Device with waveguide structure

Abstract

The present disclosure relates to an apparatus, which may be part of an automotive radar system, and comprising a substrate comprising: a first metal layer; at least one dielectric layer, the first metal layer disposed over the at least one dielectric layer; a second metal layer, the at least one dielectric layer disposed over the second metal layer; and a plurality of waveguide structures each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewalls defining a first opening extending through the first metal layer, the dielectric layer, and the second metal layer. The first metal layer may include second openings, and each of the second openings may laterally surround at least one of the plurality of waveguide structures.

Description

Devices with waveguide structures Technical Field

[0001] The embodiments of the subject matter described herein generally relate to devices having waveguide structures, such as radio frequency (RF) devices having antenna assemblies having waveguide structures formed in a substrate to which the antenna structure is attached. Background Technology

[0002] The use of millimeter-wave (mm-wave) frequencies in communication devices and radar applications, such as automotive radar, is expanding rapidly. Antennas are critical components in all these fields and face advanced requirements in terms of performance, size, weight, and environmental compliance. At mm-wave frequencies, the radio frequency (RF) performance of a given communication or radar system is no longer determined solely by the transceiver circuitry and antenna, but also significantly by the packaging and the interconnect between the transceiver and antenna. This interconnect can include a combination of one or more conductive traces, waveguides, ball grid arrays, or other coupling structures. Summary of the Invention

[0003] According to one aspect of this application, an apparatus is provided, comprising: a substrate including: a first metal layer; at least one dielectric layer, wherein the first metal layer is disposed over the at least one dielectric layer; a second metal layer, wherein the at least one dielectric layer is disposed over the second metal layer; and a plurality of waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first plurality of openings extending through the first metal layer, the dielectric layer, and the second metal layer, wherein the first metal layer includes a second plurality of openings, and each of the second plurality of openings laterally surrounds at least one of the plurality of waveguide structures.

[0004] According to one or more embodiments, the device further includes: a first plurality of conductive vias extending through the at least one dielectric layer between the first metal layer and the second metal layer and arranged to laterally surround the second plurality of openings; and a second plurality of conductive vias disposed on opposite sides of each of the plurality of waveguide structures.

[0005] According to one or more embodiments, the first plurality of conductive vias define a respective perimeter surrounding each of the second plurality of openings.

[0006] According to one or more embodiments, the second plurality of conductive vias define respective perimeters extending along at least two sides of each of the plurality of waveguide structures.

[0007] According to one or more embodiments, the second plurality of openings extend through the first metal layer to expose the upper surface of the at least one dielectric layer.

[0008] According to one or more embodiments, it further includes: an antenna structure directly disposed on the first metal layer, the antenna structure including a plurality of antennas.

[0009] According to one or more embodiments, it further includes: transceiver circuitry attached to or coupled to the substrate and configured to generate radio frequency (RF) signals and provide the RF signals to the antenna structure for transmission via the plurality of waveguide structures of the substrate.

[0010] According to one or more embodiments, the distance between the first metal layer and the second metal layer is within 10% of a quarter wavelength of the RF signal generated by the transceiver circuit.

[0011] According to a second aspect of this application, an apparatus is provided, comprising: a first metal layer; at least one dielectric layer, wherein the first metal layer is disposed over the at least one dielectric layer; a second metal layer, wherein the at least one dielectric layer is disposed over the second metal layer; and a plurality of waveguide structures defining a first plurality of openings, each of the plurality of waveguide structures extending from the first metal layer to the second metal layer and through the at least one dielectric layer, wherein the first metal layer includes a second plurality of openings, and each of the second plurality of openings laterally surrounds at least one of the plurality of waveguide structures.

[0012] According to one or more embodiments, each of the plurality of waveguides includes: a portion of the first metal layer; and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining the plurality of openings, and the plurality of openings extending through the first metal layer, the at least one dielectric layer, and the second metal layer.

[0013] According to one or more embodiments, it further includes: a first plurality of conductive vias extending through the at least one dielectric layer between the first metal layer and the second metal layer and arranged to laterally surround the second plurality of openings; and a second plurality of conductive vias disposed on opposite sides of each of the plurality of waveguide structures.

[0014] According to one or more embodiments, the first plurality of conductive vias define a corresponding perimeter surrounding each of the second plurality of openings, and the second plurality of conductive vias define a corresponding perimeter extending along at least two sides of each of the plurality of waveguide structures.

[0015] According to one or more embodiments, the second plurality of openings extend through the first metal layer to expose the upper surface of the at least one dielectric layer.

[0016] According to another aspect of this application, a radio frequency (RF) device is provided, comprising: a printed circuit board substrate including: a first metal layer; at least one dielectric layer, wherein the first metal layer is disposed over the at least one dielectric layer; a second metal layer, wherein the at least one dielectric layer is disposed over the second metal layer; and a plurality of waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first plurality of openings extending through the first metal layer, the dielectric layer, and the second metal layer; and an antenna structure disposed on and in contact with the first metal layer of the printed circuit board substrate, wherein the first metal layer includes a second plurality of openings laterally surrounding the plurality of waveguide structures.

[0017] According to one or more embodiments, it further includes: a first plurality of conductive vias extending through the at least one dielectric layer between the first metal layer and the second metal layer and arranged to laterally surround the second plurality of openings; and a second plurality of conductive vias disposed on opposite sides of each of the plurality of waveguide structures.

[0018] According to one or more embodiments, the first plurality of conductive vias define a respective perimeter surrounding each of the second plurality of openings.

