Dual-mode high-gain millimeter wave beam scanning antenna

Abstract

The invention relates to the technical field of antennas, in particular to a dual-mode high-gain millimeter wave beam scanning antenna, which comprises a bottom layer dielectric substrate, a first excitation port and a second excitation port are arranged at two ends of the bottom layer dielectric substrate; the top-layer dielectric substrate comprises a +-shaped dielectric covering layer arranged at the top of the bottom-layer dielectric substrate; two ends of the parallel plate slot waveguide are respectively connected with the first substrate integrated waveguide horn and the second substrate integrated waveguide horn; two ends of the first waveguide transition structure are respectively connected with the first excitation port and the first substrate integrated waveguide horn; two ends of the second waveguide transition structure are respectively connected with the second excitation port and the second substrate integrated waveguide horn; according to the invention, large-range beam scanning including backward end radiation can be realized, high-gain single-beam scanning is maintained, the antenna has the characteristics of simple structure, easy integrated processing, high gain and full coverage of the upper half space, and the performance of a millimeter wave wireless communication system is greatly improved.

Description

Technical Field

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

[0002] Antennas with beam scanning characteristics can effectively increase the coverage of communication systems and are suitable for application scenarios such as high-speed object tracking and radar imaging. Although traditional phased array antennas can achieve wide beam coverage, in the millimeter wave frequency band, the implementation cost of phased array antennas is high and the structure is complex. In comparison, leaky wave antennas that use frequency-controlled beam scanning can achieve low-cost millimeter wave beam scanning antennas. Leaky wave antennas have shown broad application potential in satellite communications, radar systems, wireless communications, and aircraft communications due to their low profile, simple feeding network, high directivity, and frequency scanning characteristics. 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 solve the inherent electromagnetic wave propagation challenges, enhance link reliability, and optimize coverage and capacity in dense environments.

[0003] Limited by diffraction from floor edges, existing leaky-wave antennas suffer from limited beam coverage, making it difficult to scan in the rearward radiation direction. Existing work typically employs a dual-beam approach for end-fire scanning. However, dual-beam scanning antennas suffer from low directivity and limited gain. Even with the addition of reflectors to achieve single-beam scanning, the increased processing costs and assembly steps hinder practical applications. Summary of the Invention

[0004] To solve the above problems, the present invention provides a dual-mode high-gain millimeter-wave beam scanning antenna, which aims to solve the problem of limited beam coverage of the leaky-wave antenna in the prior art, making it difficult to scan the rear radiation direction.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: The present invention provides a dual-mode high-gain millimeter wave beam scanning antenna, comprising: A bottom dielectric substrate, with a first excitation port and a second excitation port provided at both ends thereof; a top dielectric substrate, comprising a "+"-shaped dielectric covering layer disposed on top of the bottom dielectric substrate; A parallel plate slot waveguide, two ends of which are respectively connected to the first substrate integrated waveguide horn and the second substrate integrated waveguide horn; a first waveguide transition structure, two ends of which are respectively connected to the first excitation port and the first substrate integrated waveguide horn; The second waveguide transition structure has two ends connected to the second excitation port and the second substrate integrated waveguide horn respectively.

[0006] In some embodiments, the first waveguide transition structure and the second waveguide transition structure are distributed on both sides of the parallel plate slot waveguide in a mirror-symmetrical manner, and the first substrate integrated waveguide horn and the second substrate integrated waveguide horn are distributed on both sides of the parallel plate slot waveguide in a mirror-symmetrical manner.

[0007] 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.

[0008] In some embodiments, the dual-mode high-gain millimeter-wave beam scanning antenna further includes a first metal patch disposed on the upper surface of the bottom dielectric substrate and a second metal patch on the lower surface.

[0009] In some embodiments, the first waveguide transition structure is a tapered trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

[0010] In some embodiments, the first substrate integrated waveguide horn includes a first double row of metallized through holes and a second double row of metallized through holes sequentially arranged on the bottom dielectric substrate, the first double row of metallized through holes including two rows of metallized through holes arranged in parallel; the second double row of metallized through holes including two rows of metallized through holes whose spacing gradually increases along the propagation direction to form a horn-shaped opening.

