End-on-fire antenna and device

Abstract

The invention discloses an end-on-fire antenna and equipment, and relates to the technical field of antennae, and the end-on-fire antenna comprises a dielectric substrate, a transmission structure and a resonant cavity. The surface of the dielectric substrate is provided with a coupling window, and the transmission structure is integrated in the dielectric substrate. The resonant cavity comprises a first reflecting surface and a second reflecting surface; the coupling window couples electromagnetic waves into the dielectric substrate, and the electromagnetic waves are radiated towards an end fire direction after being reflected by the first reflecting surface and the second reflecting surface for multiple times along the transmission structure and coherently superposed. The antenna provided by the invention not only can realize end fire, but also has high gain.

Description

Technical Field

[0001] This application relates to the field of antenna technology, and particularly to an end-fire antenna and a device. Background Art

[0002] Among various types of antennas, the Fabry–Perot resonator antenna has attracted much attention due to its high gain and directional radiation characteristics. Traditional Fabry–Perot resonator antennas are usually designed as broadside antennas, that is, electromagnetic waves radiate perpendicular to the antenna aperture plane. This design forms a resonator through two parallel partially reflecting surfaces and a total reflecting surface, enabling the electromagnetic waves to be reflected multiple times in the cavity and coherently superposed, and finally achieving high-gain radiation in the broadside direction. However, the application scenarios of broadside antennas have certain limitations, especially in occasions where end-fire radiation is required, that is, electromagnetic waves radiate along the antenna aperture plane direction.

[0003] In contrast, end-fire antennas can achieve radiation along the antenna aperture plane direction, with the advantages of low profile and easy integration, but their gain is usually low and the bandwidth is limited. Although end-fire antennas such as microstrip patch antennas have been widely used in communication systems, their performance is difficult to meet the requirements of modern communication systems for high gain and broadband characteristics. Summary of the Invention

[0004] The main objective of this application is to propose an end-fire antenna and a device, aiming to achieve high-gain end-fire radiation by using a low-complexity antenna structure.

[0005] To achieve the above objective, the end-fire antenna proposed in this application includes: A dielectric substrate, on the surface of which a coupling window is formed; A transmission structure, integrated inside the dielectric substrate; A resonator, the resonator includes a first reflecting surface and a second reflecting surface, the first reflecting surface is the interface between the dielectric substrate and air in the vertical direction, and the second reflecting surface is the reflecting surface formed by the transmission structure in the vertical direction; The coupling window couples electromagnetic waves into the dielectric substrate, and after the electromagnetic waves are reflected multiple times by the first reflecting surface and the second reflecting surface along the transmission structure and coherently superposed, they radiate in the end-fire direction.

[0006] In an embodiment, the end-fire antenna further includes a metal plate, and the metal plate is disposed on the upper surface and the lower surface of the dielectric substrate.

[0007] In an embodiment, the metal plate includes: A main body covering part, the main body covering part matches the contour of the dielectric substrate; An extension part, the extension part extends outward from the edge of the main body covering part; Wherein, the thickness of the main body covering portion is greater than that of the extension portion.

[0008] In one embodiment, the dielectric substrate includes a head and a tail, metal layers are provided on both the upper and lower surfaces of the head and the tail, and a coupling window is formed in the metal layer of the tail.

[0009] In one embodiment, the end-fire antenna further includes: A rectangular waveguide for feeding the dielectric substrate; The rectangular waveguide is vertically coupled to the dielectric integrated waveguide through the coupling window.

[0010] In one embodiment, a metal patch is provided in the coupling window, and the size of the metal patch is smaller than that of the coupling window.

[0011] In one embodiment, the transmission structure includes: A straight section disposed at the tail of the dielectric substrate, and a portion of the straight section near the coupling window surrounds the rectangular waveguide; An open section disposed at the head of the dielectric substrate, and the open section gradually opens to both sides of the dielectric substrate along the straight section.

[0012] In one embodiment, the transmission structure includes a dielectric integrated waveguide, and the dielectric integrated waveguide includes the straight section and the open section formed by hollow metal parts spaced apart in the dielectric substrate.

