Antenna device

Abstract

The present disclosure relates to an antenna apparatus (1) for automotive radar applications, the antenna apparatus (1) comprising a printed circuit board (2) having a front surface (3) and a back surface (4), an electronic component (5) interconnected to the printed circuit board (2), and an antenna layer (6) having a front surface (7) and a back surface (8), the back surface (8) being interconnected to the front surface (7) of the printed circuit board (2). At least one waveguide opening (9) is interconnected to the front surface (7) of the antenna layer (6) and communicatively coupled to the electronic component (5) by at least one waveguide channel (10), the at least one waveguide channel (10) comprising a conductive surface (11) for guiding an electromagnetic field to or from the electronic component (5) and formed by a recess (12) disposed between the back surface (8) of the antenna layer (6) and the front surface (3) of the printed circuit board (2).

Description

[Technical Field]

[0001] The present disclosure relates to antenna arrangements for use, for example, in automotive radar applications. [Background technology]

[0002] WO 2022122319, published on June 16, 2022 in the name of the same applicant, relates to an antenna device comprising a printed circuit board and electronic components disposed thereon. The antenna device comprises at least two individual antenna elements interconnected to electronic components configured to transmit and receive signals. The antenna elements each comprise at least one waveguide channel interconnected in an antenna assembly. A first waveguide opening is disposed on the back surface of the antenna assembly. The first waveguide opening is interconnected to the electronic components and configured to transmit and / or receive signals. A second waveguide opening is disposed on the front surface of the waveguide assembly and is also configured to transmit and / or receive signals.

[0003] International Publication No. 2021163381, published on August 19, 2021 in the name of Vionia US Inc., relates to a radar sensor assembly / module with multiple waveguides, particularly for use in vehicles. Each of the multiple waveguides is defined by a waveguide groove. A slot can be arranged to extend along the axis of each of the multiple waveguide grooves. Each of the waveguides can be further defined, at least in part, by a periodic feature extending periodically back and forth along at least a portion of its respective waveguide, and by multiple periodic signal confinement structures. A first periodic signal confinement structure of the multiple periodic signal confinement structures can extend adjacent to a first side of each of the multiple waveguides, and a second periodic signal confinement structure can extend along a second side of each of the multiple waveguides, opposite the first side.

[0004] WO 2022053114, published on March 17, 2022 in the name of Konti-Temic Microelectronic GmbH, relates to a radar system for detecting surroundings, comprising a printed circuit board having at least one radio-frequency component with at least one directly transmitting or receiving element, and a molded part having one or more individual antennas on the upper surface of the molded part for transmitting and / or receiving radar signals, wherein the connection between the at least one transmitting or receiving element of the radio-frequency component and the at least one individual antenna on the upper surface of the molded part is made at least partially by a hollow internal waveguide. The transmitting and receiving element of the radio-frequency component transmits toward the printed circuit board, which is transparent to radar waves in that region. The molded part is electrically connected to the printed circuit board by soldering and / or a conductive adhesive. The printed circuit board feeds the waveguide from a transparent location on the printed circuit board, and the molded part consists of an at least partially metallized single-layer plastic part.

[0005] U.S. Patent Publication No. 20220196792, published June 23, 2022 in the name of Robert Bosch GmbH, relates to a method for manufacturing a radar sensor. In the method, a circuit board is provided. A radar transceiver is mounted on a surface of the circuit board. A waveguide structure made of a plastic material is provided. A waveguide channel is formed within the waveguide structure and on an open side, the waveguide channel including at least one metallic conductively coated sidewall. The waveguide structure is soldered to a surface of the circuit board, with the open side facing the circuit board.

[0006] U.S. Patent Publication No. 20210249784, published on August 12, 2021 in the name of Vionia US Inc., relates to a vehicle antenna and / or waveguide assembly, such as a radar sensor antenna assembly, as well as an associated signal confinement structure. In some embodiments, the assembly can include an antenna block defining one or more waveguides. A conductive layer can be coupled to the antenna block and at least partially form the walls of the waveguide. The assembly can include one or more periodic structures operably coupled to the waveguides. Each periodic structure can include a first elongated opening and a first series of repeating slots extending at least substantially transversely to the first elongated opening. Each of the first series of repeating slots is spaced apart from adjacent slots in the first series of repeating slots along the first elongated opening. Summary of the Invention [Problem to be solved by the invention]

[0007] Antenna arrangements are widely used components for communication devices and radar applications, for example in the automotive industry, or form part of driver assistance or autonomous driving systems. For these applications, signals with millimeter wave frequencies are generally used. Besides antenna performance, such as antenna gain and efficiency, which are all important parameters since they directly affect the overall system performance, a mechanically simple setup is also desirable if the production numbers of these antenna arrangements are to be large.

[0008] Antenna devices can be designed as printed circuit board antennas (PCB antennas), which are typically used at lower frequencies, but can also be used at millimeter-wave frequencies. However, they generally have drawbacks in terms of performance. More specifically, PCB antennas typically have planar metal structures as radiating elements. They are usually implemented on top of or integrated into a dielectric substrate layer. The connection between these radiating elements and the intended chips for generating / receiving the transmitted / received power (signal), respectively, is realized by additional planar structures, i.e., transmission lines, such as microstrips, coplanar waveguides, and striplines, that guide the signal from the chip to the radiating section. These antenna systems tend to be very lossy at millimeter-wave frequencies (especially above 60 GHz) due to the inherent dielectric properties of the substrate materials. These losses significantly reduce the efficiency / performance of the antenna and, at the same time, increase the power consumed within the system.

[0009] Air-filled waveguide antennas have been developed as an alternative to PCB antennas, which suffer from the drawbacks mentioned above. A typical air-filled waveguide used in microwave and millimeter-wave applications is a hollow, conductive pipe capable of guiding an electromagnetic signal from point A to point B with negligible loss (depending on the metal's conductivity). Standard millimeter-wave frequency waveguide assemblies are typically fabricated using advanced machining techniques with very low tolerance requirements, such as high-precision milling and micromachining. However, these techniques present limitations because air-filled waveguide antennas typically require complex power dividing / combining networks connecting the antenna feed point and the radiating structure. Both the radiating structure and the feed network typically contain specific features that require low tolerances (on the order of tens of microns).

[0010] One aspect of the present disclosure is to address these manufacturing limitations / drawbacks, for example, based on the significant performance advantages of waveguide technology over printed circuit boards (PCBs). [Means for solving the problem]

[0011] From a cost-effective production perspective, one goal is to achieve designs and techniques for implementing MIMO antenna arrays that can be manufactured using only a minimal number of stacked layers (components). Considering the above advantages of waveguide technology from a performance perspective and the tight tolerance requirements for manufacturing, one aspect of the present disclosure is directed to combining innovative radio frequency and mechanical design with advanced manufacturing to implement high performance millimeter wave frequency waveguide antennas and components, particularly for automotive applications, with only a maximum of one antenna layer.

[0012] An antenna device for automotive radar applications according to the present disclosure typically includes a printed circuit board (PCB) having a front and a back surface, and electronic components interconnected to the printed circuit board. The electronic components are typically radar chips, such as monolithic microwave integrated circuits (MMICs), which include multiple circuits integrated into a small package for operation at microwave frequencies. These MMICs are typically placed directly on the front or back surface of the printed circuit board. Alternatively, the electronic components can be interconnected with the printed circuit board intended to generate / receive the power (signal) to be transmitted / received, respectively, through additional planar structures, i.e., transmission lines, such as microstrips, coplanar waveguides, or striplines, that guide the signals from the chip to the radiating portion.

[0013] The antenna device generally includes an antenna layer for guiding signals from an electronic component to at least one waveguide opening configured to transmit and / or receive signals. Good signal transmission results can be achieved when the antenna layer has a front surface and a back surface, and the back surface is interconnected to the front surface of the printed circuit board. In one variation, the antenna layer is further configured to function as a radome, protecting at least the printed circuit board and / or components within the antenna device from environmental influences. Therefore, the antenna layer is at least partially made of a material that is resistant to environmental influences, for example, a material that does not absorb moisture. In one variation, the back surface of the antenna layer is in direct contact with the front surface of the printed circuit board (PCB) or a coating on the front surface of the printed circuit board. The distance between the back surface of the antenna layer and the front surface of the PCB can be substantially zero or in the form of an air gap typically shorter than the length of a wavelength (λ).