[0011] In some embodiments, the second waveguide transition structure is a tapered trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

[0012] In some embodiments, the second substrate integrated waveguide horn includes a third double row of metallized through holes and a fourth double row of metallized through holes sequentially arranged on the bottom dielectric substrate, the third double row of metallized through holes including two rows of metallized through holes arranged in parallel; the fourth double row of metallized through holes including two rows of metallized through holes with a spacing gradually increasing along the propagation direction to form a horn-shaped opening.

[0013] In some embodiments, the parallel-plate slot waveguide includes a row of periodic array elements.

[0014] In some embodiments, the array element includes a pair of symmetrical slots etched in the first metal patch.

[0015] Beneficial effects of the present invention: The present invention discloses a dual-mode, high-gain millimeter-wave beam scanning antenna, comprising: a dielectric substrate, and sequentially arranged an excitation port, a grounded 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 covering layer. The excitation port serves as a radio frequency signal input terminal or an impedance matching terminal; the grounded coplanar waveguide to substrate integrated waveguide transition structure serves as a feed transition structure; the substrate integrated waveguide horn is disposed after the grounded coplanar waveguide to substrate integrated waveguide transition structure for transmitting radio frequency signals; the parallel plate slot waveguide is disposed after the substrate integrated waveguide horn for leaking radio frequency energy; the adhesive film is disposed on the top layer of the parallel plate slot waveguide for bonding the two dielectric substrates; and the "+"-shaped dielectric covering layer is disposed on top of the adhesive film for effective radiation of surface waves and leaky waves. The antenna of the present invention can achieve large-scale beam scanning including rear-end radiation through the ingenious combination of surface wave mode and leaky wave mode, while maintaining high-gain single-beam scanning. It has the characteristics of 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the millimeter wave beam scanning antenna in one embodiment of the present invention.

[0017] Figure 2 is a perspective view of a millimeter-wave beam scanning antenna according to an embodiment of the present invention.

[0018] Figure 3 FIG. 4 is a schematic diagram of the interior of a millimeter-wave beam scanning antenna according to an embodiment of the present invention.

[0019] Figure 4 FIG. 4 is a top view of a millimeter-wave beam scanning antenna according to an embodiment of the present invention.

[0020] Figure 5 1 is a comparison diagram of the radiation patterns of the millimeter-wave beam scanning antenna with and without a dielectric cover layer loaded in one embodiment of the present invention.

[0021] Figure 6 Schematic diagram of simulation results of the reflection coefficient and transmission coefficient of the millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0022] Figure 7 Schematic diagram of gain simulation results of a millimeter-wave beam scanning antenna in one embodiment of the present invention.

[0023] Figure 81 is the radiation pattern of the millimeter-wave beam scanning antenna at 20 GHz, 21.5 GHz, 23.25 GHz and 26.5 GHz when excited by the first excitation port and the second excitation port respectively in one embodiment of the present invention.

[0024] Among them: P1-first excitation port, P2-second excitation port, W1-first waveguide transition structure, W2-first substrate integrated waveguide horn, W21-first double row of metallized through holes, W22-second double row of metallized through holes, W3-second waveguide transition structure, W4-second substrate integrated waveguide horn, W41-third double row of metallized through holes, W42-fourth double row of metallized through holes, 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 DESCRIPTION

[0025] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] In the description of this invention, "several" means an indefinite quantity, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0027] In the description of the present invention, the terms "comprises," "includes," or any other variations thereof are intended to cover a non-exclusive inclusion, meaning that in addition to the listed elements, other elements not explicitly listed may also be included. Where directional indications are used (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, lateral, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.), such directional indications are only used to explain the relative positional relationships and movement of various components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0028] Based on their geometry and operating mechanism, leaky-wave antennas can be divided into two categories: uniform (including quasi-uniform) and periodic. The former's basic transmission mode is fast wave, with the radiation beam scanning in the forward quadrant at a small scanning angle. The latter, a periodic leaky-wave antenna, has a basic transmission mode of slow wave. In conventional designs, the operating mode of a periodic leaky-wave antenna is usually configured to utilize spatial harmonics, with its radiation beam scanning in both the backward and forward quadrants. Relatively speaking, this type of antenna has a wider scanning range, but it suffers from an open stopband phenomenon. When the beam scans to the broadside direction, problems such as a sharp increase in reflection coefficient and a decrease in radiation gain occur, resulting in discontinuities in its operating frequency band and beam scanning angle.