[0019] According to one or more embodiments, the second plurality of conductive vias define respective perimeters extending along at least two sides of each of the plurality of waveguide structures.

[0020] According to one or more embodiments, the second plurality of openings extend through the first metal layer to expose the upper surface of the at least one dielectric layer.

[0021] According to one or more embodiments, it further includes: transceiver circuitry attached to or coupled to the substrate and configured to generate RF signals and provide the RF signals to the antenna structure for transmission via the plurality of waveguide structures of the substrate.

[0022] According to one or more embodiments, the distance between the first metal layer and the second metal layer is within 10% of a quarter wavelength of the RF signal generated by the transceiver circuit. Attached Figure Description

[0023] A more complete understanding of the subject matter can be derived by considering the following figures and referring to the specific embodiments and claims. The same appendages throughout the figures refer to similar elements. Elements in the figures are shown for simplicity and clarity and are not necessarily drawn to scale. The figures, together with the specific embodiments, are incorporated into and form part of this specification and are used to further illustrate examples, embodiments, etc., and to explain various principles and advantages according to this disclosure. In the figures:

[0024] Figure 1 shows a cross-sectional side view of an exemplary radio frequency (RF) device including an antenna assembly according to various embodiments;

[0025] Figure 2 shows a perspective view of a waveguide arrangement in an antenna assembly that can be used in an RF device (such as the RF device of Figure 1) according to various embodiments;

[0026] Figure 3 shows a cross-sectional view of the waveguide arrangement of Figure 2 according to various embodiments;

[0027] Figure 4 shows a perspective view of the waveguide arrangement of Figure 2 rotated relative to the perspective view shown in Figure 2 according to various embodiments, wherein the second metal layer is omitted and the dielectric layer is shown in a partially transparent manner.

[0028] Figure 5 shows a top view of the first metal layer of the waveguide arrangement of Figures 2-4 according to various embodiments;

[0029] Figure 6 shows a top view of the waveguide structure of Figure 4 and the surrounding opening in the first metal layer, which may be included in the waveguide arrangement of Figures 2-4 according to various embodiments.

[0030] Figure 7 shows a top view of the dielectric layer of the waveguide arrangement of Figures 2-4 according to various embodiments; and

[0031] Figure 8 shows a top view of the second metal layer of the waveguide arrangement of Figures 2-4 according to various embodiments. Detailed Implementation

[0032] The following detailed descriptions are merely illustrative in nature and are not intended to limit the use of the embodiments described herein and such embodiments. Furthermore, one should not be bound by any express or implied theory presented in the prior art, background art, or the following detailed descriptions.

[0033] For the sake of simplicity and clarity, the figures illustrate a general construction. Descriptions and details of well-known features and techniques may be omitted from the following detailed description to avoid unnecessarily obscuring this disclosure. For example, the dimensions of some elements or regions in the figures may be exaggerated relative to other elements or regions to aid in understanding the embodiments described herein.

[0034] The terms “first,” “second,” “third,” “fourth,” etc. (if present) used in the description and claims are used to distinguish similar elements and are not necessarily used to describe a particular sequence or time order. It should be understood that the terms thus used are interchangeable where appropriate, such that the embodiments described herein can be operated, for example, in sequences other than those shown or otherwise described herein. Furthermore, the terms “comprise,” “include,” “have,” and any variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to the process, method, article, or apparatus. As used herein, the terms “generally,” “approximately,” “essentially,” and “substantially” mean sufficient to practically achieve the stated purpose, and minor defects (if present) are not important to the stated purpose.

[0035] In accordance with these principles, when referring to measurable quantities (including, but not limited to, dimensions), these terms mean that the quantity is equal to the stated value, subject to acceptable tolerances of any method or apparatus chosen to manufacture the described structure or to measure the described quantity or dimension. Unless otherwise stated, directional references, such as “top,” “bottom,” “left,” “right,” “above,” “below,” etc., are not intended to require any preferred orientation, but rather to refer to the orientation of one or more diagrams for illustrative purposes. As used herein, the terms “exemplary” and “example” mean “serving as an example, instance, or illustration.” Any embodiment described herein as exemplary or illustrative is not necessarily to be construed as preferred or advantageous over other embodiments. Additionally, certain terms may be used herein for illustrative purposes only and are therefore not intended to be restrictive.

[0036] In this document, elements, nodes, or features are sometimes referred to as “connected” or “coupled” together. As used herein, unless explicitly stated otherwise, “connected” means that one element is directly joined to (or in direct communication with) another element in an electrical or non-electrical manner, and not necessarily mechanically joined. Similarly, unless explicitly stated otherwise, “coupled” means that one element is directly or indirectly joined to (or in direct or indirect communication with) another element in an electrical or non-electrical manner, and not necessarily mechanically joined. Therefore, although the schematic diagrams shown in the figures depict exemplary arrangements of elements, additional intermediate elements, devices, features, or components may be present in one or more embodiments of the depicted subject matter.

