Open waveguide antenna and system having the same

Abstract

A waveguide antenna system comprising: an electromagnetic (EM) transition section including a transition region having a signal feed interface and an open waveguide section, the EM transition section being configured to guide a waveguide mode of electromagnetic energy from the signal feed interface to the open waveguide section via the transition region; and a slotted waveguide antenna section configured and set to radiate electromagnetic energy received from the open waveguide section; wherein the EM transition section is electromagnetically coupled to the slotted waveguide antenna section, and the EM transition section is configured to support electromagnetic energy transmitted from the signal feed structure to the slotted waveguide antenna section.

Description

Technical Field

[0001] This invention relates to an open waveguide antenna, and more particularly to an open waveguide antenna system. Prior Technology

[0002] The present invention relates to an open waveguide antenna, and more particularly to an open waveguide antenna system.

[0003] Previous generations of millimeter-wave (mmWave) systems were constructed using multiple special-purpose MMICs (single-crystal microwave integrated circuits), typically including transmitter integrated circuits, receiver integrated circuits, and local oscillator circuits to synchronize these systems. One example of this construction is the Continental ARS-4A long-range radar sensor, which can be found at http: / / img009.hc360.cn / k2 / M0A / BF / 43 / wKhQxVq53tuEEmCQAAAAACS5hks768.pdf. The distributed nature of the transmitter and receiver MMICs in these systems reduces the distance between the radiator and the MMIC, making insertion loss acceptable despite the large antenna aperture of the radar. Recently, CMOS MMIC devices have become available, integrating TX and RX functionality into a single chip. In terms of cost, these systems offer advantages, reducing not only die costs but also assembly and manufacturing costs for radar manufacturers. This centralizes the MMIC and increases the transmission line distance between the antenna and the MMIC. Furthermore, this centralization reduces the complexity of RF signal routing between devices.

[0004] The trends of lengthening transmission lines and reducing the complexity of routing signals are making alternative methods for connecting antennas and MMICs more attractive. A common method of RF interconnection is to use etched traces on printed circuit boards. This type of transmission line structure is typically a microstrip (with the signal layer and ground separated by a dielectric) or a coplanar waveguide (with a ground structure next to the trace of the signal layer in the microstrip). At 79 GHz, this type of transmission line will exhibit an insertion loss of approximately 1 dB / inch if manufactured on "best-in-class" PCB materials, and approximately 2 dB / inch if manufactured on typical PCB materials.

[0005] As MMICs become increasingly integrated and the number of radio frequency (RF) transmission lines on PCBs decreases, older transmission structures become more suitable. Waveguides were theoretically explored in the 1890s and began practical application in the 1940s. At 79 GHz, the insertion loss of a rectangular waveguide is approximately 0.25 dB per inch. In practice, a 79 GHz system using a 3-inch transmission line loses 50% of its power in a microstrip line built on a best-in-class substrate, 75% on a typical PCB, but only about 16% in a waveguide. In radar systems, this loss difference exists both from the MMIC transmitter block to the antenna and from the antenna to the MMIC receiver block. Therefore, the "bidirectional" loss is twice the aforementioned figures. This makes reducing losses even more attractive to radar system designers.

[0006] For designers of waveguide feed networks in millimeter-wave radar or communication systems, three additional considerations determine system architecture and performance. First, how to transfer power from the MMIC to the waveguide (transition); second, how to transfer power from the waveguide to free space (antenna); and finally, for most systems, cost is also an important consideration in addition to system performance.

[0007] Two main methods for power transfer between MMICs and waveguides have been described.

[0008] The first transition method utilizes the transition from package to printed circuit board. This transition typically involves multiple sub-transitions. First, power is transferred from the semiconductor die to the fan-out layer or redistribution layer in the device package, and then from the redistribution layer to the printed circuit board, which is typically implemented through a ground-signal-ground (GSG) configuration in a spherical array. Next, the signal / power transitions to the microstrip structure through a grounded coplanar waveguide structure, which then excites radiators for transmission into the waveguide. The advantage of this method is the use of known techniques, but it also has the following disadvantages: (i) it requires the production of a controllable impedance structure on the main printed circuit board; (ii) the cost and supply chain complexity of using low-loss PCB materials on the main printed circuit board; and (iii) multiple sets of transition losses: MMIC to RDL, RDL to BGA, BGA to PCB, PCB to waveguide, etc., which partially negate the advantages of using waveguides, especially for short transmission line lengths.

[0009] The second proposed transition method is direct transmission from the package to the waveguide. A description of this method is provided on page 30 of the following document: https: / / www.ipcei-me.eu / wp-content / uploads / 2020 / 11 / 4-Pack-Trends-for-mm-wave-Radar-Infineon-Maciej-Wojnowski.pdf. This method overcomes the following disadvantages of the first method: (i) the requirement to fabricate a controllable impedance structure on the main printed circuit board; (ii) the cost and supply chain complexity of utilizing low-loss PCB materials on the main printed circuit board; and (iii) the net reduction in transition losses, i.e., BGA to PCB. The reduction in PCB cost and supply chain complexity is expected to be attractive to developers of millimeter-wave radar and communication systems.

[0010] In the design of millimeter-wave radar or communication systems, antenna selection and design are crucial considerations. There are two main use cases for radar systems: the first is radar systems designed for long-range operation; and the second is radar systems that need to operate at shorter ranges, but with a wider coverage area. In the automotive sensor field, these are typically referred to as long-range radars, used for functions such as adaptive cruise control, while corner radars or short-range radars are used for functions such as blind spot detection, lane change assist, or parking assist.

[0011] Long-range radar is typically intended to cover the lanes in front of or behind the vehicle. Angle radar supplements the coverage of long-range radar, aiming to provide 360-degree coverage around the vehicle. Redundancy in coverage is also desirable; therefore, angle radar typically attempts to cover a 120-degree horizontal field of view, while long-range radar typically covers a 60-90 degree horizontal field of view. For reference, the vertical plane is typically in the vehicle's height direction, while the horizontal plane is perpendicular to the vertical plane. In cases where the vehicle is expected to operate at a higher level of autonomy, such as SAE Level 3 or 4, mid-range radar may also be used, with a horizontal angular coverage range between that of angle and long-range radar. For the total cost of ownership of the vehicle, it may also be desirable to produce angle radar with enhanced range, thereby eliminating the need for mid-range radar.

[0012] Antenna architecture is typically selected first based on its viewing angle, followed by its bandwidth, although the antenna type will also depend on the type of antenna feed. In printed circuit board-based feed networks, the antenna is usually also formed on the printed circuit board, while in waveguide structures, it is ideal to use a construction method similar to that used for waveguide production. Polarization is another factor that designers consider when selecting an antenna. Finally, sidelobe leveling is crucial in many radar and communication systems. For long-range radar antennas, which have a narrower viewing angle (related to the antenna's horizontal half-power beamwidth), series-fed microstrip patch antennas are typically used. Parallel series feeds can be used to further reduce the viewing angle, increase antenna gain, and subsequently increase the range of the radar system.

[0013] To achieve a wide viewing angle, comb lines (sometimes called side-fed patches) or slot antennas are typically used.

[0014] Substrate integrated waveguide (SIW) with slot antennas can also be used with the feed network of a printed circuit board. Slot antennas typically exhibit some of the widest viewing angles, but they introduce additional PCB manufacturing complexity.

[0015] In waveguide-based feed networks, two basic antenna types are most commonly used. For high-gain applications, waveguide feed horns are typically used. This provides both high gain and wide bandwidth (>15% of the bandwidth). For wide-viewing-angle applications, slot antennas are typically used. Slot antennas formed in air-metal waveguides will exhibit a wider bandwidth than their counterparts from substrate-integrated waveguides, but less than the required bandwidth (e.g., 2 GHz at 79 GHz, compared to the required 4-5 GHz).

[0016] The required bandwidth depends heavily on the application. For Doppler effect radar systems, a wide bandwidth (e.g., 4-5 GHz) offers two main benefits: (i) it allows for the use of a wide portion of the bandwidth to provide high range resolution (proportional to the speed of light divided by the bandwidth), meaning a 4 GHz bandwidth would provide a range resolution of 3.5 cm. Ideally, this is when the radar detects an object close to the sensor. For example, when performing parking assistance, a distance of 1 meter or 1.05 meters is crucial, but when performing adaptive cruise control, a distance of 200 meters or 200.05 meters is less important; and (ii) the wide portion of the bandwidth can also be used to provide the radar system with the ability to use a smaller instantaneous bandwidth (i.e., 500 MHz), but switching frequencies within a wider portion of the bandwidth to avoid interference. Because angle radar or short-range radar provides a wider angular coverage, they are more susceptible to interference from nearby vehicles. Furthermore, this interference problem continues to worsen as the number of vehicles using angle radar on the road continues to increase.

[0017] In summary, while it is possible to produce narrow-angle antennas with large bandwidths in waveguide-fed radar applications, large bandwidth is not a critical feature due to the nature of radar applications. In applications where large (wide) bandwidth is important, the narrow angle of view of horn antennas is undesirable. Therefore, in the field of waveguide-fed radar antennas, there exists a performance gap that offers market value but is currently not cost-effective; this gap is a combination of wide partial bandwidth (e.g., 4-5 GHz at 79 GHz) and wide angle of view (e.g., a 120-degree half-power horizontal beamwidth).

[0018] Rogers Corporation has developed a technology to solve antenna problems, specifically a concrete implementation of dielectric resonator antennas. Rogers' dielectric resonator antennas offer a combination of wide viewing angle and wide bandwidth, making them ideal for corner radar applications. However, they have so far been used in conjunction with PCB-based integrated waveguide feed networks, which suffer from the MMIC and antenna insertion loss issues mentioned above. While combining dielectric resonator antennas with waveguide feed networks is certainly feasible and ideal in some cases, the additional cost of these two systems may prevent their use in some high-volume applications. Therefore, there is an unmet need for wide-viewing angle, wide-bandwidth antennas with waveguide feeds that are available at a competitive price, compared to standalone waveguide-with-slot antennas.

[0019] While the above background focuses on automotive radar, it is foreseeable that such needs will extend to non-automotive applications, such as a radar array (at 60 GHz) used in factory automation scenarios, which may also face a series of similar challenges.

[0020] Regarding waveguide fabrication, there are currently two main methods for producing waveguide-antenna systems for high-volume radar applications: (i) conventional multilayer molded waveguides; and (ii) bandgap waveguides. The relative benefits of these two systems are evaluated primarily by comparing their complexity and cost.

[0021] Traditional waveguides are formed by molding multiple layers of plastic, metallizing these layers, and then bonding them together with conductive adhesive, or by other means providing a consistent and reliable electrical connection from one layer to another. An example of this stacking can be found in U.S. Patent Publication No. 2020 / 0313304. The complexity of this system stems from the number of metallized plastic layers (up to 7 layers in complex structures, and 2-3 layers in simple structures) and the need for strong electrical connections between the layers to bond them together.

[0022] Bandgap waveguides utilize a special structure to form the inner walls of the waveguide. This refers to an "electromagnetic bandgap structure" or an "artificial magnetic conductor." The main advantage of this structure is that it eliminates the need for robust electrical connections between the top and bottom of the waveguide, reducing the complexity of the waveguide assembly. This advantage has demonstrated its market value.

[0023] However, this structure may introduce additional complexity to mold tolerance requirements, requiring four metal layers in a typical build. As the number of layers increases, manufacturing complexity grows non-linearly, and material costs also rise with the number of metal layers. Therefore, there is an unmet need in the market for a solution that: (i) can be excited from an antenna package or similar MMIC package; (ii) provides low insertion loss, e.g., 0.25–0.5 dB / inch at 79 GHz; (iii) can be manufactured with minimal cost and complexity; (iv) may provide an antenna solution offering a wide viewing angle and high bandwidth, e.g., a 120-degree half-power beamwidth and a 5 GHz bandwidth with a center frequency of 78.5 GHz; (v) or, a system that provides the first three points with reduced cost and complexity, offering high gain and optionally wide bandwidth for other applications. Ideal for long-range radar, for example; (vi) a feed network that can be excited from a PCB, or formed into an antenna package or similar MMIC; (vii) low insertion loss, for example, 0.25~0.5dB per inch at 79GHz; (viii) that can be manufactured using only a metallization layer and possibly a dielectric layer (optionally only metallized plastic, with the dielectric material in the ideal embodiment); (ix) an antenna that provides a wide-viewing-angle and high-bandwidth solution, for example, a 120-degree half-power beamwidth and a 5GHz bandwidth with a center frequency of 78.5GHz; and (x) or, a system that can provide high gain and optionally high bandwidth.

[0024] Some dielectric resonator antennas can be configured to the desired form over a wide bandwidth, but they suffer significant gain loss when incorporated into an antenna system due to the required feed structure and transition losses. Some molded conventional waveguide antennas can be incorporated into an antenna system with minimal feed and transition losses to achieve high gain, but these antennas offer a smaller usable bandwidth (i.e., <3 GHz).

[0025] While existing antennas may be suitable for their intended purpose, there is still a need for customizable, high-gain antenna systems (with minimal feed and transition losses) that can achieve high gain by customizing the shape and angle of the antenna in a controllable manner across a wide bandwidth (i.e., >4 GHz) down to the millimeter-wave band.

[0026] The following publications can be considered as useful background information: U.S. Patent Publication Nos. 3,015,100, 6,043,787, and 2020 / 0313304. [Previous Technical Documents] [Patent Literature]

[0027] [Patent Document 1] US2020 / 0313304 [Patent Document 2] US3,015,100 [Patent Document 3] US6,043,787 Summary of the Invention

[0028] One embodiment includes an open waveguide antenna as defined in the appended separate claim. Further advantageous modifications to the open waveguide antenna are defined in the appended supplementary claim.

[0029] An embodiment includes a waveguide antenna system comprising: an electromagnetic (EM) transition section including a transition region having a signal feed interface and an open waveguide section, the EM transition section being configured to guide a waveguide mode of electromagnetic energy from the signal feed interface to the open waveguide section via the transition region; and a slotted waveguide antenna section configured to radiate electromagnetic energy received from the open waveguide section; wherein the EM transition section is electromagnetically coupled to the slotted waveguide antenna section, and the EM transition section is configured to support electromagnetic energy transmission from the signal feed structure to the slotted waveguide antenna section.