[0014] Alternatively or additionally, electronic components in the form of chips (MMICs) can be embedded in printed circuit boards, whereby the chips can be embedded in one of the layers of substrate material, which generally consists of printed circuit board material or any other material suitable for embedding chips (silicon, ceramic, glass, molding compound).

[0015] The electromagnetic signal can be fed from the chip to at least one waveguide channel in the antenna layer by a planar or three-dimensional transition line in the form of a substrate integrated waveguide (SIW), a dielectric-loaded buried waveguide, and / or an air-filled buried waveguide. This can be true regardless of whether the chip is embedded in the printed circuit board or attached to the top or bottom of the printed circuit board.

[0016] In another variation, the back surface of the antenna layer can be interconnected to the front surface of the printed circuit board by at least one interlayer. In one variation, the interlayer can take the form of a coating or an additional antenna layer. A plate-like interlayer can be disposed between the front surface of the PCB and the back surface of the antenna layer. The front surface of the interlayer can face the back surface of the antenna layer. The back surface of the interlayer can face the front surface of the PCB. The waveguide opening is typically interconnected to the front surface of the antenna layer and communicatively connected to the electronic component by a waveguide channel. The waveguide channel can be at least partially disposed within the interlayer and extend from the back surface to the front surface of the interlayer.

[0017] The intermediate layer may include several parts or layers, for example, at least one front layer and a back layer connected thereto. The intermediate layer may have a plate-like front layer and back layer. The back layer and front layer are typically joined along a parting plane. In this variant, the front side of the intermediate layer, facing the back side of the antenna layer, is disposed on the front layer. In this variant, the back side of the intermediate layer, facing the front side of the PCB, is disposed on the back layer. A scattering surface may be implemented on the back side of the antenna layer and / or the back side of the intermediate layer and / or the back side of the front layer of the intermediate layer in the form of an array of cavities next to the waveguide channels, as described in more detail further below. The scattering surface is typically disposed to reduce or cancel reflections occurring where there is a change in the medium that is typically equal to a change in the dielectric constant. The scattering surface may reduce or cancel reflections between the front side of the antenna layer and the back side of the antenna layer. Alternatively or additionally, the scattering surface may reduce or cancel reflections between the back side of the antenna layer and an external component disposed at a certain distance from the antenna device, such as a bumper in an automotive application.

[0018] Good results can be achieved when a signal is fed into at least one waveguide channel from an electronic component, typically a radar chip in the form of an MMIC. Good results can be achieved when the waveguide channel is designed as a tubular channel, with one channel wall formed by the front surface of the PCB or the front surface of the intermediate layer, and the other channel wall formed by a recess located on or forming part of the back surface of the antenna layer. Good results can also be achieved when the waveguide channel has a waveguide cross-section of at least one of the following shapes: rectangular, rhomboid, elliptical, trapezoidal, crescent, etc., or a combination thereof. The signal is typically fed into at least one waveguide opening through at least one waveguide channel. At least one waveguide opening can be designed as a slot antenna or horn antenna integrated in, on, or behind the front surface of the antenna layer. To obtain a smooth, broadband impedance transition from the waveguide channel to the antenna layer, a material for the antenna layer with a lower electrical permittivity (dk~1-6) is preferred.

[0019] To receive or transmit signals, at least one waveguide opening is typically interconnected to the front surface of the antenna layer and communicatively connected to an electronic component by at least one waveguide channel. In one variant, the at least one waveguide channel is designed as a rectangular waveguide channel, which can generally be seen as a four-walled pipe. The waveguide channel is typically formed by a recess disposed between the rear surface of the antenna layer and the front surface of the printed circuit board. Good results can be achieved in manufacturing the waveguide channel if at least the walls of the recess are designed with draft angles. To be able to guide electromagnetic signals, the at least one waveguide channel typically has a conductive surface for guiding the electromagnetic field between the electronic component and the at least one waveguide opening. The antenna layer, which is conductive and can also function as a cover (radome), can be metallized on its back surface to create a conductive surface. The waveguide channel can be formed by directly placing the recess in direct contact with the metallized front surface of the PCB or by directly placing a conductive intermediate layer between the rear surface of the antenna layer and the PCB.

[0020] A particularly simple design can be achieved by placing the back surface of the antenna layer on the front surface of a printed circuit board, which is backed up by a back surface or a housing. The printed circuit board can be arranged in a sandwich-type structure between the antenna layer and the back surface or housing. Good results can be achieved if the antenna layer and the back surface or housing form the overall housing of the antenna device, enclosing the PCB and protecting the internal components of the antenna device from environmental influences. For simple and position-accurate assembly, the antenna layer, PCB, and back surface or housing can be assembled via connecting elements protruding from the back surface of the antenna layer. The connecting elements can be designed as pins, which in the assembled state protrude through holes in the PCB and are received by receiving openings in the back surface or housing.

[0021] The main advantage of this design compared to known designs is that it is less costly, since it does not require an antenna layer composed of several individual layers. Furthermore, no additional radome is required. The reduced number of antenna layers compared to known designs allows for a significant reduction in the overall thickness of the antenna arrangement. Furthermore, while in known designs the radome is typically positioned at a distance of λ / 4 to λ (1 mm to 4 mm at 77 GHz) from the PCB, this distance can be eliminated. This makes the present design suitable for compact sensors used, for example, as corner, front, side, or rear radars in automotive applications where cost is critical. The antenna layer does not need to be substantially flat. In appropriate cases, the antenna layer can be at least partially skeletonized to reduce the contact area between the antenna layer and the printed circuit board. This is advantageous because the minimized contact area increases the surface pressure at the contact area, thus resulting in more accurate alignment of the antenna layer with the printed circuit board.

[0022] It is desirable to design a high-precision molding parting line to minimize the effect on electromagnetic signal propagation (i.e., minimal loss and mismatch) when the antenna layer is interconnected to or placed directly on a printed circuit board. The design of the waveguide channel and antenna layer can be optimized to be compatible with various bonding techniques. In one variation, the front surface of the printed circuit board and the back surface of the antenna layer are substantially flat. This can be particularly advantageous because preferred bonding techniques can include at least one or a combination from the group consisting of soldering, welding, adhesive bonding (both conductive and non-conductive), and clamping. In one variation, the antenna layer can function as a housing for the radar device, whereby the printed circuit board is sealed by a plate-like back cover.

[0023] The antenna layer is typically at least partially made of a metal material and / or includes a metallization layer that forms a conductive surface. When the antenna layer is made by injection molding at least one plastic material, the back surface and / or the recesses are typically metallized with a conductive material. Alternatively or additionally, the antenna layer can be made of metallized plastic and / or any other material whose surface is conductive. Techniques such as high-precision plastic injection molding and, if necessary, a metallization process can be used. For variations in which an additional coating or metallization layer is desired, the coating process typically involves metallizing the back surface of the antenna layer by applying, for example, a physical vapor deposition (PVD) coating, a flame spray coating, or electroplating or electroless plating. Alternatively or additionally, injection molding can be used, whereby the conductivity of the antenna layer can be enhanced by using any additional conductive parts, such as sheet metal or metal film injection molding techniques (film injection molding). Overmolding, in which a conductive material (plastic filled with a conductive filler) is overmolded onto another non-conductive plastic material, can also be applied. With overmolding, also known as insert molding, a metal insert is overmolded with molten plastic injected into a mold to form the antenna layer.

[0024] Good results can be achieved in terms of manufacturability if the recess is at least partially formed by a deepening in the rear surface of the antenna layer. This is particularly beneficial for injection molding or die casting, since the part can be easily demolded. The recess may be at least partially formed by a deepening in the rear surface of the antenna layer and / or by a protrusion. Instead of or in addition to the protrusion, intrusions can be arranged on the rear surface of the antenna layer. The EBG structure is formed by a protrusion extending above the rear surface of the antenna layer and / or a planar metal structure on the front surface of the printed circuit board. The protrusion can be made integral with the antenna layer, laterally delimit the recess, and together with the front surface of the printed circuit board form the electromagnetic bandgap structure. Alternatively or additionally, a planar metal structure comprising a number of patches can be arranged on the front surface of the PCB, the patches laterally delimiting the recess and, together with the protrusion or the rear surface of the antenna layer, forming the electromagnetic bandgap structure. The antenna layer may comprise a ridge arranged inside the recess and extending substantially along the waveguide channel. The ridges can be disposed within the recesses of the waveguide channel to reduce the overall size of the waveguide channel. Alternatively or additionally, the waveguide channel can be implemented in the form of a coaxial waveguide by including a metallic strip in the center of the waveguide channel for further size reduction.

