Half-mode waveguide with asymmetric structure for radar system

Abstract

According to a non-limiting example, a half-mode waveguide includes a body having a bottom wall, a top wall, a first sidewall, and a second sidewall. The body has a height defined between a bottom wall and a top wall. A signal channel extends through the body from the first sidewall to the second sidewall. The signal channel includes a first sidewall portion, a second sidewall portion, and a bottom wall portion. The first sidewall portion has a first height and the second sidewall portion has a second height that is greater than the first height of the first sidewall portion.

Description

Technical Field

[0001] This disclosure relates to the field of radar systems, and more specifically, to radar systems including half-mode waveguides with asymmetric structures. Background Technology

[0002] This section provides background information relating to this disclosure, which is not necessarily prior art.

[0003] Automotive radar sensors are used in vehicle sensing systems to determine information about objects in the vehicle's environment, such as the position, size, orientation, speed, and acceleration of objects in the vehicle's environment. The sensed information can then be used, for example, by other vehicle systems (such as autonomous driving systems and / or advanced driver assistance systems (ADAS)) to control steering, braking, throttle, and / or other vehicle systems.

[0004] Some existing automotive radar systems use printed circuit board (PCB) antennas. The radar system includes a control PCB that houses the radar system's processing components, such as one or more microprocessors, one or more power supplies, other integrated circuits (ICs) such as monolithic microwave integrated circuits (MMICs), and an additional antenna PCB attached to the control PCB and connected to the MMIC. The additional antenna PCB is made of high-performance radio frequency (RF) materials and includes antenna components that serve as the antenna for the radar system. The PCB antenna radiator can be implemented, for example, using microstrip patches, microstrip stubs, microstrip zigzags, planar microstrip antennas / probes, etc. The antenna PCB can be attached to the control PCB using adhesive.

[0005] Typically, a waveguide is positioned above a planar microstrip probe. The waveguide collects and directs the RF energy from the probe. This RF energy is then directed from the radar system. In a half-mode waveguide, the RF energy travels through a conduit to reach the half-mode waveguide. The conduit directs the RF energy from the antenna to the half-mode waveguide, where it is then transferred to the radar control module. The half-mode waveguide forms a 90° bend in the RF signal.

[0006] To facilitate more efficient bending of RF energy, both conduits and half-mode waveguides incorporate open surfaces. While open surfaces reduce trapped modes and facilitate more efficient propagation of RF signals around 90° bends, they also contribute to insertion loss. Reducing insertion loss helps stronger signals reach the target, leading to stronger reflections and thus improved radar efficiency. Therefore, the industry will welcome the design changes in half-mode waveguides used to reduce insertion loss. Summary of the Invention

[0007] This section provides a general overview of this disclosure, but does not fully disclose its entire scope or all features of its characteristics.

[0008] According to a non-limiting example, a half-mode waveguide includes a body having a bottom wall, a top wall, a first sidewall, and a second sidewall. The body has a height defined between the bottom wall and the top wall. A signal path extends from the first sidewall through the body to the second sidewall. The signal path includes a first sidewall portion, a second sidewall portion, and a bottom wall portion. The first sidewall portion has a first height, and the second sidewall portion has a second height greater than the first height of the first sidewall portion.

[0009] Among other features, the top wall extends at a non-zero angle relative to the bottom wall.

[0010] Among other features, the non-zero angle is between approximately 20° and approximately 50°.

[0011] Among other features, the non-zero angle is between approximately 25° and approximately 45°.

[0012] Among other features, the non-zero angle is between approximately 35° and approximately 45°.

[0013] Among other features, the top wall includes a first chamfered edge extending along the first sidewall and a second chamfered edge extending along the second sidewall.

[0014] Among other features, the signal channel includes a first substantially linear portion extending from a first sidewall and a second substantially linear portion extending from a second sidewall, the first substantially linear portion engaging with the second substantially linear portion at a non-zero angle.

[0015] Among other features, the signal channel extends along a curved path between the first and second sidewalls.

[0016] Among other features, the top wall includes a step at the signal channel that defines a portion of the second sidewall.

[0017] Among other features, the main body is formed as a monolithic structure.