[0030] One embodiment includes a waveguide antenna system having: a plurality of waveguide antenna systems as described above, configured for antenna-on-package applications.

[0031] One embodiment includes a waveguide antenna system having: a plurality of waveguide antenna systems as described above, configured as a surface mount application on a printed circuit board.

[0032] One embodiment includes an open waveguide signal feed system comprising: a printed circuit board having a signal feed and a signal feed output; an open waveguide having a signal feed input port; a transition region disposed between the signal feed output and the signal feed input port for signal communication with them; wherein the signal feed comprises a microstrip, a coplanar waveguide, or a stripline; and wherein the signal feed output comprises a patch or a probe.

[0033] One embodiment includes an open waveguide section having: at least one bend in a slotted waveguide located in the propagation direction of electromagnetic waves in the slotted waveguide, the slotted waveguide including a slot having first and second opposing sidewalls, a partition disposed between the two, a first base disposed between the first sidewall and the partition, and a second base disposed between the partition and the second sidewall, wherein at least all surfaces of the first sidewall, the second sidewall, the partition, the first base and the second base located within the slot are conductive; and an electromagnetic radiation suppressor strategically configured and set to suppress unwanted electromagnetic radiation that could be emitted from the at least one bend in the absence of such an electromagnetic radiation suppressor.

[0034] One embodiment includes an open waveguide antenna comprising: a slot having first and second opposing sidewalls, a partition disposed therebetween, a first base disposed between the first sidewall and the partition, and a second base disposed between the partition and the second sidewall; wherein at least one or more of the surfaces of the first sidewall, the second sidewall, the partition, the first base, and the second base located within the slot are conductive; wherein the first base has a first sequence of corrugations arranged longitudinally along the length of the slot; wherein the first sequence of corrugations alternately and sequentially follow a first bending path and a second bending path, the second bending path being asymmetrical to the first bending path; wherein the second base has a second sequence of corrugations arranged longitudinally along the length of the slot; wherein the second sequence of corrugations alternately and sequentially follow the second bending path and the first bending path; wherein the first bending path and the second bending path alternately from one side of the partition to the other side of the partition along the length of the slot.

[0035] The above-described features and advantages of the present invention, as well as other features and advantages, will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. Simple Explanation of the Diagram

[0036] Referring to the exemplary non-limiting drawings, in which the same elements are numbered or described in the same way: [Figure 1] Figures 1A, 1B and 1C respectively depict a cross-sectional end view of an exemplary slot waveguide according to an embodiment, a cross-sectional end view of an exemplary slot waveguide antenna and a transparent cross-sectional side view of the exemplary slot waveguide antenna of Figure 1B. [Figure 2] Figure 2 depicts a rotating isometric transparent view of an exemplary slot waveguide antenna according to an embodiment of Figures 1B and 1C. [Figure 3] Figure 3 depicts the analytical modeling performance characteristics of an exemplary slot waveguide antenna according to an embodiment of Figure 2. [Figure 4] Figures 4A, 4B and 4C respectively depict views similar to those in Figures 1A, 1B and 1C according to an embodiment, but with a dielectric cap on top of the exemplary slot waveguide and the exemplary slot waveguide antenna. [Figure 5] Figure 5 depicts a rotating isometric transparent view of an exemplary slot waveguide antenna according to an embodiment of Figures 4B and 4C. [Figure 6] Figure 6 depicts the analytical modeling performance characteristics of an exemplary slot waveguide antenna according to an embodiment of Figure 5. [Figure 7] Figures 7A and 7B respectively depict a cross-sectional end view and a cross-sectional side view of an exemplary slotted waveguide antenna with a signal feed according to an embodiment of Figures 1B and 1C. [Figure 8] Figures 8A, 8B and 8C respectively depict top plan views, repeated top plan views and final top plan views of a single and multiple exemplary slot waveguide antennas of Figure 2 or Figure 5 according to an embodiment. [Figure 9] Figure 9 depicts the analytical modeling performance characteristics of an embodiment of Figure 8C based on an embodiment. [Fig. 10] Fig. 10A depicts a rotating isometric top view of a slot waveguide antenna according to an embodiment, and Fig. 10B depicts a rotating isometric bottom up view of an embodiment, which has features that contribute to its manufacturability. [Figure 11] Figure 11 depicts a conceptual top plan view of an antenna feed on a package with a transition according to an embodiment, in the XY plane, and an antenna with a transmit and receive slot waveguide. [Figure 12] Figure 12 depicts a conceptual end view of the antenna feed on the package of Figure 11 according to an embodiment, in the YZ plane. [Fig. 13] Fig. 13 depicts a conceptual side view of the antenna feed on the package of Fig. 11 according to an embodiment, in the XZ plane. [Figure 14] Figure 14A depicts a transparent side view of an exemplary first transition from a ridge waveguide to a slot waveguide antenna according to an embodiment. Figure 14B depicts an end view of the first transition of Figure 14A, and Figure 14C depicts exemplary electromagnetic performance characteristics of the embodiment of Figure 14A. [Fig. 15] Fig. 15A depicts a transparent rotating isometric view of an exemplary second transition disposed between a rectangular waveguide and a slotted waveguide antenna according to an embodiment, and Fig. 15B depicts the electromagnetic performance characteristics of the embodiment of Fig. 15A. [Fig. 16] Fig. 16A depicts a top block diagram of an exemplary third transition in the form of a waveguide bend according to an embodiment, and Fig. 16B depicts the electromagnetic performance characteristics of the embodiment of Fig. 16A according to an embodiment. [Fig. 17] Fig. 17A depicts a transparent side view of an exemplary fourth transition in the form of a rectangular waveguide according to an embodiment; Fig. 17B depicts a top plan view of the embodiment of Fig. 17A; and Fig. 17C depicts the electromagnetic performance characteristics of the embodiments of Fig. 17A and 17B. [Figure 18] Figure 18 is a block diagram side view depicting an exemplary conceptual diagram of a patch, a transition waveguide with bends and transition losses, a slot waveguide with losses, and a slot waveguide antenna according to an embodiment. [Figure 19] Figure 19 depicts the analytical modeling results of the channel waveguide loss according to an embodiment. [Figure 20] Figures 20A and 20B depict exemplary top block diagrams of a conceptual model for controlling the radiation at dielectric discontinuities of a slot waveguide antenna according to an embodiment. [Figure 21] Figures 21A, 21B and 21C depict a rotating isometric transparent view, a top transparent plan view and a transparent side view of the transition from the first patch to the slot waveguide according to an embodiment, respectively, wherein the patch E-polarization is parallel to the partition. [Figure 22] Figures 22A, 22B and 22C depict, with varying degrees of detail, a rotated isometric transparent view of the transition from the second patch to the slot waveguide according to an embodiment, wherein the patch E-polarization is perpendicular to the diaphragm. [Figure 23] Figure 23 depicts the performance characteristics of the patch-to-slot waveguide transition according to an embodiment shown in Figures 21A-21C. [Figure 24] Figure 24 depicts an exemplary waveguide antenna system according to an embodiment, which has an open waveguide and a slotted waveguide antenna, and is configured for an antenna application packaged in an antenna package. [Figure 25] Figures 25A and 25B depict block diagrams illustrating the fundamental differences between the open waveguide (Figure 25A) and the slotted waveguide antenna (Figure 25B) of the system of Figure 24 according to an embodiment. [Figure 26] Figure 26 depicts a configuration with a given propagation constant. An example of a waveguide. [Figure 27] Figure 27 depicts a trench waveguide of an open type as an example of an embodiment. [Figure 28] Figures 28A, 28B and 28C respectively depict a top view, a front transparent view and a side transparent view of an open trench waveguide and a slot waveguide antenna according to an embodiment. [Figure 29] Figure 29 depicts the radiation performance characteristics of an open trench waveguide slot antenna according to an embodiment of Figure 28A. [Figure 30] Figure 30 depicts a block diagram top plan view of an exemplary transition region between an electromagnetic transmission line and an open waveguide according to an embodiment. [Figure 31] Figure 31 depicts a block diagram side view of another exemplary transition region between an electromagnetic transmission line and an open waveguide according to one embodiment. [Figure 32] Figure 32A depicts a rotating isometric transparent view according to an embodiment, and Figure 32B depicts a top plan view of the bend in the open waveguide. Figures 32C and 32D depict the relevant electromagnetic performance characteristics of Figures 32A and 32B. [Fig. 33] Fig. 33 depicts a block diagram cross-sectional longitudinal view of a bend in a dual-channel open waveguide with an electromagnetic radiation absorber according to an embodiment. [Figure 34] Figures 34A and 34B depict block diagram cross-sectional longitudinal views of two versions of a double-channel open waveguide with an electromagnetic radiation choke (quarter-wave groove) at a bend according to an embodiment. [Figure 35] Figures 35A, 35B and 35C depict block diagram cross-sectional longitudinal views of three versions of a single-channel open waveguide with an alternative electromagnetic radiation choke depicted in Figures 34A and 34B, according to an embodiment. [Figure 36] According to one embodiment, Figure 36A depicts a rotational isometric transparent view of an open waveguide bend with an improved partition within the bend, and Figure 36B depicts a side transparent view of an open waveguide bend with an improved partition within the bend, and Figures 36C and 36D depict electromagnetic performance characteristics related to Figures 36A and 36B. [Figure 37] According to one embodiment, Figure 37A depicts a rotational isometric transparent view of an open waveguide bend with an improved base plate structure within the bend, and Figure 37B depicts a top plan view of an open waveguide bend with an improved base plate structure within the bend, and Figures 37C and 37D depict the relevant electromagnetic performance characteristics of Figures 37A and 37B. [Figure 38] Figure 38 depicts a block diagram cross-sectional longitudinal view of an embodiment through an open waveguide bend, in which there is an improved waveguide structure. [Figure 39] According to one embodiment, Figure 39A depicts a rotational isometric transparent view of an open waveguide bend with an improved wall structure within the bend, and Figure 39B depicts a top plan view of an open waveguide bend with an improved wall structure within the bend, and Figures 39C and 39D depict electromagnetic performance characteristics related to Figures 39A and 39B. [Figure 40] Figure 40A depicts a block diagram cross-sectional longitudinal view of a bend in an open waveguide according to an embodiment. Figure 40B depicts an improved version of Figure 40A with an inductor added to the bend. Figure 40C depicts an improved version of Figure 40A with a capacitor added to the bend. Figures 40D and 40E depict the relevant electromagnetic performance characteristics of Figures 40B and 40C, respectively.

[0037] As will be understood by those skilled in the art, the following drawings are for illustrative purposes only. It should be understood that, for the sake of simplicity and clarity, the elements shown in the drawings are not necessarily drawn to scale. For example, for clarity, the size or proportion of some elements may be enlarged relative to others. Furthermore, where appropriate, element symbols may be repeated in the drawings to indicate corresponding or similar elements, or similar elements may not be listed repeatedly in all drawings. It should be clear and understood that such omissions are essentially disclosures. Implementation

[0038] The term "implementation" as used in this specification refers to an "implementation disclosed and / or described in this invention," which may not necessarily include a specific embodiment of the invention pursuant to the appended claims, but is provided for the purpose of fully understanding the invention pursuant to the appended claims.

[0039] While the following detailed description contains numerous illustrative details, it will be understood by those skilled in the art that the scope of the claims also covers variations and modifications to these details. For example, the described features do not necessarily exclude or relate to other technical features; such combinations of non-exclusive features are considered inherent to the disclosure of this invention. Furthermore, common features may be commonly depicted in various drawings, but for the sake of brevity, they may not be specifically listed in all drawings. However, those skilled in the art will recognize them as explicitly disclosed features, even if they are not listed in a particular drawing. Therefore, the following exemplary embodiments are not without generality and are not intended to limit the disclosed claimed invention.

[0040] As presented and described in numerous diagrams and accompanying text, an antenna system provided in an embodiment can transition from a patch feed (i.e., an antenna on a package or circuit board structure) to an open waveguide antenna structure, minimizing overall structural losses and allowing for customizable high-gain antenna systems that can be used over a wide bandwidth (i.e., >4 GHz) and up to millimeter-wave frequencies.

[0041] To simplify integration, and as noted herein, the feed structure used may be a surface mount, but it may also be considered as other feed structures such as probes (e.g., coaxial cables, plated vias on a printed circuit board, or similar), loops, or vias. Surface mount structures are ideally part of the antenna chip within a package to reduce distance, allow miniaturization, and reduce costs by avoiding additional RF layers. However, surfaces can also be formed on any type of substrate layer, including add-ins, or layers within a printed circuit board.

[0042] Open waveguide antennas can be specifically designed to allow for desired antenna radiation patterns. For example, a wide field of view can be achieved, which is often useful in corner radar applications for automotive safety systems. In other cases, maximum gain may be required at a narrower field of view, such as in long-range, forward-facing automotive radar applications. Variables of an open waveguide antenna that can be adjusted to achieve the desired pattern may include the size of the open radiating aperture, the angle of the aperture, the base corrugation, or dielectric discontinuities that generate radiation. Furthermore, dielectric caps or lens structures can be added to the metallic open waveguide to further optimize the pattern. In cases requiring multiple antenna channels, such as in corner radar applications as described above, multiple open waveguide antenna structures can be combined into a single unit for ease of manufacturing, with the distance between the individual open waveguide antenna elements ranging from 0.5 to 10 times the wavelength of the signal being processed.

[0043] Various features can be incorporated into open waveguide antenna designs to facilitate manufacturing while maintaining the same excellent RF performance. These include component "shelling" to reduce material consumption and warpage, grooves and front-side features to prevent adhesion during metallization processes such as electroplating or others, and draft angles and convenient parting line locations for easy component removal.

[0044] The fabrication of single-channel or multi-channel open waveguide antenna structures can be accomplished by various methods, including metal die casting, dielectric injection molding followed by surface metallization, and extrusion followed by unification and surface metallization.

