Disclosure of Invention
The application mainly aims to provide an end-fire antenna and equipment, and aims to realize high-gain end-fire radiation by utilizing a low-complexity antenna structure.
In order to achieve the above object, an end-fire antenna according to the present application includes:
the device comprises a dielectric substrate, wherein a coupling window is formed on the surface of the dielectric substrate;
the transmission structure is integrated in the dielectric substrate;
The resonant cavity comprises a first reflecting surface and a second reflecting surface, the first reflecting surface is an interface between the dielectric substrate and air in the vertical direction, and the second reflecting surface is a reflecting surface formed by the transmission structure in the vertical direction;
the coupling window couples electromagnetic waves into the medium substrate, and the electromagnetic waves radiate towards the end-emission direction after being reflected for many times by the first reflecting surface and the second reflecting surface along the transmission structure and being coherently overlapped.
In an embodiment, the end-fire antenna further includes a metal plate disposed on the upper surface and the lower surface of the dielectric substrate.
In one embodiment, the metal plate includes:
a main body cover portion that matches a contour of the dielectric substrate;
an extension portion extending outwardly from an edge of the body cover portion;
wherein the thickness of the main body cover part is greater than the thickness of the extension part.
In an embodiment, the dielectric substrate includes a head portion and a tail portion, the upper and lower surfaces of the head portion and the tail portion are respectively provided with a metal layer, and the metal layer of the tail portion is provided with a coupling window.
In an embodiment, the end-fire antenna further comprises:
the rectangular waveguide is used for feeding the dielectric substrate;
the rectangular waveguide is vertically coupled to the dielectric integrated waveguide through the coupling window.
In one embodiment, a metal patch is provided on the coupling window, and the size of the metal patch is smaller than the size of the coupling window.
In one embodiment, the transmission structure includes:
the straight section is arranged at the tail part of the dielectric substrate, and the part of the straight section, which is close to the coupling window, surrounds the rectangular waveguide;
The opening section is arranged at the head part of the medium substrate, and the opening section gradually opens towards the two sides of the medium substrate along the straight section.
In one embodiment, the transmission structure includes a dielectric integrated waveguide including the straight section and the open section formed of hollow metal pieces spaced within a dielectric substrate.
In one embodiment, the spacing between the hollow metal pieces near the coupling window is larger than the spacing between the hollow metal pieces at other parts of the dielectric substrate;
The radius of the hollow metal piece near the coupling window is smaller than that of the hollow metal piece at other parts of the dielectric substrate.
The present application also provides an end-fire antenna apparatus comprising an end-fire antenna comprising:
the device comprises a dielectric substrate, wherein a coupling window is formed on the surface of the dielectric substrate;
the transmission structure is integrated in the dielectric substrate;
The resonant cavity comprises a first reflecting surface and a second reflecting surface, the first reflecting surface is an interface between the dielectric substrate and air in the vertical direction, and the second reflecting surface is a reflecting surface formed by the transmission structure in the vertical direction;
the coupling window couples electromagnetic waves into the medium substrate, and the electromagnetic waves radiate towards the end-emission direction after being reflected for many times by the first reflecting surface and the second reflecting surface along the transmission structure and being coherently overlapped.
According to the technical scheme, electromagnetic waves are coupled into the medium substrate through the coupling window and the transmission structure, the interface between the medium substrate and air in the vertical direction is used as a first reflecting surface, the reflecting surface of the transmission structure in the vertical direction is used as a second reflecting surface to jointly form the resonant cavity, the electromagnetic waves are reflected for many times along the transmission structure through the first reflecting surface and the second reflecting surface and are coherently overlapped, and the electromagnetic waves radiate towards the end-fire direction, so that high-gain radiation in the end-fire direction is realized by using a complex structure.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
It should be noted that, if directional indications (such as up, down, left, right, front, and rear are referred to in the embodiments of the present application), the directional indications are merely used to explain the relative positional relationship, movement conditions, and the like between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.
In addition, if there is a description of "first", "second", etc. in the embodiments of the present application, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present application.
