Radome and method for manufacturing the same

Abstract

The present invention provides two-piece and three-piece radomes and methods of manufacturing the same that involve independently optimizing the thickness profile of each piece to achieve a desired radar performance metric such that air gaps may exist or may be intentionally included between the pieces without adversely affecting the radar performance of the radome.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Provisional Application No. 62 / 835,934, filed on April 18, 2019. The disclosure of the above application is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to radomes, and more particularly, to stepped radomes and methods of manufacturing the same. Background Art

[0004] A radome or antenna cover is a device that protects a radar transceiver. Ideally, the radome should be radar transparent so as not to adversely affect the performance of the radar transceiver. To achieve an aesthetic design, the radome may have multiple layers (e.g., multiple pieces). Air gaps often occur between multi-layer or multi-piece radomes, which attenuate the radar waves transmitted therethrough, thereby adversely affecting performance. Eliminating these air gaps requires very high precision manufacturing techniques, which increases costs. Therefore, although conventional multi-layer or multi-piece radomes are effective for their intended purposes, there is still a need for improvement in the related art. Summary of the invention

[0005] According to one aspect of the present disclosure, a two-piece radome is provided. In one exemplary implementation, the two-piece radome includes: a rear component, the rear component is formed by injection molding a first radar transparent resin and defines a first stepped feature and a first thickness distribution, the first thickness distribution is independently optimized to achieve a desired radar performance metric; and a cover component, the cover component is formed by injection molding a second radar transparent resin and defines a second stepped feature complementary to the first stepped feature and a second thickness distribution, the second thickness distribution is independently optimized to achieve a desired radar performance metric, wherein an air gap exists between the rear component and the cover component.

[0006] In some implementations, the first thickness profile and the second thickness profile are independently optimized to achieve minimum radar attenuation. In some implementations, the first radar transparent resin is acrylonitrile styrene acrylate (ASA) or polycarbonate (PC), and the second radar transparent resin is PC. In some implementations, the rear component is opaque and the cover is transparent or translucent. In some implementations, the first stepped feature is part of a logo, emblem, or grille feature of the vehicle.

[0007] According to another aspect of the present disclosure, a three-piece radome is provided. In one exemplary implementation, the three-piece radome includes: a rear component formed by injection molding a first radar transparent resin and defining a substantially uniform first thickness profile; a middle component formed by injection molding a second radar transparent resin and defining a first stepped feature and a second thickness profile, the second thickness profile being independently optimized to achieve a desired radar performance metric; and a cover component formed by injection molding a third radar transparent resin and defining a second stepped feature complementary to the first stepped feature and a third thickness profile, the third thickness profile being independently optimized to achieve a desired radar performance metric, wherein an air gap exists between the rear component, the middle component, and the cover component.

[0008] In some implementations, the second thickness profile and the third thickness profile are independently optimized to achieve minimum radar attenuation. In some implementations, the first radar transparent resin and the second radar transparent resin are each one of ASA and PC, and the third radar transparent resin is PC. In some implementations, the rear component is opaque, the middle component is opaque or transparent or translucent, and the cover component is transparent or translucent. In some implementations, the first stepped feature is part of a logo, emblem, or grille feature of the vehicle.

[0009] According to another aspect of the present disclosure, a method for manufacturing a two-piece radome is provided. In one exemplary implementation, the method includes: determining a first thickness profile of a rear component of the radome, the first thickness profile being independently optimized to achieve a desired radar performance metric, the rear component defining a first stepped feature; determining a second thickness profile of a cover of the radome, the second thickness profile being independently optimized to achieve a desired radar performance metric, the cover defining a second stepped feature complementary to the first stepped feature; injection molding a first radar transparent resin and a second radar transparent resin to form the rear component and the cover, respectively; and combining the rear component and the cover to form the radome, wherein an air gap exists between the rear component and the cover.

[0010] In some implementations, the first radar transparent resin and the second radar transparent resin are injection molded and combined via two passes of a multi-shot molding process. In some implementations, the first thickness profile and the second thickness profile are independently optimized to achieve minimum radar attenuation. In some implementations, the first radar transparent resin is ASA or PC, and the second radar transparent resin is PC. In some implementations, the rear component is opaque and the cover is transparent or translucent. In some implementations, the first stepped feature is part of a logo, emblem, or grille feature of the vehicle.