[0037] The various embodiments described herein relate to antenna and waveguide structures that may be included as part of a package for a radio frequency (RF) device. As a non-limiting example, such an RF device may include transceiver circuitry for a radar system (e.g., an automotive radar system) or a wireless communication system. The antenna and waveguide structure may be part of an antenna assembly. The antenna assembly may include an antenna structure and a metallized substrate, such as a printed circuit board (PCB), wherein the waveguide structure is formed in a layer near the top surface of the substrate. The antenna assembly may include one or more antenna elements, such as a slot antenna, formed in or from a conductive (e.g., metallic) material of the antenna assembly. The waveguide structure may interface with the antenna structure, wherein each waveguide structure is aligned with a corresponding antenna element of the antenna structure such that a signal can be provided between each waveguide structure and its corresponding antenna element. It should be understood that the use of a slot antenna in one or more embodiments of the antenna assembly is intended to be illustrative and non-limiting, such that in one or more other embodiments, the antenna assembly may include other suitable types of antennas, such as horn antennas, as a non-limiting example. In one or more embodiments, each waveguide structure may extend from a first metal layer of the substrate to a second metal layer of the substrate, wherein the conductive (e.g., metallic) sidewalls of the waveguide structure extend through at least one dielectric layer of the substrate. Layers of the substrate including the waveguide structure are sometimes collectively referred to herein with the waveguide structure as a “waveguide arrangement.” In this document, unless otherwise stated, “conductive” means “electrically conductive.”

[0038] Conventional antenna assemblies often encounter performance issues caused by air gaps between the metallic antenna structure and the substrate. These air gaps are typically caused by manufacturing tolerances, lack of space for tightening screws close to the chip, or mechanically or thermally induced stress, to name a few. Avoiding or mitigating these causes in practice can be challenging, often resulting in air gaps of several hundred micrometers or larger. Such air gaps are generally detrimental to RF performance, leading to unwanted insertion loss, interference from nearby channels, or noise, which tends to worsen with increasing signal frequency.

[0039] The embodiments described herein address these challenges by providing antenna assemblies comprising waveguide structures formed in a substrate (e.g., a printed circuit board substrate) from a first metal layer of the substrate, a second metal layer of the substrate, and metallized sidewalls of one or more dielectric layers through the substrate. In one or more embodiments, each waveguide structure has an associated opening formed around the waveguide structure (e.g., where the opening can be formed by removing the first metal layer to expose one or more dielectric layers of the substrate). In one or more embodiments, conductive (e.g., metal-coated or metal-filled) vias can be formed in the dielectric layers of the substrate, extending directly between the first and second metal layers, and electrically connecting the first metal layer to the second metal layer. In one or more embodiments, a first plurality of conductive vias can form a perimeter extending around the opening and the waveguide structure, thereby laterally surrounding the waveguide structure and the corresponding opening. In one or more embodiments, a second plurality of conductive vias can extend at least partially around the waveguide structure between the waveguide structure and the opening surrounding the waveguide structure (e.g., along at least a portion of the inner perimeter defining the opening surrounding the waveguide structure). The second plurality of conductive vias may partially surround (e.g., on at least both sides) the opening defined by the waveguide structure itself (i.e., the opening defined and laterally surrounded by the sidewalls of the dielectric layer extending through the substrate by the waveguide structure).

[0040] In one or more embodiments, conductive vias can form a barrier against radio frequency (RF) signals that would otherwise be coupled to adjacent waveguide structures or to metal layers within the substrate. Conductive vias isolate waveguide structures, thereby improving signal integrity and reducing interference and noise coupling between waveguide structures and between the waveguide structure and the substrate. By forming openings around the waveguide structures in a first metal layer where the waveguide structure interfaces with the antenna structure, a parallel-plate pattern between the substrate and the antenna structure is advantageously reduced compared to conventional antenna assemblies that do not include such openings around the waveguide structures (e.g., due at least in part to improved electrical insulation between different waveguide openings at the antenna interface).

[0041] Figure 1 shows a cross-sectional side view of an exemplary radio frequency (RF) device 100. The RF device 100 includes an antenna assembly 101 and transceiver circuitry 114. The antenna assembly 101 includes a printed circuit board (PCB) 102 (sometimes referred to herein as "printed circuit board substrate 102" or "PCB substrate 102") and an antenna structure 104. The antenna structure 104 includes an antenna element 106. In one or more embodiments, the antenna structure 104 may be formed from a single continuous conductive material (e.g., metal) piece. In one or more other embodiments, the antenna structure 104 may be formed from a single continuous metallized plastic piece. In one or more embodiments, the antenna element 106 may be formed as a slot antenna (e.g., an opening) in the conductive material of the antenna structure 104. It should be understood that the use of a slot antenna as antenna element 106 in the antenna structure 104 is intended to be illustrative and non-limiting, such that in one or more other embodiments, the antenna structure 104 may include other suitable types of antennas, such as waveguide-based antennas, as a non-limiting example.

[0042] In one or more embodiments, the antenna structure 104 may be formed of one or a combination of aluminum, copper, steel, or another suitable conductive material. As a non-limiting example, the antenna structure 104 may be formed of stamped metal, laser-cut metal, or three-dimensionally (3D) printed metal.

[0043] PCB 102 includes a waveguide structure 112 (sometimes referred to herein as “waveguide 112”). Waveguide structure 112 may be formed from one or more metal layers of PCB 102 and may include conductive (e.g., metallized) sidewalls defining corresponding openings extending through one or more dielectric layers of layer 108. Layer 108 in which waveguide structure 112 is formed is sometimes referred to herein as “waveguide layer 108”. Waveguide layer 108 and waveguide structure 112 are sometimes collectively referred to herein as “waveguide arrangement”.

[0044] PCB 102 may include an additional layer 110 separate from waveguide layer 108. In one or more embodiments, an additional waveguide structure may be formed in the additional layer 110, which may provide a signal path between waveguide structure 112 and transceiver circuitry 114. In one or more other embodiments, waveguide structure 112 may extend directly through additional layer 110 to interface with transceiver circuitry 114 (e.g., to receive signals from and provide signals to transceiver circuitry 114). Additional layer 110 may include conductive structures (e.g., vias, traces, etc.) that electrically couple (e.g., connect) transceiver circuitry 114 to waveguide structure 112. In one or more embodiments, transceiver circuitry 114 includes an integrated circuit die, which, as a non-limiting example, is mounted to PCB 102 via flip-chip bonding (e.g., ball bonding), wire bonding, or another suitable bonding technique.