In a wireless communication system, an antenna is a key component for electromagnetic wave radiation and reception, and its performance directly affects communication quality. Fabry-Perot (FP) resonator antennas are widely studied for their high gain, narrow beam and strong directivity. Conventional FP cavity antennas typically employ an edge-fire radiation mode, i.e., electromagnetic waves radiate perpendicular to the antenna aperture plane. The typical structure of the electromagnetic wave resonator is a resonant cavity formed by a partial reflecting surface and a total reflecting surface, so that electromagnetic waves are reflected in the cavity for multiple times and are coherently overlapped, and finally high-gain radiation is formed in the side-emitting direction. However, the application scenario of the side-fire antenna has a limitation, for example, in a system requiring low profile, conformal installation or radiation along the antenna plane direction, the conventional FP antenna is difficult to meet.
In contrast, the end-fire antenna can radiate electromagnetic waves along the direction of the aperture plane of the antenna, has the advantages of low profile, easiness in integration and the like, and has important application value in vehicle-mounted communication, unmanned aerial vehicle data chains and portable equipment. However, existing end-fire antennas often suffer from lower gain.
In order to solve the technical problem, the present application provides an end-fire antenna 100.
Referring to fig. 1 to 4, in a first embodiment of the present application, the end-fire antenna 100 includes:
A dielectric substrate 1, wherein a coupling window 14 is formed on the surface of the dielectric substrate 1;
a transmission structure 2 integrated inside the dielectric substrate 1;
the resonant cavity 3 comprises a first reflecting surface 31 and a second reflecting surface 32, wherein the first reflecting surface 31 is an interface between the dielectric substrate 1 and air in the vertical direction, and the second reflecting surface 32 is a reflecting surface formed by the transmission structure 2 in the vertical direction;
The coupling window 14 couples electromagnetic waves into the dielectric substrate 1, and the electromagnetic waves are reflected along the transmission structure 2 for multiple times by the first reflecting surface 31 and the second reflecting surface 32 and are coherently overlapped, and then radiated towards the end-fire direction.
In the technical scheme provided by the application, the end-fire antenna 100 comprises a dielectric substrate 1, a transmission structure 2 and a resonant cavity 3, wherein the resonant cavity 3 can comprise a first reflecting surface 31, a second reflecting surface 32 and a cavity. The dielectric substrate 1 is used as a main carrier of the end-fire antenna 100 of the application, the surface of the dielectric substrate 1 is provided with a coupling window 14, the coupling window 14 is used for efficiently coupling external electromagnetic waves into the substrate, the transmission structure 2 integrated in the dielectric substrate 1 guides the propagation path of the electromagnetic waves in the dielectric substrate 1, meanwhile, the transmission structure 2 can form a second reflection surface 32 in the vertical direction, the second reflection surface 32 is parallel to a first reflection surface 31 formed by the dielectric substrate 1 and air in the vertical direction, the first reflection surface 31 realizes partial reflection by utilizing the inherent abrupt impedance characteristic of the dielectric substrate 1-air interface, the second reflection surface 32 forms total reflection by the metalized edge of the transmission structure 2 or the metal wall, the first reflection surface 31 and the second reflection surface 32 form a resonant cavity 3 effect, so that the electromagnetic waves coupled into the dielectric substrate 1 undergo multiple reflections on the propagation path, the reflection waves realize coherent superposition under specific phase conditions, and finally form an enhanced radiation field in the end-fire direction. The technical scheme ensures that the radiation intensity of the electromagnetic wave in the end-shot direction is enhanced while the end-shot radiation of the electromagnetic wave is realized.
In addition, the end-fire antenna 100 of the 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 application adopt a planar design, thereby avoiding the three-dimensional resonant cavity or three-dimensional feed structure required by the traditional end-fire antenna 100, greatly compressing the space occupation ratio in the vertical direction, and needing no external components or complex assembly, so that all electromagnetic regulation and control functions are concentrated in one planar substrate to be completed.
Alternatively, the dielectric substrate 1 may be made of a low-loss high-frequency material, so that transmission loss can be effectively reduced. The surface of the coupling window 14 can be precisely molded through a photoetching process, so that the size of the coupling window 14 can be flexibly adjusted to meet the requirements of different electromagnetic wave frequency bands.
More specifically, as shown in fig. 1, in the second embodiment of the present application, 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 respectively provided with a metal layer 13, and the metal layer 13 of the tail 12 is provided with a coupling window 14.