[0045] The transition from the feed structure to the open waveguide antenna is designed to minimize losses. Suitable transition structures for achieving this purpose include ridge waveguides with patch feeds, rectangular waveguides with patch feeds, open waveguides with patch or probe feeds, coplanar waveguides, and others.

[0046] In another embodiment, as shown and described in the figures and accompanying text, a slotted waveguide antenna (TWGA) is provided, which in one example is useful for automotive radar applications. The TWGA combines the functions of a slotted waveguide and an electromagnetic (EM) radiator (antenna). The slotted waveguide is symmetrical on both sides of its dividing plate and primarily functions as an electromagnetic transmission element for guiding modes.

[0047] In contrast, slotted waveguide antennas exhibit asymmetry on both sides of their dividing partition and must have at least one partially open top, enabling them to function as both electromagnetic transmission and electromagnetic radiation elements. As used herein, the term "open top" refers to the top, cover, or top plate of the TWGA that allows electromagnetic radiation energy to pass through. Therefore, an open top does not preclude the presence of a dielectric cover on the TWGA. A single-crystal microwave integrated circuit (MMIC) can be used to bring signals to one of the TWGA's input ports.

[0048] Although this invention refers to slotted waveguide antennas, it is understood that a more general term describing the same thing refers to open waveguide antennas, wherein the slotted waveguide antennas described above are a specific subset of open waveguide antenna structures.

[0049] As used in this invention, the term "monolithic" refers to a structure formed entirely from a single material.

[0050] While the embodiments described and illustrated in this invention depict exemplary TWGAs with specific three-dimensional (3D) geometries, it is understood that these geometries are merely one example among many geometries that can be used to design TWGAs based on their intended performance characteristics (operating frequency, bandwidth, gain, return loss, radiation pattern, etc.). It is also understood that modifications to the disclosed geometries can be made without departing from the scope of this invention. Therefore, the disclosure of this invention applies to any TWGA design falling within the scope of the appended claims, and any 3D geometries falling within the scope of this invention and suitable for the purposes disclosed herein are considered and regarded as supplementary to the specific embodiments disclosed herein.

[0051] Referring now to Figures 1A-10B, which generally relate to examples of open waveguide antennas, and particularly to examples of open slot waveguide antennas.

[0052] Figures 1A, 1B, and 1C depict, respectively, a cross-sectional end view of an exemplary open slot waveguide (TWG) 1000, a cross-sectional end view of an exemplary open slot waveguide antenna (TWGA) 2000, and a transparent cross-sectional side view of an exemplary TWGA 2000 as shown in Figure 1B. It can be seen that, compared to the TWG 1000, the TWGA 2000 has similar structural features, but the structural differences lie in the asymmetry of the left and right bases on both sides of the partition, and the corrugations present on the left and right bases of the TWGA 2000.

[0053] In one embodiment, the TWG 1000 (more generally referring to an open waveguide) has: a slot 1010 having first and second opposing sidewalls 1020 and 1030, a partition 1040 disposed between the first and second sidewalls 1020 and 1030, a first base 1050 disposed between the first sidewall 1020 and the partition 1040, and a second base 1060 disposed between the partition 1040 and the second sidewall 1030; wherein at least all surfaces 1070 of the first sidewall 1020, the second sidewall 1030, the partition 1040, the first base 1050, and the second base 1060 located within the slot 1010 are conductive. In one embodiment, as viewed from the angle of FIG. 1A, the partition 1040 extends upward from the first base 1050 and the second base 1060. In one embodiment, the TWG 1000 has a single-crystal 3D dielectric structure with a conductive surface 1070 as described above. In one embodiment, all surfaces 1070 of the first base 1050 and the second base 1060 located within the trench 1010 are conductive. In one embodiment, the conductive surface 1070 is coated with a conductive material. As used in this invention, and at least for the conductive surface of the TWG 1000 (which also refers to an open waveguide segment), the term "electrically conductive" means conductive at the operating frequency of interest, which may include non-conductive surfaces in the DC sense, but has sufficient AC conductivity at the operating frequency of interest to achieve the purpose disclosed in this invention.

[0054] In one embodiment, the TWGA 2000 (more generally referring to an open waveguide antenna) has: a slot 2010 having first and second opposing sidewalls 2020 and 2030, a partition 2040 disposed between the first and second sidewalls 2020 and 2030, a first base 2050 disposed between the first sidewall 2020 and the partition 2040, and a second base 2060 disposed between the partition 2040 and the second sidewall 2030; wherein at least all surfaces 2070 of the first sidewall 2020, the second sidewall 2030, the partition 2040, the first base 2050, and the second base 2060 located within the slot 2010 are conductive; wherein the first base 2050 has a first sequence of corrugations 2052, which are longitudinally arranged along the length of the slot 2010; wherein the first sequence of corrugations 2052 alternate (high in Figure 1C) The second base 2060 has a second sequence of corrugations 2062, which are arranged longitudinally along the length of the groove 2010. The second sequence of corrugations 2062 alternates and follows the second bending path 2012 and the first bending path 2011 in sequence, alternating from low to high (from left to right in Figure 1C). The second base 2060 has a second sequence of corrugations 2062, which are arranged longitudinally along the length of the groove 2010. The second sequence of corrugations 2062 alternates and follows the second bending path 2012 and the first bending path 2011 in sequence, alternating from low to high (from left to right in Figure 1C). The first bending path 2011 and the second bending path 2012 alternate along the length of the groove 2010 from one side of the partition 2040 to the other side of the partition 2040 (preferably referring to Figure 2), but are shown as a continuous curve from left to right in the transparent side view of Figure 1C. In one embodiment, the first sequence of corrugations 2052 and the second sequence of corrugations 2062 are asymmetrical on the partition 2040.

[0055] In one embodiment, as viewed from the angles of Figures 1B-1C, the partition 2040 extends upward from the first base 2050 and the second base 2060. In one embodiment, the TWGA 2000 has a single-crystal 3D dielectric structure on which a conductive surface formed or disposed as described above is formed. In one embodiment, the conductive surface 2070 is coated using a conductive material.

[0056] In one embodiment, at least a portion of the first sequence of corrugations 2052 comprises a dielectric material and / or at least a portion of the second sequence of corrugations 2062 comprises a dielectric material. By strategically incorporating dielectric material as part of the corrugations 2052 and 2062, the radiation of the slot TWGA 2000 can be further controlled.

[0057] As depicted in Figure 1A, the TWG 1000 has an overall waveguide height Hg relative to the outer base surface 500, a base height Hb relative to the outer base surface 500, a sidewall height Hw relative to Hb, and a partition height Hs relative to the first or second base 1050, 1060. In one embodiment, Hg is equal to the sum of Hb and Hw. In another embodiment, Hs is less than Hw.

[0058] Figure 2 depicts a rotated isometric transparent view of the exemplary TWGA 2000 of Figures 1B and 1C. In one embodiment, the TWGA 2000 is fed in a slot waveguide mode via a signal port 2400 at one end 2100 (first end) of the TWGA 2000. The opposite second end 2200 (second end) of the TWGA 2000 has a conductive short circuit 2500, which is electrically connected to a conductive surface 2600 disposed at the upper end 2300 of the TWGA 2000. Visible portions of the first and second sequence ripples 2052, 2062 are depicted in Figure 2 for comparison with the same portions in Figure 1C.

[0059] From the above discussion and description of Figures 1B-1C and 2, it can be understood that the embodiments disclosed in this invention include the following, which may or may not be structural variations of the TWGA 2000 depicted in Figures 1B-1C and 2. In one embodiment, the exposed surfaces of the first sidewall 2020, the second sidewall 2030, and the partition 2040 are not parallel to each other along the length of the groove 2010. When combined with an appropriate draft angle, the TWGA 2000 can be manufactured by molding technology. In one embodiment, at least as depicted in Figures 1B and 1C, the partition 2040 has a height less than the height of the first sidewall 2020 or the second sidewall 2030. In one embodiment, the partition 2040 is disposed at a central position between the first sidewall 2020 and the second sidewall 2030; however, it can be understood from other embodiments disclosed in this invention that such structural variations are possible. In one embodiment, as observed in FIG1C, a first sequence of ripples 2052 alternates rising from left to right along the length of groove 2010 between a first curved path 2011 and a second curved path 2012. Similarly, as observed in FIG1C, a second sequence of ripples 2062 alternates rising from left to right along the length of groove 2010 between a second curved path 2012 and a first curved path 2011. In another embodiment, and as observed in the side view of FIG1C, the first curved path 2011 of groove 2010 is a first waveform (also referred to as element symbol 2011 in this invention) with alternating peaks and valleys, and the first waveform 2011 is a composite of a first smooth waveform multiplied by a first square wave. Likewise, the second curved path 2012 of groove 2010 is a second waveform (also referred to as element symbol 2012 in this invention) with alternating peaks and valleys, and the second waveform 2012 is a composite of a second smooth waveform multiplied by a second square wave. In one embodiment, the peak and valley values ​​of the second smooth waveform and the first smooth waveform are different at all points between the two ends of the slot 2010 and inside the first and second ends 2100 and 2200.

[0060] Figure 3 depicts the analytical modeling performance characteristics of the exemplary TWGA 2000 of Figures 1B, 1C, and 2. The analytical data depicted here were collected at point P, which is sufficiently far from the TWGA 2000 and can be considered as being in the far field. As shown, one embodiment of the TWGA 2000 is configured to achieve a gain of approximately 12 dBi at a positive angle (θ=0) and exhibit specific sidelobe gain peaks and radiation patterns in the azimuth (Ф=0) and vertical (Ф=90) planes (compared to Figure 6).

[0061] Referring now to Figures 4A, 4B, 4C, 5, and 6, where Figures 4A, 4B, and 4C depict views similar to those in Figures 1A, 1B, and 1C, but with a dielectric (Dk) cover 3000 (also referred to as a lens or lid in this invention) on top of the exemplary TWG 1000 and exemplary TWGA 2000, Figure 5 depicts a rotated isometric transparent view of the TWGA 2000 of Figure 4C, which is similar to Figure 2 but has the cover 3000, and Figure 6 depicts the analytical modeling performance characteristics of the exemplary slot waveguide antenna 2000 with the cover 3000 depicted in Figure 5, which is similar to Figure 3. In general discussion, the dielectric cap refers to element symbol 3000 in this invention; when discussed in relation to TWG 1000, the dielectric cap refers to element symbol 3100; and when discussed in relation to TWGA 2000, the dielectric cap refers to element symbol 3200. As shown, the dielectric cap 3200 is disposed on and extends over the top of the slot 2010 of the TWGA 2000, and its width Wc is equal to or greater than the width Wt of the upper opening end of the slot 2010. The thickness, width, and overall shape of the dielectric cap 3100 covering the TWGA 2000 help control the azimuth and vertical electromagnetic radiation pattern and shape emanating from the TWGA 2000. As an example, cap 3100 and / or 3200 may include surface interruptions 3010, such as indentations or protrusions (not shown) depicted in Figures 4A and 4B, to control the azimuth electromagnetic radiation pattern and shape as described above. The dielectric cap 3200 also provides additional design freedom for this antenna, further improving its overall performance. This performance improvement can be envisioned as manifested in improved return loss, improved sidelobe level, and / or any other antenna output characteristics that will be thus affected. In one embodiment, the dielectric cap 3000 has a dielectric constant greater than 1 and equal to or less than 13.

[0062] Figure 5 depicts a rotated isometric transparent view of the exemplary TWGA 2000 of Figures 4B and 4C. Similar to the embodiment of Figure 2, the TWGA 2000 of Figure 5 is fed in a slot waveguide mode via a signal port 2400 on one end 2100 of the TWGA 2000. The opposite end 2200 of the TWGA 2000 has a conductive short circuit 2500, which is electrically connected to a conductive surface 2600 disposed on the upper end 2300 of the TWGA 2000.

[0063] Figure 6 depicts the analytical modeling performance characteristics of an exemplary TWGA 2000 with the cover 3200 of Figure 5. Measurements are taken at point P, sufficiently far from both the TWGA 2000 and the cover 3200 to be considered in the far field. As shown, one embodiment of the TWGA 2000 with the cover 3200 is configured to achieve a gain of approximately 12 dBi at a positive angle (θ=0), exhibiting unique sidelobe gain peaks and radiation patterns in both the azimuth (Ф=0) and vertical (Ф=90) planes (compared to Figure 3). By comparing the sidelobe gain peaks and radiation patterns of Figures 3 and 6, it is evident that the presence of the dielectric cover 3200 has a greater impact on the shape and distribution of electromagnetic radiation in the sidelobes than on the positive angle gain. It can also be observed that the dielectric cover 3200 increases the azimuth radiation gain (Ф=0) over a larger angular range.

[0064] Figures 7A and 7B depict cross-sectional end view and cross-sectional side view of the exemplary TWGA 2000 of Figures 1B and 1C, respectively. The signal feed 4000 is configured to communicate with the signal port 2400 of the first end 2100 of the TWGA 2000.

[0065] Figures 8A, 8B, and 8C depict top view, repeated top view, and final top view of a single and multiple exemplary TWGA 2000s of Figure 2 or Figure 5, respectively, wherein the assembled multiple TWGA 2000s (Figure 8C) form a multi-channel TWGA 2700.

[0066] Figure 9 depicts the analytical modeling performance characteristics of the embodiment shown in Figure 8C, which is a single example of the multi-channel TWGA 2700. By comparing the analytical plots in Figure 9 and Figure 3, it can be seen that the multi-channel TWGA 2700 produces similar gain curves at phi=90, while producing a flatter gain curve at phi=0. The combination of the TWGA profile and dielectric cap allows this multi-channel antenna design to have various shapes.