[0045] Transceiver circuitry 114 may be configured to generate an RF signal to be transmitted via antenna element 106 (e.g., in transmit mode) and may be configured to receive an RF signal received at antenna element 106 (e.g., in receive mode). In one or more embodiments, as a non-limiting example, conductive structures in additional layer 110 are arranged to pass the RF signal generated by transceiver circuitry 114 to antenna element 106 via waveguide structure 112, such that the RF signal is transmitted wirelessly via antenna element 106. In one or more embodiments, conductive structures in additional layer 110 are arranged such that the RF signal received at antenna element 106 is provided (e.g., routed) to transceiver circuitry 114 via waveguide structure 112.

[0046] Although the waveguide structure 112 is formed from layers of a PCB in this example, the arrangement shown is intended to be illustrative and not limiting. For example, in one or more other embodiments, the waveguide structure 112 may instead be formed in a suitable metallized dielectric substrate other than a PCB, such as a molded interconnect device (MID) substrate, a 3D printed substrate, or an in-mold electronics (IME) substrate, as a non-limiting example.

[0047] In one or more embodiments, antenna structure 104 may be mounted on or otherwise attached to PCB 102 such that antenna structure 104 is fixed above and in contact with PCB 102 at a suitable location (e.g., overlapping and completely or substantially covering waveguide structure 112). In one or more other embodiments, as a non-limiting example, antenna structure 104 may additionally or alternatively be attached to PCB 102 using press-fit structures, solder, solder paste, adhesives (e.g., conductive or non-conductive adhesives, such as conductive or non-conductive glue), fasteners (e.g., metal fasteners, such as screws), or any suitable combination thereof. In one or more embodiments, each of antenna elements 106 may overlap with a corresponding waveguide structure in waveguide structure 112 (e.g., in a direction perpendicular to the upper surface of antenna structure 104) (e.g., a one-to-one correspondence between antenna elements 106 and waveguide structures 112).

[0048] Ideally, when an antenna structure is attached to a PCB substrate, the connection between the PCB and the antenna structure should be gapless, with the bottom surface of the antenna structure in direct contact with the top surface of the PCB. However, in practice, one or more air gaps may exist between the surfaces of the antenna structure and the PCB substrate, which should be in direct contact with each other (e.g., at interface 116 between the top surfaces of antenna structure 104 and PCB 102 in this example). As a non-limiting example, such air gaps can be caused by manufacturing tolerances, lack of space for adequate screw tightening, mechanical stress, or thermal stress. These gaps are typically several hundred micrometers (e.g., between 0 µm and 300 µm) and, if not addressed, can negatively impact RF performance. Conventional approaches attempt to address the air gap problem by introducing periodic structures formed on the antenna side of the antenna-PCB interface (i.e., formed as part of the antenna structure itself). However, the formation of such periodic structures increases manufacturing complexity and leads to a reduction in the flatness of the antenna-PCB interface.

[0049] The RF device 100 in this example utilizes a waveguide structure 112, which is partially formed by a portion of a first metal layer of a PCB 102 corresponding to the top surface of the PCB 102, and is formed by conductive (e.g., metallic) sidewalls extending through one or more dielectric layers of the PCB 102 to contact a second metal layer of the PCB 102. Compared to the conventional methods described above, the surfaces of the PCB 102 and the antenna structure 104 at interface 116 are planar or substantially planar (e.g., not having the periodic structure of conventional methods). Openings may be formed in the first metal layer of the PCB 102, laterally surrounding each of the waveguide structures 112. These openings may extend completely through the first metal layer of the PCB 102, such that the dielectric layer beneath the first metal layer is exposed through the openings. The openings may provide physical separation between each of the waveguide structures 112 and the laterally surrounding portion of the first metal layer, such that portions of the first metal layer included in a given waveguide structure 112 do not physically contact other portions of the first metal layer. In one or more embodiments, conductive vias may be formed in waveguide layer 108, extending between a first metal layer and a second metal layer and through one or more dielectric layers. The conductive vias may include a first set of conductive vias surrounding (e.g., laterally surrounding) each of the openings surrounding the waveguide structure, and may be located at or immediately adjacent to the outer perimeter defining such openings. The conductive vias may include a second set of conductive vias surrounding (e.g., laterally surrounding) the sidewalls of each of the waveguide structures and located at or immediately adjacent to at least a portion of the inner perimeter of each of the openings surrounding the waveguide structure.

[0050] Corresponding openings in the first metal layer of waveguide structure 112 and PCB 102 can be sized and arranged to suppress parallel-plate mode scattering between PCB 102 and antenna structure 104, thereby reducing the RF performance impact of an air gap that may occur at the interface 116 between PCB 102 and antenna structure 104. In one or more embodiments, the insertion loss from the 300 μm air gap between antenna structure 104 and PCB 102 can be reduced (e.g., in some cases, by about 1 dB) compared to conventional antenna assemblies lacking such an arrangement.