[0025] Another aspect of the present disclosure is the use of artificial magnetic conductors (AMCs) in antenna devices. AMCs are approximations of perfect magnetic conductors (PMCs), which exist only in theory. However, PMCs can be approximated by AMCs in a limited bandwidth. AMCs can prevent the transmission of magnetic fields parallel to the material surface. AMCs can be generated by periodic or random patterns. This can be implemented by periodically placing metallic patches on a PCB, or by placing periodic cavities on a fully metallic surface (a complementary case to patches).

[0026] The theory underlying AMC is the perfect magnetic conductor (PMC), an idealized material that does not allow magnetic fields to propagate within it. In an antenna device, the artificial magnetic conductor can serve two purposes. When an AMC structure is placed on the front side of a PCB facing the back side of the antenna layer in the attached state, an electromagnetic bandgap (EBG) structure can be formed between the AMC structure and the back side of the antenna layer. This EBG structure prevents unwanted propagation of electromagnetic waves outside the defined waveguide channel. Alternatively or additionally, components of the AMC structure that, when attached, can form a waveguide channel together with the recess in the antenna layer, allowing the height of the waveguide channel and therefore the height / depth of the recess in the antenna layer to be reduced, thereby reducing the overall height of the antenna device.

[0027] With the AMC structure placed on the front side of the PCB, the waveguide channel can be designed as a half-mode waveguide. The concept behind the half-mode waveguide is to halve the height of the waveguide channel. To still be able to guide the signal while halving the height, the concept is to use an artificial magnetic conductor (AMC) to mirror the E-field of the signal. The shape of the patch can be, for example, rectangular, circular, pentagonal, hexagonal, elongated, or ellipsoidal. The patches can be placed on the front side of the PCB in an axisymmetric, glide symmetric, or random pattern. Another variation for creating an AMC is to place a full metal plane with polygonal openings or protrusions, for example in the form of cavities, on the back side of the antenna layer instead of having metallic patches on the front side of the PCB.

[0028] The lateral distance between the patches relative to each other - the periodicity - is generally chosen depending on the emitted wavelength. The size of the patch is related to the guided wavelength, which can be calculated as follows: TIFF2025534145000002.tif2033λ0 = free air wavelength ε rPCB =Dielectric constant of PCB substrate

[0029] The period is typically chosen to be in the range λ0 / 8 to 2λ0. The patches are typically arranged in collinear arrays, which form rows and columns. Between adjacent columns, the patches are spaced apart by a first period P x Between adjacent rows, the patches are spaced apart by a second period P y , resulting in a matrix of patches in a top view on the front side of the PCB. Furthermore, the arrays can be shifted with respect to each other. The patches within one array are spaced at intervals equal to the period, while adjacent arrays can be shifted with respect to each other by an interval equal to P / n, where n is a natural number. This results in a staggered design. The periodic pattern of patches has the advantage that any misalignment, either lateral or angular, of the antenna layer relative to the printed circuit board does not affect the magnetic and electrical properties.

[0030] In typical automotive radar applications, the free-air wavelength λ is in the millimeter-wave frequency range of 10 mm to 1 mm. In a specific variation where the frequency range is 55 GHz to 85 GHz, the free-air wavelength λ is in the range of 5.5 mm to 3.5 mm. A typical value for the period when the free-air wavelength λ is in the range of 5.5 mm to 3.5 mm is approximately λ / 3. Alternatively or additionally, protrusions can be disposed on the back surface of the antenna layer or interlayer to form an AMC structure. These protrusions can be in the form of pillars extending from the back surface of the antenna layer or interlayer toward the front surface of the printed circuit board and can be combined with patches on the front surface of the PCB.

[0031] At least one waveguide opening can be provided behind the front face of the antenna layer as a penetration in the conductive surface. The penetration can be established by a material ablation process, preferably by a laser and / or cutting process. After manufacturing the antenna layer, the waveguide openings required for radiation, for example designed as slots and / or horns, can be realized by an etching process after prior metallization of the entire surface of the waveguide channels and / or the back face of the antenna layer. In that case, the metallized surface is removed by etching techniques. Alternatively, the waveguide openings required for radiation can be realized by a mechanical subtractive process, for example by engraving, scratching, or milling, or by an ablation process, for example by a laser ablation process. The metal surface can be removed by utilizing the energy of a laser. Alternatively, the slots can be realized during the coating process by using a mask.

[0032] To reduce signal loss within the material during transmission and / or reception, if a directional radiation pattern is desired, the thickness of the material between the radiating slot and the front surface of the antenna layer is preferably kept less than two wavelengths to avoid electromagnetic wave propagation within the material. For a non-directional radiation pattern, a thicker layer of material between the front surface and the antenna opening is preferred. If the antenna layer is too thick, some of the energy cannot excite the material of the antenna layer, creating surface waves that reduce the antenna's efficiency and degrade the pattern. To reduce loss, the antenna layer can be made by a foaming process. Foam can reduce the dielectric constant compared to high-density materials without sacrificing thickness. The antenna layer can be made from foam materials by an injection molding process, providing a sandwich and / or cellular structure with a harder skin layer and a softer core. Foam injection molding is a manufacturing process that can be used to reduce the dielectric constant of the antenna layer and achieve the properties required for radiation through the antenna layer. The cellular core and thin skin allow the dielectric constant of the material to be reduced compared to conventional injection molded parts.

[0033] Alternatively or additionally, at least one waveguide opening for transmitting and / or receiving signals can be provided as a cavity at the back surface of the antenna layer or behind the front surface of the antenna layer. The cavity can be at least partially filled with a material that is transparent to electromagnetic waves. The cavity can be filled with a dielectric resonator consisting of a cube made of a material with a higher dielectric constant than the surrounding antenna layer (e.g., radome material dk = 2, dielectric resonator dk = 5.5). The dielectric resonator can be configured to increase the antenna gain. A rotated dielectric resonator can be used to change the field polarization of the radiated field. An antenna layer with a dielectric resonator can be realized by overmolding, 2K molding, where the outer layer and the dielectric resonator are made of one material and the core is made of a second material, or by foam injection molding, where the dielectric resonator is part of the skin layer.

[0034] Depending on the design, electronic components can be placed on the backside of the printed circuit board, communicatively connected to at least one waveguide channel by a feed port extending across the printed circuit board from the backside to the frontside. Electronic components, such as MMICs, can be coupled to the waveguide channel through at least one feed port designed as a hole in the PCB. This hole is generally transparent to electromagnetic waves and can be plated, filled with material, or have a ridge. Alternatively, the electronic components can be placed on the front side of the printed circuit board, surrounded by a receiving space inside the antenna layer in the assembled state and covered by an electromagnetic absorber in a layered form. In one variation, the MMIC components can be soldered to the top side of the PCB. Furthermore, an electromagnetic absorber can be placed on the chip to reduce any electromagnetic interference from the waveguide channel, or a heat sink structure can be placed to cool the electronic components.

[0035] The front surface of the antenna layer can be corrugated to further reduce the dielectric constant and perform a quarter-wave or broadband impedance transformation of the waves radiated from the waveguide opening through the front surface. Corrugation allows material to be removed from the antenna layer and replaced with air, thus reducing the overall dielectric constant of the antenna device. The waves radiated from the waveguide opening propagate in a material with a lower dielectric constant. Therefore, they are less distorted, and the above structure can achieve a more uniform radiation profile. The front surface of the antenna layer can be designed as a corrugated surface with an array of indentations to lower the overall dielectric constant.