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 with a metal layer 13, and the metal layer 13 of the tail 12 is provided with a coupling window 14 by an etching process. Specifically, the coupling window 14 of the tail portion 12 serves as an electromagnetic wave energy input port, coupling an external electromagnetic wave signal to the inside of the dielectric substrate 1. The head 11 and the tail 12 form a continuous wave guide channel through the internally integrated transmission structure 2, and guide electromagnetic waves to propagate towards the head 11. In this process, the vertical interface between the dielectric substrate 1 and air at the head 11 forms a first reflecting surface 31, while the equivalent waveguide wall generated by the transmission structure 2 in the vertical direction forms a second reflecting surface 32, which cooperate to form an asymmetric resonant cavity 3 structure. The electromagnetic wave is overlapped with the phase through multiple reflection in the resonant cavity 3, and finally an enhanced radiation field is formed in the end-fire direction.
Further, in the second embodiment of the present application, the end-fire antenna 100 further includes:
a rectangular waveguide 5, wherein the rectangular waveguide 5 is used for feeding the dielectric substrate 1;
the rectangular waveguide 5 is vertically coupled to the dielectric integrated waveguide through the coupling window 14.
As shown in fig. 1, in this embodiment, the end-fire antenna 100 further integrates a rectangular waveguide 5 to feed the dielectric substrate 1, and specifically, the energy transmission with the transmission structure 2 is implemented through a vertical coupling mechanism. The open end of the rectangular waveguide 5 is aligned with the coupling window 14 to achieve electromagnetic energy injection into the dielectric substrate 1.
Further, a metal patch 141 is provided on the coupling window 14, and the size of the metal patch 141 is smaller than the size of the coupling window 14.
As shown in fig. 2, in this embodiment, a metal patch 141 is added in the coupling window 14, and the metal patch 141 is centrally disposed in the opening area of the coupling window 14 in a floating structure, and the size of the metal patch 141 is smaller than the size of the coupling window 14. When an electromagnetic wave is 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 forms a matching network with the equivalent inductance of the transmission structure 2, so as to reduce energy reflection. Meanwhile, the introduction of the metal patch 141 changes the surface current path of the coupling region, and leads the current peak originally concentrated at the edge of the coupling window 14 to the center of the metal patch 141, thereby reducing parasitic radiation caused by edge diffraction and improving coupling efficiency.
In addition, in order to ensure that the electromagnetic wave is transmitted to the dielectric substrate 1 in an electric field coupling manner rather than direct conduction manner, the size of the metal patch 141 is set to be smaller than the size of the coupling window 14, specifically, the coupling window 14 is opened on the metal layer 13 at the tail 12 of the dielectric substrate 1, and if the size of the metal patch 141 is equal to or larger than the coupling window 14, the edge of the metal patch 141 is directly contacted with the metal layer 13 near the coupling window 14, so that the electromagnetic energy is lost through the metal layer 13 in a short circuit manner, and cannot be effectively coupled to the transmission structure 2 inside the dielectric substrate 1.
Further, the gap between the metal patch 141 and the metal layer 13 of the coupling window 14 forms a fringe capacitance. Specifically, when electromagnetic waves are transmitted from the rectangular waveguide 5 to the transmission structure 2 through the coupling window 14, the metal patch 141 acts as a conductor, and the edge of the metal layer 13 of the coupling window 14 and the edge thereof accumulate charges due to a potential difference, which is equivalent to a parallel capacitor (C), and the transmission structure 2 can be equivalent to a series inductor (L) due to inductance characteristics. The two components together form an LC matching network, which can counteract impedance mismatch between the rectangular waveguide 5 and the transmission structure 2, so that the reflection coefficient of energy transmission is reduced, thereby minimizing reflection loss and improving signal transmission efficiency.
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.
In the second embodiment of the present application, the rectangular waveguide 5 is used as a feeding core, and external electromagnetic energy is precisely injected through the vertical coupling alignment to the coupling window 14 of the dielectric substrate 1, while the gap between the metal patch 141 suspended in the coupling window 14 and the metal layer 13 of the coupling window 14 forms a fringe capacitance, and forms an LC matching network with the inductance of the transmission structure 2, so as to smoothly transition the impedance difference between the rectangular waveguide 5 and the transmission structure 2, and reduce the reflection loss. Meanwhile, the metal patch 141 guides current to concentrate from the edge of the coupling window 14 to the center, reduces parasitic radiation caused by edge diffraction, and improves coupling efficiency.
According to a third embodiment of the present application, the transmission structure 2 includes:
A straight section 21, disposed at the tail 12 of the dielectric substrate 1, where a portion of the straight section 21 near the coupling window 14 surrounds the rectangular waveguide 5;
An opening section 22 is provided 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.
