CN116053798A

CN116053798A - Dual-frequency resonant cavity antenna and terminal equipment

Info

Publication number: CN116053798A
Application number: CN202210938666.6A
Authority: CN
Inventors: 周高楠; 张澳芳; 褚少杰; 魏鲲鹏
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-08-05
Filing date: 2022-08-05
Publication date: 2023-05-02
Anticipated expiration: 2042-08-05
Also published as: CN116053798B

Abstract

The application provides a dual-frenquency resonant cavity antenna and terminal equipment, dual-frenquency resonant cavity antenna include metal body, filtering structure and feed structure, and the inside cavity structure that forms of metal body has offered a gap with cavity structure intercommunication on the surface of metal body. The dual-frequency resonant cavity antenna is characterized in that two different antenna subcavities are constructed in the same cavity structure by loading two filtering structures on a metal body, partial areas of the two antenna subcavities are overlapped, the same feeding structure is used for feeding, and the same gap is used for radiating or receiving electromagnetic wave energy, so that multiplexing of the same cavity structure and dual-frequency common cavity design of the two cavity antennas can be realized, and the dual-frequency resonant cavity antenna is flexibly applied to compact terminal equipment.

Description

Dual-frequency resonant cavity antenna and terminal equipment

Technical Field

The application relates to the technical field of wireless communication, in particular to a dual-frequency resonant cavity antenna and terminal equipment.

Background

With the popularization of intelligent terminal devices (such as tablet computers, smart phones and the like) and the development of communication technologies, wireless communication functions of the terminal devices are more and more powerful. However, as the terminal device is further miniaturized, light and thin, and has a high screen ratio, the space for arranging the antenna on the terminal device is smaller and smaller. In the design of all-metal structure, the terminal equipment adopts the structure of all-metal back cover and all-metal frame, and in order to keep pleasing to the eye simultaneously, back cover and frame all adopt seamless design, and the antenna of patch (patch) or flexible circuit board (Flexible Printed Circuit, FPC) that often uses can't be laid out. In this case, the antenna is usually only provided inside the terminal device, and radiates electromagnetic waves through a narrow area where the black edge of the screen is located.

In order to cover two working frequency bands of 2.4G and 5G of WiFi, conventional designs such as multiple single-frequency antennas or dual-frequency antennas are generally adopted in terminal equipment. However, the use of multiple single frequency antennas increases the space occupied by the antennas in the overall structure, and also increases the cost of the terminal device, for example, the cost increase caused by the increase of matching components and transmission lines. The space utilization rate of the whole machine can be improved by using the conventional double-frequency antenna, the equipment cost is reduced, and the like. However, in the design of an all-metal structure, a commonly used dual-frequency antenna cannot be laid out, and the existing dual-frequency resonant cavity antenna also faces the problems of low space utilization rate or low radiation efficiency, for example, a high-frequency resonant cavity and a low-frequency resonant cavity which are mutually independent are designed, so that the overall size of the cavity is increased, and the space utilization rate is low; 2. the higher order modes of the resonant cavity antenna cover the high frequency band, but the radiation efficiency of the higher order modes is low, resulting in poor performance of the antenna. Therefore, on the premise of ensuring the performance of the antenna, the dual-frequency co-body design of the resonant cavity antenna is realized, and the dual-frequency co-body design has important application value for intelligent terminal equipment.

Disclosure of Invention

The application provides a dual-frenquency resonant cavity antenna and terminal equipment, dual-frenquency resonant cavity antenna can realize the dual-frenquency common cavity design of two cavity antennas under the prerequisite of guaranteeing antenna performance, can improve the utilization ratio to cavity structure and reduce dual-frenquency resonant cavity antenna's whole volume is favorable to with in the terminal equipment of compact is applied to dual-frenquency resonant cavity antenna.

In a first aspect, the present application provides a dual-frequency resonant cavity antenna comprising a metal body, a first filtering structure, a second filtering structure, and a feed structure. The metal body is internally provided with a cavity structure, and the surface of the metal body is provided with a slit which is communicated with the cavity structure and takes a strip shape. The first filtering structure is arranged on the metal body and constructs a first subchamber in the chamber structure together with the metal body. The second filtering structure is arranged on the metal body and constructs a second subchamber in the chamber structure together with the metal body; the first subcavity and the second subcavity respectively comprise at least partial areas of the gaps, and an overlapping area exists between the first subcavity and the second subcavity. The feed structure is located in the overlap region. The first cavity antenna utilizes the feed structure to feed and radiates or receives electromagnetic wave energy of a first resonant frequency band through the gap. The feed structure, the gap and the second subchamber jointly form a second cavity antenna, and the second cavity antenna utilizes the feed structure to feed and radiate or receive electromagnetic wave energy of a second resonant frequency band through the gap.