[0036] Alternatively or additionally, a scattering surface can be arranged on the back surface of the antenna layer adjacent to at least one waveguide channel consisting of rows of protrusions and / or grooves, and / or on the front surface of a printed circuit board comprising an array of planar metal structures in the form of patches. The scattering surface can be implemented on the antenna layer in the form of an array of cavities adjacent to the waveguide channels to reduce reflections between the front surface of the antenna layer and the back surface of the antenna layer, respectively, and between additional components arranged in front of the antenna device, such as a car bumper. The protrusions and / or grooves of a first row are typically offset by a length substantially equal to the wavelength relative to the protrusions and / or grooves of an adjacent row. Alternatively, the antenna layer can be fabricated as an integral component of a body part, such as a bumper, windshield, headlight, etc. Good results can be achieved when the antenna layer, which is the front layer of the antenna device, is fabricated integrally with the body part, for example, by injection molding. This has the advantage that the printed circuit board and the back part / housing of the antenna device can be more easily attached and fewer components are required.

[0037] Generally, a PCB consists of several internal layers (multilayer PCB), at least two of which are of conductive material. The top layer of the PCB consists of a metallic material, which is where the waveguide channel is formed along with the antenna layer.

[0038] The antenna layer can be attached to the first metal layer of the PCB, or it can be attached to a different conductive layer of the multi-layer PCB without necessarily being mechanically connected to the top metal layer.

[0039] Alternatively, the antenna layer can be connected to the housing and all other components described herein.

[0040] To protect the PCB and electronic components from environmental influences, the back surface of the antenna layer can be welded to the housing. Instead of or in addition to welding, the antenna layer can also be attached to the housing by gluing or soldering. The back surface of the antenna layer is typically welded circumferentially to a wall of the housing. Alternatively or additionally, the antenna layer may include a pin protruding from the back surface of the antenna layer and engaging with a recess in the PCB in the mounted state. The pin can be configured to align the antenna layer with the PCB. The PCB can be clamped between the antenna layer and the housing in the mounted state.

[0041] Alternatively or additionally, the antenna layer may include a pin with a collar that forms an undercut with the printed circuit board in the mounted state to secure the PCB to the antenna layer. The collar can be formed by plastic working or thermoforming the pin. The PCB may be held in place by clamping the PCB to the antenna layer with the collar, thereby holding it in place relative to the housing. Alternatively, the antenna layer may include a pin with a screw thread. In the mounted state, the antenna layer can be secured in place relative to the housing by a nut threaded onto the pin from the back of the housing.

[0042] Alternatively, the antenna layer may be provided with pins with snap fingers. In the mounted state, the antenna layer may be fixed in place relative to the housing by snap fingers that engage with recesses in the rear face of the housing. Alternatively, in addition to collared or threaded pins, the antenna layer may be fixed in place relative to the housing by rivets. The rivets can clamp the PCB between the antenna layer and the housing. Alternatively, the pins for aligning the PCB relative to the antenna layer can be designed as press-fit pins that engage with the PCB in the mounted state. Instead of a screwed solution or pins, the antenna layer can be attached to the housing by a bayonet lock. A male pin of the bayonet lock may be arranged on the antenna layer and can be aligned with a slot in the housing in the mounted state by pressing the antenna layer and the housing together.

[0043] It is understood that both the foregoing general description and the following detailed description of the present embodiments are intended to provide an overview or framework for understanding the nature and features of the present disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the disclosed concepts. [Brief explanation of the drawings]

[0044] The disclosure set forth herein will be more fully understood from the detailed description given herein below and the accompanying drawings, which should not be construed as limiting the disclosure as set forth in the appended claims.

[0045] [Figure 1] FIG. 10 is an exploded perspective view of a first modified example of the antenna device, as viewed from the rear and above. [Figure 2] FIG. 2 is an enlarged detailed view of the antenna layer of the antenna device shown in FIG. [Figure 3] 2 is an exploded perspective view of the antenna device shown in FIG. 1 as viewed from the front and above. [Figure 4a] FIG. 2 is a front view of the antenna device shown in FIG. [Figure 4b] FIG. 2 is a cross-sectional view of the antenna device shown in FIG. [Figure 5] FIG. 10 is a perspective side view showing a second modified example of the antenna device with the antenna layer unfolded. [Figure 6] FIG. 10 is a perspective side view showing a third modified example of the antenna device with the antenna layer opened. [Figure 7] FIG. 10 is a perspective side view showing a fourth modified example of the antenna device with the antenna layer opened. [Figure 8] FIG. 10 is a perspective side view showing a fifth modified example of the antenna device with the antenna layer opened. [Figure 9] FIG. 10 is a perspective side view showing a sixth modified example of the antenna device with the antenna layer opened. [Figure 10]FIG. 13 is a perspective side view showing a seventh modified example of the antenna device with the antenna layer opened. [Figure 11] FIG. 10 is a perspective side view showing a modified example of the antenna device 8 with the antenna layer opened. [Figure 12] FIG. 13 is a perspective side view showing a ninth modified example of the antenna device with the antenna layer opened. [Figure 13] FIG. 23 is a perspective side view showing a tenth modified example of the antenna device with the antenna layer opened. [Figure 14] FIG. 23 is an exploded perspective view of an eleventh modified example of the antenna device, as viewed from the front and above. [Figure 15] FIG. 23 is a perspective side view showing a twelfth modified example of the antenna device with the antenna layer opened and disassembled. [Figure 16a] FIG. 23 is a perspective view of a twelfth modified example of the antenna device as viewed from above. [Figure 16b] FIG. 23 is a cross-sectional view of a twelfth modified example of the antenna device as viewed from above. [Figure 17] FIG. 23 is a perspective side view showing a thirteenth modified example of the antenna device with the antenna layer opened and disassembled. [Figure 18a] FIG. 23 is a perspective view of a thirteenth modified example of the antenna device as viewed from above. [Figure 18b] FIG. 23 is a cross-sectional view of a thirteenth modified example of the antenna device as viewed from above. [Figure 19] FIG. 23 is a perspective side view showing a fourteenth modified example of the antenna device with the antenna layer opened and disassembled. [Figure 20a] FIG. 23 is a perspective view of a fourteenth modified example of the antenna device as viewed from above. [Figure 20b] FIG. 23 is a cross-sectional view of a fourteenth modified example of the antenna device as viewed from above. [Figure 21] FIG. 23 is a perspective side view showing a fifteenth modified example of the antenna device with the antenna layer opened and disassembled. [Figure 22a] FIG. 23 is a perspective view of a fifteenth modified example of the antenna device as viewed from above. [Figure 22b] FIG. 23 is a cross-sectional view of a fifteenth modified example of the antenna device as viewed from above. [Figure 23]Figure 1 shows the axisymmetric periodic pattern of patches forming the AMC structure on the front side of the PCB. [Figure 24] Figure 1 shows the slip-symmetric periodic pattern of patches forming the AMC structure on the front side of the PCB. [Figure 25] Diagram showing the quasi-periodic or random pattern of patches forming the AMC structure on the front side of the PCB. [Figure 26] 10A and 10B show a variant of the antenna device with a first variant of the connecting element in an open state. [Figure 27] FIG. 27 shows a modification of the antenna arrangement shown in FIG. 26, with hidden edges displayed. [Figure 28a] FIG. 27 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 28b] Enlarged view of Figure 28a. [Figure 29] 10 shows a variant of the antenna arrangement with a second variant of the connecting element, with hidden edges displayed; FIG. [Figure 30a] FIG. 30 is a cross-sectional view of a modified example of the antenna device shown in FIG. 29. [Figure 30b] Enlarged view of Figure 30a. [Figure 31] FIG. 10 shows a variant of the antenna arrangement with a third variant of the connecting element, with hidden edges displayed. [Figure 32a] FIG. 32 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 32b] Enlarged view of Figure 32a. [Figure 33] FIG. 10 shows a variant of the antenna arrangement with a fourth variant of the connecting element, with hidden edges displayed. [Figure 34a] FIG. 34 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 34b] Enlarged view of Figure 34a. [Figure 35] FIG. 10 shows a variant of the antenna arrangement with a fifth variant of the connecting element, with hidden edges displayed. [Figure 36a] FIG. 36 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 36b]Enlarged view of Figure 36a. [Figure 37] FIG. 10 shows a variant of the antenna arrangement with a sixth variant of the connecting element, with hidden edges displayed. [Figure 38a] FIG. 38 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 38b] Enlarged view of Figure 38a. [Figure 39] FIG. 10 shows a variant of the antenna arrangement with a seventh variant of the connecting element, with hidden edges displayed. [Figure 40a] FIG. 40 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 40b] Enlarged view of Figure 40a. [Figure 41] FIG. 10 shows a variant of the antenna arrangement with an eighth variant of the connecting element, with hidden edges displayed. [Figure 42a] FIG. 42 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 42b] Enlarged view of Figure 42a. [Figure 43] FIG. 10 shows a variant of the antenna device with a ninth variant of the connecting element, with hidden edges displayed. [Figure 44a] FIG. 44 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 44b] Enlarged view of Figure 44a. [Figure 45] 1 shows a variant of the antenna device with an embedded chip (MMIC) with the antenna layer open. [Figure 46a] FIG. 46 is a cross-sectional view of a modified example of the antenna device shown in FIG. [Figure 46b] Enlarged view of Figure 46a. [Figure 47] 10 shows a variant of the antenna device with embedded chip (MMIC) and PCB waveguide with the antenna layer open. FIG. [Figure 48a] FIG. 48 is a cross-sectional view of a modified example of the antenna device shown in FIG. 47. [Figure 48b] Enlarged view of Figure 48a. DETAILED DESCRIPTION OF THE INVENTION

