A dual-mode high-gain millimeter wave beam scanning antenna

Abstract

The application relates to the technical field of antennas, in particular to a dual-mode high-gain millimeter wave beam scanning antenna, which comprises a bottom dielectric substrate provided with a first excitation port and a second excitation port at two ends; a top dielectric substrate comprising a '+'-shaped dielectric cover layer arranged on the top of the bottom dielectric substrate; parallel plate slot waveguides connected with a first substrate integrated waveguide horn and a second substrate integrated waveguide horn at two ends respectively; a first waveguide transition structure connected with the first excitation port and the first substrate integrated waveguide horn at two ends respectively; and a second waveguide transition structure connected with the second excitation port and the second substrate integrated waveguide horn at two ends respectively. The application can realize wide-range beam scanning including backward end radiation, meanwhile, high-gain single beam scanning is maintained, the application has the characteristics of simple structure, easy integration and processing, high gain and full coverage of the upper half space, and greatly improves the performance of a millimeter wave wireless communication system.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a dual-mode high-gain millimeter-wave beam scanning antenna. Background Technology

[0002] Antennas with beam-scanning characteristics can effectively increase the coverage of communication systems, making them suitable for applications such as high-speed object tracking and radar imaging. While traditional phased array antennas can achieve wide beam coverage, they are costly and structurally complex in the millimeter-wave band. In contrast, leaky-wave antennas using frequency-controlled beam scanning offer a low-cost solution for millimeter-wave beam-scanning antennas. Leaky-wave antennas, with their low profile, simple feed network, high directivity, and frequency-scanning characteristics, have shown broad application potential in satellite communications, radar systems, wireless communications, and aircraft communications. Therefore, millimeter-wave wide-angle beam-scanning antennas designed based on leaky-wave theory are crucial for the effective deployment of millimeter-wave communication systems. They can address inherent electromagnetic wave propagation challenges, enhance link reliability, and optimize coverage and capacity in dense environments.

[0003] Due to the diffraction problem at the floor edge, existing leaky wave antennas suffer from limited beam coverage, making it generally difficult to scan the rearward end-radiation direction. Current work typically employs a combination of dual beams to achieve end-fire scanning, but dual-beam scanning antennas suffer from low directivity and limited gain. Even if single-beam scanning is achieved by adding a reflector, the increased manufacturing cost and assembly process hinder practical applications. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a dual-mode high-gain millimeter-wave beam scanning antenna, aiming to solve the problem of limited beam coverage in existing leaky-wave antennas, which makes it difficult to scan the rearward radiation direction.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a dual-mode high-gain millimeter-wave beam scanning antenna, comprising:

[0007] The bottom dielectric substrate has a first excitation port and a second excitation port at both ends;

[0008] The top dielectric substrate includes a "+" shaped dielectric overlay layer disposed on top of the bottom dielectric substrate;

[0009] A parallel plate slotted waveguide, with its two ends connected to a first substrate integrated waveguide horn and a second substrate integrated waveguide horn, respectively;

[0010] The first waveguide transition structure has its two ends connected to the first excitation port and the first substrate integrated waveguide horn, respectively.

[0011] The second waveguide transition structure has its two ends connected to the second excitation port and the second substrate integrated waveguide horn, respectively.

[0012] In some embodiments, the first waveguide transition structure and the second waveguide transition structure are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide, and the first substrate integrated waveguide horn and the second substrate integrated waveguide horn are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide.

[0013] In some embodiments, the dual-mode high-gain millimeter-wave beam scanning antenna further includes an adhesive film for connecting the bottom dielectric substrate and the top dielectric substrate.

[0014] In some embodiments, the dual-mode high-gain millimeter-wave beam scanning antenna further includes a first metal patch disposed on the upper surface and a second metal patch disposed on the lower surface of the underlying dielectric substrate.

[0015] In some embodiments, the first waveguide transition structure is a tapered trapezoidal structure, wherein the width of the central conductor gradually increases along the signal transmission direction.

