to a splitter 10 that divides a transmitted signal into a first waveguide channel branch 12 and a second waveguide channel branch 14. Figure 12 is a perspective view from the front and above, and Figure 13 is a side view. Waveguide channel 4 is interconnected to each of the splitters 10 that divide the signal into two branches via primary ports. A portion of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and a portion of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each include an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0061] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerline L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0062] As is best seen in Figure 13, the radial channel 7 in the illustrated modified example is horn-shaped. The waveguide channel 4, splitter 10, waveguide channel branches 12, 14, radial channel 7, and waveguide aperture 5 are all located in antenna layer 1. The radial aperture 6 merges with the radial channel 7 by a substantially rectangular transition region 9 having a mold take-out bevel for mold take-out of antenna layer 1.

[0063] Figures 14 and 15 illustrate a third modification of the waveguide channel, interconnected to a splitter that divides the transmitted signal into a first waveguide channel branch and a second waveguide channel branch. Figure 14 is a perspective view from the front and above, and Figure 15 is a side view. The waveguide channel 4 is interconnected via primary ports to each of the splitters 10 that divide the signal into two branches. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each comprise an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0064] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned collinearly with respect to the centerlines L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are collinear with respect to each other. The radial openings 6 have a rectangular cross-section and are oriented longitudinally with respect to the corresponding waveguide channel 4 or waveguide branch 31. The cross-sectional area of ​​the radial openings 6 is smaller than the cross-sectional area of ​​the waveguide 31.

[0065] As can be seen from Figure 15, the waveguide channel 4, splitter 10, and waveguide channel branches 12, 14, or better waveguide channel branch 31 are located partially in antenna layer 1 and partially in the second antenna layer 21. The splitting surface P of antenna layer 1 is located in the radial channel 7, spaced a distance D away from the transition region 9 of the radial channel 7 toward the front surface 3 of antenna layer 1. The radial channel 7 merges into the waveguide opening 5. The illustrated transition region 9 is chamfered.

[0066] The waveguide branch 31 has a rectangular cross-section with a long extension a and a short extension b perpendicular to each other, where a > b. The radial openings 6 are located in the wall portion of the waveguide branch 31, substantially parallel to the long extension a. In this example, the waveguide branch 31 has a rectangular cross-section.

[0067] Figures 16 and 17 illustrate a fourth modification of the waveguide channel, interconnected to a splitter that divides the transmitted signal into a first waveguide channel branch and a second waveguide channel branch. Figure 16 is a perspective view from the front and above, and Figure 17 is a side view. The waveguide channel 4 is interconnected via primary ports to each of the splitters 10 that divide the signal into two branches. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each comprise an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0068] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerline L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0069] As can be seen from Figure 17, the waveguide channel 4, splitter 10, and waveguide channel branches 12 and 14 are located partially on antenna layer 1 and partially on the second antenna layer 21. The splitting surface P of antenna layer 1 is located on the radial channel 7, spaced a distance D away from the transition region 9 of the radial channel 7 toward the front surface 3 of antenna layer 1. The radial channel 7 merges into the waveguide aperture 5. The illustrated transition region 9 between waveguide channel 4 and radial channel 7 is rounded. The ratio of the radius of the transition region 9 to the distance between the radial aperture 6 and the splitting line 8 is substantially 0.8 in the illustrated modified example.

[0070] Figures 18 and 19 illustrate a fifth modification of the waveguide channel, interconnected to a splitter that divides the transmitted signal into a first waveguide channel branch and a second waveguide channel branch. Figure 18 is a perspective view from the front and above, and Figure 19 is a side view. The waveguide channel 4 is interconnected via primary ports to each of the splitters 10 that divide the signal into two branches. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each comprise an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0071] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerline L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0072] As can be seen from Figure 19, the waveguide channel 4 is partially located on antenna layer 1 and partially on the second antenna layer 21. The splitter 10 and waveguide channel branches 12 and 14 are located independently on the rear surface 2 of antenna layer 1. The splitting surface P of antenna layer 1 is located on the radial channel 7, a certain distance away from the transition region 9 of the radial channel 7 toward the front surface 3 of antenna layer 1. The radial channel 7 merges into the waveguide opening 5. The illustrated transition region 9 between waveguide channel 4 and radial channel 7 is rounded. The ratio of the radius of the transition region 9 to the distance between the radial opening 6 and the splitting line 8 is substantially 0.3 in the illustrated modified example.