[0067] Figure 10A depicts a rotating isometric top view of an exemplary TWGA 2000, and Figure 10B depicts its rotating isometric bottom view. This exemplary TWGA 2000 has a feature 5000 that contributes to its manufacturability without substantially impairing its electromagnetic properties. For example, manufacturability feature 5000 may include one or more of the following: (i) a front-projecting manufacturability feature 5010 that does not allow flat surfaces or surface features to stick together during the barrel plating process (i.e., the front-projecting feature disrupts the continuous flatness); (ii) a screw location 5020, which may or may not have a groove (as shown) for receiving a flat-head screw or similar fastener; (iii) a rib feature 5030 to reduce material consumption and warping; (iv) a groove feature 5040 to reduce the tendency to stick during plating; (v) a forming draft angle feature 5050 of equal to or greater than 2 degrees provided on the top side / surface of the TWGA 2000 monocrystalline 3D dielectric structure; (vi) a forming draft angle feature 5060 of equal to or greater than 4 degrees provided on the bottom side / surface of the TWGA 2000 monocrystalline 3D dielectric structure; and (vii) on the TWGA The parting line feature 5070 near the bottom surface of the single-crystal 3D dielectric structure of 2000. Although the present invention proposes specific draft angles, such as 2 degrees and 4 degrees, it is understood that these are merely exemplary draft angles that may be suitable for a particular purpose and surface, and are not intended to limit the invention disclosed herein in any way, and may include any draft angle suitable for manufacturing processes that may include uniaxial molding.

[0068] Referring now to Figures 11-23B, which generally pertain to an exemplary TWGA system having at least one TWGA 2000.

[0069] Figure 11 depicts a conceptual top plan view of a TWGA system 6000 having an antenna-on-package (AoP) feed 6100 on an underlying package 6050, an XY plane, a waveguide transition (which may alternatively refer to a transition region in this invention) 6200 with electromagnetic connections, and transmit and receive antennas 2800 and 2850, respectively, which are electromagnetically connected to the waveguide transition 6200 in the form of a TWGA 2000. In one embodiment, the AoP feed 6100 includes a patch antenna 6150 disposed on the underlying package 6050. In one embodiment, the AoP feed 6100 and / or the patch antenna 6150 have a planar signal feed structure.

[0070] Figure 12 depicts a conceptual end view of the TWGA system 6000 of Figure 11, featuring an AoP feed 6100 on a base package 6050, a YZ plane, a waveguide transition (transition region) 6200, and transmit and receive antennas 2800 and 2850. The dielectric caps 3000 on the TWGAs 2800 and 2950 are also depicted. Solder ball connections 6060 for electrically connecting the TWGA system 6000 to a base PCB (printed circuit board) (not shown) and an integrated RFIC (radio frequency integrated circuit) chip 6070 are also depicted. As depicted, a waveguide signal feed interface 6205 is disposed between the AoP feed 6100 and the waveguide transition region 6200 to form part of the electromagnetic EM transition section 100. In one embodiment, according to the embodiment of the structure disclosed below, each electromagnetic transition section 100 is configured to guide electromagnetic energy from the signal feed interface 6205 to the electromagnetic energy of the open waveguide section 1000 via the transition region 6200 in a waveguide mode. In one embodiment, the waveguide signal feed interface 6205 includes a waveguide input port of the waveguide transition 6200. The AoP feed 6100, or any signal feed disclosed herein, combined with the waveguide signal feed interface 6205, or any signal feed interface disclosed herein, can be considered as the region where electromagnetic signals are emitted to the electromagnetic transition section 100.

[0071] Figure 13 depicts a conceptual side view of the TWGA system 6000 of Figure 11, which has AoP feeds 6100 configured on the base package 6050 in the left and right hand configurations, the XZ plane, the waveguide transition 6200, the transmit and receive antennas 2800 and 2850, and the dielectric cover 3000 on the TWGA 2800 and 2850.

[0072] Figure 14A depicts a transparent side view of an exemplary first transition region 6210 (collectively referred to as element 6200), which transitions (from left to right) to the TWGA 2000 in the form of a ridge waveguide 1100; Figure 14B depicts an end view of the first transition of Figure 14A; and Figure 14C depicts the electromagnetic performance characteristics of an embodiment of Figure 14A. Here, the AoP feed 6100 is located centrally between the lower ridge (see h1) and the upper ridge (see h3), and the first transition 6210 is similar to the TWG 1000 described above, except that it has a partition 1041 similar to the partition 1040 described above. The partition 1041 slopes upward from port -1 6300 (the analytical port used for analytical modeling) on ​​the upper left side of the first transition 6210 to TWGA 2000 on the upper right side of the first transition 6210. Its overall height varies from h1 to h2 relative to the base 500, where h2 is greater than h1 in this example. In one embodiment, H1 is also greater than H2. As depicted, the height of the partition 1041 increases from port -1 6300 to TWGA 2000, where h2 + H2 is greater than h1 + H1. As depicted and similar to Figure 12, a signal feed interface 6205 is disposed between the AoP feed 6100 and the first transition region 6210 to form part of the electromagnetic transition portion 100, which also includes a ridge waveguide 1100. As depicted, port-2 6400 (the analytical port used for analytical modeling) is depicted on the right side of the TWGA 2000. The analytical purpose of ports-1 6300 and 6400 in this invention is to analyze the S-matrix network parameters S11 and S21, as shown in the S-matrix diagram (db) depicted in Figure 14, which shows the low electromagnetic reflection from input port 6300, S11, and the high electromagnetic transmission between input port 6300 and output port 6400, S21, both of which are ideal performance characteristics of the embodiments disclosed in this invention. As depicted, favorable return loss, S11, and electromagnetic transmission, S21, are observed at frequencies of 75 GHz or higher.

[0073] Further regarding Figure 14A, the functional relationship between the partition height (i.e., (h1, H1)) and (h2, H2) can be linear or quadratic, depending on the relative values ​​of the (h1, H1) and (h2, H2) pairs.

[0074] Figure 15A depicts a transparent rotational isometric view of an exemplary second transition 6220 disposed between the rectangular waveguide 900 and the TWGA 2000; and Figure 15B depicts the electromagnetic performance characteristics of the embodiment of Figure 15A. As depicted, the second transition 6220 of Figure 15 is structurally similar to the first transition 6210 of Figure 14 as described above, and is also in the form of a ridge waveguide 1200, but has the following differences. Here, the second transition 6220 has a partition 1042 similar to the partition 1041 as described above, but wherein the partition 1042 is inclined upward from the height H1 of the rectangular waveguide 900 (as depicted in Figure 15) at 0 (see, for example, Figure 14) to the height H2 of the TWGA 2000 (as depicted in Figure 15). Another difference between the second transition 6220 and the first transition 6210 is that the first and second bases 105, 1060 are not inclined. Similar to the embodiment in Figure 14, Figure 15 depicts ports -1 6300 and -2 6400. The analytical purpose of these ports in this invention is to analyze the return losses S11 and S21 depicted in the S-matrix diagram (db) in Figure 15, which shows low electromagnetic reflection from input port 6300, S11, and high electromagnetic transmission between input port 6300 and output port 6400, S21. Both are ideal performance characteristics of the embodiment disclosed in this invention. As depicted, favorable return loss S11 and electromagnetic transmission S21 are observed at frequencies of 60 GHz or higher.

[0075] Referring now to Figures 16A-23B, these figures illustrate various embodiments of transitions consistent with the embodiments disclosed in this invention.

[0076] Figure 16A depicts a top block diagram view of an exemplary third transition 6230 in the form of a waveguide with a 90-degree bend 6202 between input port-1 6300 and output port-2 6400; and Figure 16B depicts the electromagnetic performance characteristics of the embodiment of Figure 16A. As depicted, favorable return loss, S11, and electromagnetic transmission, S21, are observed at frequencies of 80 GHz or higher.

[0077] Figure 17A depicts a transparent side view of an exemplary fourth transition 6240 in the form of a rectangular waveguide, disposed between patch 6150 and TWGA 2000 (not shown). In one embodiment, patch 6150 is disposed on package 6050 to provide AoP feed 6100. Figure 17B depicts a top plan view of the embodiment of Figure 17A. Figure 17C depicts the electromagnetic performance characteristics of the embodiments of Figures 17A and 17B. As depicted, favorable return loss, S11, and electromagnetic transmission, S21, are observed at a frequency of approximately 79 GHz.

[0078] Figure 18 depicts a block diagram side view of an exemplary conceptual system 6000, which includes a patch 6150 disposed on a base package 6050, a waveguide transition region 6200 with a bend 6202 and a transition loss estimated at 0.7 dB, a TWG 1000 with a loss estimated at 0.1 dB / inch, and a radiating element in the form of a TWGA 2000, all of which are electromagnetically coupled to each other. As depicted, and similar to other embodiments disclosed in this invention, a signal feed interface 6205 is disposed between the patch 6150 and the waveguide transition region 6200 to form a portion of an electromagnetic transition section 100. In one embodiment, each electromagnetic transition section 100 is configured to couple electromagnetic energy from the signal feed interface 6205 through the transition region 6200 to a waveguide mode that guides the electromagnetic energy, and then guide the electromagnetic energy to the TWGA 2000.

[0079] Figure 19 depicts exemplary analytical modeling results of the (S21) transmission loss versus frequency for an exemplary ½-inch TWG 1000. Figure 19 illustrates the correlation between (S21) transmission loss and metal conductivity. Al represents aluminum, and different curves represent the decrease in (S21) transmission loss (i.e., relative to the conductivity of aluminum) for different metals.

[0080] Figures 20A and 20B depict exemplary top block diagram plan views of a conceptual model for controlling radiation at a dielectric discontinuity of a TWGA 2000 having bases 2050, 2060 separated by a partition 2040, where the bases 2050, 2060 may or may not have curved paths 2011, 2012 with corrugations 2052, 2062, but do indeed include discrete dielectric radiation elements 2001, 200, having different dielectric constants along the electromagnetic wave propagation direction. Comparing the embodiments of Figures 20A and 20B, each radiation element 2001, 2002 may be separated by air to provide individual radiation elements (Figure 20A), or may be connected by an intervening dielectric medium 2003 (see detail - 20.1) to provide a single unit structure (Figure 20B), as depicted in detail - 20.1, the individual radiation elements 2001, 2002 may be composed of different dielectric constants, these dielectric constants having different Dk values in the electromagnetic wave propagation direction, and in one embodiment may vary according to the following dielectric constant value pattern: Dk1 - Dk2 - Dk3 - Dk2 - Dk1. However, in one embodiment, Dk1 < Dk2 < Dk3, and the Dk values need not follow an increasing or decreasing order, only the adjacent discrete Dk values need to be different. As depicted in detail - 20.2, the intervening dielectric medium 2003 has a dielectric constant value Dk4, which is distinct from Dk1 to Dk3. In one embodiment, Dk4 is significantly less than any of Dk1, Dk2, and Dk3, and the dielectric constant difference between Dk4 and any of Dk1, Dk2, and Dk3 is at least 3.

[0081] Figures 21A, 21B, and 21C depict a rotated isometric transparent view, a transparent top view, and a transparent side view of the first patch-to-slot waveguide transition 6255, respectively. The E-polarization (Ē) of patch 6150 is parallel to the partition 1040, and a ridge waveguide 6256 is disposed between patch 6150 and slot-to-waveguide 6257, which together form the first patch-to-slot waveguide transition 6255. Here, slot-to-waveguide 6257 includes a bend 6258, which does not radiate electromagnetic energy as long as symmetry is maintained along the cross-section of the slot-to-waveguide. The partition 1040 maintains a constant wave impedance along the bend by traversing its profile, which can be achieved according to an embodiment of the structure disclosed in this invention. Figure 21A also depicts an input port 6300 and an output port 6400, which are used for analytical modeling purposes to establish the performance characteristics depicted in Figure 23, as discussed below. In the embodiment of Figure 21A, patch 6150 is fed from one side of the waveguide by a microstrip line (generally referring to element symbol 4000), which is edge-dependent on patch 6150 and aligned with separator 1040, generating an ideal E-polarization parallel to separator 1040. Appropriate electrical gaps are provided to allow the microstrip to connect to patch 6150 without short-circuiting, and the impedance of the stripline is the same as and matched to the feed line. Alternatively, patch 6150 of Figure 21A can also be fed from the bottom via a coaxial port without substantially altering the design. As depicted in Figure 21C, and similar to other embodiments disclosed herein, signal feed interface 6205 is disposed between patch 6150 and ridge waveguide 6256 to form part of electromagnetic transition portion 100, which also includes slot waveguide 6257. In one embodiment, each electromagnetic transition section 100 is configured to couple electromagnetic energy from the signal feed interface 6205 to a guided waveguide mode of electromagnetic energy from the slot waveguide 6257 via the ridge waveguide 6257, and then guide the electromagnetic energy to the TWGA 2000 (not specifically shown in Figure 21C).

[0082] Figures 22A, 22B, and 22C depict rotated isometric transparent views of the second patch-to-slot waveguide transition 6260 at different levels of detail, wherein the E-polarization of patch 6150 is perpendicular to the separator 1040. As can be seen from Figures 22A-22C, the signal probe 6160 is positioned at the edge relative to patch 6150 (i.e., the signal probe 6160 is positioned close to the edge of patch 6150) and offset to the side from the separator 1040 (i.e., the signal probe 6160 is not in a straight line with the separator 1040 as in Figures 21A-21C) to produce an ideal E-polarization perpendicular to the separator 1040.

[0083] It is conceivable that the geometry of Figures 21A-21C and 22A-22C is castable or moldable, and includes appropriate draft angles that would typically be included by one of ordinary skill in the art of casting or molding techniques suitable for the purposes disclosed herein.

[0084] Figure 23 depicts the analytical performance characteristics of the patch-to-slot waveguide transition 6255 depicted in Figure 21A, specifically the S(1, 1) and S(1, 2) characteristics.

[0085] Referring now to Figures 24-29, which generally pertain to exemplary feed configurations for exemplary waveguide antenna systems.