[0011] According to another aspect of the present disclosure, a method for manufacturing a three-piece radome is provided. In one exemplary implementation, the method includes: determining a substantially uniform first thickness distribution of a rear component of the radome; determining a second thickness distribution of a middle component of the radome, the second thickness distribution being independently optimized to achieve a desired radar performance metric, the middle component defining a first stepped feature; determining a third thickness distribution of a cover component of the radome, the third thickness distribution being independently optimized to achieve a desired radar performance metric, the cover component defining a second stepped feature complementary to the first stepped feature; injection molding a first radar transparent resin, a second radar transparent resin, and a third radar transparent resin to form a rear component, a middle component, and a cover component, respectively; and combining the rear component, the middle component, and the cover component to form the radome, wherein an air gap exists between the rear component, the middle component, and the cover component.

[0012] In some implementations, the first radar transparent resin, the second radar transparent resin, and the third radar transparent resin are injection molded and combined via three times of a multi-shot injection molding process. In some implementations, the second thickness profile and the third thickness profile are independently optimized to achieve minimum radar attenuation. In some implementations, the first radar transparent resin and the second radar transparent resin are each one of ASA and PC, and the third radar transparent resin is PC. In some implementations, the rear component is opaque, the middle component is opaque or transparent or translucent, and the cover component is transparent or translucent. In some implementations, the first stepped feature is part of a logo, emblem, or grille feature of the vehicle.

[0013] Other areas of applicability of the teachings of the present disclosure will become apparent from the detailed description and drawings provided below, wherein similar reference numerals refer to similar features throughout the several views of the drawings. It should be understood that the detailed description, including the disclosed embodiments and drawings cited therein, is merely exemplary in nature and is for illustrative purposes only, and is not intended to limit the scope of the present disclosure, its application or use. Therefore, variations that do not depart from the essence of the present disclosure are intended to be within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A to Figure 1B is a cross-sectional view of an exemplary multi-piece stepped radome according to some implementations of the present disclosure;

[0015] FIG. 2A to FIG. 2B is a graph of exemplary performance data for non-optimized and optimized two-piece stepped radomes with air gaps according to some implementations of the present disclosure; and

[0016] FIG. 3A to FIG. 3B is a flow chart of an exemplary method of manufacturing a multi-piece stepped radome according to some implementations of the present disclosure. DETAILED DESCRIPTION

[0017] As described above, conventional multi-layer or multi-piece radomes require very high precision manufacturing processes to avoid air gaps that can increase radar attenuation and thus reduce radar performance. Therefore, improved multi-layer or multi-piece radomes and methods of manufacturing the same are proposed. Each piece of these multi-piece radomes has an independently designed or optimized thickness distribution to achieve the desired radar performance metric (i.e., minimum radar attenuation / loss or reflection). Then, once the multiple pieces are stacked together to form the radome, the radome will be able to achieve optimal radar performance regardless of the presence or size of the air gaps therebetween. In addition to the performance benefits, these improved multi-piece radomes can be manufactured without the very high precision manufacturing processes required for conventional multi-piece radomes. The ability to include air gaps can also enhance visual aesthetics. Although a two-piece radome configuration can reduce costs and / or make manufacturing easier, a three-piece radome configuration can also provide various benefits (e.g., greater design flexibility).

[0018] See now Figure 1A , shows an exemplary embodiment of a two-piece radome 100 according to the present disclosure. The radome 100 includes a rear component 104 defining a stepped feature 108. The stepped feature 108 may be, for example, part of a logo, emblem, grille feature, or any three-dimensional design effect of a vehicle. The thickness distribution of the rear component 104 ranges from a first thickness T1 to a second thickness T2 at the stepped feature 108. The thickness distribution of the rear component 104 is independently optimized to achieve the desired radar performance metrics (loss, reflection, etc.). The rear component 104 may be formed by injection molding (e.g., in one of a multi-shot injection molding process) a suitable radar transparent resin such as acrylonitrile styrene acrylate (ASA) or polycarbonate (PC). In an exemplary implementation, the rear component 104 is opaque, but it should be understood that the rear component 104 may be transparent or translucent. It should also be understood that a radar transparent coating such as a radar transparent metalloid may be applied to the top surface of the rear component 104.