[0018] An automotive radar system includes a printed circuit board (PCB) formed of multiple layers. The PCB includes a first surface and a second surface opposite the first surface. A monolithic microwave integrated circuit (MMIC) is mounted to the first surface. A radar control module is mounted to the second surface of the PCB. A half-mode waveguide system extends along the second surface of the PCB, connecting the MMIC to the radar control module. The half-mode waveguide system includes a half-mode waveguide, which includes a body having a bottom wall, a top wall, a first sidewall, and a second sidewall. The body has a height defined between the bottom wall and the top wall. A signal path extends from an inlet defined at the first sidewall through the body to an outlet defined at the second sidewall. The signal path includes a first sidewall portion, a second sidewall portion, and a bottom wall portion. The first sidewall portion has a first height, and the second sidewall portion has a second height greater than the first height of the first sidewall portion.

[0019] Among other features, the top wall extends at a non-zero angle relative to the bottom wall.

[0020] Among other features, the non-zero angle is between approximately 20° and approximately 50°.

[0021] Among other features, the non-zero angle is between approximately 35° and approximately 45°.

[0022] Among other features, the top wall includes a first chamfered edge extending along the first sidewall and a second chamfered edge extending along the second sidewall.

[0023] Among other features, the signal channel includes a first substantially linear portion extending from a first sidewall and a second substantially linear portion extending from a second sidewall, the first substantially linear portion engaging with the second substantially linear portion at a non-zero angle.

[0024] Among other features, the signal channel extends along a curved path between the first and second sidewalls.

[0025] Among other features, the top wall includes a step at the signal channel that defines a portion of the second sidewall.

[0026] Among other features, the main body is formed as a monolithic structure.

[0027] Among other features, the half-mode waveguide defines a 90° bend in the half-mode waveguide system.

[0028] Further applicability will become apparent from the description provided herein. The descriptions and specific examples in this invention are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0029] The accompanying drawings described herein are for illustrative purposes only, representing selected embodiments and not all possible implementations, and are not intended to limit the scope of this disclosure.

[0030] Figure 1 The image shown is a top right perspective view of a radar system according to this disclosure, which includes a half-mode waveguide with an asymmetric structure.

[0031] Figure 2 It is based on this disclosure, Figure 1 A side view of the radar system;

[0032] Figure 3 This is a perspective view of a half-mode waveguide with an asymmetric structure according to this disclosure;

[0033] Figure 4 It is based on this disclosure, Figure 3 Top view of a half-mode waveguide;

[0034] Figure 5 This is a perspective view of a half-mode waveguide with an asymmetric structure according to another aspect of this disclosure;

[0035] Figure 6 It is based on this disclosure, Figure 5 Top view of a half-mode waveguide;

[0036] Figure 7 This is a perspective view of a half-mode waveguide with an asymmetric structure according to another aspect of this disclosure;

[0037] Figure 8 It is based on this disclosure, Figure 7 Top view of a half-mode waveguide;

[0038] Figure 9 This is a perspective view of a half-mode waveguide with an asymmetric structure according to another aspect of this disclosure; and

[0039] Figure 10 It is based on this disclosure, Figure 9 Side view of a half-mode waveguide.

[0040] In the several views of the accompanying drawings, the corresponding reference numerals indicate the corresponding parts. Detailed Implementation

[0041] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0042] Although the radar system formed according to this disclosure is described in the context of a vehicle, the radar system can be used for fixed applications and / or other applications.

[0043] A radar system directs RF energy from a source toward a target. The RF energy reflected from the target is received and processed to determine various information, including target position, range, and velocity. At the source, the RF energy travels through an interconnect path from the MMIC to the waveguide. The RF energy leaves the MMIC and transitions to a track in the PCB. Then, the RF energy travels along the track from the MMIC toward the waveguide / antenna. Again, the RF energy undergoes a transition from the track to the waveguide / antenna. Finally, the RF energy travels through the waveguide toward the target. Energy loss occurs along the interconnect path. The energy loss at the transition points is greater than the energy loss within the track. Reducing energy loss improves radar efficiency and sensitivity.

[0044] According to the automotive radar system disclosed herein Figure 1 and Figure 2 The radar system 10 is generally indicated by 10. The radar system 10 includes a printed circuit board (PCB) 16, which includes a first side 18, a second side 20, and multiple intermediate layers 24. According to this disclosure, a monolithic microwave integrated circuit (MMIC) 30 is mounted on the first side 18. A radar control module 34 is mounted on the second side 20. A half-mode waveguide system 40 is connected between the MMIC 30 and the radar control module 34. The half-mode waveguide system 40 directs RF energy from the MMIC 30 to the radar control module 34, where the RF energy is then transmitted to the target.