[0046] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all, of the features are shown. Indeed, the embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, like reference numerals will be used to refer to like components or parts.

[0047] 1 to 4 show a first variant of the antenna device 1. FIG. 1 is an exploded perspective view of the first variant from the rear and above. FIG. 2 is an enlarged detailed view of the antenna layer 6 of the first variant of the antenna device 1. FIG. 3 shows the exploded perspective views from the front and above. FIG. 4a shows a front view of the antenna device, and FIG. 4b shows a cross-sectional view. The illustrated antenna device 1 for automotive radar applications comprises a printed circuit board (PCB) 2 having a front surface 3 and a back surface 4, and an electronic component 5 interconnected to the printed circuit board 2. The electronic component 5 is in the form of a monolithic microwave integrated circuit (MMIC) and comprises multiple circuits integrated into a small package for operation at microwave frequencies. In the illustrated variant, the MMIC is disposed directly on the front surface 3 of the printed circuit board 2. The antenna device 1 comprises an antenna layer 6 having a front surface 7 and a back surface 8, which is interconnected to the front surface 3 of the printed circuit board 2, to guide signals from the electronic component 5 to at least one waveguide opening 9 configured to transmit and / or receive signals. In the illustrated variant, the antenna layer 6 is further configured to function as a radome, protecting the antenna device 1 from environmental influences. Therefore, the antenna layer 6 is typically made of a material that is resistant to environmental influences, for example a material that does not absorb moisture. The illustrated antenna layer 6 can be made at least partially of a metallic material and / or can be provided with a metallization layer that forms a conductive surface. If the antenna layer 6 is made by injection molding of at least one plastic material, the back surface 8 and / or the recess 12 are typically metallized with a conductive material.

[0048] As can be best seen in FIGS. 2 and 3 , for receiving or transmitting signals, the illustrated waveguide openings 9 are interconnected to the front surface 7 of the antenna layer 6 and communicatively connected to electronic components by at least one waveguide channel 10. In a variant, the at least one waveguide channel 10 is designed as a substantially rectangular waveguide channel 10, which can generally be seen as a four-walled pipe. The illustrated waveguide channel 10 is formed by a recess 12 arranged between the back surface 8 of the antenna layer 6 and the front surface 3 of the printed circuit board 2. To be able to guide electromagnetic signals, the at least one waveguide channel 10 generally comprises a conductive surface 11 for guiding the electromagnetic field between the electronic component and the at least one waveguide opening 9. The illustrated waveguide channel 10 is formed by placing the edge of the recess 12 in direct contact with the metallized front surface 3 of the PCB 2 or by placing a conductive intermediate layer between the back surface 8 of the antenna layer 6 and the front surface 3 of the PCB 2. The illustrated waveguide opening 9 can be provided behind the front surface 7 of the antenna layer 6 as a penetration 17 in the conductive surface 11. Good results in terms of manufacturability can be achieved if the recess 12 is at least partly formed by a deepening 13 in the back surface 8 of the antenna layer 6, as shown in this variant. This is particularly beneficial for injection molding or die casting, as the part can be easily demolded.

[0049] 4 shows a variant having an antenna layer 6 in which a waveguide channel 10 extends. The illustrated waveguide opening 9 is provided as a cavity 16 in the rear surface 8 of the antenna layer 6. The illustrated cavity in the rear surface 8 of the antenna layer 6 may be at least partially filled with a material that is transparent to electromagnetic fields in order to protect at least the waveguide channel 10 and the interior of the antenna device 1 from the environment. The cavity 16 can be filled with a dielectric resonator 29 consisting of a cube made of a material with a higher dielectric constant than the surrounding antenna layer 6 (e.g., radome material dk=2, dielectric resonator dk=5.5).

[0050] 5 is a perspective side view showing a second variant of the antenna device 1 with the antenna layer 6 open. Electronic components (not shown) are arranged on the back side of the printed circuit board 2 and are communicatively connected to at least one waveguide channel 10 by feed ports 18 that extend across the printed circuit board 2 from the back side to the front side 3. Electronic components (not shown) in the form of MMIC components are coupled to the waveguide channel 10 through the illustrated feed ports 18, which are designed as holes through the PCB 2. These holes are generally transparent to electromagnetic waves and may or may not be plated and filled with material.

[0051] 6 is a perspective side view showing a third variant of the antenna device 1 with the antenna layer 6 opened. The illustrated electronic components 5 are arranged on the front surface 3 of the assembled printed circuit board 2, surrounded by a receiving space 19 inside the antenna layer 6 and covered by an electromagnetic absorber in the form of a layer 20. The illustrated feed port 18 is arranged on the back surface 8 of the antenna layer 6 and merges laterally from the receiving space 19 into several waveguide channels 10. Signals are fed from the electronic components 5 to the waveguide channels 10 via planar transition lines 35. The illustrated electromagnetic absorber 20 in the form of a layer is arranged on the electronic components 5 to reduce electromagnetic interference from the waveguide channels 10.

[0052] FIG. 7 is a perspective side view showing a fourth variant of the antenna device 1 with the antenna layer 6 unfolded. The illustrated variant includes a scattering surface 26 arranged on the back surface 8 of the antenna layer 6 adjacent to at least one waveguide channel 10, the scattering surface 26 consisting of intrusions in the form of rows of protrusions 27 and / or grooves. The illustrated scattering surface 26 is implemented on the antenna layer 6 in the form of an array of protrusions 27 adjacent to the waveguide channel 10 to reduce reflections between the front surface 7 of the antenna layer 6 and the back surface 8 of the antenna layer 6, respectively, and between additional components arranged in front of the antenna device 1, such as a car bumper. A first row of protrusions 27 and / or grooves (not shown) is typically offset by a length substantially equal to a wavelength with respect to adjacent rows of protrusions 27 and / or grooves. FIG. 8 is a perspective side view showing a fifth variant of the antenna device 1 with the antenna layer 6 unfolded. In the illustrated variant, the scattering surface 26 is implemented on the front surface 3 of the PCB 2 adjacent to the feed port 18 in the form of an array of metal planar patches 28, e.g., square patches.

[0053] 9 to 13 show sixth to tenth variants in which the waveguide channel 10 is partially formed by an electromagnetic bandgap structure (EBG). The recess 12 in the illustrated variants is formed by a protrusion 14 forming the electromagnetic bandgap structure (EBG) that extends above the back surface 8 of the antenna layer 6 and / or the front surface 3 of the printed circuit board 2. The illustrated protrusion 14 forms the recess 12 by laterally delimiting the waveguide channel 10. The protrusion 14 can be made integral with the antenna layer 6 or it can be arranged on the front surface 3 of the printed circuit board 2 in the form of a number of metallized patches 28 arranged on the front surface 3 of the PCB 2.