[0051] Figures 2, 3, and 4 show various views 200, 300, and 400 of waveguide arrangement 208 (e.g., waveguide arrangement including waveguide layer 108 and waveguide structure 112 of Figure 1), and are described simultaneously. Each of Figures 2, 3, and 4 includes axes (e.g., X, Y, Z) to better understand the relative orientation of waveguide arrangement 208 across views 200, 300, and 400. Figure 2 shows an exemplary perspective view 200 of waveguide arrangement 208 including waveguide structure 212. Figure 3 shows a cross-sectional side view 300 of waveguide arrangement 208 shown in Figure 2, wherein cross-sectional view 300 shows a first metal layer 222, a second metal layer 304, a sidewall 220 of waveguide structure 212 extending between the first metal layer 222 and the second metal layer, one or more dielectric layers 210 disposed between the first metal layer 222 and the second metal layer, and vias 302 including a first set of vias 302(1) and a second set of vias 302(2). Figure 4 shows a perspective view 400 (rotated about the X and Z axes relative to view 200 of Figure 2), shown as in which the second metal layer is omitted and one or more dielectric layers 210 are partially transparent.

[0052] In one or more embodiments, waveguide arrangement 208 may correspond to a layer of a PCB (e.g., waveguide layer 108 of PCB 102 in FIG. 1). In one or more other embodiments, waveguide arrangement 208 may instead be formed from a layer of a suitable metallized dielectric substrate other than a PCB, such as, as a non-limiting example, a molded interconnect device (MID) substrate, a 3D printed substrate, or an in-mold electronics (IME) substrate.

[0053] As shown in the figure, one or more dielectric layers 210 of waveguide arrangement 208 are directly disposed between the first metal layer 222 and the second metal layer 304. In one or more embodiments, as a non-limiting example, dielectric layer 210 may comprise epoxy resin, polyimide, nonwoven glass cloth, or any suitable combination thereof (e.g., as a composite material), or may be formed of epoxy resin, polyimide, nonwoven glass cloth, or any suitable combination thereof (e.g., as a composite material). In one or more embodiments, as a non-limiting example, the first metal layer 222 and the second metal layer 304 may comprise copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof, or may be formed of copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof. In one or more embodiments (e.g., embodiments where dielectric layer 210 includes two or more dielectric layers), one or more additional metal layers may be inserted between adjacent dielectric layers in dielectric layer 210. In one or more embodiments, the distance between the first metal layer 222 and the second metal layer 304 (i.e., the thickness of the dielectric layer 210) is within 10% of the quarter wavelength of the RF signal generated by the transceiver circuit coupled to the waveguide arrangement 208 (e.g., transceiver circuit 114 of FIG. 1) (e.g., considering the effect of the material properties of the dielectric layer 210, such as its relative permittivity, on the wavelength). For example, the distance between the first metal layer 222 and the second metal layer 304 may be approximately 500 μm to 600 μm, with tolerances ranging from 5% to 20%.

[0054] Waveguide structure 212 may include portions of a first metal layer 222 and sidewalls 220 (sometimes referred to as “conductive sidewalls 220”) extending from the first metal layer 222 and the second metal layer 304. The sidewalls 220 may be formed of metal that covers portions of one or more dielectric layers 210 that would otherwise be exposed in opening 216 (i.e., such that the sidewalls 220 can be considered “metallized” sidewalls). In one or more embodiments, as a non-limiting example, the sidewalls 220 may include copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof, or may be formed of copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof. In one or more embodiments, the sidewalls 220 may be formed of the same material as the first metal layer 222 and the second metal layer 304. As shown, except for openings 216, 218, the upper surface of the first metal layer 222 is planar or substantially planar.

[0055] Each of the waveguide structures 212 may have a sidewall 220 defining a corresponding opening 216 extending through the first metal layer 222, the second metal layer 304, and the dielectric layer 210. That is, each opening 216 may extend completely through the waveguide arrangement 208. In one or more embodiments, the opening 216 may correspond to an inflatable cavity. In one or more embodiments, an antenna structure (e.g., antenna structure 104 of FIG. 1) is attached to the waveguide arrangement 208. In one or more embodiments, the antenna element of the antenna structure is perpendicularly aligned (e.g., aligned along the Z-axis) with the opening 216 of the waveguide structure 212. In one or more other embodiments, the antenna element of the antenna structure is laterally offset from the opening 216 of the waveguide structure 212 (i.e., not perpendicularly aligned with respect to the opening 216 of the waveguide structure 212).

[0056] Additional openings 218 may be formed to surround (e.g., laterally surround) each of the waveguide structures 212. Openings 218 may extend completely through the first metal layer 222, such that the upper surface of the dielectric layer or the uppermost dielectric layer of one or more dielectric layers 210 is exposed through openings 218. Openings 218 may separate each waveguide structure 212 from the laterally surrounded portion of the first metal layer 222. That is, for a given waveguide structure 212, the portion of the first metal layer 222 included in the waveguide structure 212 may be physically separated from all other portions of the first metal layer 222 through the corresponding opening in opening 218. In one or more embodiments, a single opening in opening 218 may laterally surround multiple waveguide structures in the waveguide structure 212. In one or more embodiments, a single opening in opening 218 may laterally surround only a single waveguide structure in the waveguide structure 212. By forming an opening 218 that laterally surrounds the waveguide structure 212 (at least relative to the first metal layer 222), unwanted scattering of the parallel plate waveguide mode can be advantageously suppressed or mitigated (e.g., attributable to the gap between the waveguide arrangement 208 and the attached antenna structure (e.g., antenna structure 104 of FIG. 1).