[0073] The cross-section of the radial apertures 6 is modified to affect the directivity. The cross-sections of neighboring radial apertures 6 in a single array may differ, with radial apertures 6 having smaller cross-sections placed next to radial apertures 6 having larger cross-sections. Good results can be achieved by arranging radial apertures 6 with smaller and larger cross-sections alternately in a row. This compensates for the radiation pattern, resulting in linear radiation. The difference in the cross-section of the radial apertures 6 creates a phase difference in the radiation from the radial apertures 6. This phase difference causes a slope in the radiation pattern.

[0074] Figures 20 and 21 illustrate a sixth modification of the waveguide channel, interconnected to a splitter that divides the transmitted signal into a first waveguide channel branch and a second waveguide channel branch. Figure 20 is a perspective view from the front and above, and Figure 21 is a side view. The waveguide channel 4 is interconnected via primary ports to each of the splitters 10 that divide the signal into two branches. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each comprise an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0075] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerline L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0076] As can be seen from Figure 21, the waveguide channel 4 is partially located on antenna layer 1 and partially on the second antenna layer 21. The splitter 10 and waveguide channel branches 12 and 14 are located independently on the rear surface 2 of antenna layer 1. The splitting surface P of antenna layer 1 is located on the radial channel 7, a certain distance away from the transition region 9 of the radial channel 7 toward the front surface 3 of antenna layer 1. The radial channel 7 merges into the waveguide opening 5. The illustrated transition region 9 between waveguide channel 4 and radial channel 7 is rounded. The ratio of the radius of the transition region 9 to the distance between the radial opening 6 and the splitting line 8 is substantially 0.5 in the illustrated modified example.

[0077] A single funnel-shaped radial channel 7, as illustrated, can expand the radiating surface of the radial aperture 6. In addition, the funnel can be positioned asymmetrically with respect to the centerlines of the waveguide channel branches 12 and 14, resulting in an asymmetric radiation pattern. The asymmetrically displaced funnel adds a slope to the radiation characteristics of the antenna device. The effect of lateral displacement can result in localized maximums in the antenna's directivity. These maximums may help concentrate antenna energy in a specific region. The sloped pattern may further extend the range of a particular region of radar.

[0078] Figures 22 and 23 illustrate a seventh modification of the waveguide channel, interconnected to a splitter 10 that divides the transmitted signal into a first waveguide channel branch and a second waveguide channel branch. Figure 22 is a perspective view from the front and above, and Figure 23 is a side view. The waveguide channel 4 is interconnected to each of the splitters 10 that divide the signal into two branches via its primary port. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each comprise an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0079] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerline L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0080] As can be seen in Figure 23, the illustrated modification differs from other modifications in that the division line of the antenna layer substantially coincides with the front surface 3. The waveguide channel 4 is partially located in antenna layer 1 and partially in the second antenna layer 21. The splitter 10 and waveguide channel branches 12,14 are located independently on the rear surface 2 of antenna layer 1. The division surface P of antenna layer 1 is located on the front surface 3 of the antenna layer. The radial channel 7 merges into the waveguide opening 5 located on the front surface 3 of antenna layer 1. The illustrated transition region 9 between waveguide channel 4 and radial channel 7 is rounded. The illustrated radial opening 6 merges into the waveguide opening 5 via the radial channel 7 without its cross-section expanding toward the front.

[0081] Figures 24 and 25 illustrate an eighth modification of the waveguide channel 4. Figure 24 is a perspective view from the front and above, and Figure 25 is a side view. The illustrated waveguide channel 4 differs from the other modifications in that the waveguide channel 4 is fed laterally. The illustrated modification does not have a splitter. The waveguide channels 4 are designed in a staggered arrangement so that the radial apertures 6 can be aligned collinearly with respect to the center line L of the waveguide channel 4. This design modulates the electric field so that the radial apertures 6 are collinear with respect to each other. As is best seen in Figure 25, the radial channel 7 of the illustrated modification is horn-shaped. The waveguide channels 4, radial channel 7, and waveguide apertures 5 are all located in antenna layer 1. The radial apertures 6 merge into the radial channel 7 by a substantially rectangular transition region 9 having a mold take-out bevel for mold take-out of antenna layer 1.