[0013] In one embodiment, the spacing between the hollow metal parts near the coupling window is greater than the spacing between the hollow metal parts in other parts of the dielectric substrate; The radius of the hollow metal parts near the coupling window is smaller than the radius of the hollow metal parts in other parts of the dielectric substrate.

[0014] The present application also provides an end-fire antenna device, including an end-fire antenna, and the end-fire antenna includes: A dielectric substrate, on the surface of which a coupling window is formed; A transmission structure integrated inside the dielectric substrate; A resonant cavity, the resonant cavity includes a first reflecting surface and a second reflecting surface, the first reflecting surface is the interface between the dielectric substrate and air in the vertical direction, and the second reflecting surface is the reflecting surface formed by the transmission structure in the vertical direction; The coupling window couples electromagnetic waves into the dielectric substrate, and after the electromagnetic waves are reflected multiple times by the first reflecting surface and the second reflecting surface along the transmission structure and coherently superposed, they are radiated in the end-fire direction.

[0015] The technical solution of this application couples electromagnetic waves into the dielectric substrate through a coupling window and a transmission structure, and uses the interface between the dielectric substrate and air in the vertical direction as the first reflection surface, and the reflection surface of the transmission structure in the vertical direction as the second reflection surface to jointly form a resonant cavity. The electromagnetic waves are reflected multiple times by the first reflection surface and the second reflection surface along the transmission structure and coherently superposed, and radiate in the end-fire direction, so as to achieve high-gain radiation in the end-fire direction by using a complex structure. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0017] Figure 1 Schematic three-dimensional structure diagram of the end-fire antenna provided by the present application; Figure 2 is Figure 1 partial structure schematic diagram of; Figure 3 Partial structure schematic diagram of the end-fire antenna provided by the present application; Figure 4 is Figure 1 partial structure perspective view of.

[0018] Explanation of the reference numerals in the drawings: 100, end-fire antenna; 1, dielectric substrate; 11, head; 12, tail; 13, metal layer; 14, coupling window; 141, metal patch; 2, transmission structure; 21, straight section; 22, open section; 23, hollow metal part; 3, resonant cavity; 31, first reflection surface; 32, second reflection surface; 4, metal plate; 41, main body covering part; 42, extension part; 5, rectangular waveguide.

[0019] The realization of the purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the drawings. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0021] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of this application, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0022] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of this application, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0023] In a wireless communication system, as a key component for electromagnetic wave radiation and reception, the performance of an antenna directly affects communication quality. The Fabry - Perot (FP) resonant cavity antenna has been widely studied due to its high gain, narrow beam, and strong directivity. Traditional FP resonant cavity antennas usually adopt the end - fire radiation mode, that is, electromagnetic waves radiate perpendicular to the antenna aperture plane. Its typical structure consists of a partially reflecting surface and a fully reflecting surface to form a resonant cavity, enabling electromagnetic waves to be reflected multiple times and coherently superposed within the cavity, and finally forming high - gain radiation in the end - fire direction. However, the application scenarios of end - fire antennas have certain limitations. For example, in systems that require low profile, conformal installation, or radiation along the antenna plane direction, traditional FP antennas are difficult to meet the requirements.

[0024] In contrast, end - fire antennas can achieve the radiation of electromagnetic waves along the antenna aperture plane direction, with advantages such as low profile and easy integration, and have important application values in vehicle - mounted communication, UAV data links, and portable devices. However, existing end - fire antennas usually face problems such as low gain.

[0025] To solve this technical problem, this application provides an end - fire antenna 100.

[0026] Please refer to Figures 1 to 4 , in the first embodiment of this application, the end - fire antenna 100 includes: A dielectric substrate 1, on the surface of which a coupling window 14 is opened; A transmission structure 2, integrated inside the dielectric substrate 1; The resonant cavity 3, the resonant cavity 3 includes a first reflecting surface 31 and a second reflecting surface 32, the first reflecting surface 31 is the interface between the dielectric substrate 1 and air in the vertical direction, and the second reflecting surface 32 is the reflecting surface formed by the transmission structure 2 in the vertical direction; The coupling window 14 couples the electromagnetic wave into the dielectric substrate 1. After the electromagnetic wave is reflected multiple times by the first reflecting surface 31 and the second reflecting surface 32 along the transmission structure 2 and coherently superposed, it radiates in the end-fire direction.