[0016] In some embodiments, the first substrate integrated waveguide horn includes a first double-row metallized via and a second double-row metallized via sequentially disposed on the bottom dielectric substrate. The first double-row metallized via includes two rows of parallel metallized vias; the second double-row metallized via includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

[0017] In some embodiments, the second waveguide transition structure is a tapered trapezoidal structure, wherein the width of the central conductor gradually increases along the signal transmission direction.

[0018] In some embodiments, the second substrate integrated waveguide horn includes a third double-row metallized via and a fourth double-row metallized via sequentially disposed on the bottom dielectric substrate. The third double-row metallized via includes two rows of parallel metallized vias; the fourth double-row metallized via includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

[0019] In some embodiments, the parallel plate slot waveguide includes a row of periodic array elements.

[0020] In some embodiments, the array element includes a pair of symmetrically etched slots in the first metal patch.

[0021] The beneficial effects of this invention: This invention discloses a dual-mode high-gain millimeter-wave beam scanning antenna, the antenna comprising: a dielectric substrate, and sequentially arranged an excitation port, a ground coplanar waveguide-to-substrate integrated waveguide transition structure, a substrate integrated waveguide horn, a parallel plate slot waveguide, an adhesive film, and a "+" shaped dielectric capping layer. The excitation port serves as either a radio frequency signal input or an impedance matching port; the ground coplanar waveguide-to-substrate integrated waveguide transition structure serves as a feed transition structure; the substrate integrated waveguide horn is located after the ground coplanar waveguide-to-substrate integrated waveguide transition structure and is used for radio frequency signal transmission; the parallel plate slot waveguide is located after the substrate integrated waveguide horn and is used for radio frequency energy leakage; the adhesive film is located on the top layer of the parallel plate slot waveguide and is used for bonding the two dielectric substrate layers; the "+" shaped dielectric capping layer is located on top of the adhesive film and is used for effective radiation of surface waves and leakage waves. The antenna of this invention, through the ingenious combination of surface wave mode and leaky wave mode, can achieve wide-range beam scanning including back-end radiation, while maintaining high-gain single-beam scanning. It features simple structure, easy integration and processing, high gain and full coverage of the upper half space, greatly improving the performance of millimeter-wave wireless communication systems. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of a millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0023] Figure 2 This is a perspective view of a millimeter-wave beam scanning antenna according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the internal structure of a millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0025] Figure 4 This is a top view of a millimeter-wave beam scanning antenna according to an embodiment of the present invention.

[0026] Figure 5 This is a comparison diagram of the radiation patterns of a millimeter-wave beam scanning antenna with and without a loaded dielectric covering layer, according to an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the simulation results of the reflection coefficient and transmission coefficient of a millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the gain simulation results of a millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0029] Figure 8The radiation patterns of the millimeter-wave beam scanning antenna at 20 GHz, 21.5 GHz, 23.25 GHz and 26.5 GHz are shown in one embodiment of the present invention when the antenna is excited by the first excitation port and the second excitation port, respectively.

[0030] Wherein: P1-first excitation port, P2-second excitation port, W1-first waveguide transition structure, W2-first substrate integrated waveguide horn, W21-first double-row metallized via, W22-second double-row metallized via, W3-second waveguide transition structure, W4-second substrate integrated waveguide horn, W41-third double-row metallized via, W42-fourth double-row metallized via, W5-parallel plate slot waveguide, S1-bottom dielectric substrate, S2-top dielectric substrate, G1-adhesive film, M1-first metal patch, M2-second metal patch. Detailed Implementation

[0031] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] In the description of this invention, "several" means an indefinite quantity, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0033] In the description of this invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, which includes not only the listed elements but also other elements not expressly listed. Where directional indications (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, lateral, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) are involved, such directional indications are only used to explain the relative positional relationships and movements of the components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly.