[0045] According to this disclosure, a half-mode waveguide system 40 includes a delivery channel 44 projected outward from a PCB 16. The delivery channel 44 is operatively connected to an output (not separately labeled) of an MMIC 30. The delivery channel 44 is also operatively coupled to a transition member 46 including a 90° bend. The transition member 46 is coupled to a transmission channel 50 extending across a second side 20 of the PCB 16. The transmission channel 50 includes a first end 52 and a second end 54 connected to the transition member 46. A slotted opening 56 extends along the transmission channel 50 between the first end 52 and the second end 54.

[0046] according to Figure 3 and Figure 4 As shown in the disclosure, the half-mode waveguide 70 is operatively coupled to the transmission channel 50 at its second end 54. The half-mode waveguide 70 includes a body 74 formed as a monolithic component or a single piece. The body 74 can be formed using various manufacturing techniques, including casting, molding, machining, three-dimensional (3D) printing, and by using other forming techniques.

[0047] According to this disclosure, body 74 includes a bottom wall 80, a top wall 82, a first side wall 84, and a second side wall 86. Body 74 also includes additional side walls (not separately labeled). Body 74 includes a height defined along an axis “x” extending between the bottom wall 80 and the top wall 82. Signal channel 96 extends through body 74 between the first side wall 84 and the second side wall 86. In a non-limiting example, signal channel 96 may have a depth between approximately 2 mm and approximately 6 mm.

[0048] The signal channel 96 includes an inlet 98 at a first sidewall 84 and an outlet 100 at a second sidewall 86. The signal channel 96 forms a 90° bend between the inlet 98 at the first sidewall 84 and the outlet 100 at the second sidewall 86 to deliver RF energy to the radar control module 34. According to this disclosure, the signal channel 96 includes a first sidewall portion 110, a second sidewall portion 112, and a bottom wall portion 114. The signal channel 96 is exposed at a top wall 82.

[0049] The first sidewall portion 110 includes a first height measured along the axis "X", and the second sidewall portion 112 includes a second height measured along the axis "X". The height of the second sidewall portion 112 is greater than the height of the first sidewall portion 110. This difference in height results in a reduction in insertion loss through the signal channel 96. In other words, by optimizing the height of the second sidewall portion 112, which forms a 90° curved outer surface, the insertion loss through the signal channel 96 is reduced.

[0050] According to one aspect of this disclosure, the height difference is achieved by tilting the top wall 82 relative to the bottom wall 80. In a non-limiting example, the top wall 82 may have an angle between approximately 20° and approximately 50° relative to the bottom wall 80. In another non-limiting example, the top wall 82 may have an angle between approximately 25° and approximately 45° relative to the bottom wall 80. According to yet another non-limiting example, the top wall 82 may have an angle between approximately 35° and approximately 45° relative to the bottom wall 80.

[0051] The specific angle of the top wall 82 relative to the bottom wall 80 can be driven by the operating frequency of the RF energy passing through the signal channel 96. With this configuration, the signal channel 96 is defined by walls with asymmetrical heights. That is, the angle of the top wall 82 ensures that the second sidewall portion 112 of the signal channel 96 is elevated relative to the first sidewall portion 110 of the signal channel 96. This height difference created by the angle of the top wall 82 results in a reduction in insertion loss through the signal channel 96.

[0052] Continue to refer to Figure 3 and Figure 4The 90° bend in the signal channel 96 can be achieved through various configurations. For example, the body 74 includes a first chamfered edge 140 between the top wall 82 and the first side wall 84, and a second chamfered edge 142 between the top wall 82 and the second side wall 86. The first chamfered edge 140 includes an angle of 22.5°, and the second chamfered edge 142 also includes an angle of 22.5°. The first and second chamfered edges 140 and 142 help to confine the RF energy passing through the signal channel 96 to the half-mode waveguide 70.

[0053] The signal channel 96 includes a first portion 144 extending from the first sidewall 84 across the first chamfered edge 140, a second portion 146 extending from the first chamfered edge 140 to the midpoint (not separately labeled) of the top wall 82, a third portion 148 extending from the midpoint of the top wall 82 to the second chamfered edge 142, and a fourth portion 150 extending through the second chamfered edge 142 to the second sidewall 86. The second portion 146 and the third portion 148 meet at an angle of 135°. With this configuration, the signal channel 96 forms a 90° bend through the body 74 between the inlet 98 at the first sidewall 84 and the outlet 100 at the second sidewall 86.