[0029] In fact, due to the limitations of practical applications, the ground plane is usually limited. Therefore, due to the influence of diffraction at the edge of the floor, the main beam of the leaky wave antenna cannot generally be accurately scanned in the end-fire direction. Accurate end-fire radiation can be achieved through a variety of technologies, such as double-layer slot substrate integrated waveguide, back-to-back half-mode waveguide, anti-phase double-sided parallel stripline structure, cascaded diamond elements, etc. However, the above-mentioned leaky wave antenna can only achieve a single radiation characteristic, that is, beam scanning performance or fixed beam radiation. Existing work generally adopts dual-beam combination to achieve end-fire scanning, but dual-beam scanning antennas have problems such as low directivity and limited gain. Even if single-beam scanning is achieved by adding a reflector, the processing cost and assembly procedures increase, which is not conducive to practical application. Therefore, it is still a great challenge to realize a millimeter-wave beam scanning antenna with wide-angle beam coverage capability, including backward end radiation and high-gain single-beam scanning characteristics.

[0030] Limited by the diffraction problem at the edge of the floor, the main beam of the leaky-wave antenna cannot generally be accurately scanned in the end-fire direction. Further research is needed to realize a high-gain millimeter-wave wide-angle beam scanning antenna including the end-fire direction.

[0031] In order to solve the technical problems in the background technology, the example of the present invention provides a dual-mode high-gain millimeter-wave beam scanning antenna with full coverage in the upper half of the space. The beam scanning antenna of the present invention can achieve large-range beam scanning including rear-end radiation through the clever combination of surface wave mode and leakage wave mode, while maintaining high-gain single-beam scanning. It has the characteristics of simple structure, easy integration and processing, high gain and full coverage in the upper half of the space, greatly improving the performance of the millimeter-wave wireless communication system.

[0032] Please also see Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , an embodiment of the present invention provides a dual-mode high-gain millimeter-wave beam scanning antenna, comprising: The bottom dielectric substrate S1 has a first excitation port P1 and a second excitation port P2 provided at both ends thereof; A top dielectric substrate S2, comprising a "+"-shaped dielectric covering layer disposed on top of the bottom dielectric substrate S1; The parallel plate slot waveguide W5 has two ends connected to the first substrate integrated waveguide horn W2 and the second substrate integrated waveguide horn W4 respectively; A first waveguide transition structure W1, two ends of which are respectively connected to the first excitation port P1 and the first substrate integrated waveguide horn W2; The second waveguide transition structure W3 has two ends connected to the second excitation port P2 and the second substrate integrated waveguide horn W4 respectively.

[0033] In the embodiments provided herein, the first excitation port P1 and the second excitation port P2 serve as RF signal inputs or impedance matching terminals. The underlying dielectric substrate S1 implements the feed network and the parallel-plate slot waveguide W5. A "+"-shaped dielectric cover layer is provided on top of the underlying dielectric substrate S1 to effectively radiate surface waves and leaky waves. Adjusting the shape and dimensions of the dielectric cover layer enables precise rearward radiation, effectively promoting surface wave radiation. The parallel-plate slot waveguide W5 is used to radiate RF energy and achieve high antenna gain.

[0034] The first excitation port P1, the first waveguide transition structure W1, and the first substrate-integrated waveguide horn W2 are sequentially connected. The first waveguide transition structure W1 and the first substrate-integrated waveguide horn W2 are used to transmit the radio frequency signal from the first excitation port P1 to the parallel plate slot waveguide W5. The radio frequency 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 a TEM mode to a quasi-TEM mode. When the first excitation port P1 is excited, the second excitation port P2 acts as a matching load.

[0035] The second excitation port P2, the second waveguide transition structure W3, and the second substrate-integrated waveguide horn W4 are sequentially connected. The second waveguide transition structure W3 and the second substrate-integrated waveguide horn W4 are used to transmit the radio frequency signal from the second excitation port P2 to the parallel plate slot waveguide W5. The radio frequency 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 a TEM mode to a quasi-TEM mode. When the second excitation port P2 is excited, the first excitation port P1 acts as a matching load.