According to the dual-frequency resonant cavity antenna, two filtering structures are loaded on the metal body of the dual-frequency resonant cavity antenna, two different antenna subcavities (the first subcavities and the second subcavities) can be constructed in the same cavity structure, and therefore two cavity antennas covering different frequency bands are obtained. And the partial areas of the two antenna subchambers are overlapped and fed by using the same feed structure, and electromagnetic wave energy is radiated or received by using the same slot, so that the multiplexing of the same cavity structure and the dual-frequency common cavity design of the two cavity antennas can be realized, the utilization rate of the cavity structure is improved, the whole volume of the dual-frequency resonant cavity antenna is reduced, and the dual-frequency resonant cavity antenna is flexibly applied to compact terminal equipment.

In addition, the dual-frequency resonant cavity antenna can enable the two cavity antennas to be respectively covered in WiFi-2.4G/5G frequency bands by loading the first filtering structure and the second filtering structure, can meet antenna performance requirements of WiFi-2.4G/5G, and can enable the two cavity antennas to work in TE with high radiation efficiency _m01 The mode ensures that the dual-frequency resonant cavity antenna still has higher radiation efficiency when being applied to terminal equipment adopting all-metal structural design, and further can ensure the antenna performance.

In a possible implementation manner of the first aspect, the frequency of the first resonant frequency band is lower than the frequency of the second resonant frequency band. The first filtering structure adopts a low-resistance high-pass filtering structure and is also used for binding an electric field of a first resonant frequency band generated by the first cavity antenna in the first subcavity, so that the first cavity antenna can exert the antenna performance of the corresponding low-frequency cavity antenna.

In a possible implementation manner of the first aspect, the first filtering structure includes a plurality of first filtering units arranged at intervals, where a distance between two adjacent first filtering units is smaller than one fourth of an electromagnetic wave wavelength of the first resonant frequency band and larger than one half of an electromagnetic wave wavelength of the second resonant frequency band. Therefore, the filtering effect of high-frequency pass and low-frequency resistance can be realized by loading the first filtering structure based on the characteristic that the wavelengths of the two different frequency bands are different, so that the first cavity antenna can play the antenna performance of the corresponding low-frequency cavity antenna, and the blocking effect on the high-frequency electric field is not formed.

In a possible implementation manner of the first aspect, the plurality of first filter units are arranged along a first direction, and the first direction is parallel to a length direction of the slit. The first filter structure and the metal body together construct the first subcavity containing all areas of the gap and a third subcavity far away from the gap in the cavity structure, and the sum of the volumes of the first subcavity and the third subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the second filtering structure adopts a low-pass high-resistance filtering structure, and the second filtering structure is further configured to bind an electric field of a second resonant frequency band generated by the second cavity antenna in the second subchamber, so that the second cavity antenna can exert the antenna performance of the corresponding high-frequency cavity antenna.

In a possible implementation manner of the first aspect, the second filter structure and the metal body together form the second subchamber including at least a partial region of the gap and other subchambers located on one side or both sides of the second subchamber in the cavity structure, and a sum of volumes of the second subchamber and the other subchambers is equal to a volume of the cavity structure.

The dual-frequency resonant cavity antenna can be in TE of WiFi-5G frequency band by loading the second filtering structure _1.501 The excitation near the mode produces a relatively efficient higher order mode TE _0.503 The module is used for widening the whole bandwidth of the WiFi-5G frequency band, so that the antenna efficiency can be effectively improved. In addition, by adjusting the physical dimensions of the second sub-cavity, for example, adjusting the length of the second sub-cavity in the direction perpendicular to the length of the slit, the higher order mode TE with relatively high efficiency can be adjusted _0.503 The resonant frequency of the mode is such that the higher order mode TE _0.503 The module is close to the frequency band of the WiFi-5G to widen the frequency band of the WiFi-5G, so that the radiation efficiency of the frequency band of the WiFi-5G can be improved.