[0057] Conductive vias 302 (shown in Figures 3 and 4) may be formed in waveguide arrangement 208. Each of the vias 302 may extend from the first metal layer 222 to the second metal layer 304 and may completely penetrate the dielectric layer 210. Each of the vias 302 may have direct physical and electrical contact with the first metal layer 222 and the second metal layer 304. As a non-limiting example, each of the vias 302 may comprise copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof, or may be formed of copper, iron, nickel, tin, gold, silver, aluminum, another suitable conductive material, or any suitable combination thereof.

[0058] As shown in view 300, vias 302 may laterally surround each of the waveguide structure 212. The vias 302 include a first set of vias 302 (1) and a second set of vias 302 (2). In one or more embodiments, the first set of vias 302 (1) may be located at or immediately adjacent to the outer perimeter of each of the openings 218, and the second set of vias 302 (2) may be located at or immediately adjacent to at least a portion of the inner perimeter of each of the openings 218. In this manner, the first set of vias 302 (1) may laterally surround each of the openings 218 at their respective outer perimeters, and the second set of vias 302 (2) may be laterally surrounded by the openings 218. In one or more embodiments, the second set of vias 302(2) includes subgroups of vias, wherein each subgroup at least partially surrounds the sidewall 220 of the corresponding waveguide structure 212 and the associated opening 216 (e.g., there is a one-to-one correspondence between the subgroups of the second set of vias 302(2) and the corresponding waveguide structure 212). In one or more embodiments, each subgroup of the second set of vias 302(2) is disposed only on both sides (e.g., opposite sides) of the opening 216 corresponding to the subgroup. In one or more embodiments, the vias 302 may suppress or eliminate the parallel plate pattern between the first metal layer 222 and the second metal layer 304.

[0059] Although Figures 3 and 4 show a via 302 surrounding the waveguide structure 212, it should be understood that such an arrangement is illustrative and not limiting. For example, in one or more other embodiments, the waveguide structure 212 may instead be surrounded by a solid metal wall (e.g., surrounding the waveguide structure 212; in the example shown, disposed along the boundary defined by the via 302).

[0060] Figure 5 shows a top view 500 of the first metal layer 222 of the waveguide arrangement 208 of Figures 2-4. As shown, each portion of the first metal layer 222 included in one of the waveguide structures 212 laterally surrounds a corresponding one of the openings 216 and is laterally surrounded by one of the openings 218. In some regions, such as region 502, the portion of the first metal layer 222 included in a single waveguide structure 212 is laterally surrounded by a single opening 218, wherein the opening 218 does not surround the portion of the first metal layer 222 corresponding to any other waveguide structure 212. In other regions, a given opening 218 may laterally surround portions of the first metal layer 222 corresponding to multiple waveguide structures 212.

[0061] In one or more embodiments, each waveguide structure 212 may be defined by an outer perimeter at the first metal layer 222. In this example, the outer perimeter and cross-section of the waveguide structure 212 are each shown as having a rounded rectangular shape (i.e., a rectangle with rounded corners). However, the shape of the waveguide structure 212 shown is intended to be illustrative and not limiting. For example, in one or more other embodiments, as a non-limiting example, the shape of the outer perimeter or cross-section of the waveguide structure may be elliptical, rectangular, circular or oval, dog-bone shaped, or may have other suitable shapes. In one or more embodiments, a portion of a given waveguide structure 212 formed by the first metal layer 222 may have a substantially straight first edge and a second edge (e.g., a long edge) and substantially curved third and fourth edges (e.g., short edges), wherein the third edge extends in an arc between the distal ends of the first edge and the distal ends of the second edge, and the fourth edge extends in an arc between the proximal ends of the first edge and the proximal ends of the second edge. The opening 216 and sidewall 220 may each have a cross-section similar in shape to the cross-section of the waveguide structure 212 (e.g., a rounded rectangle shape in this example). In one or more embodiments, the outer perimeter defining a given one of the opening 216 or sidewall 220 may have a substantially straight first and second edge (e.g., a long edge), and substantially curved third and fourth edges (e.g., short edges), wherein the third edge extends in an arc between the distal ends of the first and second edges, and the fourth edge extends in an arc between the proximal ends of the first and second edges. In one or more embodiments, the opening 218 surrounding the waveguide 212 may have an outer perimeter and an inner perimeter that are similar in shape to the outer perimeter or cross-section of the waveguide 212, but scaled up. In one or more embodiments, relatively closely adjacent openings 218 may overlap to effectively form a larger opening surrounding a plurality of waveguides 212.

[0062] Top view 500 further illustrates an example arrangement of vias 302. It should be noted that in practice, vias 302 are not necessarily visible at the top surface of the first metal layer 222. As shown, a first set of vias 302 (1) defines the outer perimeter of each of the openings 218, and a second set of vias 302 (2) defines at least a portion of the inner perimeter of each of the openings 218. In one or more embodiments, each subgroup of the second set of vias forms a partial via fence on or near either side (e.g., the long side) of each of the openings 216 and sidewalls 220 of the associated waveguide 212. This partial via fence can at least partially block one or more RF paths between waveguide structures 212, thereby improving signal integrity and reducing interference and noise coupling between waveguide structures 212.

[0063] For example, a first set of vias 302(1) may laterally surround each of the openings 218 at their respective outer perimeters, and a second set of vias 302(2) may be laterally surrounded by corresponding openings in the openings 218, wherein subgroups of the second set of vias 302(2) laterally surround corresponding openings 216 of the waveguide structure 212 (e.g., there is a one-to-one correspondence between subgroups of the second set of vias 302(2) and corresponding waveguide structures 212). Each subgroup of the second set of vias 302(2) may directly contact the portion of the first metal layer 222 included in the waveguide structure 212 corresponding to the subgroup.