[0034] Based on their geometry and operating mechanism, leaky-wave antennas can be divided into two main categories: uniform (including quasi-uniform) and periodic. The former's basic transmission mode is fast wave, with the radiated beam scanning in the forward quadrant at a relatively small scanning angle. The latter, periodic leaky-wave antennas, uses a slow wave transmission mode. In conventional designs, periodic leaky-wave antennas are typically configured to utilize spatial harmonics, allowing their radiated beam to scan in both the backward and forward quadrants. Relatively speaking, this type of antenna has a wider scanning range, but it suffers from stopband issues. When the beam scans to the side-firing direction, problems such as a sharp increase in reflection coefficient and a drop in radiation gain occur, causing discontinuities in its operating frequency band and beam scanning angle.

[0035] In practice, the ground plane is typically finite due to limitations in real-world applications. Therefore, due to the diffraction effect at the ground plane edge, the main beam of a leaky wave antenna generally cannot accurately scan the end-fire direction. Precise end-fire radiation can be achieved through various techniques, such as double-layer slotted substrate integrated waveguides, back-to-back half-mode waveguides, anti-phase double-sided parallel stripline structures, and cascaded rhombic elements. However, these leaky wave antennas can only achieve a single radiation characteristic, namely beam scanning performance or fixed beam radiation. Existing work generally uses a combination of dual beams to achieve end-fire scanning, but dual-beam scanning antennas suffer from low directivity and limited gain. Even if single-beam scanning is achieved by adding reflectors, the increased manufacturing cost and assembly process hinder practical applications. Therefore, realizing a millimeter-wave beam-scanning antenna with wide-angle beam coverage, simultaneously including backward end-fire radiation and high-gain single-beam scanning characteristics, remains a significant challenge.

[0036] Due to the diffraction problem at the floor edge, the main beam of a leaky wave antenna generally cannot be accurately scanned to the end-fire direction. Further research is needed to realize a high-gain millimeter-wave wide-angle beam scanning antenna that includes the end-fire direction.

[0037] To address the technical problems in the background art, this invention provides a dual-mode high-gain millimeter-wave beam scanning antenna with full upper half-space coverage. This beam scanning antenna, through a clever combination of surface wave and leaky wave modes, can achieve wide-range beam scanning, including rear-end radiation, while maintaining high-gain single-beam scanning. It features simple structure, ease of integration and fabrication, high gain, and full upper half-space coverage, greatly improving the performance of millimeter-wave wireless communication systems.

[0038] Please also refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 This invention provides a dual-mode high-gain millimeter-wave beam scanning antenna, comprising:

[0039] The bottom dielectric substrate S1 has a first excitation port P1 and a second excitation port P2 at both ends.

[0040] The top dielectric substrate S2 includes a "+" shaped dielectric cover layer disposed on top of the bottom dielectric substrate S1;

[0041] A parallel plate slot waveguide W5 is connected at both ends to a first substrate integrated waveguide horn W2 and a second substrate integrated waveguide horn W4, respectively.

[0042] The first waveguide transition structure W1 is connected at both ends to the first excitation port P1 and the first substrate integrated waveguide horn W2, respectively.

[0043] The second waveguide transition structure W3 is connected at both ends to the second excitation port P2 and the second substrate integrated waveguide horn W4, respectively.

[0044] In the embodiments provided by this invention, the first excitation port P1 and the second excitation port P2 are radio frequency signal input terminals or impedance matching terminals; the bottom dielectric substrate S1 is used to realize the feed network and the parallel plate slot waveguide W5; a "+" shaped dielectric capping layer is disposed on the top of the bottom dielectric substrate S1 for effective radiation of surface waves and leakage waves. By adjusting the shape and size of the dielectric capping layer, precise back-end radiation can be achieved, effectively promoting the radiation of surface waves; the parallel plate slot waveguide W5 is used to realize the radiation of radio frequency energy and high antenna gain.

[0045] The first excitation port P1, the first waveguide transition structure W1, and the first substrate integrated waveguide horn W2 are connected in sequence. The first waveguide transition structure W1 and the first substrate integrated waveguide horn W2 are used to transmit the radio frequency (RF) signal from the first excitation port P1 to the parallel plate slot waveguide W5. The RF signal is transmitted from the first excitation port P1 to the first waveguide transition structure W1, and the transmitted electromagnetic wave mode is converted from TEM mode to quasi-TEM mode. When the first excitation port P1 is excited, the second excitation port P2 acts as a matching load.