In a possible implementation manner of the first aspect, the second filtering structure includes a plurality of second filtering units that are disposed at intervals, where a distance between two adjacent second filtering units at a junction of the second sub-cavity and the other sub-cavity is smaller than a quarter of an electromagnetic wave wavelength of the second resonant frequency band, so that the second filtering structure can achieve a filtering effect of low-frequency pass and high-frequency resistance, and the second cavity antenna can perform an antenna performance of the corresponding high-frequency cavity antenna, and does not form a blocking effect on a low-frequency electric field.

In a possible implementation manner of the first aspect, the second filtering unit is disposed on a surface of the metal body, and the second filtering unit adopts an SRR DGS structure, and the SRR DGS structure resonates in the second resonant frequency band.

In a possible implementation manner of the first aspect, each second filtering unit includes two annular first slit structures and second slit structures formed on the surface of the metal body, where a side length of the first slit structure is smaller than a side length of the second slit structure, and the second slit structures are enclosed outside the first slit structures.

The dual-frequency resonant cavity antenna can be in TE of WiFi-5G frequency band by loading the second filtering structure _1.501 The excitation near the mode produces a relatively efficient higher order mode TE _0.503 The module is used for widening the whole bandwidth of the WiFi-5G frequency band, so that the antenna efficiency can be effectively improved. In addition, TE can be adjusted by adjusting the side length of the first slit structure of the SRR DGS structure _1.501 The resonant frequency of the mode, thereby being capable of moving the high-frequency resonant point into the frequency band of WiFi-5G; TE can be obtained by adjusting the side length of the second gap structure of the SRR DGS structure _1.501 Higher order mode TE with relatively low efficiency near the mode _0.503 The resonance point of the mode moves towards the low frequency direction to be far away from the WiFi-5G frequency band, so that the radiation efficiency of the WiFi-5G frequency band can be prevented from being affected by the TE of the higher-order mode with lower efficiency _0.503 The die pull was low.

In a possible implementation manner of the first aspect, the metal body is integrally in a cuboid shape, and includes a first metal panel, a second metal panel and a connecting portion, where the first metal panel, the second metal panel and the connecting portion jointly enclose the cavity structure, and the first metal panel is provided with the gap.

In a possible implementation manner of the first aspect, the metal body is integrally L-shaped, and includes a flat plate portion and an extension portion bent and extended from one end of the flat plate portion, the flat plate portion and the interior of the extension portion together form the cavity structure, and an end surface of the extension portion away from the flat plate portion forms the gap. The metal body comprises a first metal panel, a second metal panel, a bending part and a connecting part, wherein the first metal panel and the second metal panel are oppositely arranged, the bending part bends and extends out from one end of the first metal panel, the connecting part is arranged between the first metal panel and the second metal panel, and the first metal panel, the second metal panel, the bending part and the connecting part jointly enclose into a cavity structure; the first metal panel, the second metal panel and the connecting part are partially structured to form the flat plate part, and the bending part and the connecting part are partially structured to form the extending part.

Therefore, when the dual-frequency resonant cavity antenna is applied to the accommodating cavity of the terminal equipment, the extension part can be arranged at the position, opposite to the black edge area of the screen, in the accommodating cavity, so that the gap is as close to the black edge of the screen as possible, the dual-frequency resonant cavity antenna can radiate or receive electromagnetic wave energy conveniently, and the antenna efficiency of the dual-frequency resonant cavity antenna can be improved.

In a possible implementation manner of the first aspect, the plurality of second filtering units are arranged in two L-shaped structures on the surface of the first metal panel or the second metal panel, and positions of orthographic projections of the gaps on the first metal panel and the second metal panel are staggered from positions of the two L-shaped structures. The two L-shaped structures and the metal body together construct the second subcavities containing all areas of the gaps, and fourth subcavities and fifth subcavities which are positioned at two sides of the second subcavities and do not contain the areas where the gaps are positioned in the cavity structures; the orthographic projection of the second subchamber on the second metal panel is in a T shape, and the sum of the volumes of the second subchamber, the fourth subchamber and the fifth subchamber is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the plurality of second filtering units are arranged on the surface of the second metal panel along a direction perpendicular to the length direction of the slit, and are arranged in two rows in a direction parallel to the length direction of the slit to form a "|" shape structure, and the orthographic projection of the slit on the second metal panel covers part structures of the two "|" shape structures. The second subcavity, the fourth subcavity and the fifth subcavity which are positioned on two sides of the second subcavity are constructed in the cavity structure together with the metal body, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity, the fourth subcavity and the fifth subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the plurality of second filter units are arranged on the surface of the second metal panel along a direction perpendicular to a length direction of the slit, and an orthographic projection of the slit on the second metal panel covers at least one second filter unit. The second filter units and the metal bodies together construct a second subcavity containing a partial area of the gap and a fourth subcavity positioned at one side of the second subcavity in the cavity structure, wherein orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the plurality of second filtering units are arranged in an L-shaped structure on the surface of the first metal panel or the second metal panel, and positions of orthographic projections of the gaps on the first metal panel and the second metal panel are staggered from positions of the L-shaped structure. The L-shaped structure and the metal body together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned at one side of the second subcavity and does not contain the area where the gap is located in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is L-shaped, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the plurality of second filtering units are arranged in an L-shaped structure on a surface of the second metal panel, and an orthographic projection of the slit on the second metal panel covers a part of the L-shaped structure. The L-shaped structure and the metal body together construct the second subcavity of the partial area containing the gap and a fourth subcavity positioned at one side of the second subcavity in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, or the orthographic projection of the second subcavity on the second metal panel is L-shaped; the sum of the volumes of the second subchamber and the fourth subchamber is equal to the volume of the chamber structure.