As shown in fig. 1 and fig. 3, after electromagnetic energy is injected into the dielectric substrate 1 through the coupling window 14 by the rectangular waveguide 5, the straight section 21 of the transmission structure 2 serves as an energy transition area, the part of the straight section 21 close to the coupling window 14 surrounds the rectangular waveguide 5, matching is enhanced, reflection caused by mode mismatch is reduced, then, electromagnetic waves propagate along the straight section 21 to the head 11 of the dielectric substrate 1, after entering the opening section 22, the opening section 22 gradually expands towards two sides of the dielectric substrate 1 along the straight section 21, the electromagnetic waves are guided to expand the beam width in the horizontal direction by expanding the transverse dimension of the waveguide, and meanwhile, the resonance effect of the resonant cavity 3 is utilized, so that the electromagnetic waves reflected for multiple times are coherently overlapped in the end-emission direction, and finally, high-gain end-emission radiation is formed.
It should be noted that the straight section 21 is disposed at the tail 12 of the dielectric substrate 1 and serves as a starting section of the transmission structure 2, and its core function is to implement energy transition between the rectangular waveguide 5 and the transmission structure 2. The part of the straight section 21 close to the coupling window 14 forms a closed boundary equivalent to the rectangular waveguide 5 by surrounding the rectangular waveguide 5, so that the electromagnetic wave is restrained from transmitting in the waveguide, and the energy leakage is reduced.
The opening section 22 is disposed at the head 11 of the dielectric substrate 1, and simultaneously serves as an expansion section of the transmission structure 2, the opening section 22 gradually expands towards two sides of the dielectric substrate 1 along the straight section 21, so as to expand the transverse propagation space of electromagnetic waves, spread the beams in the horizontal direction, and simultaneously form a resonance enhancement effect similar to a horn mouth by using the first reflecting surface 31 and the second reflecting surface 32.
Further, the third embodiment of the present application further comprises that the transmission structure 2 comprises a dielectric integrated waveguide comprising the straight section 21 and the open section 22 formed by hollow metal members 23 arranged in the dielectric substrate 1 at intervals.
Referring to fig. 2 and 3, the transmission structure 2 of the present embodiment includes a dielectric integrated waveguide, where the dielectric integrated waveguide includes the straight section 21 and the open section 22 formed by hollow metal pieces 23 arranged in the dielectric substrate 1 at intervals, and the straight section 21 and the open section 22 form a closed waveguide boundary through the continuous arrangement of the hollow metal pieces 23, so as to simulate the electromagnetic confinement characteristic of the conventional waveguide.
It should be noted that, in the high-frequency mode, the skin effect of the electromagnetic wave is significantly enhanced, and the inner wall of the conventional solid metal waveguide may concentrate current on the surface layer due to the skin effect, so as to generate a larger resistance loss. The hollow metal piece 23 is adopted in the embodiment, so that the electromagnetic constraint capacity of the waveguide boundary is ensured, and the effective conduction area of high-frequency current is reduced, thereby reducing resistance loss. In addition, the internal medium of the hollow metal member 23 and the external medium substrate 1 form a composite structure, and the equivalent dielectric constant is between the two, and the mode distortion and the energy leakage caused by abrupt change of the dielectric constant are reduced with the wavelength of the high-frequency electromagnetic wave.
It can be seen that, the opening section 22 gradually opens to two sides of the dielectric substrate 1 along the straight section 21, alternatively, the hollow metal piece 23 of the opening section 22 is designed as a gradual via array, the gradual process is gradually opened to two sides of the dielectric substrate 1, and smooth transition of electromagnetic wave field distribution is realized through gradual transmission path adjustment, specifically, abrupt expansion of the conventional waveguide, such as direct widening, can cause reflection of electromagnetic waves at abrupt positions, and the gradual structure gradually reduces the difference between the wave impedance of the straight section 21 and the wave impedance of the opening section 22 through gradual adjustment of the waveguide width, so that the reflection coefficient is reduced. The gradual expansion of the open section 22 cooperates with the resonant cavity 3 to enable the reflected waves to be coherently superimposed in the end-fire direction after the electromagnetic waves are reflected for multiple times in the propagation process, thereby enhancing the radiation field intensity.