[0019] The radome 100 also includes a cover 112 that defines a stepped feature 116 complementary to the stepped feature 108 of the rear component 104 and an air gap 120 between the components 104 and 112. The thickness distribution of the cover 112 is within the range of a fourth thickness T4 to a fifth thickness T5 at the stepped feature 116. The thickness distribution of the cover 112 is also optimized to achieve the desired radar performance metric. However, the optimization is independent of or independent of the optimization of the thickness distribution of the rear component 104. In other words, both the rear component 104 and the cover 112 are independently optimized to achieve the desired radar performance metric. The cover 112 can also be formed by injection molding (e.g., in another of the multiple injection molding processes) a suitable radar transparent and transparent or translucent resin (such as PC). The cover 112 is transparent or translucent so that the stepped feature 108 is visible. It should also be appreciated that the cover 112 may be formed from an opaque resin and / or a radar transparent coating (such as a radar transparent metalloid) may be applied to the bottom surface of the cover 112 .

[0020] In one exemplary implementation, thicknesses T1, T2, T4, and T5 are optimized according to the following formula:

[0021] ,

[0022] Where d is the thickness, n is the refractive index of the material, ϴ is the angle of incidence, m is an integer, and λ is the wavelength of the radar. When thicknesses T1, T2, T4, and T5 are optimized as described above, the air gap 120 will not affect the reflection. However, if thickness T3 is too large, and more importantly, if thickness T6 is too large, the individual thicknesses in these regions will not follow the above, which is why thickness T6 should be as small as possible.

[0023] See now Figure 1B, shows an exemplary embodiment of a three-piece radome 150 according to the present disclosure. The radome 150 includes a rear member 154 that defines a substantially uniform thickness T1. The rear member 154 can be formed by injection molding (e.g., in one of a multi-shot injection molding process) a suitable radar transparent resin (such as ASA or PC). In an exemplary implementation, the rear member 154 is opaque, but it should be understood that the rear member 154 can be transparent or translucent. It should also be understood that a radar transparent coating (such as a radar transparent metalloid) can be applied to the top surface of the rear member 154. The radome 150 also includes an intermediate member 158 that defines a stepped feature 162 and an air gap 174 between the members 154 and 158. The stepped feature 162 can be, for example, part of a logo or emblem of a vehicle. The thickness of the intermediate member 158 is distributed in a range from a second thickness T2 at the stepped feature 162 to a third thickness T3. The thickness profile of the intermediate piece 158 is independently optimized to achieve the desired radar performance metric.The intermediate piece 158 may be formed by injection molding (eg, in another pass of a multi-shot molding process) a suitable radar transparent resin such as PC.

[0024] In one exemplary implementation, the intermediate piece 158 is opaque, but it should be understood that the intermediate piece 158 can be transparent or translucent. It should also be understood that a radar transparent coating (such as a radar transparent metalloid) can be applied to the top and / or bottom surfaces of the intermediate piece 158. The radome 150 also includes a cover piece 166 that defines a stepped feature 170 complementary to the stepped feature 162 of the intermediate piece 158 and an air gap 178 between the pieces 158 and 166. The thickness distribution of the cover piece 166 ranges from a fifth thickness T5 to a sixth thickness T6 at the stepped feature 170. The thickness distribution of the cover piece 166 is optimized independently of and independent of the thickness distribution of the intermediate piece 158 to achieve the desired radar performance metric. The cover piece 166 can also be formed by injection molding (e.g., in another pass of a multi-shot injection molding process) a suitable radar transparent and transparent or translucent resin (such as PC). The cover 166 is transparent or translucent so that the stepped feature 162 is visible. It should also be understood that a radar transparent coating, such as a radar transparent metalloid, may be applied to the bottom surface of the cover 166 .

[0025] See now FIG. 2A to FIG. 2B And continue to refer to Figure 1A, graphs 200, 210 showing exemplary radar performance of an exemplary optimized two-piece radome with an air gap according to the present disclosure. The thickness of the rear component 104 is distributed in the range of 2.365 millimeters (mm) (T1) to 3.548 mm (T2) and the thickness of the cover 112 is distributed in the range of 3.547 mm (T4) to 4.730 mm (T5). Graph 200 (left side) shows the radar attenuation or loss of various thicknesses of the air gap 120 in the area where the rear component is 2.365 mm thick (T1) and the cover 112 is 4.730 mm thick (T5). Graph 210 (right) shows the radar attenuation or loss of various widths of the air gap 120 in the area where the rear component 104 is 3.548 mm thick (T2) and the cover 112 is 3.547 mm thick (T4). It can be seen that a relatively large thickness can be selected for the air gap 120 without seriously affecting the radar performance. For example, an air gap of 0.4 mm may be selected as a balance between the radar performance of graphs 200, 210. However, it should be understood that the above thicknesses and illustrated radar performance metrics are merely exemplary data for purposes of this disclosure, and any optimized thickness profile may be determined and utilized.