[0046] The second excitation port P2, the second waveguide transition structure W3, and the second substrate integrated waveguide horn W4 are connected in sequence. The second waveguide transition structure W3 and the second substrate integrated waveguide horn W4 are used to transmit the radio frequency (RF) signal from the second excitation port P2 to the parallel plate slot waveguide W5. The RF signal is transmitted from the second excitation port P2 to the second waveguide transition structure W3, and the transmitted electromagnetic wave mode is converted from TEM mode to quasi-TEM mode. When the second excitation port P2 is excited, the first excitation port P1 acts as a matching load.

[0047] The antenna of this invention features a simple structure, ease of integration and fabrication, high gain, and full coverage of the upper half of the space, which greatly improves the performance of millimeter-wave wireless communication systems.

[0048] The first waveguide transition structure W1, the first substrate integrated waveguide horn W2, the second waveguide transition structure W3, and the second substrate integrated waveguide horn W4 constitute the antenna's feed network.

[0049] Compared with existing technologies, the present invention provides a dual-mode high-gain upper half-space full-coverage millimeter-wave beam scanning antenna. Through a clever combination of surface wave mode and leaky wave mode, it can achieve wide-range beam scanning, including back-end radiation, while maintaining high-gain single-beam scanning. The millimeter-wave beam scanning antenna proposed in this invention features upper half-space full coverage, single-beam scanning, and high gain, making it valuable for various millimeter-wave applications.

[0050] In some embodiments, the first waveguide transition structure W1 and the second waveguide transition structure W3 are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide W5, and the first substrate integrated waveguide horn W2 and the second substrate integrated waveguide horn W4 are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide W5.

[0051] In some embodiments, the dual-mode high-gain millimeter-wave beam scanning antenna further includes an adhesive film G1 for connecting the bottom dielectric substrate S1 and the top dielectric substrate S2.

[0052] like Figure 2 As shown, the adhesive film G1 is disposed on the top layer of the parallel plate slot waveguide W5, located between the bottom dielectric substrate S1 and the top dielectric substrate S2, and is used to bond the bottom dielectric substrate S1 and the top dielectric substrate S2 to realize the integrated design of the antenna.

[0053] In some embodiments, the dual-mode high-gain millimeter-wave beam scanning antenna further includes a first metal patch M1 disposed on the upper surface and a second metal patch M2 disposed on the lower surface of the underlying dielectric substrate S1.

[0054] Specifically, the first metal patch M1 and the second metal patch M2 are printed on the upper and lower surfaces of the bottom dielectric substrate S1, and the storage and leakage of radio frequency energy are controlled by the first metal patch M1 and the second metal patch M2.

[0055] In some embodiments, the first waveguide transition structure W1 is a tapered trapezoidal structure, wherein the width of its central conductor gradually increases along the signal transmission direction.

[0056] The first waveguide transition structure W1 is a tapered trapezoidal structure, with the width of its central conductor gradually increasing along the signal transmission direction (from the first excitation port P1 to the first substrate integrated waveguide horn W2). The narrow end is connected to the first excitation port P1, and the wide end is connected to the first substrate integrated waveguide horn W2. This tapered trapezoidal structure enables the transmission of electromagnetic wave modes from quasi-TEM mode to TE mode.

[0057] In some embodiments, the first substrate integrated waveguide horn W2 includes a first double-row metallized via W21 and a second double-row metallized via W22 sequentially disposed on the bottom dielectric substrate S1. The first double-row metallized via W21 includes two rows of parallel metallized vias; the second double-row metallized via W22 includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

[0058] Specifically, the sidewalls of the first substrate integrated waveguide horn W2 are arranged in a metallized via array, which is divided into two functional regions: the first part, the first double-row metallized via W21, uses parallel double-row metallized vias to maintain the transmission characteristics of the standard substrate integrated waveguide; the second part, the second double-row metallized via W22, uses double-row metallized vias with gradually increasing row spacing, forming a horn-shaped opening to achieve directional transmission of electromagnetic waves. This metallized via array is mirror-symmetrical about the centerline of the underlying dielectric substrate S1. The signal is transmitted from the first substrate integrated waveguide horn W2 to the parallel plate slot waveguide W5, where the transmitted electromagnetic wave mode is converted from TE mode to TEM mode, achieving the wideband, low-loss transmission characteristics required for beam scanning.