[0027] In the technical solution provided by the present application, the end-fire antenna 100 includes a dielectric substrate 1, a transmission structure 2 and a resonant cavity 3. The resonant cavity 3 may include a first reflecting surface 31, a second reflecting surface 32 and a cavity. The dielectric substrate 1 serves as the main carrier of the end-fire antenna 100 of the present application, and a coupling window 14 is formed on its surface. The coupling window 14 is used to efficiently couple external electromagnetic waves into the substrate. The transmission structure 2 integrated inside the dielectric substrate 1 guides the propagation path of the electromagnetic wave inside the dielectric substrate 1. At the same time, the transmission structure 2 can form a second reflecting surface 32 in the vertical direction. The second reflecting surface 32 is parallel to the first reflecting surface 31 formed by the dielectric substrate 1 and air in the vertical direction. The first reflecting surface 31 utilizes the inherent impedance mutation characteristic of the dielectric substrate 1-air interface to achieve partial reflection. The second reflecting surface 32 forms total reflection through the metallized edge or metal wall of the transmission structure 2. The first reflecting surface 31 and the second reflecting surface 32 form the resonant cavity 3 effect, so that the electromagnetic wave coupled into the dielectric substrate 1 experiences multiple reflections on the propagation path. These reflected waves are coherently superposed under specific phase conditions, and finally an enhanced radiation field is formed in the end-fire direction. The above technical solution enables the electromagnetic wave to achieve end-fire radiation while enhancing the radiation intensity of the electromagnetic wave in the end-fire direction.

[0028] In addition, the end-fire antenna 100 of the present application has the advantages of low profile and easy integration. Specifically, the transmission structure 2 and the resonant cavity 3 integrated inside the dielectric substrate 1 of the present application adopt a planar design, avoiding the three-dimensional resonant cavity or three-dimensional feeding structure required by the traditional end-fire antenna 100, greatly compressing the space occupation ratio in the vertical direction, and without external components or complex assembly, so that all electromagnetic regulation functions are completed in a planar substrate.

[0029] Optionally, the dielectric substrate 1 can be made of a low-loss high-frequency material, which can effectively reduce transmission loss. The coupling window 14 can be accurately formed on its surface by photolithography technology, so that the size of the coupling window 14 can be flexibly adjusted to meet the requirements of different electromagnetic wave frequency bands.

[0030] More specifically, as Figure 1As shown, in the second embodiment of the present application, the dielectric substrate 1 includes a head 11 and a tail 12. Metal layers 13 are provided on the upper and lower surfaces of the head 11 and the tail 12, and a coupling window 14 is formed in the metal layer 13 of the tail 12.

[0031] In this embodiment, the dielectric substrate 1 includes a head 11 and a tail 12. The upper and lower surfaces of the head 11 and the tail 12 are both provided as metal layers 13. Among them, the coupling window 14 is formed in the metal layer 13 of the tail 12 by an etching process. Specifically, the coupling window 14 of the tail 12 serves as an electromagnetic wave energy input port to couple an external electromagnetic wave signal into the dielectric substrate 1. The head 11 and the tail 12 form a continuous waveguide channel through an internally integrated transmission structure 2 to guide the electromagnetic wave to propagate in the direction of the head 11. During this process, the vertical interface between the dielectric substrate 1 located at the head 11 and the air forms a first reflecting surface 31, and the equivalent waveguide walls generated by the transmission structure 2 in the vertical direction constitute a second reflecting surface 32. The two cooperate to form an asymmetric resonant cavity 3 structure. The electromagnetic wave is reflected and phase-superimposed multiple times in the resonant cavity 3, and finally an enhanced radiation field is formed in the end-fire direction.

[0032] Furthermore, in the second embodiment of the present application, the end-fire antenna 100 further includes: A rectangular waveguide 5, which is used to feed the dielectric substrate 1; The rectangular waveguide 5 is vertically coupled to the dielectric integrated waveguide through the coupling window 14.