[0086] Figure 24 depicts an exemplary waveguide antenna system 7000, similar to, for example, the TWGA system 6000 of Figure 11, wherein similar components are numbered the same, featuring open waveguides 1000, 1500 and slotted waveguide antennas 2800, 2850, and configured for use in an on-pack antenna 6100 application. The ideal electromagnetic structure of this system 7000 can be implemented in series using a low-loss waveguide or transmission line feed. As depicted, the open waveguide can be an open TWG1000 without any bends, or an open TWG1500 with one or more bends 1520. This configuration may be advantageous for use in automotive radar antennas, which are ideally positioned relatively far from the radar MMIC, where manufacturing and implementation costs and complexities need to be considered. The general form of this ideal electromagnetic structure is that open waveguides 1000 and 1500 (collectively referred to as element 1000) feed to slot waveguide antennas 2000, 2800, and 2850 (collectively referred to as element 2000). These two elements are very different from each other, because the former aims to confine all electromagnetic energy to its vicinity, while the latter aims to rapidly convert the electromagnetic energy at its feed point into radiation. This is depicted in Figures 25A and 25B, which illustrate the basic differences between the open waveguide 1000 (see Figure 25A) and the slot waveguide antenna 2000 (see Figure 25B) in block diagram form. This can be implemented in system 7000 of Figure 24. The fundamental difference between these two components (i.e., the open waveguide and the slotted waveguide antenna) is the type of electromagnetic wave each structure can support: the pilot wave of waveguide 1000 (input power equal to P1, and output power equal to (substantially equal to) P1), and the slotted wave of antenna 2000 (input power equal to P1, power radiation equal to (substantially equal to) P1, and output power equal to (substantially equal to) zero). As depicted in FIG24, and similar to other embodiments disclosed in this invention, the electromagnetic transition portion 100 includes a waveguide transition region 6200 and a TWG 1000, and is configured to couple electromagnetic energy from the signal feed interface 6205 to the pilot waveguide mode of electromagnetic energy of the TWG 1000 via path 6150, and then guide the electromagnetic energy to the TWGA 2000.

[0087] Referring now to Figure 26, an example of a pilot wave is depicted. A pilot wave is a wave with a given propagation constant. The wave, in which , and This is a traditional Cartesian coordinate unit vector, where each wavenumber kx, ky, and kz is a complex number, determined by the following formula: k = -iγ = β - iα, where β represents the phase response of the waveguide / antenna, α represents the amount of slotting across the waveguide / antenna, and γ refers to the propagation constant. Along the z-axis, kz is purely imaginary (except for material losses), and the propagation constant (ky) along the transverse direction of the waveguide interval is purely real (fading away). On the other hand, the propagation constant kz of a slotted waveguide antenna is complex, where the real part indicates the radiation loss. The transverse propagation is also complex, indicating that these waves will radiate.

[0088] By definition, a guided wave does not radiate and can be obtained in various ways. For example, a rectangular dielectric waveguide confines energy within its dielectric material, or a rectangular metallic waveguide confines energy within its metallic walls. An open waveguide is simply a metallic structure that guides the wave and is open at one or more of its ends or sides. The only requirement for an open waveguide 1000 is that it must support guided waveguide modes. As depicted in Figure 27, a trench waveguide 1015 with dimensions a1, a2, and b is an example of an open waveguide. The main advantages of this type of waveguide are its low-loss properties and potentially cost-effective manufacturing method. The electric field guiding mode of the trench waveguide 1015 is indicated by arrow Ē in Figure 27.

[0089] The open waveguide 1000 is a natural-guiding structure used for electromagnetic coupling and feeding to the slot waveguide antenna 2000. The slot waveguide antenna operates by appropriately designing the leakage (alpha) and phase response (beta) across the antenna (see, for example, the examples of alpha α and beta β in Figure 26). Both can be designed to give the radiated beam certain characteristics, namely directionality, beamwidth, sidelobe level, and shape. Figures 28A, 28B, and 28C depict examples of this type of antenna structure with an open waveguide 1000 electromagnetically coupled to and fed to the slot waveguide antenna 2000. The figures show a top view, a front transparent view, and a side transparent view of the open slot waveguide 1000 electromagnetically coupled to and fed to the slot waveguide antenna 2000, respectively. Its radiation performance characteristics are depicted in Figure 29. As can be seen at least in Figure 28A, the sidewalls 1020 and 1030 of waveguide 1000 have no electromagnetic interface features, while the sidewalls 2020 and 2030 of slot waveguide antenna 2000 include electromagnetic radiation enhancement features 2004 (e.g., equivalent to corrugations 2052 and 2062), which are configured to provide the required radiation loss by slot waveguide antenna 2000.

[0090] Referring now to Figures 30-31 and 33-50, which generally relate to exemplary waveguide transmitting structures and associated transition regions for the exemplary waveguide antenna system disclosed in this invention, and exemplary waveguide radiation correction features.

[0091] Figure 30 is a block diagram top plan view depicting an exemplary transition region 6200 between a signal feed 4000 in the form of an electromagnetic transmission line 4010 on a base package 6050, such as a printed circuit board (PCB), and an open waveguide 1000. In one embodiment, the PCB transmission line may be a coplanar waveguide (CPW), microstrip, or stripline. Here, the transition region 6200 is fed to the open waveguide 1000 in the form of an edge feed.

[0092] Figure 31 is a block diagram side view depicting another exemplary transition region 6200 between a signal feed 4000 in the form of an electromagnetic transmission line 4020 on a base package 6050, such as a PCB, and an open waveguide 1000. In one embodiment, the PCB transmission line may be a substrate integrated waveguide (SIW), a stripline, or a CPW. Here, the transition region 6200 is in the form of capacitive or inductive coupling via a slot / hole 4030 on the conductive surface 4040 of the PCB transmission line 4020 near the signal input terminal 1080 of the open waveguide 1000. As depicted in Figure 31, and similar to other embodiments disclosed in this invention, a signal feed interface 6205 is disposed between the signal feed 4000 and the transition region 6200 to form a portion of an electromagnetic transition section 100, which also includes the open waveguide 1000. In one embodiment, each electromagnetic transition section 100 is configured to couple electromagnetic energy from the signal feed interface 6205 through the transition region 6200 to a waveguide mode that guides electromagnetic energy from the open waveguide section 1000, and then guides the electromagnetic energy to the TWGA 2000 (not specifically shown in Figure 31).

[0093] Figure 32A depicts a rotated isometric transparent view of the bend 1500 in the open waveguide, Figure 32B depicts a top plan view of the bend 1500 in the open waveguide, and Figures 32C and 32D depict the relevant electromagnetic performance characteristics of the embodiments of Figures 32A and 33B. This helps to illustrate that, without correction, the bend 1520 in the open waveguide may generate undesirable electromagnetic radiation. As long as the symmetry within the waveguide is maintained, the open waveguide can ideally guide electromagnetic waves. Therefore, a bend in the waveguide will, in principle, generate an infinite number of modes of different intensities, some of which are undesirable radiation modes. To compensate for this, one or more of the following methods can be used to minimize the stronger, redundant radiation modes generated at the bend. Strategically placed electromagnetic radiation absorbers; electromagnetic radiation suppression mechanisms installed within waveguides; structural modifications to the height of waveguide partitions, such as gradually reducing the height of the partitions from their original height to a smaller height within the bend, thereby guiding electromagnetic waves by the distance between the partition and the wall; structural modifications to the inner surface of open waveguides that affect phase velocity and / or waveguide impedance, keeping the phase velocity and / or waveguide impedance constant or substantially constant along one path of the bend; and other structural modifications to the internal characteristics of the slotted waveguide within the bend to maintain the phase velocity and / or waveguide impedance constant along the bend.

[0094] Referring to FIG33 in conjunction with FIG32A and FIG33, a block diagram cross-sectional longitudinal view is depicted through a bend in the dual-channel open waveguide 1600, wherein an electromagnetic radiation absorber 1610 is disposed on a corresponding dielectric cap 3000 having a dielectric constant Dk value greater than 1, which helps to eliminate or substantially eliminate unwanted electromagnetic radiation from the bend 1520 and improve channel-to-channel separation. Although the exemplary embodiment of the present invention depicts an electromagnetic radiation absorber 1610 disposed along the bend 1520 of the open waveguide 1500, it is understood that the electromagnetic radiation absorber may be strategically placed in other locations of the antenna system disclosed herein to suppress unwanted radiation. The radar absorbing material used is not limited to a composite material, i.e., a combination of radar absorbing material and polymer binder. Exemplary radar absorbing materials may be fibrous or granular, or other forms. For example, radar absorbing materials may be carbon fibers, carbon nanotubes, carbon black, polyaniline, ferrite, or similar materials. Exemplary polymers used as adhesives may include epoxy resins, neoprene rubber, polyesters such as polybutylene terephthalate (PBT), or similar materials. The amount of radar-absorbing material is selected to provide the desired radar absorption without significantly adversely affecting the desired properties of the composite material, such as processability, and its amount may be, for example, 1 to 40 volume percent, or 5 to 30 volume percent, or 10 to 20 volume percent, each based on the total volume of the composite material. Other additives known in the art may also be present. An exemplary material suitable as one of the electromagnetic radiation absorbers is polybutylene terephthalate (PBT) containing 15 volume percent carbon fibers.

[0095] Referring to Figures 34A and 34B in conjunction with Figure 32A, Figures 34A and 34B depict two versions of block diagram cross-sectional longitudinal views showing a bend 1520 in a dual-channel open waveguide 1600, in which an electromagnetic radiation choke (quarter-wave groove) 1620 is provided, which helps to eliminate or substantially eliminate unwanted electromagnetic radiation from the bend and improve channel-to-channel separation. As depicted, an exemplary choke can be formed at the bend of the open waveguide by creating quarter-wave grooves on the sidewalls 1020 and 1030 of the waveguide. Since electromagnetic radiation leaves the waveguide primarily via a parallel plate pattern, suppressing this pattern by using a quarter-wave choke groove helps to suppress unwanted radiation. As depicted, the quarter-wave choke 1620 may be cut horizontally (Fig. 34A), vertically (Figs. 34A and 34B), or both horizontally and vertically (Fig. 34A) into one or both of the sidewalls 1020 and 1030 of the open waveguide 1600. It may be located in the bend 1520, or strategically elsewhere in the antenna system as disclosed in this invention, to suppress unwanted radiation.

[0096] Referring to Figures 35A, 35B, and 35C, and in conjunction with Figures 32A, Figures 35A, 35B, and 35C depict three versions of block diagram cross-sectional longitudinal views. These views show the electromagnetic radiation chokes 1621, 1622, and 1623 at the bend 1520 in the single-channel open waveguide 1500, which can replace the chokes depicted in Figures 34A and 34B. The chokes used in this replacement include: a quarter-wavelength groove 1621 formed in the draft sidewalls 1020 and 1030 of the slot 1010 (Figure 35A), optionally combined with the cover 3000; a Bragg reflector 1622 dielectric material, or other electromagnetic reflector with total internal reflection characteristics, replacing the dielectric cover 3000; and a dielectric material 1623 with a high dielectric constant (Dk equal to or greater than 6) replacing the dielectric cover 3000.

[0097] Referring to Figures 36A, 36B, 36C, and 36D, and in conjunction with Figure 32A, Figure 36A depicts a rotated isometric transparent view of an open waveguide 1500 having one or more bends 1520 containing modified septa 1040, and Figure 36B depicts a side transparent view of the open waveguide 1500 having one or more bends 1520 containing modified septa 1040, and Figures 36C and 36D depict electromagnetic performance characteristics related to Figures 36A and 36B. Here, the height Hs of the septa 1040 within the waveguide 1500 is structurally modified, for example, by gradually reducing the height of the septa from the original height Hs at both ends of the bend 1520 to a smaller height Hsm within the bend 1520, thereby guiding electromagnetic waves by the septa-to-wall distance 1630. An open slot waveguide with short septa will produce a tightly guided slot mode just above its cutoff frequency. The resulting modes tightly guide electromagnetic waves, with minimal radiation at bends because the modes are tightly confined within the partitions and walls.

[0098] Referring to Figures 37A, 37B, 37C, and 37D, and in conjunction with Figure 32A, Figure 37A depicts a rotational isometric transparent view of an open waveguide 1500 with a bend 1520 containing modified base plate (base) structures 1050 and 1060, while Figure 37B depicts a top plan view of the open waveguide 1500 with a bend 1520 containing modified base plate (base) structures 1050 and 1060. Figures 37C and 37D depict electromagnetic performance characteristics related to Figures 37A and 37B. Here, the inner surface of the open waveguide is structurally modified, affecting the phase velocity and / or waveguide impedance to make the phase velocity and / or waveguide impedance constant or substantially constant along a path at the bend. Since the slot waveguide can be considered as two open rectangular waveguides separated by a partition 1040 (see, for example, Figure 1), the waveguide on the outer side of the bend 1520 (represented by the associated basic element symbol 1060, see Figure 37B) will have a longer path to move than the waveguide on the inner side of the bend 1520 (represented by the associated basic element symbol 1050, see Figure 37B). Therefore, the two waveguide modes do not phase shift along the bend, each generating a small amount of radiation and reaching opposite ends at the bend. However, if the phase velocity of the outer waveguide increases slowly or the phase velocity of the inner waveguide decreases slowly, the two guided waves will phase shift in such a way that their corresponding radiation components cancel each other out. In one embodiment, this is accomplished by slowly tapering the bottom surface (base) 1060 of the waveguide slot 1010 between the partition 1040 and the corresponding sidewalls 1020, 1030, where the tapered profile determines the optimal impedance and the correct compensated phase velocity. In the embodiment depicted in Figure 37A, the bottom surface 1060 of the waveguide groove 1010 on the outer side of the bend 1520 gradually slopes upward from the partition 1040 toward the outer wall 1030. However, it is conceivable that other tapered profiles of either bottom surface 1050, 1060 of the groove 1010 may be suitably adopted to conform to the purpose disclosed in this invention.

[0099] Referring to Figure 38 in conjunction with Figure 32A, Figure 38 depicts a block diagram cross-sectional longitudinal view of the bend 1520 of an open waveguide 1500 having an improved waveguide structure within the bend 1520. Here, further structural modifications are made to the internal features of the slot 1010 of the open waveguide 1500 within the bend 1520, which helps to maintain a constant phase velocity and waveguide impedance along the bend 1520. Examples of such structural modifications may include one or more of the following: variations in the base plate height of one groove (represented by the relevant basic element symbol 1050, see Figure 1A) compared to another groove (represented by the relevant basic element symbol 1060, see Figure 1A); variations in the width W5 of one groove 1050 compared to the width W6 of another groove 1060; variations in the lateral position of the partition 1040 within the groove 1010 to increase the asymmetry of the open waveguide 1500 structure; variations in the thickness W4 of the partition 1040; and variations in the height H4 of the partition 1040. This structural modification may vary along the length of the bend 1520.