In a possible implementation manner of the first aspect, the plurality of second filtering units are arranged in a Z-shaped structure on the surface of the first metal panel or the second metal panel, and positions of orthographic projections of the gaps on the first metal panel and the second metal panel are staggered from positions of the Z-shaped structure. The Z-shaped structure and the metal body together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned at one side of the second subcavity and does not contain the area where the gap is located in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is L-shaped, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the plurality of second filter units are arranged on the surface of the first metal panel or the second metal panel along a direction parallel to the length direction of the slit, and the positions of orthographic projections of the slit on the first metal panel and the second metal panel are staggered from the positions of the plurality of second filter units. The second filter units and the metal bodies together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned on one side of the second subcavity and far away from the gap in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

In a possible implementation manner of the first aspect, the cavity structure and the gap are filled with a medium. The feed structure comprises a feed branch and a feed port arranged on the feed branch, the feed branch is arranged in the gap through the medium and extends along the length direction of the gap, and the feed branch is arranged at intervals with the metal structure of the metal body; the feed port is used for feeding the feed branch knot, and the feed branch knot is used for coupling excitation of the metal body.

In a second aspect, the application provides a terminal device, including a housing, a display screen, and a dual-frequency resonant cavity antenna according to the first aspect. The shell and the display screen jointly enclose a containing cavity. The dual-frequency resonant cavity antenna is arranged in the accommodating cavity, and a gap formed in the surface of the metal body of the dual-frequency resonant cavity antenna is opposite to the joint between the edge of the shell and the edge of the display screen.

According to the terminal equipment, the dual-frequency resonant cavity antenna is arranged in the accommodating cavity of the terminal equipment, the gap is opposite to the joint between the edge of the shell and the edge of the display screen, namely, the gap is opposite to the black edge area of the screen, and the dual-frequency resonant cavity antenna can radiate electromagnetic wave energy or receive external electromagnetic wave energy to the outer side of the display screen through the gap and the black edge area of the screen, so that wireless communication between the terminal equipment and other electronic equipment is achieved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below. It is apparent that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 is a schematic diagram of a back structure of a terminal device according to an embodiment of the present application.

Fig. 2 is a schematic cross-sectional structure of the terminal device shown in fig. 1 along the direction II-II, where the terminal device includes a dual-frequency resonant cavity antenna.

Fig. 3 is a schematic structural diagram of the dual-frequency resonant cavity antenna shown in fig. 2.

Fig. 4 is a schematic structural diagram of another dual-frequency resonant cavity antenna according to an embodiment of the present application.

Fig. 5 is a schematic top view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a schematic structure of a low-frequency subchamber constructed in a cavity structure of the dual-frequency resonant cavity antenna.

Fig. 6 is a schematic side view of the cavity structure and low frequency subchamber shown in fig. 5.

Fig. 7 (a) is a simulation diagram of the distribution of the electric field generated in the cavity structure when the dual-frequency resonant cavity antenna shown in fig. 5 is loaded with only the first filtering structure and the feeding frequency is 2.45 GHz.

Fig. 7 (b) is a simulation diagram of the distribution of the electric field generated in the cavity structure when the dual-frequency resonant cavity antenna shown in fig. 5 is loaded with only the first filtering structure and the feeding frequency is 5.5 GHz.

Fig. 8 (a) is a schematic structural diagram of a first reference antenna configured in an embodiment of the present application.