[0082] Figures 26 and 27 illustrate a ninth modification of waveguide channel 4, interconnected to a splitter 10 that divides the transmitted signal into a first waveguide channel branch 12 and a second waveguide channel branch 14. Figure 26 is a perspective view from the front and above, and Figure 27 is a side view. Waveguide channel 4 is interconnected to each of the splitters 10 that divide the signal into two branches via its primary port. Part of the signal is transmitted to the first waveguide channel branch 12, which is interconnected to the first secondary port of the splitter, and part of the signal is transmitted to the second waveguide channel branch 14, which is interconnected to the second secondary port of the splitter 10. The illustrated first waveguide channel branch 12 and second waveguide channel branch 14 each include an array of radial apertures 6, the radial apertures 6 being aligned in a straight line with respect to the centerline L of the respective waveguide channel branches 12 and 14. The illustrated waveguide splitter 10 includes a deflection element 16 positioned adjacent to the primary port and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical.

[0083] In addition, a necking 29 is positioned on the splitter. The necking 29 is in the form of an inwardly facing projection, or a partition positioned on the central splitter 10 between the first waveguide channel branch 12 and the second waveguide channel branch 14, which are the first and second secondary ports, respectively. The two branches 12 and 14 are designed in a staggered arrangement to allow the radial openings 6 to be aligned in a straight line with respect to the centerlines L of the first waveguide channel branch 12 and the second waveguide channel branch 14. This design modifies the electric field so that the radial openings 6 of the first waveguide channel branch 12 and the radial openings 6 of the second waveguide channel branch 14 are aligned in a straight line with respect to each other.

[0084] As is best seen in Figure 27, the radial channel 7 in the illustrated modification is horn-shaped. The waveguide channel 4, splitter 10, waveguide channel branches 12, 14, radial channel 7, and waveguide aperture 5 are all located in antenna layer 1. The radial aperture 6 merges with the radial channel 7 by a substantially rectangular transition region 9 having a mold take-out bevel for mold take-out of antenna layer 1. In the illustrated modification, the radial channel merges with the aperture via a sharp transition in the form of a step. Thus, the dividing line 8 extends along the edge between the radial channel 7 and the aperture 5.

[0085] Figures 28 to 30 illustrate a third modification of the antenna assembly 17 according to the present disclosure. In this embodiment, a single linear, i.e., unbranched waveguide channel 4 has four waveguide openings 5 ​​arranged in series, through which electromagnetic radiation is coupled from the waveguide to the outside.

[0086] As is particularly evident from Figure 29, the rear surface 2 of the antenna layer 1 comprises a periodic array of electromagnetic bandgap structures in the form of pillars 30 that replace the lateral walls of the waveguide channel 4. Otherwise, the waveguide channel 4 is defined by grooves 31 in the rear surface 2 of the antenna layer 1. On the other hand, the rear portion 20 of the antenna assembly 17 is flat. The rear portion 20 of the antenna assembly 17 can be formed, for example, from a PCB.

[0087] The bandgap structure is configured to compensate for potential manufacturing and assembly tolerances between the front 18 and the rear 20, as direct ohmic contact between them is not necessarily required. This reduces leakage between antenna layers. [Explanation of symbols]

[0088] 1. Antenna layer 2. Rear view (antenna layer) 3. Front (Antenna Layer) 4 Waveguide Channels 5 Waveguide opening 6. Radial openings 7. Radial Channels 8 division lines 9 Transition region 10 Splitter 11 Primary Port 12. First waveguide channel branching 13. First secondary port 14. Second waveguide channel branching 15 Second secondary port 16 Deflection element 17 Antenna Assembly 18 Front section (antenna assembly) 19. Intermediate section (antenna assembly) 20. Rear (Antenna Assembly) 21. Second antenna layer 22 Front (Second antenna layer) 23 Antenna devices 24 Electrical components 25 radar chips 26 Printed circuit board (PCB) 27 strip wires 28 Power supply opening 29 Necking 30 Electromagnetic Bandgap Structure / Pillar 31 Waveguides / Waveguide Branches L center line P split plane D distance a. Long extension b Short extension

Claims

1. An antenna layer (1) having a rear surface (2) and a front surface (3), The antenna layer (1) is a. comprising at least two waveguide channels (4) extending to the rear surface (2), b. Each of the at least two waveguide channels (4) comprises at least one waveguide opening (5) located on the front surface (3) for transmitting and / or receiving signals, Each of the at least two waveguide channels (4) comprises at least one radial opening (6) located in the antenna layer (1) and interconnected to the waveguide opening (5) by at least one radial channel (7), The dividing line (8) is positioned in the at least one radial channel (7) between the rear surface (2) and the front surface (3), The dividing line (8) is spaced a distance (D) from the at least one radial opening (6) toward the at least one waveguide opening (5) and extends circumferentially within the at least one radial channel (7), Antenna layer (1).