More specifically, the space between the hollow metal pieces 23 near the coupling window 14 is larger than the space between the hollow metal pieces 23 at other parts of the dielectric substrate 1, and the radius of the hollow metal pieces 23 near the coupling window 14 is smaller than the radius of the hollow metal pieces 23 at other parts of the dielectric substrate 1.
In this embodiment, the hollow metal member 23 inside the dielectric substrate 1 forms the boundary of the transmission structure 2, and restricts and guides the propagation of electromagnetic signals to the radiation surface of the antenna.
Specifically, the space between the hollow metal pieces 23 near the coupling window 14 is larger than the space between the hollow metal pieces 23 at other parts of the dielectric substrate 1, so that the space between the holes is increased, and thus the metal shielding area near the coupling window 14 is reduced, and the electromagnetic signal encounters less resistance when entering the inside of the dielectric substrate 1, and is more likely to propagate along the transmission structure 2 to the radiation surface. Meanwhile, the larger space enables the electromagnetic environment of the area to be closer to the signal environment of the external feed port, and the phenomenon that signals are accumulated or reflected at the entrance due to too dense through holes is avoided, so that smooth transmission from the feed port to the antenna radiation surface is realized.
It will be appreciated that the radius of the hollow metal piece 23 directly affects its ability to confine electromagnetic signals, i.e. the smaller the radius, the weaker the hollow metal piece 23 limits the surrounding electromagnetic field, and the impedance of that region will be adjusted accordingly.
The radius of the hollow metal piece 23 is reduced at the coupling window 14, specifically, the radius of the hollow metal piece 23 near the coupling window 14 is smaller than the radius of the hollow metal piece 23 at other parts of the dielectric substrate 1. The purpose is to make the signal impedance of the external feed 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, and at the same time make the transition of electromagnetic signals from the outside of the dielectric substrate 1 to the inside smoother, so as to avoid signal distortion or interference caused by abrupt impedance changes.
Based on this, in one possible embodiment, the electromagnetic wave propagates in the dielectric integrated waveguide end-fire direction composed of the metal via array after being injected into the dielectric substrate 1 through the coupling window 14. In the propagation process, referring to fig. 4, electromagnetic waves undergo multiple round trip reflections between the first reflecting surface 31 and the second reflecting surface 32, the first reflecting surface 31 is an interface between the dielectric substrate 1 and air in the vertical direction, the dielectric substrate 1 is usually made of a high dielectric constant material, the interface between the dielectric substrate 1 and air forms a natural 'impedance discontinuous surface', namely a partial reflecting surface, due to abrupt change of dielectric constant, and hollow metal pieces 23 inside the dielectric substrate 1 are arranged according to intervals to simulate the metal walls of a traditional waveguide. Due to the high electrical conductivity of the metal, electromagnetic waves are almost totally reflected when they encounter the hollow metal piece 23, forming a totally reflecting surface.
The partial reflecting surface and the total reflecting surface are combined to form the Fabry-Perot resonant cavity, electromagnetic waves undergo repeated back and forth reflection between the partial reflecting surface and the total reflecting surface, and when the phase difference of the back and forth paths in the cavity meets the resonance condition, the reflected waves are overlapped in the end-fire direction in phase to form a standing wave field, so that the radiation intensity is remarkably enhanced.
According to the end-fire antenna 100 of the third embodiment of the application, the transmission structure 2 comprises an opening section 22 of the straight section 21, the straight section 21 is positioned at the tail 12 of the dielectric substrate 1 and tightly surrounds the rectangular waveguide 5, external signals are more smoothly injected into the substrate by increasing the distance between hollow metal pieces 23 near the coupling window 14 and reducing the radius of the hollow metal pieces, reflection and accumulation at an entrance are avoided, the opening section 22 is positioned at the head 11 and is gradually opened towards two sides of the substrate to form a gradual via hole array, the transverse propagation space of a wave beam is enlarged, and the radiation intensity in the end-fire direction is enhanced by matching with the repeated reflection coherent superposition of the resonant cavity 3. In addition, the transmission structure 2 adopts the hollow metal piece 23 to form a dielectric integrated waveguide, so that the confinement capacity of the waveguide is reserved at high frequency, skin loss is reduced through the hollow design, the composite dielectric constant is matched with the wavelength, and mode distortion is avoided. The end-shot radiation with low loss and high gain is realized, and a practical scheme is provided for a high-frequency communication scene.
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.