Fig. 8 (b) is a schematic diagram of a simulation curve of the reflection coefficient and the antenna efficiency of the first reference antenna shown in fig. 8 (a).

Fig. 9 is a schematic diagram comparing the antenna performance of the dual-frequency resonant cavity antenna shown in fig. 5 with the antenna performance of the first reference antenna shown in fig. 8 (a) when the dual-frequency resonant cavity antenna is loaded with only the first filtering structure.

Fig. 10 (a) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a schematic first structure of a high-frequency subchamber formed in a chamber structure of the dual-frequency resonant cavity antenna.

Fig. 10 (b) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a second schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (c) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a third schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (d) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a fourth schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (e) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a fifth schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (f) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a sixth schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (g) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and a seventh schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 10 (h) is a schematic bottom view of the dual-frequency resonant cavity antenna shown in fig. 3 or fig. 4, and an eighth schematic structure of a high-frequency subchamber formed in the cavity structure of the dual-frequency resonant cavity antenna.

Fig. 11 (a) is a simulation diagram of the distribution of the electric field generated in the cavity structure when the dual-frequency resonant cavity antenna shown in fig. 10 (a) is loaded with only the second filtering structure and the feeding frequency is 2.45 GHz.

Fig. 11 (b) is a simulation diagram of the distribution of the electric field generated in the cavity structure when the dual-frequency resonant cavity antenna shown in fig. 10 (a) is loaded with only the second filtering structure and the feeding frequency is 5.5 GHz.

Fig. 12 is a schematic diagram of the front and back structures of the dual-frequency resonant cavity antenna shown in fig. 10 (a), and schematic diagrams of the structures of the low and high frequency subchambers and electric field distribution simulation diagrams of the structures.

Fig. 13 (a) is a schematic structural diagram of a second reference antenna configured in an embodiment of the present application.

Fig. 13 (b) is a simulation diagram of the distribution of the electric field generated by the second reference antenna shown in fig. 13 (a) at a resonant frequency of 5.5 GHz.

Fig. 14 is a schematic diagram showing the comparison between the antenna performance of the dual-frequency resonant cavity antenna shown in fig. 12 and the simulation result of the antenna performance of the second reference antenna shown in fig. 13 (a).

Fig. 15 (a) is a graph showing the relationship between the antenna efficiency and the physical parameter b of the dual-frequency resonant cavity antenna shown in fig. 12.

Fig. 15 (b) is a graph showing the relationship between the antenna efficiency and the physical parameter a1 of the dual-frequency resonant cavity antenna shown in fig. 12.

Fig. 15 (c) is a graph showing the relationship between the antenna efficiency and the physical parameter a2 of the dual-frequency resonant cavity antenna shown in fig. 12.

Fig. 15 (d) is a graph showing the relationship between the antenna efficiency of the dual-frequency resonant cavity antenna shown in fig. 12 and the installation position of the feed structure.

Description of the main reference signs

The following detailed description will further illustrate the application in conjunction with the above-described figures.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Wherein the drawings are for illustrative purposes only and are shown as schematic representations and are not to be construed as limiting the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

Current terminal devices, such as notebook computers, tablet computers, mobile phones, and the like, are being miniaturized, thinned, and have a high screen ratio, so that the space for arranging antennas on the terminal devices is becoming smaller and smaller. In the design of all-metal structure, terminal equipment adopts the structure of lid and all-metal frame behind all-metal, and in order to keep pleasing to the eye simultaneously, lid and frame all adopt seamless design behind, and patch antenna or FPC antenna that is used often can't the overall arrangement. In this case, the antenna can generally only be disposed inside the terminal device, the layout of the antenna hidden under the display screen is more flexible, the antenna has a good adaptability to the appearance of the terminal device, the influence on peripheral electronic components is small, and electromagnetic waves can be radiated through a narrow area where the black edge of the screen is located (i.e., an area between the edge of the display screen and the edge of the housing).

In order to cover two frequency bands of 2.4G and 5G of WiFi, aiming at the problems that the design scheme of adopting a plurality of conventional single-frequency antennas in terminal equipment with an all-metal structure is low in space utilization rate and high in equipment cost, the design scheme of adopting a conventional double-frequency antenna cannot be laid out, the design scheme of adopting the conventional double-frequency resonant cavity antenna is low in space utilization rate or low in radiation efficiency and the like, the application provides the terminal equipment and the double-frequency resonant cavity antenna applied to the terminal equipment, wherein the double-frequency resonant cavity antenna can realize the double-frequency common cavity design of two cavity antennas on the premise of guaranteeing the antenna performance, the utilization rate of the cavity structure can be improved, the whole volume of the double-frequency resonant cavity antenna is reduced, and the double-frequency resonant cavity antenna is beneficial to being applied to compact terminal equipment.