2. The antenna layer (1) is manufactured by a molding process, injection molding, or die casting, according to claim 1.

3. The antenna layer (1) according to claim 1 or 2, wherein at least one radial opening (6) merges with the radial channel (7) by a rounded or chamfered transition region (9).

4. The antenna layer (1) according to claim 3, wherein the ratio of the radius of the transition region (9) to the distance between the radial opening (6) and the dividing line (8) is less than 1, preferably less than 0.8, and more preferably less than 0.

6.

5. The antenna layer (1) according to any one of claims 1 to 4, wherein the radial channel (7) is horn-shaped.

6. The at least one waveguide channel (4) is interconnected to a splitter (10) via a primary port (11), and the splitter (10) receives the signal to be transmitted. a. A first waveguide channel splitter (12) interconnected to the first secondary port (13) of the splitter (10), b. A second waveguide channel splitter (14) interconnected to the second secondary port (15) of the splitter (10), An antenna layer (1) according to any one of claims 1 to 5, configured to be divided into:

7. The aforementioned splitter (10) At least one deflection element (16) is positioned adjacent to the primary port (11) and configured to twist the polarization of the electric field by 90 degrees from the horizontal to the vertical, At least one deflection element (16) is positioned adjacent to the first secondary port (13) and the second secondary port (15) and configured to twist the polarization again from the vertical to the horizontal direction, The antenna layer (1) according to claim 6, comprising:

8. The antenna layer (1) according to claim 6 or 7, wherein the length of at least one waveguide channel (4) is longer than the length of the first waveguide channel branch (12) and the length of the second waveguide channel branch (14).

9. The antenna layer (1) according to any one of claims 6 to 8, wherein each of the first waveguide channel branch (12) and the second waveguide channel branch (14) comprises at least one radial opening (6), and the radial opening (6) is arranged collinearly with respect to the center line (L).

10. The antenna layer (1) according to claim 9, wherein the first waveguide channel branch (12) and the second waveguide channel branch (14) are designed in a staggered arrangement configuration configured to modify the electric field such that the at least one radial opening (6) of the first waveguide channel branch (12) and the at least one radial opening (6) of the second waveguide channel branch (14) are aligned in the same straight line with respect to each other.

11. The antenna layer (1) according to claim 9 or 10, wherein the radial openings (6) have a changing cross-section to tilt the radiation pattern.

12. The antenna layer (1) according to any one of claims 6 to 11, wherein the at least one waveguide opening (5) of the first waveguide channel branch (12) and the at least one waveguide opening (5) of the second waveguide channel branch (14) are interconnected.

13. The antenna layer (1) according to any one of claims 1 to 12, wherein at least one radial opening (6) has a rectangular cross-section and is oriented longitudinally with respect to the corresponding waveguide channel (4).

14. An antenna assembly (17) comprising an antenna layer (1) according to any one of claims 1 to 13, An antenna assembly (17) wherein the antenna layer (1) is the front part (18) or the middle part (19) of the antenna assembly (17).

15. The second antenna layer (21), which is the rear part (20) of the antenna assembly (17), The antenna assembly (17) according to claim 14, further comprising:

16. The antenna assembly (17) according to claim 15, wherein the at least one waveguide channel (4) extends at least partially to the front surface (22) of the second antenna layer (21).

17. An antenna assembly (17) according to any one of claims 14 to 16, wherein a waveguide (31) is at least partially formed by one of the at least two waveguide channels (4) extending to the rear surface (2) of the antenna layer (1), the waveguide (31) having a rectangular cross-section comprising a long extension (a) and a short extension (b) perpendicular to each other, the extension (a) being longer than the extension (b), and at least one radial opening (6) being located in the wall portion of the waveguide (31) parallel to the long extension (a).

18. The antenna assembly (17) according to claim 17, wherein the waveguide (31) has a cross-section selected from the group consisting of rectangles, trapezoids, triangles, ellipses, semi-ellipses, and polygons.

19. The antenna assembly (17) according to any one of claims 14 to 18, wherein the cross-sectional area of ​​at least one radial aperture (6) is smaller than the cross-sectional area of ​​the waveguide (31).

20. An antenna device (23) for automotive radar applications, An antenna assembly (17) according to any one of claims 14 to 19, Electronic components (24) and An antenna device (23) comprising:

21. A method for manufacturing an antenna layer (1) according to any one of claims 1 to 13, wherein the antenna layer (1) is manufactured by injection molding or die casting.

22. The method according to claim 21, wherein the antenna layer (1) is manufactured by injection molding of a plastic material and then its surface is metallized.

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