[0064] It should be understood that the arrangement of via 302 shown in this example is intended to be illustrative and not limiting. For example, via 302 may be arranged along the inner and outer perimeters of opening 218 at a different spacing distance (i.e., the distance between adjacent vias) than the spacing distance currently shown, wherein the spacing distance used may be selected based on the desired or expected frequency of the signal to be transmitted through waveguide structure 212.

[0065] Figure 6 shows a top view of region 502 of the first metal layer 222 shown in Figure 5, and illustrates the dimensions of the openings (e.g., openings 216, 218) and the portion of the first metal layer 222 surrounding one of the waveguide structures 212. For example, distance 602 corresponds to the shortest distance between the waveguide structure 212 and the portion of the first metal layer 222 that it surrounds. For example, distance 602 may correspond to the width of opening 218. In one or more embodiments, distance 602 may be between 400 μm and 600 μm, with tolerances ranging from 5% to 20%.

[0066] The distance 604 corresponds to the length of the opening 216 along its major axis (e.g., relative to the XY plane). In one or more embodiments, the distance 604 may be between 2400 μm and 2700 μm, with tolerances ranging from 5% to 20%.

[0067] The distance 606 corresponds to the width of the opening 216 along its minor axis (e.g., relative to the XY plane). In one or more embodiments, the distance 606 may be between 1050 μm and 1250 μm, with tolerances ranging from 5% to 20%.

[0068] The distance 608 corresponds to the distance between openings 216 and 218 on the thick side of the portion of the first metal layer 222 included in the waveguide structure 212. For example, the distance 608 may correspond to the width of the thickest (e.g., along the X direction) segment of the portion of the first layer 222 included in the waveguide structure 212. In one or more embodiments, the distance 608 may be between 475 μm and 575 μm, with tolerances ranging from 5% to 20%.

[0069] Distance 610 corresponds to the distance between openings 216 and 218 on the thin side of the portion of the first metal layer 222 included in the waveguide structure 212. In one or more embodiments, distance 610 may be between 225 μm and 275 μm, with tolerances ranging from 5% to 20%.

[0070] Figure 7 shows a top view of the dielectric layer 210 of the waveguide arrangement 208 of Figures 2-4. Although via 302 is not shown in this example, it should be understood that in one or more embodiments, via 302 may extend through the dielectric layer 210 (e.g., as shown in view 400 of Figure 4). As shown, the sidewall 220 of the defining opening 216 of the waveguide structure 212 extends through the dielectric layer 210. The opening 218 shown in view 500 of Figure 5 does not extend into the dielectric layer 210.

[0071] Figure 8 shows a top view 800 of the second metal layer 304 of the waveguide arrangement 208 of Figures 2-4. As shown, the opening 216 corresponding to the waveguide structure 212 extends through the second metal layer 304. The opening 218 shown in view 500 of Figure 5 does not extend into the second metal layer 304.

[0072] Top view 800 further illustrates an example arrangement of the through holes 302. As shown, each of the openings 216 is laterally surrounded by the through hole 302. The arrangement of the through holes 302 shown in this example may correspond to the arrangement shown in view 500 of FIG5 (e.g., relative to the placement of the openings 216).

[0073] Various exemplary embodiments are presented below. Some simplifications and omissions may have been made in the following examples to highlight and illustrate some aspects of the various exemplary embodiments, rather than to limit the scope.

[0074] In an example embodiment, an apparatus includes a substrate comprising: a first metal layer; at least one dielectric layer disposed over the first metal layer; a second metal layer disposed over the first dielectric layer; and a plurality of waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first opening extending through the first metal layer, the dielectric layer, and the second metal layer. The first metal layer may include a second opening, and each of the second openings may laterally surround at least one of the plurality of waveguide structures.

[0075] In one or more embodiments, the device includes: a first conductive via extending through at least one dielectric layer between a first metal layer and a second metal layer and disposed laterally surrounding a second opening; and a second conductive via disposed on opposite sides of each of a plurality of waveguide structures.

[0076] In one or more embodiments, the first conductive via defines a corresponding perimeter surrounding each of the second openings.

[0077] In one or more embodiments, the second conductive via defines a corresponding perimeter extending along at least both sides of each of the plurality of waveguide structures.

[0078] In one or more embodiments, the second opening extends through the first metal layer to expose the upper surface of at least one dielectric layer.

[0079] In one or more embodiments, the device includes an antenna structure directly mounted on a first metal layer, the antenna structure including a plurality of antennas.

[0080] In one or more embodiments, the device includes transceiver circuitry attached to or coupled to a substrate and configured to generate radio frequency (RF) signals and provide the RF signals to an antenna structure for transmission via a plurality of waveguide structures on the substrate.

[0081] In one or more embodiments, the distance between the first metal layer and the second metal layer is within 10% of a quarter wavelength of the RF signal generated by the transceiver circuit.

[0082] In an example embodiment, an apparatus includes: a first metal layer; at least one dielectric layer disposed over the at least one dielectric layer; a second metal layer disposed over the at least one dielectric layer; and a waveguide structure defining a first opening, each of the waveguide structures extending from the first metal layer to the second metal layer and through the at least one dielectric layer. The first metal layer may include a second opening, and each of the second openings may laterally surround at least one of the waveguide structures.

[0083] In one or more embodiments, each of the waveguides includes a portion of a first metal layer and a conductive sidewall extending from the first metal layer through at least one dielectric layer to a second metal layer, the sidewall defining a first opening, and the first opening extending through the first metal layer, at least one dielectric layer, and the second metal layer.