[0054] FIG. 9 is a perspective side view of a sixth variant of the antenna device 1 with the antenna layer 6 open. In the variant shown in the figure, the waveguide channel 10 is designed as a recess 13 arranged on the back surface 8 of the antenna layer 6 and as a patch 34 arranged on the front surface 3 of the PCB 2 surrounding the recess 12. The patch 34 on the front surface 3 of the PCB 2 shown in the figure is a metasurface to avoid leakage. FIG. 10 is a perspective side view of a seventh variant of the antenna device 1 with the antenna layer 6 open. A signal is fed from an MMIC electronic component (not shown) to the waveguide channel 10. The waveguide channel 10 in turn feeds a planar antenna, for example, a patch antenna, or an SIW slot antenna integrated on the front surface 3 of the PCB 2 as shown in the figure. FIG. 11 shows an eighth variant of the antenna device 1 in a perspective side view with the antenna layer 6 open, in which the waveguide channel 10 is formed by a protrusion 14.

[0055] FIG. 12 is a perspective side view showing a ninth modified example of the antenna device 1 with the antenna layer 6 in an open state. The antenna layer may include a ridge 33 disposed in the recess 12 and extending substantially along the waveguide channel 10. The ridge 33 can extend substantially from the feed port 18 to at least one waveguide opening 9. The ridge 33 can be disposed in the recess 12 of the waveguide channel 10 to reduce the overall size of the waveguide channel 10. FIG. 13 is a perspective side view showing a tenth modified example of the antenna device 1 with the antenna layer 6 in an open state. The waveguide channel 10 shown in the figure constitutes a coaxial waveguide by including a metal strip in the center of the waveguide channel that functions as an inner conductor 21. The inner conductor 21 allows for further reduction in the size of the waveguide channel 10.

[0056] FIG. 14 is an exploded front and top perspective view of an eleventh variant of the antenna device 1 having a corrugated front surface. The front surface 7 of the illustrated antenna layer 6 is corrugated to further reduce the dielectric constant and perform a quarter-wave impedance transformation for waves radiated from the waveguide opening through the front surface 7. The corrugations 24 allow material to be removed from the antenna layer 6, allowing the material to be replaced with air, thus reducing the overall dielectric constant of the antenna device 1. The waves radiated from the waveguide opening 9 propagate in a material with a lower dielectric constant. Therefore, the radiated waves are less distorted, and the above structure can achieve a more uniform radiation profile. The front surface 7 of the illustrated antenna layer 6 is designed as a corrugated surface 24 with an array of indentations 25 to reduce the overall dielectric constant.

[0057] 15 and 16 show a twelfth variant of the antenna device 1. The antenna device 1 shown in the figures comprises a printed circuit board (PCB) 2 having a front surface 3 and a back surface 4, and an electronic component 5 disposed on the back surface 4 of the PCB 2. A waveguide aperture 9 is interconnected to the front surface 7 of the antenna layer 6 and communicatively connected to the electronic component 5 by a waveguide channel 10. The waveguide channel 10 shown in the figures is formed by a recess 12 partially disposed in the back surface 8 of the antenna layer 6 and the front surface 3 of the PCB 2. A number of metallic patches 34 are disposed on the front surface 3 of the PCB 2 to form an AMC structure. The metallic patches 34 are arranged on the front surface 3 of the PCB 2 in a symmetrical pattern at periodic intervals. This design utilizes the underlying concept of half-mode waveguides to halve the height of the waveguide channel. To achieve this halving, the E-field of the signal is mirrored by a planar metallic structure 28. The electromagnetic field is fed into the waveguide channel 10 via a feed port 18 arranged in the PCB 2. Furthermore, the antenna layer 6 comprises a scattering surface 26 arranged on a back surface 8 of the antenna layer 6 adjacent to the waveguide channel 10. The illustrated scattering surface 26 is implemented on the back surface 8 of the antenna layer 6 in the form of an array of cavities adjacent to the waveguide channel 10 in order to reduce reflections between the front surface 7 of the antenna layer 6 and the back surface 8 of the antenna layer 6, respectively, and between additional components arranged in front of the antenna device 1, such as, for example, a car bumper. The illustrated antenna layer 6 is configured to function as a radome, protecting at least the front surface 3 of the printed circuit board 2 from environmental influences.

[0058] 17 and 18 show a thirteenth variant of the antenna device 1. The antenna device 1 shown in the figures includes a printed circuit board (PCB) 2 having a front surface 3 and a back surface 4, and an electronic component 5 arranged on the back surface 4 of the PCB 2. An intermediate layer 36 is arranged between the front surface 4 of the PCB 2 and the back surface 8 of the antenna layer 6. A front surface 37 of the intermediate layer 36 faces the back surface 8 of the antenna layer 6. A back surface 38 of the intermediate layer 36 faces the front surface 3 of the PCB 2. A waveguide opening 9 is interconnected to the front surface 7 of the antenna layer 6 and is communicatively connected to the electronic component 5 by a waveguide channel 10 arranged in the intermediate layer 36 and extending from the back surface 38 to the front surface 37. The waveguide channel 10 includes a conductive surface 11 for guiding an electromagnetic field between the electronic component 5 and the waveguide opening 9. The electromagnetic field is supplied to the waveguide channel 10 through a feed port arranged in the PCB 2. The antenna layer 6 shown in the figure comprises a scattering surface 26 implemented on the back surface 8 in the form of an array of cavities adjacent to the waveguide channels 10 in order to reduce reflections between the front surface 7 of the antenna layer 6 or additional components and the back surface 8 of the antenna layer 6.

[0059] 19 and 20 show a fourteenth variant of the antenna device 1. The antenna device 1 shown in the figures comprises a printed circuit board (PCB) 2 having a front surface 3 and a back surface 4, and electronic components 5 arranged on the back surface 4 of the PCB 2. An intermediate layer 36 is arranged between the front surface 3 of the PCB 2 and the back surface 8 of the antenna layer 6. The front surface 37 of the intermediate layer 36 faces the back surface 8 of the antenna layer 6. The antenna layer 6 of the variant shown in the figures is made by insert molding. A metal insert 39 is loaded into a mold and then overmolded with molten plastic injected into the mold to form the antenna layer 6. In the variant shown in the figures, the scattering surface 26 is implemented on the back surface of the metal insert 39 of the antenna layer 6 in the form of an array of cavities adjacent to the waveguide channels 10 to reduce reflections between the back surface 8 and the front surface 7 of the antenna layer 6. The back surface layer 40 and the front surface layer 39 are joined along a parting plane 41. The waveguide opening 9 is interconnected to the front surface 7 of the antenna layer 6 and communicatively connected to the electronic component 5 by a waveguide channel 10 disposed in the intermediate layer 36 and extending from the back surface 38 to the front surface 37. The waveguide channel 10 comprises a conductive surface 11 for directing the electromagnetic field between the electronic component 5 and the waveguide opening 9.

[0060] 21 and 22 show a fifteenth variant of the antenna device 1. The antenna device 1 shown in the figures comprises a printed circuit board (PCB) 2 having a front surface 3 and a back surface 4, and electronic components 5 arranged on the back surface 4 of the PCB 2. An intermediate layer 36 is arranged between the front surface 3 of the PCB 2 and the back surface 8 of the antenna layer 6. In the variant shown in the figures, the intermediate layer 36 comprises a protrusion 14 arranged on a front surface 37 of the intermediate layer. The antenna layer 6 of the variant shown in the figures is made by insert molding. A metal insert 39 is loaded into a mold and then overmolded with molten plastic injected into the mold to form the antenna layer 6. In the variant shown in the figures, the scattering surface 26 is implemented on the back surface of the metal insert 39 of the antenna layer 6 in the form of an array of cavities adjacent to the waveguide channels 10 in order to reduce or cancel out reflections between the back surface 8 and the front surface 7 of the antenna layer 6. The waveguide aperture 9 is interconnected to the front surface 7 of the antenna layer 6 and communicatively connected to the electronic component 5 by a waveguide channel 10 partially disposed in the intermediate layer 36 and extending from the back surface 38 to the front surface 37. The waveguide channel 10 comprises a conductive surface 11 for guiding the electromagnetic field between the electronic component 5 and the waveguide aperture 9. The electromagnetic field is fed to the waveguide channel 10 via a feed port 18 disposed in the PCB 2. This design utilizes the underlying concept of half-mode waveguides to halve the height of the waveguide channel.