[0059] In some embodiments, the second waveguide transition structure W3 is a tapered trapezoidal structure, wherein the width of its central conductor gradually increases along the signal transmission direction.

[0060] The second waveguide transition structure W3 is a tapered trapezoidal structure, with the width of its central conductor gradually increasing along the signal transmission direction (from the second excitation port P2 towards the second substrate integrated waveguide horn W4). The narrow end is connected to the second excitation port P2, and the wide end is connected to the second substrate integrated waveguide horn W4. This tapered trapezoidal structure enables the transmission of electromagnetic wave modes from quasi-TEM mode to TE mode.

[0061] In some embodiments, the second substrate integrated waveguide horn W4 includes a third double-row metallized via W41 and a fourth double-row metallized via W42 sequentially disposed on the bottom dielectric substrate S1. The third double-row metallized via W41 includes two rows of parallel metallized vias; the fourth double-row metallized via W42 includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

[0062] Specifically, the sidewalls of the second substrate integrated waveguide horn W4 are arranged in a metallized via array. This metallized via array is divided into two functional regions: the third via array in the first part uses a parallel double-row of metallized vias to maintain the transmission characteristics of a standard substrate integrated waveguide; the fourth via array in the second part uses a double-row of metallized vias with gradually increasing row spacing, forming a horn-shaped opening to achieve directional transmission of electromagnetic waves. The entire metallized via array is mirror-symmetrical about the centerline of the underlying dielectric substrate S1. The signal is transmitted from the second substrate integrated waveguide horn W4 to the parallel plate slot waveguide W5, and the transmitted electromagnetic wave mode is converted from TE mode to TEM mode to achieve the wideband, low-loss transmission characteristics required for beam scanning.

[0063] In some embodiments, the parallel plate slot waveguide W5 includes a row of periodic array elements.

[0064] Based on this periodic slot structure, a leaky wave radiation mode is realized, thereby achieving frequency-controlled beam scanning characteristics.

[0065] In some embodiments, the array element includes a pair of symmetrically etched slots in the first metal patch M1.

[0066] Specifically, the parallel plate slot waveguide W5 includes multiple sets of periodically arranged array elements, each set of elements including a pair of symmetrically etched slots on the first metal patch M1. The parallel plate slot waveguide W5 is obtained by etching a row of periodic array elements on the first metal patch M1.

[0067] In a preferred embodiment, the parallel plate slot waveguide W5 consists of 25 array elements. Each array element is composed of a pair of symmetrical slots etched onto the first metal patch M1. The period of each array element is 3.8 mm, the slot width is 0.1 mm, the length is 22 mm, and the spacing between each pair of slots is 1 mm. Increasing the slot length helps to improve the antenna gain. Adjusting the element period and slot size helps to control the antenna's dispersion characteristics, thereby achieving control over the leakage wave mode.

[0068] The effective integration of the parallel plate slotted waveguide W5 and the top dielectric substrate S2 enables dual-mode operation, namely leaky wave mode and surface wave mode. This dual-mode operation facilitates precise back-end radiation, such as... Figure 5 As shown. From Figure 5 It can be seen that the antenna with the dielectric cladding layer can achieve precise rearward radiation, while the main beam of the antenna without the dielectric cladding layer cannot fully scan the rearward radiation direction. Therefore, by adding a dielectric cladding layer to the parallel plate slotted waveguide W5, the effective radiation of surface waves can be utilized to enable the main beam to accurately scan the rearward radiation direction, thus effectively solving the floor diffraction problem.