As shown in fig. 1, the end-fire antenna 100 of the present embodiment adds metal plates 4 on the upper surface and the lower surface of the dielectric substrate 1, and optimizes the transition characteristic of electromagnetic waves from the medium to the air, reduces the energy leakage, and improves the radiation efficiency in the end-fire direction by the synergistic effect of the metal plates 4, the dielectric substrate 1, the transmission structure 2 and the resonant cavity 3.
Specifically, the metal plate 4 is used as an electromagnetic transition layer and is closely attached to the upper and lower surfaces of the dielectric substrate 1, when the transmission structure 2 inside the dielectric substrate 1 guides electromagnetic waves to propagate in the end-emission direction, the metal plate 4 restrains the electromagnetic waves through the conductive characteristics of the electromagnetic waves to prevent the electromagnetic waves from leaking in the upper and lower directions of the substrate, and meanwhile, the metal plate 4 is used as a transition structure of the interface between the dielectric substrate 1 and air, so that the abrupt impedance change between the dielectric substrate 1 and the air can be relieved, the electromagnetic waves are smoothly radiated into the air from the inside of the dielectric substrate 1, and the reflection loss is reduced. The transmission structure 2 and the metal plate 4 form a closed guided wave environment together, so that energy is ensured to be concentrated in a transmission path, and finally, the radiation intensity in the end-emission direction is enhanced through coherent superposition of the resonant cavity 3.
Further, in the fourth embodiment of the present application, the metal plate 4 includes:
a main body cover 41, wherein the main body cover 41 matches the outline of the dielectric substrate 1;
an extension 42, the extension 42 extending outwardly from an edge of the body cover 41;
wherein the thickness of the body cover 41 is greater than the thickness of the extension 42.
As shown in fig. 1, in the present embodiment, the metal plate 4 includes a thicker main body cover portion 41 and a thinner extension portion 42, and the main body cover portion 41 is attached to the main area of the dielectric substrate 1, and because the thickness is larger, the main body cover portion has stronger conductivity, forms a stronger constraint boundary, limits electromagnetic waves from leaking in the vertical direction of the substrate, and ensures that energy is concentrated and propagates in the transmission structure 2. The thicker design can effectively counteract the skin effect under high frequency, and ensure the stability of electromagnetic restraint.
The extension 42 is a thin metal layer 13 extending outwardly from the body cover 41 of the metal plate 4, forming a buffer boundary. The thin thickness weakens the electromagnetic wave confinement capability of the region, and when the electromagnetic wave propagates to the edge of the dielectric substrate 1, it propagates to the thin metal layer 13 of the extension 42 first, and then radiates into the air, avoiding abrupt reflection. Meanwhile, the extension portion 42 is designed to wrap the electromagnetic wave at the edge of the substrate, so as to reduce the leakage of the electromagnetic wave in the non-end-fire direction, and concentrate more energy to radiate in the end-fire direction.
The thickness ratio of the main body cover 41 to the extension 42 may be specifically adjusted according to the operating frequency band. The extension 42 may be designed as a straight extension or a zigzag extension, which may further scatter the side-leaking electromagnetic waves, but it is necessary to keep the extension direction perpendicular to the end-fire direction, avoiding affecting the main direction of the end-fire radiation.
The end-fire antenna 100 according to 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 body cover part 41 and an extension part 42, wherein the main body cover part 41 is matched with the outline of the substrate and has large thickness, a constraint boundary is formed by virtue of strong conductivity to limit electromagnetic waves to leak to the upper and lower directions of the substrate, offset a high-frequency skin effect and ensure that energy is concentrated in the transmission structure 2, the extension part 42 extends from the outside of the edge of the main body and has small thickness, and is used as a buffer boundary to weaken constraint, alleviate the impedance mutation of the dielectric substrate 1 and air, avoid reflection and reduce side leakage through epitaxial design. The two cooperate to realize smooth transition of electromagnetic waves from the medium to the air, reduce energy loss and improve radiation efficiency in the end-fire direction.
The application also provides an end-fire antenna device comprising the end-fire antenna of each embodiment. The specific structure of the end-fire antenna refers to the above embodiments, and because all the technical solutions of all the embodiments are adopted, the end-fire antenna at least has all the beneficial effects brought by the technical solutions of the embodiments, and the detailed description is omitted herein.
The foregoing description is only exemplary embodiments of the present application and is not intended to limit the scope of the application, and all equivalent structural changes made by the description of the present application and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the present application.