[0036] The antenna of the present invention has the characteristics of simple structure, easy integration and processing, high gain and full coverage of the upper half space, which greatly improves the performance of the millimeter wave wireless communication system.

[0037] 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 feeding network of the antenna. Compared to existing technologies, the dual-mode, high-gain, upper-half-space, full-coverage millimeter-wave beam-scanning antenna provided by this invention achieves wide-range beam scanning, including rearward radiation, through a clever combination of surface wave and leaky wave modes, while maintaining high-gain single-beam scanning. The millimeter-wave beam-scanning antenna proposed in this invention offers full upper-half-space coverage, single-beam scanning, and high gain, making it highly valuable in various millimeter-wave applications.

[0038] In some embodiments, the first waveguide transition structure W1 and the second waveguide transition structure W3 are distributed in a mirror-symmetrical 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-symmetrical manner on both sides of the parallel plate slot waveguide W5.

[0039] 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.

[0040] like Figure 2 As shown, the adhesive film G1 is provided on the top layer of the parallel plate slot waveguide W5, 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.

[0041] 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 of the bottom dielectric substrate S1 and a second metal patch M2 disposed on the lower surface.

[0042] 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 .

[0043] In some embodiments, the first waveguide transition structure W1 is a tapered trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

[0044] The first waveguide transition structure W1 is a tapered trapezoidal structure. The width of its central conductor gradually increases along the signal transmission direction (from the first excitation port P1 toward 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 converts the transmitted electromagnetic wave mode from a quasi-TEM mode to a TE mode.

[0045] In some embodiments, the first substrate integrated waveguide horn W2 includes a first double row of metallized through holes W21 and a second double row of metallized through holes W22 sequentially arranged on the bottom dielectric substrate S1, wherein the first double row of metallized through holes W21 includes two rows of metallized through holes arranged in parallel; and the second double row of metallized through holes W22 includes two rows of metallized through holes whose spacing gradually increases along the propagation direction to form a horn-shaped opening.

[0046] Specifically, the sidewalls of the first substrate-integrated waveguide horn W2 are arranged with an array of plated through holes (PTHs). This array is divided into two functional areas: the first double row of PTHs W21 in the first section utilizes parallel rows of PTHs to maintain the transmission characteristics of a standard substrate-integrated waveguide. The second double row of PTHs W22 in the second section utilizes a double row of PTHs with a gradually increasing spacing along the propagation direction, forming a horn-shaped opening to achieve directional transmission of electromagnetic waves. This PTH array is arranged in a mirror-symmetric pattern about the centerline of the underlying dielectric substrate S1. Signals are 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 the TE mode to the TEM mode, achieving the broadband, low-loss transmission characteristics required for beam scanning.

[0047] In some embodiments, the second waveguide transition structure W3 is a tapered trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

[0048] The second waveguide transition structure W3 is a tapered trapezoidal structure. The width of its central conductor gradually increases along the signal transmission direction (from the second excitation port P2 toward 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 converts the transmitted electromagnetic wave mode from a quasi-TEM mode to a TE mode.

[0049] In some embodiments, the second substrate integrated waveguide horn W4 includes a third double row of metallized through holes W41 and a fourth double row of metallized through holes W42 sequentially arranged on the bottom dielectric substrate S1, wherein the third double row of metallized through holes W41 includes two rows of metallized through holes arranged in parallel; and the fourth double row of metallized through holes W42 includes two rows of metallized through holes whose spacing gradually increases along the propagation direction to form a horn-shaped opening.

[0050] Specifically, the sidewalls of the second substrate-integrated waveguide horn W4 are arranged with an array of metallized through-holes (PTHs). This array is divided into two functional areas: the third PTH array in the first section utilizes a double row of parallel PTHs to maintain the transmission characteristics of a standard substrate-integrated waveguide. The fourth PTH array in the second section utilizes a double row of PTHs with a gradually increasing spacing along the propagation direction, forming a horn-shaped opening to achieve directional transmission of electromagnetic waves. The entire PTH array is arranged in mirror-symmetric fashion about the centerline of the underlying dielectric substrate S1. Signals are transmitted from the second substrate-integrated waveguide horn W4 to the parallel-plate slot waveguide W5, where the transmitted electromagnetic wave mode is converted from the TE mode to the TEM mode, achieving the broadband, low-loss transmission characteristics required for beam scanning.