Referring to fig. 1 and fig. 2 together, fig. 1 and fig. 2 exemplarily show a schematic structural diagram of a terminal device 100 according to an embodiment of the present application. The terminal device 100 in the embodiment of the present application takes a mobile phone as an example. The terminal device 100 includes a housing 11 and a display 12, where the housing 11 and the display 12 together define a housing cavity 13 for housing other components of the terminal device 100, such as a battery, a circuit board, and the like. In this embodiment, the housing 11 is of an all-metal structure, and includes a rear cover and a frame integrally formed. A screen black region 14 is formed at a junction between an edge of the case 11 and an edge of the display screen 12, and a caulking black (not shown) may be provided in the screen black region 14.

It should be noted that fig. 1 and 2 only schematically show some structural components included in the terminal device 100, the actual configuration and positions of these structural components are not limited by fig. 1 and 2, and the terminal device 100 may actually have more or fewer structural components with respect to the structural components shown in fig. 1 and 2, for example, the terminal device 100 may further include a rear camera, a front camera 15, a fingerprint module, and the like.

In this embodiment, the terminal device 100 further includes a dual-frequency resonant cavity antenna 20 disposed in the accommodating cavity 13, where the dual-frequency resonant cavity antenna 20 is configured to operate in a first resonant frequency band and a second resonant frequency band, and the frequency of the first resonant frequency band is lower than that of the second resonant frequency band. In this embodiment, the first resonant frequency band is a WiFi 2.4G frequency band, i.e. a WiFi low frequency band. The second resonance frequency band is a 5G frequency band of WiFi, namely a WiFi high-frequency band. In other embodiments, the first resonant frequency band and the second resonant frequency band may be other resonant frequency bands.

In this embodiment, the dual-frequency resonant cavity antenna 20 adopts a dual-frequency half-mode waveguide resonant cavity antenna structure, and includes a metal body 21, a cavity structure 211 is formed inside the metal body 21, and a slot 212 which is communicated with the cavity structure 211 and is in a strip shape is formed on the surface of the metal body 21. The cavity structure 211 and the gap 212 are filled with a medium 22 (as shown in fig. 3). The medium 22 may be made of non-metal materials such as air, plastic, ceramic, glass, etc., and specific materials of the medium 22 are not specifically limited in the embodiment of the present application, and those skilled in the art may select corresponding medium materials according to actual needs.

In this embodiment, the metal body 21 is provided with the cavity structure 211 on a surface thereof close to the display screen 12, and the slit 212 is used for transmitting electromagnetic wave energy. When the dual-band resonant cavity antenna 20 is disposed in the housing cavity 13 of the terminal device 100, the slit 212 is opposite to the connection between the edge of the housing 11 and the edge of the display screen 12, that is, the slit 212 is opposite to the screen black edge region 14. The dual-band resonant cavity antenna 20 radiates electromagnetic wave energy to the outside of the display screen 12 or receives external electromagnetic wave energy through the slit 212 and the screen black border region 14, thereby enabling wireless communication between the terminal device 100 and other electronic devices.

The dual-frequency resonant cavity antenna 20 further comprises a grounding element 23, and the grounding element 23 is electrically connected between the outer surface of the metal body 21 and the reference ground, so as to achieve grounding of the dual-frequency resonant cavity antenna 20. Wherein the reference ground includes a metal frame of the display 12, a housing 11 or a middle frame (not shown) of the terminal device 100, etc., and the grounding element 23 includes, but is not limited to, conductive foam, a spring sheet, or a screw.

Referring to fig. 2 and 3 together, in the present embodiment, the metal body 21 is generally L-shaped and includes a flat plate portion 2101 and an extension portion 2102 bent and extended from one end of the flat plate portion 2101, wherein the flat plate portion 2101 and the extension portion 2102 together form the cavity structure 211, and an end surface of the extension portion 2102 remote from the flat plate portion 2101 forms the gap 212.