[0100] Figure 39A depicts a rotated isometric transparent view of an open waveguide 1500 with a bend 1520 containing modified wall structures 1020 and 1030; Figure 39B depicts a top plan view of the open waveguide 1500 with a bend 1520 containing modified wall structures 1020 and 1030; and Figures 39C and 39D depict electromagnetic performance characteristics related to Figures 39A and 39B. As described above, the modification of the slotted waveguide 1500 within the bend 1520 can be used to adjust the electromagnetic waves on the inner and outer sides of the bend 1520 so that they move in phase with each other, thereby canceling out the corresponding radiation modes within the bend 1520. The modification in the bend 1520 acts as a radiation suppressor, configured to affect the phase velocity and waveguide impedance, thereby keeping the phase velocity and waveguide impedance constant or substantially constant along the path length of at least one bend 1520. As described above, the slot waveguide 1500, particularly the bend 1520, can be considered as two open waveguides: an inner waveguide (denoted by element symbol 1050) located inside the bend 1520, and an outer waveguide (denoted by element symbol 1060) located outside the bend 1520, wherein the outer waveguide has a longer travel path than the inner waveguide. Therefore, without the improvements disclosed in this invention, the two waveguide modes, inner and outer, will not move in phase along the bend, resulting in undesirable radiation along the bend. However, by adjusting the phase velocities of the inner and outer waveguides to make the two waves move in phase, their corresponding radiation modes tend to cancel each other out. Furthermore, by adjusting the impedance of the individual guides, their corresponding radiation modes tend to cancel each other out. An alternative method is to gradually reduce the bottom surface of the groove, the position of the partition within the groove, and the width of the groove, as discussed above in relation to Figures 37A, 37B, and 38. The following will further discuss the parts related to Figures 40A-40E. In Figures 39A and 39B, another method to achieve the desired electromagnetic phase velocity and impedance within the bend 1520 is to pull in the outer wall 1030 to reduce the width of the outer waveguide 1060 within the bend 1520, preferably as shown in Figure 39B. At least one bend 1520's first sidewall refers to the inner sidewall 1020; at least one bend 1520's second sidewall refers to the outer sidewall 1030; a first base 1050 has a first width between the first sidewall 1020 and the partition 1040; a second base 1060 has a second width between the partition 1040 and the second sidewall 1030; and the first width is greater than the second width. An adjustment is achieved by establishing a width difference between the first width of the first base 1050 on the inner side of the bend and the second width of the second base 1060 on the outer side of the bend, such that the two waves move in phase with equal wave impedances and their corresponding radiation modes are canceled out.

[0101] Referring now to Figures 40A-40E in conjunction with Figure 32A, Figure 40A depicts a cross-sectional longitudinal view of the open waveguide 1500 through a block diagram at the bend 1520 outside the open waveguide 1500. Figure 40B depicts an improved version of Figure 40A, in which an inductor is added within the bend 1520 of the open waveguide 1500. Figure 40C depicts an improved version of Figure 40A, in which a capacitor is added within the bend 1520 of the open waveguide 1500. Figures 40D and 40E respectively depict the electromagnetic performance characteristics related to Figures 40B and 40C.

[0102] In the embodiment depicted in conjunction with Figures 40A and 40B, the channel waveguide 1500 has a first depth D1 (depicted in Figure 40A) extending to the first base 1050 and the second base 1060 on the outer side of at least one bend, and a second depth D2 (depicted in Figure 40B) extending to the first base 1050' and the second base 1060' on the inner side of at least one bend; and the first depth D1 is greater than the second depth D2. By adjusting the depths of the first and second bases on the inner side of the bend relative to the respective depths of the outer side of the bend, a change in waveguide inductive impedance can be achieved, and by providing matching impedance through the inductance within the bend, the waves on the inner and outer sides of the bend can be shifted in phase, thereby canceling out their corresponding radiation modes.

[0103] In the embodiment depicted in conjunction with Figures 40A and 40C, the partition 1040 has a first wall thickness T1 on the outer side of at least one bend 1520 and a second wall thickness T2 on the inner side of at least one bend 1520; and the first wall thickness T1 is smaller than the second wall thickness T2. By adjusting the wall thickness of the partition 1040' on the inner side of the bend 1520 and the wall thickness on the outer side of the bend 1520, the capacitance of the waveguide 1500 can be varied, and by providing matching impedance through the capacitance within the bend, the waves on the inner and outer sides of the bend can be shifted in phase, causing their corresponding radiation modes to cancel each other out.

[0104] Referring collectively to Figures 1A-40C, it will be understood that the present invention discloses various embodiments of a particular, which at least conform to, but are not limited to, the following embodiments and / or combinations thereof.

[0105] Sample 1: A waveguide antenna system comprising: an electromagnetic (EM) transition section including a transition region having a signal feed interface and an open waveguide section, the electromagnetic transition section being configured to guide a waveguide mode of electromagnetic energy from the signal feed interface to the open waveguide section via the transition region; and a slotted waveguide antenna section configured and set to radiate electromagnetic energy received from the open waveguide section; wherein the electromagnetic transition section is electromagnetically coupled to the slotted waveguide antenna section, and the electromagnetic transition section is configured to support electromagnetic energy transmitted from the signal feed structure to the slotted waveguide antenna section.

[0106] State 2: The waveguide antenna system as described in State 1, wherein: the electromagnetic transition section is configured to support electromagnetic energy transmitted from the planar signal feed structure to the slot waveguide antenna section.

[0107] Sample 3: A waveguide antenna system as described in either Sample 1 or 2, wherein: the open waveguide segment comprises an open slot waveguide.

[0108] Sample 4: A waveguide antenna system as described in either Sample 1 or 2, wherein: the open waveguide segment comprises an open trench waveguide.

[0109] Sample 5: A waveguide antenna system as described in any one of Samples 1 to 4, wherein: the open waveguide segment has no discontinuities along its respective length; the slotted waveguide antenna portion includes significant discontinuities along its respective length; and the open waveguide segment and the slotted waveguide antenna portion are electromagnetically coupled at an electromagnetic coupling point between them, wherein the change of discontinuity transitions from the absence of discontinuities in the open waveguide segment to the significant discontinuities in the slotted waveguide antenna portion.

[0110] Sample 6: A waveguide antenna system comprising: a plurality of waveguide antenna systems as described in any one of Samples 1 to 5, configured for use in an antenna application.

[0111] Sample 7: A waveguide antenna system comprising: a plurality of waveguide antenna systems as described in any one of Samples 1 to 5, configured for surface mount applications on a printed circuit board.

[0112] Sample 8: A waveguide antenna system as described in any one of claims 6 to 7, wherein: in transmit mode and configuration, each open waveguide segment is configured to receive electromagnetic energy from an antenna element on the package or a surface mount element on a printed circuit board, and to deliver the electromagnetic energy to a corresponding slot waveguide antenna portion; and in receive mode and configuration, each open waveguide segment is configured to receive electromagnetic energy from a corresponding slot waveguide antenna portion, and to deliver the electromagnetic energy to an antenna element on the package or a surface mount element on a printed circuit board.

[0113] Sample 9: An open waveguide signal feed system, comprising: a printed circuit board having a signal feed and a signal feed output; an open waveguide having a signal feed input port; a transition region disposed between the signal feed output and the signal feed input port and communicating with them; wherein the signal feed includes a microstrip, a coplanar waveguide, or a stripline; wherein the signal feed output includes a patch or a probe.

[0114] State 10: An open waveguide signal feed system as described in State 9, wherein: the transition region contains a closed waveguide.

[0115] State 11: An open waveguide signal feed system as described in State 9, wherein: the transition region includes the edge feed between the signal feed output and the signal feed input port.

[0116] Sample 12: An open waveguide signal feed system as described in Sample 9, wherein: the transition region includes an aperture located at the signal feed output, which is directly electromagnetically coupled to the signal feed input port.

[0117] Sample 13: An open waveguide section comprising: at least one bend in a slotted waveguide located in the propagation direction of an electromagnetic wave in the slotted waveguide, the slotted waveguide comprising a slot having first and second opposing sidewalls, a partition disposed between the two, a first base disposed between the first sidewall and the partition, and a second base disposed between the partition and the second sidewall, wherein at least all surfaces of the first sidewall, the second sidewall, the partition, the first base and the second base located within the slot are conductive; and an electromagnetic radiation suppressor strategically configured and set to suppress unwanted electromagnetic radiation that may be emitted from the at least one bend in the absence of such an electromagnetic radiation suppressor.

[0118] Sample 14: An open waveguide section as described in Sample 13, wherein: the electromagnetic radiation suppressor includes electromagnetic radiation absorbing material disposed on the open end of at least one bend in the slotted waveguide.

[0119] Sample 15: An open waveguide section as described in Sample 13, wherein: the electromagnetic radiation suppressor includes an electromagnetic choke mechanism disposed in at least one bend of the slotted waveguide.

[0120] Sample 16: An open waveguide section as described in Sample 15, wherein: the electromagnetic choke mechanism includes at least one quarter-wavelength groove cut out on each of the first and second sidewalls of the slot.

[0121] State 17: An open waveguide section as described in State 16, wherein: the at least one quarter-wavelength trench comprises at least a pair of symmetrically arranged trenches disposed in the first and second sidewalls of the trench.

[0122] Sample 18: An open waveguide segment as described in any one of Samples 16 to 17, wherein: the at least one quarter-wavelength trench comprises a horizontal portion and an adjacent vertical portion.

[0123] Sample 19: An open waveguide segment as described in any one of Samples 16 to 17, wherein: the first and second sidewalls of the trench have inclined sidewalls, and the at least one quarter-wavelength trench is formed on each respective inclined sidewall.

[0124] Sample 20: An open waveguide section as described in Sample 15, wherein: the electromagnetic choke mechanism includes an electromagnetic reflector having total internal reflection (TIR) ​​characteristics, the electromagnetic reflector being disposed in the form of a cap on the upper open end of the at least one bend in the slot waveguide, and extending from the first sidewall to the second sidewall through the at least one bend in the slot, the TIR reflector being composed of a dielectric material having a dielectric constant that varies along the normal direction of the cap, thereby producing total internal reflection.

[0125] State 21: An open waveguide section as described in State 15, wherein: the electromagnetic choke mechanism includes a dielectric material disposed on an open end of at least one bend in the grooved waveguide, and the at least one bend extending from the first sidewall to the second sidewall through the groove, the dielectric material being composed of a dielectric material with a dielectric constant greater than 6.

[0126] Sample 22: An open waveguide section as described in Sample 13, wherein: the electromagnetic radiation suppressor includes a modified septum having a reduced height at the at least one bend, which is lower than the original height of the outer septum at the at least one bend.

[0127] State 23: An open waveguide section as described in State 22, wherein: the modified partition gradually decreases in size from the original height to the reduced height.

[0128] Sample 24: An open waveguide section as described in Sample 13, wherein: the electromagnetic radiation suppressor includes a modified inner surface of the groove in the at least one bend, the inner surface being configured to affect the phase velocity and / or waveguide impedance such that the phase velocity and / or waveguide impedance are constant or substantially constant along the path length of the at least one bend.

[0129] Sample 25: an open waveguide section as described in claim 24, wherein: the modified inner surface of the groove includes the tapered bottom surface of the waveguide groove between the partition and at least one of the first sidewalls and the second sidewall.

[0130] State 26: An open waveguide section as described in State 25, wherein: the tapered bottom surface gradually decreases in size from the partition to the outer sidewall outside the at least one bend.

[0131] State 27: An open waveguide segment as described in State 24, wherein: the modified inner surface of the slot includes the height difference between the first base of the slot and the second base of the slot.

[0132] Sample 28: An open waveguide section as described in Sample 24, wherein the groove includes a first groove portion between the first sidewall and the partition, and a second groove portion between the second sidewall and the partition, wherein the first groove portion is disposed on the inner curvature of the at least one bend, and the second groove portion is disposed on the outer curvature of the at least one bend, and further wherein: the modified inner surface of the groove includes the width difference between the first groove portion and the second groove portion.

[0133] Sample 29: An open waveguide section as described in Sample 24, wherein: the modified inner surface of the slot includes the lateral positioning of the partition in at least one bend, the lateral positioning being asymmetrical relative to the first and second sidewalls.

[0134] State 30: an open waveguide section as described in State 24, wherein: the modified inner surface of the groove includes the septum thickness in the at least one bend, the septum thickness being different from the septum thickness outside the at least one bend.

[0135] State 31: An open waveguide section as described in State 24, wherein: the first sidewall is the inner sidewall of the at least one bend; the second sidewall is the outer sidewall of the at least one bend; the first base has a first width between the first sidewall and the partition, the width defining a first groove portion disposed on the inner curvature of the at least one bend; the second base has a second width between the partition and the second sidewall, the width defining a second groove portion disposed on the outer curvature of the at least one bend; and the first width is greater than the second width.

[0136] State 32: An open waveguide section as described in State 31, wherein: the cross-section of the second groove portion inside the at least one bend has a width smaller than the width of the corresponding cross-section outside the at least one bend, which helps to increase the capacitance of the second groove portion inside the at least one bend.

[0137] State 33: An open waveguide segment as described in any one of states 31 to 32, wherein: the cross-section of the first groove portion inside the at least one bend has a width greater than the width of the corresponding cross-section outside the at least one bend, which helps to reduce the capacitance of the first groove portion inside the at least one bend.

[0138] State 34: an open waveguide segment as described in State 32, wherein: the cross-sectional width of the second groove portion inside the at least one bend has a width dimension as low as 200 micrometers or less.

[0139] State 35: An open waveguide section as described in State 33, wherein: the width dimension of the cross-sectional width of the first groove portion inside the at least one bend is not greater than half the wavelength of the operating frequency of the open waveguide section inside the at least one bend.