[0033] As Figure 1 shown, in this embodiment, the end-fire antenna 100 further integrates a rectangular waveguide 5 to feed the dielectric substrate 1, and specifically realizes the energy transmission with the transmission structure 2 through a vertical coupling mechanism. The open end of the rectangular waveguide 5 is aligned with the coupling window 14 to inject electromagnetic energy into the dielectric substrate 1.

[0034] Furthermore, a metal patch 141 is provided in the coupling window 14, and the size of the metal patch 141 is smaller than the size of the coupling window 14.

[0035] As Figure 2As shown in the figure, in this embodiment, a metal patch 141 is added in the coupling window 14. The metal patch 141 is centrally arranged in the opening area of the coupling window 14 in a suspended structure, and the size of the metal patch 141 is smaller than that of the coupling window 14. When electromagnetic waves are transmitted from the rectangular waveguide 5 to the transmission structure 2 through the coupling window 14, the metal patch 141 generates a local electric field enhancement effect at the coupling interface. The fringe capacitance formed between the edge of the metal patch 141 and the metal layer 13 of the coupling window 14 and the equivalent inductance of the transmission structure 2 constitute a matching network to reduce energy reflection. At the same time, the introduction of the metal patch 141 changes the surface current path in the coupling region, guiding the current peak originally concentrated at the edge of the coupling window 14 towards the center of the metal patch 141, reducing the parasitic radiation caused by edge diffraction and improving the coupling efficiency.

[0036] In addition, to ensure that electromagnetic waves are transmitted to the dielectric substrate 1 in the form of electric field coupling rather than direct conduction, the size of the metal patch 141 is set to be smaller than that of the coupling window 14. Specifically, the coupling window 14 is opened in the metal layer 13 at the tail 12 of the dielectric substrate 1. If the size of the metal patch 141 is equal to or larger than that of the coupling window 14, the edge of the metal patch 141 will be in direct contact with the metal layer 13 near the coupling window 14, resulting in the short - circuit loss of electromagnetic energy through the metal layer 13 and unable to be effectively coupled to the transmission structure 2 inside the dielectric substrate 1.

[0037] Furthermore, a fringe capacitance will be formed between the metal patch 141 and the metal layer 13 of the coupling window 14. Specifically, when electromagnetic waves are transmitted from the rectangular waveguide 5 to the transmission structure 2 through the coupling window 14, as a conductor, the edge of the metal patch 141 and the edge of the metal layer 13 of the coupling window 14 will accumulate charges due to the potential difference, which is equivalent to a parallel capacitor (C); while the transmission structure 2 can be equivalent to a series inductor (L) due to its inductance characteristics. The two together constitute an LC matching network, which can cancel the impedance mismatch between the rectangular waveguide 5 and the transmission structure 2, reduce the reflection coefficient of energy transmission, thereby minimizing the reflection loss and improving the signal transmission efficiency.

[0038] It should be noted that the size difference between the metal patch 141 and the coupling window 14 can be flexibly adjusted according to the target frequency band.

[0039] In the second embodiment of the present application, the rectangular waveguide 5 serves as the feeding core, and accurately injects external electromagnetic energy by vertically coupling and aligning with the coupling window 14 of the dielectric substrate 1; while the fringe capacitance formed by the gap between the suspended metal patch 141 and the metal layer 13 of the coupling window 14 in the coupling window 14 and the inductance of the transmission structure 2 form an LC matching network to smoothly transition the impedance difference between the rectangular waveguide 5 and the transmission structure 2 and reduce the reflection loss. At the same time, the metal patch 141 guides the current to concentrate from the edge of the coupling window 14 to the center, reducing the parasitic radiation caused by edge diffraction and improving the coupling efficiency.

[0040] Based on the second embodiment of the present application, in the third embodiment of the present application, the transmission structure 2 includes: A straight section 21 is disposed at the tail 12 of the dielectric substrate 1, and a part of the straight section 21 close to the coupling window 14 surrounds the rectangular waveguide 5; An opening section 22 is disposed at the head 11 of the dielectric substrate 1, and the opening section 22 gradually opens to both sides of the dielectric substrate 1 along the straight section 21.