[0054] According to this disclosure, in addition to adjusting the angle between the top wall 82 and the bottom wall 80, the total length of the signal channel 96 can also be varied. That is, the signal channel 96 may include a first length (such as...). Figure 3 and Figure 4 (as shown above) and a second length, the second length being shorter than the first length, such as Figure 5 and Figure 6 As shown in the diagram, the length of the signal channel 96 can be adjusted based on the operating frequency of the automotive radar system 10. Furthermore, the shape of the signal channel 96 can be varied. Figure 3 , Figure 4 , Figure 5 and Figure 6 Signal channel 96 is shown as being formed by connected linear segments.

[0055] In a manner similar to that discussed in this article, Figure 7 and Figure 8 A half-mode waveguide 70 with a height difference between a first surface portion 110 and a second surface portion 112 is depicted. The height difference is achieved by tilting a top wall 82 relative to a bottom wall 80. In a non-limiting example, the top wall 82 may have an angle between approximately 20° and approximately 50° relative to the bottom wall 80. In another non-limiting example, the top wall 82 may have an angle between approximately 25° and approximately 45° relative to the bottom wall 80. According to yet another non-limiting example, the top wall 82 may have an angle between approximately 35° and approximately 45° relative to the bottom wall 80.

[0056] In addition to its high degree of asymmetry, the signal channel 96 is curved. That is, the 90° bend of the signal channel 96 is defined by an arc. The arc can have a radius between approximately 4 mm and approximately 5 mm. The high degree of asymmetry between the first sidewall portion 110 and the second sidewall portion 112, created by the angle of the top wall 82 together with the radius of the signal channel 96, reduces the insertion loss through the half-mode waveguide 70.

[0057] According to another aspect of this disclosure, in addition to forming a signal channel 96 having an arc shape as described herein, the height difference between the first sidewall portion 110 and the second sidewall portion 112 can be achieved by forming a step 182 in the top wall 82, such as... Figure 9 and Figure 10 As shown. Step 182 includes a first surface 184 defining the height of a first sidewall portion 110, a raised portion 186 defining the height of a second sidewall portion 112, and a second surface 188. The first surface 184 and the second surface 188 together form a top wall 82. In a manner similar to that described herein, step 182 raises the second surface 188 relative to the first surface 184 via the second sidewall portion 112. In a non-limiting example, the second surface 188 is raised between approximately 0.5 mm and approximately 1.5 mm.

[0058] The asymmetry created by step 182 results in a reduction in insertion loss through signal channel 96. Specifically, by increasing the height of the second sidewall portion 112 forming the 90° curved outer surface, a height asymmetry is created between the first sidewall portion 110 and the second sidewall portion 112. This height asymmetry causes the second surface 188 to rise relative to the first surface 184. This height asymmetry, together with the radius of signal channel 96, reduces the insertion loss of RF energy through half-mode waveguide 70.

[0059] The half-mode waveguide according to this disclosure includes an asymmetric signal channel that reduces signal loss between the inlet and outlet. The asymmetric geometry is created by forming one sidewall portion of the channel with a height greater than that of the opposite sidewall portion. This height difference better retains the RF signal in the signal channel, thereby reducing loss through the open surface. Furthermore, the asymmetric signal channel is formed with a 90° bend, which allows the half-mode waveguide to be incorporated into microwave / millimeter-wave transmission lines and / or routing applications.

[0060] The terms “approximately” and “substantially” are intended to include the degree of error associated with measurements of a specific quantity based on available equipment at the time of application submission. For example, “approximately” and “substantially” can include a range of ±8% for a given value.

[0061] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope of protection to those skilled in the art. Numerous specific details, such as examples of specific components, devices, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are unnecessary and that exemplary embodiments may be implemented in many different forms, none of which should be construed as limiting the scope of this disclosure. In some example embodiments, well-known procedures, well-known device structures, and well-known technologies are not described in detail.

[0062] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may also mean including the plural forms unless the context explicitly specifies otherwise. The terms “comprising,” “including,” “containing,” and “having” are inclusive and thus specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Unless expressly identified as an order of execution, the method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown. It should also be understood that additional or alternative steps may be employed.