[0084] In one or more embodiments, the device includes: a first conductive via extending through at least one dielectric layer between a first metal layer and a second metal layer and disposed laterally surrounding a second opening; and a second conductive via disposed on opposite sides of each of the waveguide structures.

[0085] In one or more embodiments, a first conductive via defines a respective perimeter surrounding each of the second openings, and a second conductive via defines a respective perimeter extending along at least both sides of each of the waveguide structures.

[0086] In one or more embodiments, the second opening extends through the first metal layer to expose the upper surface of at least one dielectric layer.

[0087] In an example embodiment, a radio frequency (RF) device includes: a printed circuit board substrate comprising: a first metal layer; at least one dielectric layer disposed over the at least one dielectric layer; a second metal layer disposed over the at least one dielectric layer; and waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first opening extending through the first metal layer, the dielectric layer, and the second metal layer; and an antenna structure disposed on and in contact with the first metal layer of the printed circuit board substrate. The first metal layer may include a second opening laterally surrounding the waveguide structure.

[0088] In one or more embodiments, the RF device includes: a first conductive via extending through at least one dielectric layer between a first metal layer and a second metal layer and positioned laterally to surround a second opening; and a second conductive via disposed on opposite sides of each of the waveguide structures.

[0089] In one or more embodiments, the first conductive via defines a corresponding perimeter surrounding each of the second openings.

[0090] In one or more embodiments, the second conductive via defines a corresponding perimeter extending along at least both sides of each of the waveguide structures.

[0091] In one or more embodiments, the second opening extends through the first metal layer to expose the upper surface of at least one dielectric layer.

[0092] In one or more embodiments, the RF device includes transceiver circuitry attached to or coupled to a substrate and configured to generate radio frequency (RF) signals and provide the RF signals to an antenna structure for transmission via a waveguide structure of the substrate.

[0093] In one or more embodiments, the distance between the first metal layer and the second metal layer is within 10% of a quarter wavelength of the RF signal generated by the transceiver circuit.

[0094] Although the operations of the methods are shown and described herein in a specific order, the order of operations for each method may be changed, such that a particular operation may be performed in reverse order, or that a particular operation may be performed at least partially concurrently with other operations. In one or more other embodiments, instructions or sub-operations of different operations may be implemented intermittently and / or alternately.

[0095] While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that numerous variations exist. It should also be understood that the exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. In fact, the foregoing detailed description will provide a convenient guide for those skilled in the art to implement one or more of the described embodiments. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope defined by the claims, which includes known and foreseeable equivalents at the time of filing this patent application.

Claims

1. An apparatus, characterized in that, include: A substrate comprising: a first metal layer; at least one dielectric layer disposed over the at least one dielectric layer; a second metal layer disposed over the at least one dielectric layer; and a plurality of waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first plurality of openings extending through the first metal layer, the dielectric layer, and the second metal layer, wherein the first metal layer includes a second plurality of openings, and each of the second plurality of openings laterally surrounds at least one of the plurality of waveguide structures.

2. The apparatus according to claim 1, characterized in that, Further includes: A plurality of conductive vias extend through the at least one dielectric layer between the first metal layer and the second metal layer and are arranged to laterally surround the plurality of openings; And a second plurality of conductive vias, which are disposed on opposite sides of each of the plurality of waveguide structures.

3. The apparatus according to claim 2, characterized in that, The first plurality of conductive vias define a corresponding perimeter surrounding each of the second plurality of openings.

4. The apparatus according to claim 3, characterized in that, The second plurality of conductive vias define respective perimeters extending along at least two sides of each of the plurality of waveguide structures.

5. The apparatus according to claim 1, characterized in that, The second plurality of openings extend through the first metal layer to expose the upper surface of the at least one dielectric layer.

6. The apparatus according to claim 1, characterized in that, Further includes: An antenna structure is directly mounted on the first metal layer, and the antenna structure includes multiple antennas.

7. The apparatus according to claim 6, characterized in that, Further includes: A transceiver circuit is attached to or coupled to the substrate and configured to generate a radio frequency (RF) signal and provide the RF signal to the antenna structure for transmission via the plurality of waveguide structures of the substrate.

8. The apparatus according to claim 7, characterized in that, The distance between the first metal layer and the second metal layer is within 10% of a quarter wavelength of the RF signal generated by the transceiver circuit.

9. An apparatus, characterized in that, include: First metal layer; At least one dielectric layer, wherein the first metal layer is disposed over the at least one dielectric layer; A second metal layer, wherein at least one dielectric layer is disposed above the second metal layer; The waveguide structure defines a first plurality of openings, each of the plurality of waveguide structures extending from the first metal layer to the second metal layer and through the at least one dielectric layer, wherein the first metal layer includes a second plurality of openings, and each of the second plurality of openings laterally surrounds at least one of the plurality of waveguide structures.

10. A radio frequency (RF) device, characterized in that, include: A printed circuit board substrate includes: a first metal layer; at least one dielectric layer disposed over the at least one dielectric layer; a second metal layer disposed over the at least one dielectric layer; and a plurality of waveguide structures, each including a portion of the first metal layer and a conductive sidewall extending from the first metal layer through the at least one dielectric layer to the second metal layer, the sidewall defining a first plurality of openings extending through the first metal layer, the dielectric layer, and the second metal layer; and an antenna structure disposed on and in contact with the first metal layer of the printed circuit board substrate, wherein the first metal layer includes a second plurality of openings laterally surrounding the plurality of waveguide structures.

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