[0041] As Figure 1 and Figure 3 shown, after the rectangular waveguide 5 injects electromagnetic energy into the dielectric substrate 1 through the coupling window 14, the straight section 21 of the transmission structure 2 serves as an energy transition region. A part of the straight section 21 close to the coupling window 14 surrounds the rectangular waveguide 5 to enhance the matching and reduce the reflection caused by mode mismatch. Subsequently, the electromagnetic wave propagates along the straight section 21 towards the head 11 of the dielectric substrate 1. After entering the opening section 22, the opening section 22 gradually opens to both sides of the dielectric substrate 1 along the straight section 21. By expanding the transverse size of the waveguide, the electromagnetic wave is guided to expand the beam width in the horizontal direction. At the same time, by using the resonance effect of the resonance cavity 3, the electromagnetic waves reflected multiple times are coherently superimposed in the end-fire direction, and finally a high-gain end-fire radiation is formed.

[0042] It should be noted that the straight section 21 is disposed at the tail 12 of the dielectric substrate 1 and also serves as the starting section of the transmission structure 2. Its core function is to realize the energy transition between the rectangular waveguide 5 and the transmission structure 2. A part of the straight section 21 close to the coupling window 14 forms an equivalent closed boundary with the rectangular waveguide 5 to constrain the electromagnetic wave to transmit in the waveguide and reduce the energy leakage.

[0043] The opening section 22 is disposed at the head 11 of the dielectric substrate 1 and also serves as the expansion section of the transmission structure 2. The opening section 22 gradually opens to both sides of the dielectric substrate 1 along the straight section 21 to expand the transverse propagation space of the electromagnetic wave, so that the beam diverges in the horizontal direction. At the same time, by using the first reflecting surface 31 and the second reflecting surface 32, a resonance enhancement effect similar to a "flare" is formed.

[0044] Furthermore, the third embodiment of the present application further includes: the transmission structure 2 includes a dielectric integrated waveguide, and the dielectric integrated waveguide includes the straight section 21 and the opening section 22 formed by hollow metal parts 23 spaced apart in the dielectric substrate 1.

[0045] Please refer to Figure 2 and Figure 3, the transmission structure 2 of this embodiment includes a dielectric integrated waveguide, and the dielectric integrated waveguide includes the straight section 21 and the opening section 22 formed by hollow metal parts 23 spaced in the dielectric substrate 1. The straight section 21 and the opening section 22 form a closed waveguide boundary through the continuous arrangement of the hollow metal parts 23, simulating the electromagnetic confinement characteristics of a traditional waveguide.

[0046] It should be noted that in the high-frequency mode, the skin effect of electromagnetic waves is significantly enhanced. The inner wall of a traditional solid metal waveguide will cause the current to concentrate on the surface layer due to the skin effect, resulting in a large resistance loss. In this embodiment, the hollow metal parts 23 are used, which not only ensure the electromagnetic confinement ability of the waveguide boundary but also reduce the effective conduction area of high-frequency currents, thereby reducing the resistance loss. In addition, the internal medium of the hollow metal parts 23 and the external dielectric substrate 1 form a composite structure, and the equivalent dielectric constant is between the two, which is in line with the wavelength of high-frequency electromagnetic waves, reducing the mode distortion and energy leakage caused by the sudden change of the dielectric constant.

[0047] It can be seen that the opening section 22 gradually opens to both sides of the dielectric substrate 1 along the straight section 21. Optionally, the hollow metal parts 23 of the opening section 22 are designed as a tapered via array, and the tapering process is to gradually open to both sides of the dielectric substrate 1. Through the gradual adjustment of the transmission path, a smooth transition of the electromagnetic wave field distribution is achieved. Specifically, the sudden expansion of a traditional waveguide, such as directly widening, will cause the electromagnetic wave to generate reflection at the sudden change, while the tapered structure gradually adjusts the waveguide width, reducing the difference between the wave impedance of the straight section 21 and the wave impedance of the opening section 22, and reducing the reflection coefficient. The tapered expansion of the opening section 22 and the resonant cavity 3 cooperate with each other, so that after the electromagnetic wave is reflected multiple times during the propagation process, the reflected waves are coherently superimposed in the end-fire direction, thereby enhancing the radiation field strength.