Specifically, the metal body 21 includes a first metal panel 213, a second metal panel 214, a bending portion 215, and a connecting portion 216, where the first metal panel 213 and the second metal panel 214 are disposed opposite to each other, the bending portion 215 bends and extends from one end of the first metal panel 213, the connecting portion 216 is disposed between the first metal panel 213 and the second metal panel 214, and the first metal panel 213, the second metal panel 214, the bending portion 215, and the connecting portion 216 jointly enclose the cavity structure 211. The first metal panel 213, the second metal panel 214, and the connection portion 216 have a partial structure that together form the flat plate portion 2101, and the bent portion 215 and the connection portion 216 have a partial structure that together form the extension portion 2102.

The dual-frequency cavity antenna 20 further comprises a feed structure 24, the feed structure 24 being arranged in the slot 212 via the medium 22. Specifically, the feeding structure 24 includes a feeding port 241 and a feeding stub 242, the feeding port 241 is disposed on the feeding stub 242, the feeding stub 242 is disposed in the slot 212 through the medium 22 and extends along the length direction of the slot 212, and the feeding stub 242 is disposed at a distance from the metal structure of the metal body 21. Accordingly, the dielectric 22 may be a non-metallic material such as plastic, ceramic, glass, etc. to provide a load bearing function to the feed structure 24. In this embodiment, as shown in fig. 3, the slit 212 and the feeding branch 242 each extend in a direction parallel to the Y-axis. The feed port 241 is used for feeding the feed stub 242, and the feed stub 242 is used for coupling excitation of the metal body 21, i.e. the feed stub 242 couples energy into the cavity structure 211 of the metal body 21 by means of electric field/magnetic field coupling, thereby generating an electric field/magnetic field in the cavity structure 211. In other embodiments, the feeding port 241 may be directly disposed on the metal body 21 to directly feed the metal body 21, so that the feeding branch 242 may be omitted, and accordingly, the medium 22 may be made of non-metal materials such as air, plastic, ceramic, glass, etc.

In this embodiment, the extension part 2102 is disposed in the accommodating cavity 13 opposite to the black edge region 14 of the screen, so that the slot 212 is as close to the black edge of the screen as possible, so as to facilitate the dual-frequency resonant cavity antenna 20 to radiate or receive electromagnetic wave energy, thereby improving the antenna efficiency of the dual-frequency resonant cavity antenna 20.

In another embodiment, as shown in fig. 4, the metal body 21 is in a rectangular parallelepiped shape, and includes the first metal panel 213, the second metal panel 214, and the connecting portion 216, where the first metal panel 213, the second metal panel 214, and the connecting portion 216 jointly enclose the cavity structure 211, and the slit 212 is formed in the first metal panel 213. It will be appreciated that, with the structure shown in fig. 4, a portion of electromagnetic wave energy radiated from the slot 212 by the dual-frequency resonant cavity antenna 20 is confined inside the housing cavity 13 and cannot be radiated to the outside, which results in a decrease in antenna efficiency of the dual-frequency resonant cavity antenna 20.

Referring to fig. 2 and 3 again, in the present embodiment, the dual-band resonant cavity antenna 20 further includes a filtering structure 25, and the filtering structure 25 is disposed on the metal body 21 and located in the cavity structure 211 or located on an outer surface of the metal body 21. The filter structure 25 and the metal body 21 together form a first sub-cavity A1 (as shown in fig. 5 and 6) and a second sub-cavity B1 (as shown in fig. 10 (a) -10 (h)) in the cavity structure 211, wherein the first sub-cavity A1 and the second sub-cavity B1 respectively comprise at least partial areas of the gap, an overlapping area exists between the first sub-cavity A1 and the second sub-cavity B1, and the feed structure 24 is located in the overlapping area between the first sub-cavity A1 and the second sub-cavity B1.

In this embodiment, the feeding structure 24, the slot 212 and the first sub-cavity A1 together form a first cavity antenna (low frequency cavity antenna), that is, the first sub-cavity A1 forms a resonant cavity of the first cavity antenna, and the first cavity antenna feeds by using the feeding structure 24 and radiates or receives electromagnetic wave energy of the first resonant frequency band through the slot 212.

Similarly, the feeding structure 24, the slot 212 and the second sub-cavity B1 together form a second cavity antenna (high frequency cavity antenna), that is, the second sub-cavity B1 forms a resonant cavity of the second cavity antenna, and the second cavity antenna uses the feeding structure 24 to feed and radiate or receive electromagnetic wave energy in the second resonant frequency band through the slot 212.