[0051] In some embodiments, the parallel plate slot waveguide W5 includes a row of periodic array elements.

[0052] Based on the periodic slot structure, a leaky wave radiation mode is realized, thereby achieving a frequency-controlled beam scanning characteristic.

[0053] In some embodiments, the array element includes a pair of slots symmetrically etched in the first metal patch M1.

[0054] Specifically, the parallel plate slot waveguide W5 includes multiple groups of periodically arranged array elements, each group of array elements includes a pair of slots symmetrically etched 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.

[0055] In a preferred embodiment, the parallel plate slot waveguide W5 consists of 25 array elements, each consisting of a pair of symmetrical slots etched into the first metal patch M1. Each element has a period of 3.8 mm, a slot width of 0.1 mm, a length of 22 mm, and a spacing of 1 mm between each pair of slots. Increasing the slot length improves antenna gain. Adjusting the element period and slot size helps control the antenna's dispersion characteristics, thereby controlling leaky wave modes.

[0056] The effective integration of the parallel plate slot waveguide W5 and the top dielectric substrate S2 realizes a dual-mode operation mode, namely a leaky wave mode and a surface wave mode. The dual-mode operation mode is conducive to the realization of precise rear-end radiation, such as Figure 5 As shown. Figure 5 It can be seen that the antenna with the dielectric coating can achieve precise rearward radiation, while the main beam of the antenna without the dielectric coating cannot fully scan the rearward radiation direction. Therefore, adding a dielectric coating to the parallel plate slot waveguide W5 can utilize the effective radiation of surface waves to accurately scan the main beam to the rearward radiation direction, effectively solving the floor diffraction problem.

[0057] 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 through-hole 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 through-holes is 0.8 mm, and the through-hole spacing is 1 mm, which can simulate the waveguide side wall and effectively suppress the leakage of electromagnetic wave energy; 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 opening of 19.42 mm and a length of 25.35 mm, which is conducive to 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 falls within the millimeter wave band. The slot length is 22 mm, which is conducive to the antenna achieving good radiation gain. The thickness of the adhesive film G1 is 0.1 mm, which is conducive to the antenna integration processing. The length of the loaded "+"-shaped dielectric covering layer is 112.3 mm and the width is 26 mm, which is conducive to the antenna achieving precise backward radiation scanning.

[0058] refer to Figure 6 , this embodiment simulates and verifies the antenna, Figure 6 The figure is a schematic diagram of the simulation results of the reflection coefficient and transmission coefficient of the millimeter wave beam scanning antenna array of this embodiment. The reflection coefficient represents the impedance matching characteristics of the antenna, and its value directly reflects the magnitude of the return loss. The larger the reflection coefficient, the worse the antenna matching performance. When the reflection coefficient is less than -10 dB, it can be considered that the antenna has achieved good radiation efficiency. Figure 6 It can be concluded that the operating frequency band of the millimeter wave antenna array proposed in this embodiment is 19.25-27 GHz. The transmission coefficient characterizes the signal transmission characteristics of the two-port network. The lower the transmission coefficient of the leaky wave antenna, the more radio frequency energy is leaked out, which is conducive to achieving good radiation efficiency. Figure 6 It can be seen that the transmission coefficient is lower than -15 dB within the operating frequency band. Figure 7 : is a schematic diagram of the gain simulation results of the millimeter wave beam scanning antenna array proposed in this embodiment. Figure 7 It can be observed that within the operating frequency band, the peak gain is 18.6 dBi, which indicates that the proposed millimeter-wave antenna has a high gain. Figure 8The figure shows 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 when excited by the first excitation port P1 and the second excitation port P2 respectively. It can be observed from the figure that the cross-polarization of the antenna of the proposed millimeter-wave beam scanning antenna array is relatively low (less than -20 dB) in the entire working frequency band. The beam generated by the excitation of the first excitation port P1 scans in the range of -90° to 0°, and the beam generated by the excitation of the second excitation port P2 scans in the range of +90° to 0°, ultimately achieving full coverage of the upper half space. In addition, Figure 8 The precise rearward radiation beam can be observed, which further verifies the dual-mode operation of the proposed antenna. Figure 6 、 Figure 7 as well as Figure 8 The present invention proposes a novel dual-mode, high-gain, upper half-space full-coverage millimeter-wave beam scanning antenna array, which utilizes a parallel plate slot waveguide W5 and a "+"-shaped dielectric covering layer to achieve dual-mode (surface wave mode and leaky wave mode) operation. The surface wave mode is used to achieve precise rear-end radiation beams, while the leaky wave mode is used to generate a wide range of beam scanning capabilities. The present invention achieves full coverage of the upper half-space through pattern reconfiguration technology, and on this basis only uses the rear-facing beam, thereby reducing the required working bandwidth. At the same time, a feeding network based on a substrate-integrated waveguide horn is designed to meet the aperture width requirements of the parallel plate slot waveguide W5. Simulation results show that in the range of 19.25-27 GHz, the peak gain of the antenna is as high as 18.6 dBi, and by switching the input port, the scanning beam can achieve full coverage of the upper half-space from -90° to +90°.