[0048] More specifically, the spacing of the hollow metal parts 23 near the coupling window 14 is greater than the spacing of the hollow metal parts 23 in other parts of the dielectric substrate 1; the radius of the hollow metal parts 23 near the coupling window 14 is smaller than the radius of the hollow metal parts 23 in other parts of the dielectric substrate 1.

[0049] In this embodiment, the hollow metal parts 23 inside the dielectric substrate 1 form the boundary of the transmission structure 2, restricting and guiding the electromagnetic signal to propagate towards the antenna radiation surface.

[0050] Specifically, the spacing of the hollow metal part 23 near the coupling window 14 is greater than that of the hollow metal part 23 in other parts of the dielectric substrate 1, so that the via hole spacing is increased, and then the metal shielding area near the coupling window 14 is reduced. When the electromagnetic signal enters the interior of the dielectric substrate 1, it encounters less resistance and is more likely to propagate along the transmission structure 2 to the radiation surface. At the same time, the larger spacing makes the electromagnetic environment in this area closer to the signal environment of the external feeding port, avoiding signal accumulation or reflection at the entrance due to overly dense vias, thereby realizing smooth transmission from the feeding port to the antenna radiation surface.

[0051] It can be understood that the radius of the hollow metal part 23 directly affects its ability to constrain electromagnetic signals, that is, the smaller the radius, the weaker the restriction of the hollow metal part 23 on the surrounding electromagnetic field, and the impedance of this area will be adjusted accordingly.

[0052] In the embodiment of the present application, the radius of the hollow metal part 23 is reduced at the coupling window 14. Specifically, the radius of the hollow metal part 23 near the coupling window 14 is smaller than that of the hollow metal part 23 in other parts of the dielectric substrate 1. The purpose is to make the signal impedance of the external feeding port closer to the impedance of the internal transmission structure 2 of the antenna, so as to reduce the reflection of electromagnetic signals at the entrance. At the same time, it makes the transition of electromagnetic signals from the outside to the inside of the dielectric substrate 1 smoother, avoiding signal distortion or interference caused by impedance mutation.

[0053] Based on this, in a feasible embodiment, after the electromagnetic wave is injected into the dielectric substrate 1 through the coupling window 14, it propagates along the end-fire direction of the dielectric integrated waveguide composed of the metal via hole array. During the propagation process, referring to Figure 4 , the electromagnetic wave undergoes multiple round-trip reflections between the first reflection surface 31 and the second reflection surface 32. The first reflection surface 31 is the interface between the dielectric substrate 1 and air in the vertical direction. The dielectric substrate 1 usually uses a high-dielectric-constant material, and the interface with air forms a natural "impedance discontinuity surface" due to the sudden change in dielectric constant, that is, a partial reflection surface; the hollow metal parts 23 inside the dielectric substrate 1 are arranged at intervals, simulating the metal walls of a traditional waveguide. Due to the high conductivity of the metal, the electromagnetic wave will be almost completely reflected when it encounters the hollow metal part 23, forming a total reflection surface.

[0054] The partial reflection surface and the total reflection surface of the present application cooperate to form a Fabry-Perot resonant cavity. The electromagnetic wave undergoes multiple round-trip reflections between the partial reflection surface and the total reflection surface. When the phase difference of the round-trip path in the cavity satisfies the resonance condition, the reflected waves at each time are in-phase superimposed in the end-fire direction, forming a standing wave field and significantly enhancing the radiation intensity.