[0026] Corresponding to Figure 2A Compared with the optimal design, Figure 2B A graph 250 of exemplary radar performance of a non-optimized two-piece radome with varying air gaps is shown in FIG. In this example, the cover piece 112 is 5.322 mm thick and the rear piece 104 is 2.950 mm thick. As shown in FIG. Figure 2B As can be seen in Figure 1, radar loss is relatively low when the air gap is thin (e.g., less than 0.25 mm), but increases significantly as the thickness of the air gap increases (e.g., the loss is almost -4.0 decibels (dB) at a thickness of approximately 1.00 mm). The thickness of the air gap can be an issue due to variations in manufacturing, so it needs to be tightly controlled, which increases cost and complexity.

[0027] Reference now Figure 3A , a flow chart of an exemplary method 300 for manufacturing a two-piece radome is shown. Although specific reference is made herein to Figure 1Aradome 100, but it should be understood that the method 300 can be used to form other two-piece radomes. At 304, a first thickness profile of the rear component 104 is determined for minimum radar attenuation, wherein the rear component 104 defines a first stepped feature 108. At 308, a second thickness profile of the cover 112 is determined for minimum radar attenuation, wherein the cover 112 defines a complementary second stepped feature 116. At 312, the first radar transparent resin and the second radar transparent resin are injection molded to form the rear component 104 and the cover 112, respectively. At 316, the rear component 104 and the cover 112 are combined to form the radome 100, wherein an air gap 120 exists between the rear component 104 and the cover 112. In one exemplary implementation, steps 312 and 316 are a multi-shot injection molding process.

[0028] Reference now Figure 3B , a flow chart of an exemplary method 350 for manufacturing a three-piece radome is shown. Although specific reference is made herein to Figure 1B radome 150, but it should be understood that the method 350 can be used to form other three-piece radomes. At 354, a substantially uniform first thickness profile of the rear component 154 is determined. At 358, a second thickness profile of the middle component 158 ​​is determined, wherein the middle component 158 ​​defines a first stepped feature 162. At 362, a third thickness profile of the cover component 166 is determined for minimum radar attenuation, wherein the cover component 166 defines a complementary second stepped feature 170. At 366, the first radar transparent resin, the second radar transparent resin, and the third radar transparent resin are injection molded to form the rear component 154, the middle component 158, and the cover component 166, respectively. At 370, the rear component 154, the middle component 158, and the cover component 166 are combined to form the radome 150, wherein air gaps 174, 178 exist between the rear component 154, the middle component 158, and the cover component 166. In one exemplary implementation, steps 366 and 370 are a multi-shot injection molding process.

[0029] Exemplary embodiments are provided so that the present disclosure will be exhaustive and will fully convey the scope to those skilled in the art. Several specific details, such as examples of specific components, devices, and methods, are set forth to provide a thorough understanding of the embodiments of the present disclosure. It will be appreciated by those skilled in the art that the exemplary embodiments need not be employed in detail, may be implemented in many different forms, and should not be construed as limiting the scope of the present disclosure. In some exemplary embodiments, well-known procedures, well-known device structures, and well-known techniques are not described in detail.

[0030] The terms used herein are only used for the purpose of describing specific exemplary embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "an" and "the" may also be intended to include plural forms. The term "and / or" includes any and all combinations of one or more items in the associated listed items. The terms "comprises, comprising, including" and "having" are inclusive and therefore specify the presence of the described features, integers, steps, operations, elements and / or parts, but do not exclude the presence or increase of one or more other features, integers, steps, operations, elements, parts and / or their groups. Unless specifically specified to be performed in sequence, the method steps, processes and operations described herein should not be understood as they must be performed in the specific order discussed or described. It should also be understood that additional or optional steps can be adopted.