[0059] It should be noted that the core of this invention lies in the ingenious combination of surface wave and leaky wave modes to achieve a wide-angle beam-scanning antenna with a rearward-facing radiation direction. The embodiment of this invention is only one implementation form. By modifying its structure, such as replacing the transmission line, modifying the shape of the dielectric cover layer, and optimizing the radiating structure, various forms of millimeter-wave beam-scanning antennas can be realized. Therefore, the technical solutions of the embodiments of this invention serve as an example to demonstrate the implementation of a millimeter-wave wide-angle beam-scanning antenna with an end-fire direction.

[0060] The embodiments described in the embodiments of the present invention are intended to more clearly illustrate the technical solutions of the embodiments of the present invention and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are also applicable to similar technical problems.

[0061] It will be understood by those skilled in the art that the technical solutions shown in the drawings do not constitute a limitation on the embodiments of the present invention, and the terms "first", "second", "third", "fourth", etc. (if any) in the description of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0062] It should be understood that in the present invention, "at least one (item)" refers to one or more, and "plurality" refers to two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can represent: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one 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, c can be single or multiple.

[0063] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the invention is not limited thereby. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the invention should be within the scope of the invention.

Claims

1. A dual-mode high-gain millimeter-wave beam scanning antenna, characterized in that: include: A bottom dielectric substrate, with a first excitation port and a second excitation port provided at both ends thereof; a top dielectric substrate comprising a "+"-shaped dielectric covering layer disposed on top of the bottom dielectric substrate; A parallel plate slot waveguide, two ends of which are respectively connected to the first substrate integrated waveguide horn and the second substrate integrated waveguide horn; a first waveguide transition structure, two ends of which are respectively connected to the first excitation port and the first substrate integrated waveguide horn; The second waveguide transition structure has two ends connected to the second excitation port and the second substrate integrated waveguide horn respectively.

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 on both sides of the parallel plate slot waveguide in a mirror-symmetrical manner, and the first substrate integrated waveguide horn and the second substrate integrated waveguide horn are distributed on both sides of the parallel plate slot waveguide in a mirror-symmetrical manner.

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 further 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 dual-mode high-gain millimeter wave beam scanning antenna further includes a first metal patch arranged on the upper surface of the bottom dielectric substrate and a second metal patch on the lower surface.

5. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that: The first waveguide transition structure is a gradual trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

6. 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 of metallized through holes and a second double row of metallized through holes sequentially arranged on the bottom dielectric substrate, the first double row of metallized through holes including two rows of metallized through holes arranged in parallel; the second double row of metallized through holes including two rows of metallized through holes with a spacing gradually increasing along the propagation direction to form a horn-shaped opening.

7. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that: The second waveguide transition structure is a gradual trapezoidal structure, and the width of the central conductor thereof gradually increases along the signal transmission direction.

8. 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 of metallized through holes and a fourth double row of metallized through holes sequentially arranged on the bottom dielectric substrate, the third double row of metallized through holes including two rows of metallized through holes arranged in parallel; the fourth double row of metallized through holes including two rows of metallized through holes with a spacing gradually increasing along the propagation direction to form a horn-shaped opening.

9. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 1, characterized in that: The parallel plate slot waveguide includes a row of periodic array elements.

10. The dual-mode high-gain millimeter-wave beam scanning antenna according to claim 9, characterized in that: The array element includes a pair of slots symmetrically etched in a first metal patch.

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