[0055] The end-fire antenna 100 of the third embodiment of the present application, the transmission structure 2 includes a straight section 21 and an opening section 22. The straight section 21 is located at the tail 12 of the dielectric substrate 1 and closely surrounds the rectangular waveguide 5. By increasing the spacing between the hollow metal parts 23 near the coupling window 14 and reducing its radius, the external signal can be injected into the substrate interior more smoothly, avoiding reflection and accumulation at the entrance; the opening section 22 is located at the head 11 and gradually opens to both sides of the substrate, forming a tapered via array to expand the lateral propagation space of the beam, and cooperating with the multiple reflections and coherent superposition of the resonant cavity 3 to enhance the radiation intensity in the end-fire direction. In addition, the transmission structure 2 uses hollow metal parts 23 to form a dielectric integrated waveguide, which not only retains the confinement ability of the waveguide at high frequencies but also reduces the skin effect loss through the hollow design. The complex dielectric constant is more matched with the wavelength, avoiding mode distortion. It realizes low-loss and high-gain end-fire radiation, providing a practical solution for high-frequency communication scenarios.

[0056] Further, in the fourth embodiment of the present application, the end-fire antenna 100 further includes a metal plate 4, and the metal plate 4 is disposed on the upper surface and the lower surface of the dielectric substrate 1.

[0057] As Figure 1 shown, in the end-fire antenna 100 of this embodiment, metal plates 4 are added to the upper surface and the lower surface of the dielectric substrate 1. Through the synergistic effect of the metal plate 4, the dielectric substrate 1, the transmission structure 2, and the resonant cavity 3, the transition characteristics of electromagnetic waves from the dielectric to the air are optimized, energy leakage is reduced, and the radiation efficiency in the end-fire direction is improved.

[0058] Specifically, the metal plate 4 serves as an electromagnetic transition layer here and closely adheres to the upper and lower surfaces of the dielectric substrate 1. When the transmission structure 2 inside the dielectric substrate 1 guides the electromagnetic waves to propagate in the end-fire direction, the metal plate 4 restricts the electromagnetic waves through its conductive characteristics, avoiding the leakage of electromagnetic waves in the up and down directions of the substrate; at the same time, the metal plate 4 serves as a transition structure at the interface between the dielectric substrate 1 and the air, and can alleviate the impedance mutation between the dielectric substrate 1 and the air, enabling the electromagnetic waves to radiate from the inside of the dielectric substrate 1 to the air more smoothly, reducing the reflection loss. The transmission structure 2 and the metal plate 4 jointly form a closed waveguide environment, ensuring that the energy is concentrated on the transmission path, and finally through the coherent superposition of the resonant cavity 3, the radiation intensity in the end-fire direction is enhanced.

[0059] Further, in the fourth embodiment of the present application, the metal plate 4 includes: A main body covering portion 41, and the main body covering portion 41 matches the contour of the dielectric substrate 1; An extension portion 42, and the extension portion 42 extends outward from the edge of the main body covering portion 41; Wherein, the thickness of the main body covering portion 41 is greater than the thickness of the extension portion 42.

[0060] As Figure 1As shown, in this embodiment, the metal plate 4 includes a relatively thick main covering portion 41 and a relatively thin extending portion 42. The main covering portion 41 fits the main area of the dielectric substrate 1. Because of its relatively large thickness, it has strong conductivity, forms a strong constraint boundary, restricts the leakage of electromagnetic waves in the up and down directions of the substrate, and ensures that the energy is concentrated in the transmission structure 2 for propagation. Its relatively thick design can effectively offset the skin effect at high frequencies and ensure the stability of electromagnetic constraint.

[0061] The extending portion 42 is a relatively thin metal layer 13 that extends outward from the main covering portion 41 of the metal plate 4 to form a buffer boundary. Its relatively thin thickness weakens the ability of this area to constrain electromagnetic waves. When the electromagnetic wave propagates to the edge of the dielectric substrate 1, it first propagates to the thin metal layer 13 of the extending portion 42 and then radiates into the air, avoiding sudden reflection. At the same time, the outward extension design of the extending portion 42 can wrap the electromagnetic waves at the edge of the substrate, reduce their leakage in non-end-fire directions, and make more energy concentrated in the end-fire direction for radiation.

[0062] It should be noted that the thickness ratio of the main covering portion 41 to the extending portion 42 can be specifically adjusted according to the working frequency band. The extending portion 42 can be designed to extend linearly or in a serrated shape. The latter can further scatter the electromagnetic waves leaking from the side, but it is necessary to keep the extending direction perpendicular to the end-fire direction to avoid affecting the main direction of end-fire radiation.