[0063] Although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0064] For ease of description, this document uses spatially related terms such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” and “upper” to describe the relationship between an element or feature as shown in the figure and (multiple) other elements or features. Spatially relative terms may also be intended to cover different orientations of the device during use or operation, in addition to those shown in the figure. For example, if the device shown in the figure is flipped, then an element described as being “below” or “below” other elements or features will be “above” relative to those other elements or features. Therefore, the example term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

[0065] The foregoing description of the embodiments is provided for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of the present disclosure. Although not explicitly shown or described, individual elements or features of a particular embodiment are not generally limited to that particular embodiment, but are interchangeable and can be used in the selected embodiments where applicable. These elements or features can also be varied in many ways. Such variations should not be considered as departing from the present disclosure, but all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A half-mode waveguide, comprising: A main body having a bottom wall, a top wall, a first side wall, and a second side wall, the main body having a height defined between the bottom wall and the top wall; as well as A signal channel extends from the first sidewall through the body to the second sidewall. The signal channel includes a first sidewall portion, a second sidewall portion, and a bottom wall portion. The first sidewall portion has a first height, and the second sidewall portion has a second height, which is greater than the first height of the first sidewall portion.

2. The half-mode waveguide according to claim 1, characterized in that, The top wall extends at a non-zero angle relative to the bottom wall.

3. The half-mode waveguide according to claim 2, characterized in that, The non-zero angle is between approximately 20° and approximately 50°.

4. The half-mode waveguide according to claim 3, characterized in that, The non-zero angle is between approximately 25° and approximately 45°.

5. The half-mode waveguide according to claim 3, characterized in that, The non-zero angle is between approximately 35° and approximately 45°.

6. The half-mode waveguide according to claim 2, characterized in that, The top wall includes a first chamfered edge extending along the first sidewall and a second chamfered edge extending along the second sidewall.

7. The half-mode waveguide according to claim 1, characterized in that, The signal channel includes a first substantially linear portion extending from the first sidewall and a second substantially linear portion extending from the second sidewall, the first substantially linear portion engaging with the second substantially linear portion at a non-zero angle.

8. The half-mode waveguide according to claim 1, characterized in that, The signal channel extends along a curved path between the first sidewall and the second sidewall.

9. The half-mode waveguide according to claim 1, characterized in that, The top wall includes a step at the signal channel, the step defining a portion of the second sidewall.

10. The half-mode waveguide according to claim 1, characterized in that, The main body is formed as a single-piece structure.

11. A vehicle radar system, comprising: A printed circuit board (PCB) is formed of multiple layers, the PCB including a first surface and a second surface opposite to the first surface; A monolithic microwave integrated circuit (MMIC) is mounted on the first surface; A radar control module, wherein the radar control module is mounted on the second surface of the PCB; as well as A half-mode waveguide system extending along a second surface of the PCB connecting the MMIC to the radar control module, the half-mode waveguide system including a half-mode waveguide comprising: A main body having a bottom wall, a top wall, a first side wall, and a second side wall, the main body having a height defined between the bottom wall and the top wall; as well as A signal channel extends from an inlet defined at a first sidewall through the body to an outlet defined at a second sidewall, the signal channel including a first sidewall portion, a second sidewall portion and a bottom wall portion, the first sidewall portion having a first height and the second sidewall portion having a second height, the second height being greater than the first height of the first sidewall portion.

12. The automotive radar system according to claim 11, characterized in that, The top wall extends at a non-zero angle relative to the bottom wall.

13. The automotive radar system according to claim 12, characterized in that, The non-zero angle is between approximately 20° and approximately 50°.

14. The automotive radar system according to claim 13, characterized in that, The non-zero angle is between approximately 35° and approximately 45°.

15. The automotive radar system according to claim 12, characterized in that, The top wall includes a first chamfered edge extending along the first sidewall and a second chamfered edge extending along the second sidewall.

16. The automotive radar system according to claim 11, characterized in that, The signal channel includes a first substantially linear portion extending from the first sidewall and a second substantially linear portion extending from the second sidewall, the first substantially linear portion engaging with the second substantially linear portion at a non-zero angle.

17. The automotive radar system according to claim 11, characterized in that, The signal channel extends along a curved path between the first sidewall and the second sidewall.

18. The automotive radar system according to claim 11, characterized in that, The top wall includes a step at the signal channel, the step defining a portion of the second sidewall.

19. The automotive radar system according to claim 11, characterized in that, The main body is formed as a single-piece structure.

20. The automotive radar system according to claim 11, characterized in that, The half-mode waveguide is defined by a 90° bend in the half-mode waveguide system.

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