[0140] State 36: An open waveguide section as described in State 24, wherein: the slot waveguide has a first depth to the first base and the second base outside the curvature at the at least one bend, and a second depth to the first base and the second base inside the curvature at the at least one bend; and the first depth outside the curvature at the bend is greater than the second depth inside the curvature at the bend.

[0141] State 37: An open waveguide section as described in any one of States 24 and 36, wherein the groove includes a first groove portion between the first sidewall and the partition, and a second groove portion between the second sidewall and the partition, and further wherein: the cross-section of the second groove portion inside the at least one bend has a depth less than the corresponding cross-section depth outside the at least one bend, which helps to increase the impedance of the second groove portion inside the at least one bend and increase the phase velocity of the electromagnetic wave, when present, propagating through the second groove portion.

[0142] State 38: An open waveguide section as described in State 37, wherein: the cross-section of the first groove portion inside the at least one bend has a depth greater than the corresponding cross-section depth outside the at least one bend, which helps to reduce the impedance of the first groove portion inside the at least one bend and reduce the phase velocity of electromagnetic waves propagating through the first groove portion when it is present.

[0143] State 39: An open waveguide section as described in State 37, wherein: the cross-sectional depth of the second groove portion is at least as deep as the height of the partition.

[0144] Sample 40: An open waveguide section as described in Sample 38, wherein: relative to the cross-sectional depth of the first groove portion outside the at least one bend, the cross-sectional depth of the first groove portion inside the at least one bend increases by at most one-quarter wavelength of the operating frequency of the open waveguide section inside the at least one bend.

[0145] State 41: An open waveguide section as described in State 24, wherein: the partition has a first wall thickness on the outer side of the at least one bend and a second wall thickness on the inner side of the at least one bend; and the first wall thickness is less than the second wall thickness.

[0146] Sample 42: An open waveguide antenna, comprising: a slot having first and second opposing sidewalls, a partition disposed therebetween, a first base disposed between the first sidewall and the partition, and a second base disposed between the partition and the second sidewall; wherein at least one or more surfaces of the first sidewall, the second sidewall, the partition, the first base, and the second base located within the slot are conductive; wherein the first base has a first sequence of corrugations, which are longitudinally arranged along the length direction of the slot; wherein the first sequence of corrugations alternately and sequentially follow a first bending path and a second bending path, the second bending path being asymmetrical to the first bending path; wherein the second base has a second sequence of corrugations, which are longitudinally arranged along the length direction of the slot; wherein the second sequence of corrugations alternately and sequentially follow the second bending path and the first bending path; wherein the first bending path and the second bending path alternately from one side of the partition to the other side of the partition along the length of the slot.

[0147] State 43: An open waveguide antenna as described in State 42, wherein: all surfaces of the first base and the second base located within the slot are conductive.

[0148] State 44: an open waveguide antenna as described in State 42, wherein at least a portion of the first sequence of ripples comprises a dielectric material.

[0149] State 45: An open waveguide antenna as described in State 42, wherein at least a portion of the second sequence of ripples comprises a dielectric material.

[0150] Sample 46: An open waveguide antenna as described in any one of Samples 42 to 45, wherein: the slot is an integral non-conductive structure on which the conductive surface is formed.

[0151] Sample 47: An open waveguide antenna as described in any one of Samples 42 to 46, wherein: the partition extends upward from the first and second bases.

[0152] Sample 48: An open waveguide antenna as described in any one of Samples 42 to 47, wherein: the exposed surfaces of the first sidewall, the second sidewall, and the partition are not parallel to each other along the length of the slot.

[0153] Sample 49: An open waveguide antenna as described in any one of Samples 42 to 48, wherein: the height of the partition is less than the height of the first sidewall or the second sidewall.

[0154] Sample 50: An open waveguide antenna as described in any one of Samples 42 to 49, wherein: the partition is disposed at the center between the first sidewall and the second sidewall.

[0155] State 51: An open waveguide antenna as described in any one of states 42 to 50, wherein the first sequence of ripples and the second sequence of ripples are asymmetrical around the partition.

[0156] Sample 52: An open waveguide antenna as described in any one of Samples 42 to 51, wherein: along the length of the slot, the first sequence of ripples alternates between the first curved path and the second curved path.

[0157] State 53: An open waveguide antenna as described in any one of states 42 to 52, wherein: along the length of the slot, the second sequence of ripples alternates between the second curved path and the first curved path.

[0158] Sample 54: An open waveguide antenna as described in any of Samples 42 to 53, wherein: as observed in the side view of the slot, the first curved path is a first waveform with alternating peaks and valleys, the first waveform being a composite of a smooth waveform multiplied by a square wave.

[0159] State 55: An open waveguide antenna as described in State 54, wherein: as observed in the side view of the conductive groove, the second curved path is a second waveform with alternating peaks and valleys, the second waveform being a composite of a smooth waveform multiplied by a square wave.

[0160] State 56: An open waveguide antenna as described in State 55, wherein the peak and valley values ​​of the second smooth waveform and the first smooth waveform are different at all points between and inside the slot.

[0161] Sample 57: An open waveguide antenna as described in any one of Samples 42 to 56, further comprising: a dielectric cap disposed on the slot, covering and extending at least a portion of the length of the slot, and extending through the slot from the first sidewall to the second sidewall, the dielectric cap being composed of a dielectric material having a dielectric constant greater than 1.

[0162] Sample 58: An open waveguide antenna as described in Sample 57, wherein: the outer surface of the dielectric cover has a longitudinal indentation that extends along the length of the groove.

[0163] Sample 59: An open waveguide antenna as described in Sample 58, wherein: the longitudinal indentation is located at the center of the length of the slot.

[0164] Sample 60: An open waveguide antenna as described in any one of Samples 58 to 59, wherein: the longitudinal indentation has a concave cross-sectional profile.

[0165] State 61: An open waveguide antenna as described in State 60, wherein: the concave cross-sectional profile can be represented by a polynomial curve.

[0166] Sample 62: An open waveguide antenna as described in Sample 57, wherein: the outer surface of the dielectric cover has a longitudinal protrusion that extends along the length of the groove.

[0167] Sample 63: An open waveguide antenna as described in Sample 62, wherein: the longitudinal protrusion is located at the center of the length of the slot.

[0168] Sample 64: An open waveguide antenna as described in any one of Samples 62 to 63, wherein: the longitudinal protrusion has a convex cross-sectional profile.

[0169] State 65: An open waveguide antenna as described in State 64, wherein: the convex cross-sectional profile can be represented by a polynomial curve.

[0170] Sample 66: An open waveguide antenna as described in Sample 57, wherein: the inner surface beneath the dielectric cover has a longitudinal indentation that extends along the length of the groove.

[0171] Sample 67: An open waveguide antenna as described in Sample 66, wherein: the longitudinal indentation is located at the center of the length of the slot.

[0172] Sample 68: An open waveguide antenna as described in any of Samples 66 to 67, wherein: the longitudinal indentation has a concave cross-sectional profile.

[0173] State 69: An open waveguide antenna as described in State 68, wherein: the concave cross-sectional profile can be represented by a polynomial curve.

[0174] Sample 70: An open waveguide antenna as described in Sample 57, wherein: the inner surface beneath the dielectric cover has a longitudinal protrusion that extends along the length of the groove.

[0175] Sample 71: An open waveguide antenna as described in Sample 70, wherein: the longitudinal protrusion is located at the center of the length of the slot.

[0176] Sample 72: An open waveguide antenna as described in any one of Samples 70 to 71, wherein: the longitudinal protrusion has a convex cross-sectional profile.

[0177] State 73: An open waveguide antenna as described in State 72, wherein: the convex cross-sectional profile can be represented by a polynomial curve.

[0178] Sample 74: An open waveguide antenna as described in any one of Samples 42 to 73, having a malleable construction, wherein: the malleable construction includes one or more of the following: (i) a front-side manufacturing feature that does not allow flat surface features to adhere during the roller plating process; (ii) one or more screw positions incorporated in the construction; (iii) a shell construction to reduce material consumption and warping; (iv) an integrally formed groove to reduce adhesion tendency during the plating process; (v) a forming draft angle of equal to or greater than 2 degrees provided on the top side; (vi) a forming draft angle of equal to or greater than 4 degrees provided on the bottom side; and (vii) a forming parting line located near the bottom surface.

[0179] Sample 75: An open waveguide antenna as described in any one of Samples 42 to 73, wherein: the slot is a die-cast construction.

[0180] Sample 76: An open waveguide antenna as described in any one of Samples 42 to 73, wherein: the slot is an injection-molded plastic structure.

[0181] Sample 77: An open waveguide antenna as described in Sample 76, wherein: the injection-molded plastic structure is metallized to provide a conductive surface thereon.

[0182] Sample 78: An open waveguide antenna system comprising an open waveguide antenna as described in any one of Samples 42 to 77, the open waveguide antenna system further comprising: a signal feed port disposed at one end of the slot; and an electrical short circuit disposed at the second opposite end of the slot.

[0183] Sample 79: The open waveguide antenna system as described in Sample 78 further includes: a conductive surface disposed near the upper end of the slot; wherein the electrical short circuit is electrically connected to the conductive surface; and wherein the conductive surface has a hole configured to expose the upper end of the slot for electromagnetic coupling thereto.

[0184] Sample 80: An open waveguide antenna system as described in any of Samples 78 to 79, wherein: the patch-to-slot guide transition is configured such that the E-polarization of the patch is parallel to the partition.

[0185] Sample 81: An open waveguide antenna system as described in any of Samples 78 to 79, wherein: the guide transition from patch to slot is configured such that the E-polarization of the patch is perpendicular to the partition.

[0186] Sample 82: A multi-channel open waveguide antenna comprising: a plurality of open waveguide antennas as described in any one of Samples 42 to 63 arranged side by side, wherein the center-to-center spacing between adjacent slots is equal to or greater than λ / 2 and equal to or less than 10 times λ, wherein λ is the wavelength at the operating frequency of the multi-channel open waveguide antenna.

[0187] Sample 83: A multi-channel open waveguide antenna as described in Sample 82, wherein: the side-by-side configuration is a multi-integral structure.

[0188] Sample 84: A multi-channel open waveguide antenna as described in any one of Samples 82 to 83, wherein: the side-by-side configuration includes a plurality of receiver channels and a plurality of transmitter channels.

[0189] Sample 85: A multi-channel open waveguide antenna as described in Sample 84, wherein: the plurality of receiver channels includes at least 4 receiver channels.

[0190] Sample 86: A multi-channel open waveguide antenna as described in Sample 84, wherein: the plurality of transmitter channels includes at least 3 transmitter channels.

[0191] Sample 87: An open waveguide antenna system, comprising: a signal feed; an electromagnetic transition portion including a signal feed interface disposed at a first end of the electromagnetic transition portion and communicating electromagnetically with the signal feed, and an open waveguide section having a second end opposite to the first end; and an open waveguide antenna according to any one of Samples 42 to 61, configured to communicate electromagnetically with the second end of the electromagnetic transition portion; wherein the electromagnetic transition portion is configured to couple electromagnetic energy from the signal feed to the signal feed interface, to a pilot waveguide mode of the electromagnetic energy, and to the open waveguide section and the open waveguide antenna.

[0192] Sample 88: An open waveguide antenna system as described in Sample 87, wherein: the signal feed includes any one of the following: an encapsulated antenna; a circuit board structure; a patch; a signal probe; a signal loop; and a signal aperture.

[0193] Sample 89: An open waveguide antenna system comprising: an on-package antenna; an open waveguide antenna according to any one of Samples 42 to 61; and an electromagnetic transition device configured to communicate electromagnetic signals with and between the on-package antenna and the open waveguide antenna.

[0194] State 90: An open waveguide antenna system as described in State 89, wherein: the electromagnetic transition comprises a ridge waveguide.

[0195] Sample 91: An open waveguide antenna system as described in Sample 89, wherein: the electromagnetic transition device comprises a rectangular waveguide.

[0196] Sample 92: An open waveguide antenna system as described in Sample 89, wherein: the electromagnetic transition device includes a waveguide bend.

[0197] Some embodiments disclosed in this invention may have one or more of the following advantages: simultaneously achieving high gain, minimizing feed and transition losses; enabling the formulation of a given antenna mode and bandwidth; lower sensitivity to small-batch manufacturing variations compared to prior art DRA-with dielectric waveguide systems; and a highly efficient antenna system formed by combining open waveguide segments and slotted waveguide antenna sections, thereby forming an antenna system suitable for modern multiple input multiple output (MIMO) automotive radar antennas.

[0198] The term "equal to about" as used in this invention is intended to describe manufacturing tolerances and / or non-material deviations from nominal values, which do not depart from the purpose of this invention and fall within the scope of the appended claims.

[0199] While certain combinations of individual features have been described and illustrated in this specification, it should be understood that such combinations are for illustrative purposes only, and any combination of any of these individual features may be used depending on the implementation, whether or not such combination is explicitly stated, and consistent with the disclosure of this invention. Any and all such combinations of features disclosed in this specification, when considered in relation to this invention, are considered to be within the understanding of one skilled in the art to which this invention pertains, and are considered to be within the scope of the disclosed invention, in a manner that would be understood by one skilled in the art to which this invention pertains, provided that they fall within the scope of this invention as defined by the appended claims.

[0200] Although the invention disclosed in this specification is based on exemplary embodiments, it will be understood by those skilled in the art that various changes and equivalent substitutions of elements can be made without departing from the scope of the claims. Many modifications can be made to adapt particular situations or materials to the teachings of this invention without departing from the substantial scope. Therefore, this invention is not limited to limiting the specific embodiments or implementations disclosed in this specification to the best or only mode for carrying out the invention; rather, it includes all embodiments falling within the scope of the appended claims. Exemplary embodiments have been disclosed in the drawings and description, and although specific terms and / or dimensions may have been used, they are for general, exemplary, and / or descriptive purposes only, and not for limiting purposes, unless otherwise stated, and therefore the scope of the claims is not limited thereto. When an element such as a layer, film, region, substrate, or other descriptive feature is mentioned as being "on" or "engaged with" another element, it may be directly on or engaged with the other element, or there may be an intermediate element present. Conversely, when an element is mentioned as being "directly" on or "directly engaged with" another element, no intermediate element exists. The terms "first," "second," etc., do not indicate any order or importance, but are used to distinguish one element from another. The term "one," etc., does not indicate a limitation on quantity, but indicates that at least one of the referred items exists. The use of terms such as "top," "bottom," "up," "down," "left," "right," "front," "back," etc., or any reference to direction in this specification, does not indicate a limitation on the structure; therefore, the structure can be viewed from more than one direction, but rather indicates the relative structural relationship between one or more related features disclosed in this invention. The term "comprising" in this specification does not exclude the possibility of including one or more additional technical features. Furthermore, any prior art information provided in this specification is intended to disclose information that the applicant deems potentially relevant to the present invention. It should not be acknowledged or interpreted that any such prior art information constitutes prior art to the embodiments of the present invention disclosed herein.