[0063] The end-fire antenna 100 of the fourth embodiment of the present application optimizes the electromagnetic wave radiation characteristics by adding metal plates 4 on the upper and lower surfaces of the dielectric substrate 1. The metal plate 4 is divided into a main covering portion 41 and an extending portion 42: the main covering portion 41 matches the substrate contour and has a relatively large thickness, forms a constraint boundary with strong conductivity, restricts the leakage of electromagnetic waves in the up and down directions of the substrate, offsets the high-frequency skin effect, and ensures that the energy is concentrated in the transmission structure 2; the extending portion 42 extends outward from the main body edge and has a relatively small thickness, serves as a buffer boundary to weaken the constraint, relieve the impedance mutation between the dielectric substrate 1 and the air, avoid reflection, and reduce the side leakage through the outward extension design. The two work together to achieve a smooth transition of electromagnetic waves from the dielectric to the air, reduce energy loss, and improve the radiation efficiency in the end-fire direction.

[0064] The present application also provides an end-fire antenna device, and the end-fire antenna device includes the end-fire antenna of each of the above embodiments. The specific structure of the end-fire antenna refers to the above embodiments. Since all the technical solutions of all the above embodiments are adopted, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0065] The above description is only an exemplary embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. An end-fire antenna, characterized in that, Comprising: A dielectric substrate, on the surface of which a coupling window is provided; A transmission structure integrated inside the dielectric substrate; A resonant cavity, the resonant cavity including a first reflecting surface and a second reflecting surface, the first reflecting surface being the interface between the dielectric substrate and air in the vertical direction, and the second reflecting surface being the reflecting surface formed by the transmission structure in the vertical direction; The coupling window couples electromagnetic waves into the dielectric substrate, and after the electromagnetic waves are reflected multiple times by the first reflecting surface and the second reflecting surface along the transmission structure and coherently superposed, they are radiated in the end-fire direction.

2. The end-fire antenna according to claim 1, wherein The end-fire antenna further includes a metal plate disposed on the upper surface and the lower surface of the dielectric substrate.

3. The end-fire antenna according to claim 2, characterized in that, The metal plate includes: A main body covering portion, the main body covering portion matching the contour of the dielectric substrate; An extending portion, the extending portion extending outward from the edge of the main body covering portion; Wherein, the thickness of the main body covering portion is greater than the thickness of the extending portion.

4. The end-fire antenna according to claim 1, wherein, The dielectric substrate includes a head portion and a tail portion, metal layers are provided on the upper and lower surfaces of the head portion and the tail portion, and a coupling window is provided in the metal layer of the tail portion.

5. The end-fire antenna according to claim 4, wherein The end-fire antenna further includes: A rectangular waveguide for feeding the dielectric substrate; The rectangular waveguide is vertically coupled to the dielectric integrated waveguide through the coupling window.

6. The end-fire antenna according to claim 4, wherein A metal patch is provided in the coupling window, and the size of the metal patch is smaller than the size of the coupling window.

7. The end-fire antenna according to claim 5, wherein The transmission structure includes: A straight section disposed at the tail portion of the dielectric substrate, and a portion of the straight section close to the coupling window surrounds the rectangular waveguide; An opening section disposed at the head portion of the dielectric substrate, and the opening section gradually opens to both sides of the dielectric substrate along the straight section.

8. The end-fire antenna according to claim 7, wherein The transmission structure includes a dielectric integrated waveguide, and the dielectric integrated waveguide includes the straight section and the opening section formed by hollow metal parts spaced apart in the dielectric substrate.

9. The end-fire antenna according to claim 8, wherein The spacing between the hollow metal parts close to the coupling window is greater than the spacing between the hollow metal parts in other parts of the dielectric substrate; The radius of the hollow metal parts close to the coupling window is smaller than the radius of the hollow metal parts in other parts of the dielectric substrate.

10. An end - fire antenna device, characterized in that, Including the end-fire antenna according to any one of claims 1-9.

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