[0069] In some preferred embodiments, the characteristic impedance of the first excitation port P1 and the second excitation port P2 is set to 50 ohms; the narrow side width of the signal conductor of the first waveguide transition structure W1 and the second waveguide transition structure W3 is 0.27 mm, the wide side width is 2.57 mm, and the length is 4.95 mm, which helps to achieve a smooth impedance transition from the grounded coplanar waveguide structure to the substrate integrated waveguide; the metallized via diameter of the first substrate integrated waveguide horn W2 and the second substrate integrated waveguide horn W4 is 0.8 mm, the radius of the two rows of metal vias is 0.8 mm, and the via spacing is 1 mm, which can simulate the waveguide sidewall and effectively suppress electromagnetic wave energy leakage; the first part of the first substrate integrated waveguide horn W2 and the second substrate integrated waveguide horn W4 is a substrate integrated waveguide with a waveguide width of 3.35 mm, ensuring the TE of the substrate integrated waveguide. 10 The mode cutoff frequency is 17.5 GHz. The second part is a horn structure with a horn aperture of 19.42 mm and a length of 25.35 mm, which is beneficial for providing a wider radiation aperture for the parallel plate slot waveguide W5. The array element period of the parallel plate slot waveguide W5 is set to 3.8 mm, so that its operating frequency is in the millimeter wave band. The slot length is 22 mm, which is beneficial for the antenna to achieve good radiation gain. The adhesive film G1 has a thickness of 0.1 mm, which is beneficial for antenna integration and processing. The loaded "+" shaped dielectric cover layer has a length of 112.3 mm and a width of 26 mm, which is beneficial for the antenna to achieve accurate back-end radiation scanning.

[0070] refer to Figure 6 This embodiment uses simulation to verify the antenna. Figure 6 This is a schematic diagram illustrating the simulation results of the reflection coefficient and transmission coefficient of the millimeter-wave beam scanning antenna array in this embodiment. The reflection coefficient characterizes the impedance matching characteristics of the antenna, and its value directly reflects the magnitude of return loss. A larger reflection coefficient indicates poorer antenna matching performance; when the reflection coefficient is less than -10 dB, the antenna can be considered to have achieved good radiation efficiency. Figure 6 It can be concluded that the millimeter-wave antenna array proposed in this embodiment operates in the 19.25-27 GHz frequency band. The transmission coefficient characterizes the signal transmission characteristics of a two-port network; a lower transmission coefficient for a leaky antenna indicates that most of the radio frequency energy is leaked out, which is beneficial for achieving good radiation efficiency. Figure 6 As can be seen, the transmission coefficient is below -15 dB within the operating frequency band. Figure 7 This is a schematic diagram illustrating the gain simulation results of the millimeter-wave beam scanning antenna array proposed in this embodiment. From... Figure 7 As can be observed, the peak gain is 18.6 dBi within the operating frequency band, indicating that the proposed millimeter-wave antenna has high gain. Figure 8The figures show the radiation patterns of the millimeter-wave beam-scanning antenna array provided in this embodiment at 20 GHz, 21.5 GHz, 23.25 GHz, and 26.5 GHz, respectively, when excited by the first excitation port P1 and the second excitation port P2. As can be observed from the figures, the proposed millimeter-wave beam-scanning antenna array exhibits relatively low antenna cross-polarization (less than -20 dB) across the entire operating frequency band. The beam generated by the first excitation port P1 scans within the range of -90° to 0°, while the beam generated by the second excitation port P2 scans within the range of +90° to 0°, ultimately achieving full coverage of the upper half of space. Furthermore, in Figure 8 A precise rear-end radiated beam can be observed, further verifying the dual-mode operation of the proposed antenna. The results obtained from the comprehensive simulation... Figure 6 , Figure 7 as well as Figure 8 This invention proposes a novel dual-mode, high-gain, upper-half-space full-coverage millimeter-wave beam scanning antenna array. Utilizing a parallel-plate slotted waveguide W5 and a "+"-shaped dielectric cladding layer, it achieves dual-mode (surface wave mode and leaky wave mode) operation. The surface wave mode is used to achieve precise back-end radiated beam, while the leaky wave mode generates a wide-range beam scanning capability. This invention achieves upper-half-space full coverage through pattern reconfiguration technology and, based on this, uses only the back-end beam, thereby reducing the required operating bandwidth. A feed network based on a substrate-integrated waveguide horn is also designed to meet the aperture width requirements of the parallel-plate slotted waveguide W5. Simulation results show that the antenna achieves a peak gain of up to 18.6 dBi in the 19.25-27 GHz range, and upper-half-space full coverage with a scanning beam from -90° to +90° can be achieved by switching the input ports.