[0061] 23 shows a schematic axisymmetric periodic pattern of metallic patches 34 forming an AMC structure on the front side of PCB 2. The substantially square metallic patches 34 are arranged axisymmetrically with respect to one another and equally spaced in the x and y directions. The lateral distance between the patches relative to one another—the periodicity—is generally selected depending on the wavelength to be emitted. The size of the patches is related to the guided wavelength, which can be calculated as follows: TIFF2025534145000003.tif2042λ0 = free air wavelength ε rPCB=Dielectric constant of PCB substrate

[0062] The period is typically chosen to be in the range λ0 / 8 to 2λ0. The patches are typically arranged in collinear arrays, which form rows and columns. Between adjacent columns, the patches are spaced apart by a first period P x Between adjacent rows, the patches are spaced apart by a second period P y This will create spacing.

[0063] Figure 24 shows a shear-symmetric periodic pattern of metallic patches 34 forming an AMC structure on the front side of PCB 2. Compared to the variant shown in Figure 23, the patches within an array are again spaced apart at intervals equal to the period. Adjacent arrays are shifted relative to each other by a distance equal to P / n, where n is a natural number.

[0064] Figure 25 shows a quasi-periodic or random pattern of patches forming an AMC structure on the front side of a PCB. Substantially circular metallic patches 34 are arranged asymmetrically with respect to one another at random spacings in the x and y directions. The lateral spacing between the patches with respect to one another—the period—is typically selected as follows: TIFF2025534145000004.tif2227N=Number of patches d n = Spacing between patches

[0065] 26 to 28 are diagrams illustrating a modified example of the antenna device 1 having a first modified example of the connecting element 31. The illustrated antenna device 1 includes a printed circuit board (PCB) 2 and electronic components interconnected to the printed circuit board 2. The illustrated antenna layer 6 has a front surface 7 and a back surface 8, and the back surface 8 is interconnected to the front surface 3 of the printed circuit board 2. In the illustrated variant, the antenna layer 6 is further configured to function as a radome, protecting the antenna device 1 from environmental influences. As best seen in FIG. 27, the back surface 8 of the antenna layer 6 is welded to the housing 40 to seal the PCB 2 and electronic components from environmental influences. Instead of or in addition to welding, the antenna layer 6 can also be attached to the housing 40 by gluing or soldering. In the illustrated variant, the back surface 8 of the antenna layer 6 is circumferentially welded to the wall of the housing 40. As best seen in FIG. 28, the antenna layer 6 is attached to the housing 40 by welding. The illustrated antenna layer 6 includes pins 41. Pins 41 protrude from the back surface 8 of the antenna layer 6 and engage recesses 42 in the PCB 2 in the mounted state. The two pins 41 shown in the figure are configured to align the antenna layer 6 with the PCB 2. The PCB 2 is in a fixed mounted state clamped between the antenna layer 6 and the housing 40.

[0066] 29 and 30 are diagrams illustrating a modified example of the antenna device 1 including a second modified example of the connecting element 31. The antenna device 1 illustrated in the figures includes the same components as the modified example illustrated in FIGS. 26 to 28. As best seen in FIG. 29, the antenna layer 6 illustrated in the figure is attached to the housing 40 by welding in the attached state, and in the modified example illustrated in the figure, it is attached by ultrasonic welding. The antenna layer 6 also includes a pin 41 configured to align the antenna layer 6 with the PCB 2. Furthermore, as best seen in FIG. 30, the antenna layer 6 includes the pin 41 with a collar 43. In the attached state, the collar 43 forms an undercut with the printed circuit board 2 to secure the PCB 2 to the antenna layer 6. The collar 43 is formed by plastically or thermoforming the pin 41. The PCB 2 is clamped to the antenna layer 6 by the collar 43, thereby maintaining the PCB 2 in a predetermined position relative to the housing 40.

[0067] 31 and 32 are diagrams illustrating a modified example of the antenna device 1 including a third modified example of the connecting element 31. The antenna device 1 illustrated in the figures includes the same components as the modified example illustrated in FIGS. 26 to 28. As can be best seen in FIG. 31, the antenna layer 6 illustrated in the figures is also attached to the housing 40 in an attached state via a connecting element 31 including a pin 41, such as the pin illustrated in FIGS. 26 to 28. Furthermore, as can be best seen in FIG. 32, the antenna layer 6 includes a pin with a screw thread 44. In the attached state, the antenna layer 6 is fixed in place relative to the housing 40 by a nut 45 threaded onto the pin 41 from the rear of the housing 40. This clamps the PCB 2 between the antenna layer 6 and the housing 40.

[0068] 33 and 34 are diagrams illustrating a modified example of the antenna device 1 including a fourth modified example of the connecting element 31. The antenna device 1 illustrated in the figures includes the same components as the modified example illustrated in FIGS. 26 to 28. As can be best seen in FIG. 33, the antenna layer 6 illustrated in the figures is also attached to the housing 40 in the attached state via a connecting element 31 including a pin 41 like the pin illustrated in FIGS. 26 to 28. Furthermore, as can be best seen in FIG. 34, the antenna layer 6 includes a pin including snap fingers 46. In the attached state, the antenna layer 6 is fixed in place relative to the housing 40 by the snap fingers 46 engaging with recesses 42 in the rear surface of the housing 40. The snap joint clamps the PCB 2 between the antenna layer 6 and the housing 40.

[0069] 35 and 36 are diagrams showing a modified example of the antenna device 1 including a fifth modified example of the connecting element 31. The antenna device 1 shown in the figures includes the same components as the modified example shown in FIGS. 26 to 28. As can be best seen in FIG. 35, the antenna layer 6 shown in the figure is attached to the housing 40 via a connecting element 31 including pins 41, such as the pins shown in FIGS. 26 to 28, in an attached state. Furthermore, as can be best seen in FIG. 36, the antenna layer 6 is fixed in place relative to the housing 40 by rivets 47. The rivets 47 clamp the PCB 2 between the antenna layer 6 and the housing 40.

[0070] 37 and 38 are diagrams showing a modified example of the antenna device 1 including a sixth modified example of the connecting element 31. The antenna device 1 shown in the figures includes the same components as the modified example shown in FIGS. 26 to 28. As can be seen best in FIG. 37, the antenna layer 6 shown in the figures is welded, glued, or soldered to the housing 40. The antenna layer also includes a press-fit pin 48, as can be seen best in FIG. 38. The antenna layer 6 includes a pin 41 for aligning the PCB 2 with respect to the antenna layer 6 by engaging with a recess 42 in the PCB 2. The press-fit pin 48 engages with the PCB 2 in the mounted state. This clamps the PCB 2 to the antenna layer 6, and the antenna layer 6 is fixed to the housing 40.

[0071] 39 and 40 are diagrams showing a modified example of the antenna device 1 including a seventh modified example of the connecting element 31. The antenna device 1 shown in the figures includes the same components as the modified example shown in FIGS. 26 to 28. As can be seen best in FIG. 39, the antenna layer 6 shown in the figures is also attached to the housing 40 in the attached state via the connecting element 31 including pins 40 like the pins shown in FIGS. 26 to 28. Furthermore, as can be seen best in FIG. 40, the antenna layer 6 includes hot-stamped pins 41 that engage with holes 49 in the housing 40 in the attached state and secure the antenna layer 6 to the housing 40. The PCB 2 is thereby clamped between the antenna layer 6 and the housing 40.

[0072] 41 and 42 are diagrams showing a modified example of the antenna device 1 including an eighth modified example of the connecting element 31. The antenna device 1 shown in the figures includes the same components as the modified example shown in FIGS. 26 to 28. As can be seen best in FIG. 41, the antenna layer 6 shown in the figures is also attached to the housing 40 in an attached state via a connecting element 31 including a pin 41 like the pins shown in FIGS. 26 to 28. Furthermore, as can be seen best in FIG. 42, the antenna layer 6 is fixed to the housing 40 from its rear side with a screw. The head of the screw is thereby positioned in the recess 50 in the rear side of the housing 40 in the attached position. The PCB 2 is clamped between the antenna layer 6 and the housing 40.