[0201] This invention claims the benefits of U.S. Provisional Application No. 63 / 244,018, filed September 14, 2021, and U.S. Provisional Application No. 63 / 286,839, filed December 7, 2021, the entire contents of which are incorporated herein by reference.

[0202] 100: Electromagnetic transition section 1000: Open-type channel waveguide (TWG) 1010: Slot 1015: Channel waveguide 1020: First sidewall 1030: Second sidewall 1040: Partition 1040': Partition 1041: Partition 1050: First base 1050': First base 1060: Second base 1060': Second base 1070: Surface 1080: Signal Input Terminal 1100: Ridge waveguide 1200: Ridge waveguide 1500: Open waveguide 1520: Bend 1600: Dual-channel open waveguide 1610: Electromagnetic radiation absorber 1620: Quarter-wave choke 1621: Electromagnetic Radiation Choke 1622: Electromagnetic Radiation Choke 1623: Electromagnetic Radiation Choke 1630: Distance from partition to wall 2000: Open-type slotted waveguide antenna (TWGA) 2001: Radiation Element 2002: Radiation Element 2003: Intermediate Dielectric 2004: Enhanced characteristics of electromagnetic radiation 2010: Slot 2011: First Curved Path 2012: Second Curved Path 2020: First sidewall 2030: Second sidewall 2040: Partition 2050: First Base 2052: First Sequence Ripple 2060: Second base 2062: Second Sequence Ripple 2070: Surface 2100: First end 2200: Second end 2300: Upper end 2400: Signal Port 2500: Conductive short circuit 2600: Conductive surface 2700: Multi-channel TWGA 2800: Transmitting antenna, slotted waveguide antenna 2850: Receiving antenna, slotted waveguide antenna 3000: Dielectric cap 3010: Surface Interruption 3100: Dielectric cover 3200: Dielectric cap 4000: Signal Feed 4010: Electromagnetic transmission line 4020: Electromagnetic transmission line 4030: Slot / Hole 4040: Conductive surface 500: Outer base surface 5010: Prominent manufacturing features on the front 5020: Screw position 5030: Rib Characteristics 5040: Groove feature 5050: A forming draft angle feature equal to or greater than 2 degrees. 5060: Draft angle feature equal to or greater than 4 degrees. 5070: Molding parting line features near the bottom surface 6000:TWGA System 6050: Basic Package 6060: Solder ball connection 6070: Integrated RFIC (Radio Frequency Integrated Circuit) chip 6100: AoP feed 6150: Patch Antenna 6160: Signal Probe 6200: Waveguide transition / transition region 6202: Bend 6205: Signal Feed Interface 6210: First Transition 6220: Second Transition 6230: Third Transition 6240: Fourth Transition 6255: First patch to slot waveguide transition 6256: Ridge waveguide 6257: Slot Waveguide 6258: Bend 6260: Second patch to slot waveguide transition 6300: Input Port-1, Input Port 6400: Output Port-2, Output Port 7000: System 900: Rectangular waveguide

Claims

1. A waveguide antenna system comprising: an electromagnetic (EM) transition section including a transition region having a signal feed interface and an open waveguide section, the EM transition section being configured to guide a waveguide mode of electromagnetic energy from the signal feed interface to the open waveguide section via the transition region; and a slotted waveguide antenna section configured to radiate electromagnetic energy received from the open waveguide section; wherein the signal feed interface is disposed between the planar signal feed structure and the transition region; and wherein... The electromagnetic transition section is electromagnetically coupled to the slot waveguide antenna section, and the electromagnetic transition section is configured to support electromagnetic energy transmitted from the signal feed structure to the slot waveguide antenna section.

2. The waveguide antenna system as described in claim 1, wherein: The electromagnetic transition section is configured to support electromagnetic energy transmitted from the planar signal feed structure to the slot waveguide antenna section.

3. The waveguide antenna system as described in claim 1, wherein: This open waveguide section contains an open trough waveguide.

4. The waveguide antenna system as described in claim 1, wherein: This open waveguide section contains an open groove waveguide.

5. The waveguide antenna system as described in claim 1, wherein: The open waveguide section has no discontinuities along its respective length; the slotted waveguide antenna section includes significant discontinuities along its respective length; and the open waveguide section and the slotted waveguide antenna section are electromagnetically coupled at an electromagnetic coupling point between them, wherein the change of discontinuity transitions from the absence of discontinuities in the open waveguide section to the significant discontinuities in the slotted waveguide antenna section.

6. A waveguide antenna system comprising: a plurality of waveguide antenna systems as described in any one of claims 1 to 5, configured for antenna-on-package applications or configured for surface mount applications on printed circuit boards.

7. The waveguide antenna system as described in claim 6, wherein: In the transmit mode and configuration, each open waveguide segment is configured to receive electromagnetic energy from an antenna element on the package or a surface mount element on a printed circuit board, and to deliver the electromagnetic energy to the corresponding slot waveguide antenna portion; and in the receive mode and configuration, each open waveguide segment is configured to receive electromagnetic energy from the corresponding slot waveguide antenna portion, and to deliver the electromagnetic energy to an antenna element on the package or a surface mount element on a printed circuit board.

8. The waveguide antenna system as described in claim 1, further comprising an open waveguide signal feed system, the open waveguide signal feed system comprising: a printed circuit board having a signal feed and a signal feed output; an open waveguide having a signal feed input port; and a transition region disposed between the signal feed output and the signal feed input port for signal communication with them; wherein, The signal feed includes a microstrip, a coplanar waveguide, or a stripline; the output of the signal feed includes a patch or a probe.

9. The waveguide antenna system as described in claim 8, wherein: The transition region contains a closed waveguide.

10. The waveguide antenna system as described in claim 8, wherein: The transition area includes the edge feed between the signal feed output and the signal feed input port.

11. The waveguide antenna system as described in claim 8, wherein: The transition region includes an aperture located at the signal feed output, which is directly electromagnetically coupled to the signal feed input port.

12. The waveguide antenna system of claim 1, further comprising an open waveguide section comprising: at least one bend in a slotted waveguide located in the direction of propagation of electromagnetic waves in the slotted waveguide, the slotted waveguide comprising a slot having first and second opposing sidewalls, a partition disposed between the two, a first base disposed between the first sidewall and the partition, and a second base disposed between the partition and the second sidewall, wherein at least all surfaces of the first sidewall, the second sidewall, the partition, the first base, and the second base located within the slot are conductive; and an electromagnetic radiation suppressor strategically configured and set to suppress unwanted electromagnetic radiation that might be emitted from the at least one bend in the absence of such an electromagnetic radiation suppressor.

13. The waveguide antenna system as described in claim 12, wherein: The electromagnetic radiation suppressor includes electromagnetic radiation absorbing material disposed on the open end above at least one bend of the channel waveguide.

14. The waveguide antenna system as described in claim 12, wherein: The electromagnetic radiation suppressor includes an electromagnetic choke mechanism disposed at at least one bend in the channel waveguide.

15. The waveguide antenna system as described in claim 14, wherein: The electromagnetic choke mechanism includes at least one quarter-wavelength groove cut out on each of the first and second sidewalls of the slot.

16. The waveguide antenna system as described in claim 15, wherein: The at least one quarter-wavelength trench comprises at least a pair of symmetrically arranged trenches disposed in the first and second sidewalls of the trench.

17. A waveguide antenna system as described in any one of claims 15 or 16, wherein: The at least one quarter-wavelength trench comprises a horizontal portion and an adjacent vertical portion.

18. The waveguide antenna system as described in claim 15 or 16, wherein: The first and second sidewalls of the groove have inclined sidewalls, and at least one quarter-wavelength groove is formed on each respective inclined sidewall.

19. The waveguide antenna system as described in claim 14, wherein: The electromagnetic choke mechanism includes an electromagnetic reflector with total internal reflection (TIR) ​​characteristics. The electromagnetic reflector is disposed in the form of a cap on the upper open end of the at least one bend in the channel waveguide and extends from the first sidewall to the second sidewall through the at least one bend in the channel. The TIR reflector is composed of a dielectric material having a dielectric constant that varies along the normal direction of the cap, thereby producing total internal reflection.

20. The waveguide antenna system as described in claim 14, wherein: The electromagnetic choke mechanism includes a dielectric material disposed on an open end above at least one bend of the slotted waveguide, and the at least one bend extending through the slot from the first sidewall to the second sidewall. The dielectric material is composed of a dielectric material with a dielectric constant greater than 6.

21. The waveguide antenna system as described in claim 12, wherein: The electromagnetic radiation suppressor includes a modified partition with a reduced height at the at least one bend, which is lower than the original height of the partition outside the at least one bend.

22. The waveguide antenna system as described in claim 21, wherein: The improved partition gradually decreases in size from its original height to the reduced height.

23. The waveguide antenna system as described in claim 12, wherein: The electromagnetic radiation suppressor includes a modified inner surface of the groove in the at least one bend, the inner surface being configured to affect the phase velocity and / or waveguide impedance such that the phase velocity and / or waveguide impedance are constant or substantially constant along the path length of the at least one bend.

24. The waveguide antenna system as described in claim 23, wherein: The modified inner surface of the groove includes the tapered bottom surface of the waveguide groove between the partition and at least one of the first sidewall and the second sidewall.

25. The waveguide antenna system as described in claim 24, wherein: The tapering bottom surface gradually decreases in size from the partition towards the outer sidewall outside the at least one bend.

26. The waveguide antenna system as described in claim 23, wherein: The improved inner surface of the groove includes the height difference between the first base of the groove and the second base of the groove.

27. The waveguide antenna system as described in claim 23, wherein, The groove includes a first groove portion between the first sidewall and the partition, and a second groove portion between the second sidewall and the partition, wherein the first groove portion is disposed on the inner curvature of the at least one bend, and the second groove portion is disposed on the outer curvature of the at least one bend, and further wherein: the modified inner surface of the groove includes the width difference between the first groove portion and the second groove portion.

28. The waveguide antenna system as described in claim 23, wherein: The modified inner surface of the groove includes the lateral positioning of the partition in at least one bend, the lateral positioning being asymmetrical relative to the first and second sidewalls.

29. The waveguide antenna system as described in claim 23, wherein: The modified inner surface of the groove includes the thickness of the partition in the at least one bend, which is different from the thickness of the partition outside the at least one bend.

30. The waveguide antenna system as described in claim 23, wherein: The first sidewall is the inner sidewall of the at least one bend; the second sidewall is the outer sidewall of the at least one bend; the first base has a first width between the first sidewall and the partition, the width being defined by a first groove portion disposed on the inner curvature of the at least one bend; the second base has a second width between the partition and the second sidewall, the width being defined by a second groove portion disposed on the outer curvature of the at least one bend; and the first width is greater than the second width.

31. The waveguide antenna system as described in claim 30, wherein: The width of the cross-section of the second groove portion inside the at least one bend is smaller than the width of the corresponding cross-section outside the at least one bend, which helps to increase the capacitance of the second groove portion inside the at least one bend.

32. The waveguide antenna system as described in claim 30, wherein: The width of the cross-section of the first groove portion inside the at least one bend is greater than the width of the corresponding cross-section outside the at least one bend, which helps to reduce the capacitance of the first groove portion inside the at least one bend.

33. The waveguide antenna system as described in claim 31, wherein: The width dimension of the cross-sectional width of the second groove portion inside the at least one bend is as low as 200 micrometers or less.

34. The waveguide antenna system as described in claim 32, wherein: The width dimension of the cross-sectional width of the first groove portion inside the at least one bend is not greater than half the wavelength of the operating frequency of the open waveguide segment inside the at least one bend.

35. The waveguide antenna system as described in claim 23, wherein: The slot waveguide has a first depth to the first base and the second base outside the curvature at the at least one bend, and a second depth to the first base and the second base inside the curvature at the at least one bend; and the first depth outside the curvature at the bend is greater than the second depth inside the curvature at the bend.

36. A waveguide antenna system as described in any one of claims 23 and 35, wherein, The groove includes a first groove portion between the first sidewall and the partition, and a second groove portion between the second sidewall and the partition, and further wherein: the cross-section of the second groove portion inside the at least one bend has a depth less than the corresponding cross-section depth outside the at least one bend, which helps to increase the impedance of the second groove portion inside the at least one bend and increase the phase velocity of the electromagnetic wave, when present, propagating through the second groove portion.

37. The waveguide antenna system as described in claim 36, wherein: The cross-section of the first groove portion inside the at least one bend has a greater depth than the corresponding cross-section depth on the outside of the at least one bend, which helps to reduce the impedance of the first groove portion inside the at least one bend and reduce the phase velocity of electromagnetic waves, when present, propagating through the first groove portion.

38. The waveguide antenna system as described in claim 36, wherein: The depth of the cross section of the second groove is at least as deep as the height of the partition.

39. The waveguide antenna system as described in claim 37, wherein: The cross-sectional depth of the first groove portion on the outer side of the at least one bend is increased by at most one-quarter wavelength of the operating frequency of the open waveguide segment on the inner side of the at least one bend, relative to the cross-sectional depth of the first groove portion on the outer side of the at least one bend.

40. The waveguide antenna system as described in claim 23, wherein: The partition has a first wall thickness on the outer side of the at least one bend and a second wall thickness on the inner side of the at least one bend; and the first wall thickness is less than the second wall thickness.

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