[0071] It should be noted that the core of this invention lies in the ingenious combination of surface wave mode and leaky wave mode to achieve a wide-angle beam scanning antenna with rearward end-radiating direction. The embodiments of this invention are only one implementation form. By modifying its structure, such as replacing the transmission line, modifying the shape of the dielectric cladding layer, and optimizing the radiating structure, various forms of millimeter-wave beam scanning antennas can be realized. Therefore, the technical solution of this invention embodiment serves as an example to demonstrate the implementation of a millimeter-wave wide-angle beam scanning antenna with end-radiating direction.

[0072] The embodiments described in this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems.

[0073] Those skilled in the art will understand that the technical solutions illustrated in the figures do not constitute a limitation on the embodiments of the present invention. The terms "first," "second," "third," "fourth," etc. (if present) in the specification and the aforementioned figures are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0074] It should be understood that in this invention, "at least one (item)" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0075] The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and spirit of the present invention should be within the scope of the claims of the present invention.

Claims

1. A dual-mode high-gain millimeter-wave beam scanning antenna, characterized in that, include: The bottom dielectric substrate has a first excitation port and a second excitation port at both ends; A top dielectric substrate includes a "+" shaped dielectric overlay layer disposed on top of a bottom dielectric substrate; the dielectric overlay layer is disposed on top of the bottom dielectric substrate. A parallel plate slotted waveguide, with its two ends connected to a first substrate integrated waveguide horn and a second substrate integrated waveguide horn, respectively; The first waveguide transition structure has its two ends connected to the first excitation port and the first substrate integrated waveguide horn, respectively. The second waveguide transition structure has its two ends connected to the second excitation port and the second substrate integrated waveguide horn, respectively. The dual-mode high-gain millimeter-wave beam scanning antenna also includes a first metal patch disposed on the upper surface and a second metal patch disposed on the lower surface of the underlying dielectric substrate. The parallel plate slot waveguide includes a row of periodic array elements, each array element including a pair of symmetrically etched slots on a first metal patch; the dielectric overlay layer covers the parallel plate slot waveguide; The parallel plate slotted waveguide and dielectric capping layer enable dual-mode operation: leakage wave mode and surface wave mode. The first substrate integrated waveguide horn includes a metallized via disposed on the bottom dielectric substrate, and the second substrate integrated waveguide horn includes a metallized via disposed on the bottom dielectric substrate.

2. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The first waveguide transition structure and the second waveguide transition structure are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide, and the first substrate integrated waveguide horn and the second substrate integrated waveguide horn are distributed in a mirror-symmetric manner on both sides of the parallel plate slot waveguide.

3. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The dual-mode high-gain millimeter-wave beam scanning antenna also includes an adhesive film for connecting the bottom dielectric substrate and the top dielectric substrate.

4. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The first waveguide transition structure is a gradually increasing trapezoidal structure, with the width of its central conductor gradually increasing along the signal transmission direction.

5. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The first substrate integrated waveguide horn includes a first double-row metallized via and a second double-row metallized via sequentially disposed on the bottom dielectric substrate. The first double-row metallized via includes two rows of parallel metallized vias; the second double-row metallized via includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

6. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The second waveguide transition structure is a gradually increasing trapezoidal structure, with the width of its central conductor gradually increasing along the signal transmission direction.

7. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that, The second substrate integrated waveguide horn includes a third double-row metallized via and a fourth double-row metallized via sequentially disposed on the bottom dielectric substrate. The third double-row metallized via includes two rows of parallel metallized vias; the fourth double-row metallized via includes two rows of metallized vias with a gradually increasing spacing along the propagation direction to form a horn-shaped opening.

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