[0031] Although the first, second, third and other terms can be used to describe various elements, components, regions, layers and / or parts in this article, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or part from another region, layer or part. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used herein. Therefore, without departing from the teaching content of exemplary embodiments, the first element, component, region, layer or part discussed below can be referred to as the second element, component, region, layer or part.

[0032] The foregoing description of the embodiments has been provided for the purpose of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable if appropriate and can be used in selected embodiments, even if not specifically shown or described. This can also be varied in a variety of ways. These variations should not be considered as departing from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

[0033] It should be understood that the mixing and matching of features, elements, methods and / or functions between the various examples may be expressly contemplated herein, such that those skilled in the art will recognize from the present teachings that the features, elements and / or functions of one example may be combined into another example as appropriate, unless otherwise described above.

Claims

1. A two-piece radome, the two-piece radome comprising: a rear component formed by injection molding a first radar transparent resin and defining a first stepped feature and a first thickness profile; and a cover formed by injection molding a second radar transparent resin and defining a second stepped feature and a second thickness profile, the second stepped feature being complementary to the first stepped feature, wherein an air gap exists between the rear component and the cover, and wherein the first thickness profile and the second thickness profile are independently optimized for a desired radar performance metric such that the radome has optimized radar performance independent of the size of the air gap.

2. The radome of claim 1, wherein the first thickness profile and the second thickness profile are independently optimized to achieve minimum radar attenuation. 3 . The radome of claim 1 , wherein the first radar transparent resin is acrylonitrile styrene acrylate (ASA) or polycarbonate (PC), and the second radar transparent resin is polycarbonate (PC).

4. The radome of claim 1, wherein the rear member is opaque and the cover is transparent or translucent. 5 . The radome of claim 1 , wherein the first stepped feature is part of a logo, emblem, or grille feature of a vehicle.

6. A three-piece radome, the three-piece radome comprising: a rear member formed by injection molding a first radar transparent resin and defining a uniform first thickness profile; an intermediate piece formed by injection molding a second radar transparent resin and defining a first stepped feature and a second thickness profile; and a cover formed by injection molding a third radar transparent resin and defining a second stepped feature and a third thickness profile, the second stepped feature being complementary to the first stepped feature, wherein an air gap exists between the rear component, the intermediate component and the cover component, and wherein the second thickness distribution and the third thickness distribution are independently optimized for a desired radar performance metric such that the radome has optimized radar performance independent of the size of the air gap.

7. The radome of claim 6, wherein the second thickness profile and the third thickness profile are independently optimized to achieve minimum radar attenuation. 8 . The radome of claim 6 , wherein each of the first radar transparent resin and the second radar transparent resin is one of acrylonitrile styrene acrylate (ASA) and polycarbonate (PC), and the third radar transparent resin is polycarbonate (PC).

9. The radome of claim 6, wherein the rear member is opaque, the intermediate member is opaque, transparent or translucent, and the cover member is transparent or translucent.

10. The radome of claim 6, wherein the first stepped feature is part of a logo, emblem, or grille feature of a vehicle.

11. A method of manufacturing a two-piece radome, the method comprising: determining a first thickness profile of a rear portion of the radome, the rear portion defining a first stepped feature; determining a second thickness profile of a cover of the radome, the cover defining a second stepped feature complementary to the first stepped feature; injection molding a first radar transparent resin and a second radar transparent resin to form the rear member and the cover member, respectively; as well as combining the rear member and the cover to form the radome, wherein an air gap exists between the rear member and the cover, The first thickness distribution and the second thickness distribution are independently optimized for a desired radar performance metric such that the radome has optimized radar performance independent of the size of the air gap. 12 . The method of claim 11 , wherein the first radar transparent resin and the second radar transparent resin are injection molded and combined via two shots in a multi-shot injection molding process.

13. The method of claim 11, wherein the first thickness profile and the second thickness profile are independently optimized to achieve minimum radar attenuation. 14 . The method of claim 11 , wherein the first radar transparent resin is acrylonitrile styrene acrylate (ASA) or polycarbonate (PC), and the second radar transparent resin is polycarbonate (PC).

15. The method of claim 11, wherein the rear member is opaque and the cover is transparent or translucent. 16 . The method of claim 11 , wherein the first stepped feature is part of a logo, emblem, or grille feature of a vehicle.

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