[0073] 43 and 44 are diagrams showing a modified example of the antenna device 1 including a ninth modified example of the connecting element 31. The antenna device 1 shown in the figures includes the same components as the modified example shown in FIGS. 26 to 28. As can be seen best in FIG. 43, the antenna layer 6 shown in the figure is also attached to the housing 40 in the attached state via a connecting element 31 including pins 41 like those shown in FIGS. 26 to 28. Furthermore, as can be seen best in FIG. 44, the antenna layer 6 is attached to the housing 40 by a bayonet lock 51. A male pin 52 disposed on the antenna layer is attached in the attached state aligned with a slot 53 in the housing by pressing the antenna layer and the housing together.

[0074] 45 and 46 show variants of the antenna device 1 with an embedded electronic component 5. The electronic component 5 shown in the figures is a chip (MMIC), typically a radar chip, which typically comprises multiple circuits integrated in a small package for operation at microwave frequencies. The chip is embedded in a printed circuit board 2. In the variant shown in the figures, the chip is embedded in one of the layers of substrate material. Such substrate material typically consists of printed circuit board material or any other material suitable for embedding chips (silicon, ceramic, glass, molding compound). The electromagnetic signal is fed from the integrated MMIC to the waveguide channel 10 in the antenna layer 6 by a planar transition line 35.

[0075] 47 and 48 show variants of the antenna device 1 with an embedded chip (MMIC) and PCB waveguide. Similar to the variants shown by FIGS. 45 and 46, the electronic component 5 is also embedded in one of the layers of the printed circuit board 2 by being embedded in the substrate material. Unlike the variants shown by FIGS. 45 and 46, the electromagnetic signal is fed from the electronic component 5 to the waveguide channel 10 inside the antenna layer 6 by a three-dimensional transition line 54. The three-dimensional transition line 54 takes the form of a substrate integrated waveguide (SIW), a dielectric-loaded buried waveguide, and / or an air-filled buried waveguide.

[0076] Rather, the words used in this specification are words of description rather than limitation, and it is understood that various changes are possible without departing from the spirit and scope of the disclosure. [Explanation of symbols]

[0077] 1 Antenna device 2. Printed Circuit Board (PCB) 3 Front (PCB) 4 Back side (PCB) 5. Electronic Components 6 Antenna Layer 7 Front 8 Back 9 Waveguide opening 10 Waveguide Channel 11 Conductive Surface 12 recess 13 Depth 14 protrusions 15 Metallization Layer 16 cavities 17 Penetration 18 Power supply port 19 Receptive Space 20 Electromagnetic absorber 21 Inner conductor 22 Skin layer 23 cores 24 Corrugated Surface 25 Indentation 26 Scattering surface 27 Protrusion 28 Planar metal structure 29 Dielectric Resonator 30 Back layer / chassis 31 Connecting Elements 32 holes 33 Ridge 34 Patch 35 Planar transition line 36 Middle class 37 Front 38 Back 39 Insert (antenna layer) 40 cabinets 41 pin 42 recess (PCB) 43 Color (pin) 44 threads 45 Nut 46 Snap Finger 47 Rivet 48 Press-fit pins 49 holes 50 recess 51 Bayonet Lock 52 pin (bayonet lock) 53 slot (bayonet lock) 54 3D transition line

Claims

1. An antenna device (1) for automotive radar applications, comprising: The antenna device (1) a. a printed circuit board (2) having a front surface (3) and a back surface (4), and electronic components (5) interconnected to said printed circuit board (2); b. an antenna layer (6) having a front surface (7) and a back surface (8), said back surface (8) being interconnected to said front surface (7) of said printed circuit board (2); Equipped with i. at least one waveguide aperture (9) interconnected to said front surface (7) of said antenna layer (6) and communicatively connected to said electronic component (5) by at least one waveguide channel (10); ii. the at least one waveguide channel (10) has a conductive surface (11) for guiding an electromagnetic field to and from the electronic component (5) and is formed by a recess (12) disposed between the back surface (8) of the antenna layer (6) and the front surface (3) of the printed circuit board (2); Antenna device (1).

2. 2. The antenna device (1) according to claim 1, wherein the front surface (7) of the antenna layer (6) is configured to act as a radome to protect at least the front surface (3) of the printed circuit board (2) from environmental influences.

3. 3. The antenna device (1) according to claim 1 or 2, wherein the recess (12) is at least partially formed by a depth (13) in the rear surface (8) of the antenna layer (6) and / or a protrusion (14) extending above the rear surface (8) of the antenna layer (6) and / or a planar metal structure (28) on the front surface (3) of the printed circuit board (2).

4. 4. The antenna device (1) according to claim 3, wherein the protrusion (14) laterally delimits the recess (12) and forms an electromagnetic bandgap structure with the front surface (3) of the printed circuit board (2).

5. 5. The antenna device (1) according to claim 3 or 4, wherein the planar metal structure (28) comprises a number of patches (34) that laterally delimit the recess (12) and form an electromagnetic bandgap structure with the protrusion (14) or the back surface (8) of the antenna layer (6).

6. The antenna device (1) according to any one of claims 1 to 5, wherein the front surface (3) of the printed circuit board (2) is at least partially covered by a number of metallic patches (34) arranged as a periodic structure and forming an artificial magnetic conductor (AMC).

7. Antenna device (1) according to any one of claims 1 to 6, wherein the antenna layer (6) is at least partly made from a metallic material and / or comprises a metallization layer (15) forming a conductive surface.

8. The antenna device (1) according to any one of claims 1 to 7, wherein at least one waveguide opening (9) is provided behind the front surface (7) of the antenna layer (6) as a penetration (17) in a conductive surface.

9. 9. The antenna arrangement (1) according to claim 8, wherein the penetration (17) is established by a material ablation process step, preferably a laser process and / or a cutting process.

10. 10. The antenna device (1) according to any one of claims 1 to 9, wherein at least one waveguide opening (9) is provided as a cavity (16) in the back surface (8) of the antenna layer (6), the cavity (16) being at least partially filled with a material that is transparent to electromagnetic waves.

11. 11. The antenna device (1) of claim 1, wherein the electronic component (5) is disposed on the rear surface (4) of the printed circuit board (2) communicatively connected to the at least one waveguide channel (10) by a feed port (18) extending across the printed circuit board (2) from the rear surface (4) to the front surface (3).

12. The antenna device (1) according to any one of claims 1 to 10, wherein the electronic component (5) is arranged on the front surface (3) of the printed circuit board (2) surrounded by a receiving space (19) inside the antenna layer (6) in an assembled state.

13. 13. The antenna device (1) according to claim 12, wherein a feed port (18) is arranged on the back surface (8) of the antenna layer (6), the feed port (18) merges into a waveguide channel (10), and the waveguide channel (10) merges into the waveguide opening (9) arranged on the front surface (7) of the antenna layer (6).

14. The antenna device (1) according to any one of claims 1 to 13, wherein the antenna layer (6) comprises a ridge (33) disposed in the recess (12) and extending substantially along the waveguide channel (10).

15. The antenna device (1) according to any one of claims 1 to 14, wherein the antenna layer (6) is made from a foam material by injection molding.

16. The antenna device (1) according to any one of claims 1 to 15, wherein the front surface (7) of the antenna layer (6) is designed as a corrugated surface (24) with an array of indentations (25) for reducing the overall dielectric constant.

17. The scattering surface (26) a. on the back surface (8) of the antenna layer (6) adjacent to the at least one waveguide channel (10) consisting of a row of protrusions (27) and / or grooves; and / or b. said front surface (3) of said printed circuit board (2) comprising an array of planar metal structures (28); The antenna device (1) according to any one of claims 1 to 16, arranged

18. 18. The antenna device (1) according to claim 17, wherein the protrusions (27) and / or grooves (27) of a first row are offset relative to the protrusions (27) and / or grooves (27) of an adjacent row by a length substantially equal to a multiple of half the wavelength.

19. Antenna device (1) according to any one of claims 1 to 18, wherein the antenna layer (6) is made as an integral component of the body portion.

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