That is, the first sub-cavity A1 and the second sub-cavity B1 are not two relatively independent cavities, and there is not only an overlapping area between the two, but also the same feeding structure 24 is used for feeding, and the same slit 212 is used for radiating or receiving electromagnetic wave energy.

In this embodiment, since the partial areas of the first sub-cavity A1 and the second sub-cavity B1 overlap, the utilization rate of the cavity structure 211 may be improved, and the overall volume of the cavity structure 211 may be reduced, so that the volume occupied by the dual-frequency resonant cavity antenna 20 in the housing cavity 13 of the terminal device 100 may be reduced, which is beneficial to flexibly applying the dual-frequency resonant cavity antenna 20 to the compact terminal device 100.

Referring to fig. 3, fig. 5, and fig. 6 together, the filter structure 25 includes a first filter structure 251, the first filter structure 251 is a low-resistance high-pass filter structure, and the first filter structure 251 is further configured to bind an electric field of a first resonant frequency band generated by the first cavity antenna in the first sub-cavity A1, so that the first cavity antenna can perform an antenna performance of the corresponding low-frequency cavity antenna. Specifically, the first filtering structure 251 includes a plurality of first filtering units arranged at intervals, where a distance between two adjacent first filtering units is smaller than one fourth of an electromagnetic wave wavelength of the first resonant frequency band (e.g., 2.45 GHz) and larger than one half of an electromagnetic wave wavelength of the second resonant frequency band (e.g., 5.5 GHz), so that a filtering effect of high-frequency pass and low-frequency resistance can be achieved by loading the first filtering structure 251 based on the characteristic that wavelengths of two different frequency bands are different, so that the first cavity antenna can exert an antenna performance of the low-frequency cavity antenna, and a blocking effect is not formed on a high-frequency electric field of the high-frequency cavity antenna.

In this embodiment, the plurality of first filter units are arranged along a first direction, and the first direction is parallel to the length direction of the slit 212. In this embodiment, the slit 212 extends in a direction parallel to the Y-axis, i.e., the length direction of the slit 212 is parallel to the Y-axis. The first filter structure 251 and the metal body 21 together form the first sub-cavity A1 (the range of a dashed line frame S0 shown in fig. 5) containing the entire area of the slit 212 and the third sub-cavity A2 far from the slit 212 in the cavity structure 211, that is, the first sub-cavity A1 and the third sub-cavity A2 are arranged side by side in a direction parallel to the X axis, and the sum of the volumes of the first sub-cavity A1 and the third sub-cavity A2 is equal to the volume of the cavity structure 211. In this way, the lengths of the first sub-cavity A1 and the cavity structure 211 in the Y-axis direction are equal, and are all L0. The width L1 of the first sub-cavity A1 in the X-axis direction is smaller than the width L2 of the cavity structure 211 in the X-axis direction.

In one embodiment, the first filtering unit is disposed between the first metal panel 213 and the second metal panel 214, and is electrically connected to the inner surface of the first metal panel 213 and the inner surface of the second metal panel 214, respectively. That is, the first filtering unit is disposed in the cavity structure 211. For example, as shown in fig. 3, 5, and 6, the first filtering unit may use a metal pillar, that is, the dual-frequency resonant cavity antenna 20 forms a low-resistance high-pass filtering structure by loading the metal pillar in the cavity structure 211, thereby implementing the configuration of the first sub-cavity A1 (i.e., a low-frequency sub-cavity).

In other embodiments, the first filtering unit may also use other forms of low-resistance high-pass filtering structures to construct the low-frequency subchamber, for example, the first filtering unit may use a metal structure loaded on the inner surface of the first metal panel 213 or the inner surface of the second metal panel 214 and protruding toward the chamber structure 211, or a slit structure etched on the outer surface of the first metal panel 213 or the outer surface of the second metal panel 214, etc. The form of the first filtering structure 251 is not particularly limited in the embodiments of the present application, as long as the first filtering structure 251 can form a low-frequency resonant structure and can generate a corresponding low-resistance high-pass filtering effect.

The electric field distribution in the cavity structure 211 of the dual-frequency resonant cavity antenna 20 loaded with only the first filtering structure 251 is analyzed in the following with reference to fig. 7 (a) -7 (b).

Fig. 7 (a) -7 (b) are simulation graphs of the distribution of the electric field generated in the cavity structure 211 at the feeding frequencies of 2.45GHz and 5.5GHz of the dual-frequency resonant cavity antenna 20 loaded with only the first filtering structure 251.

As shown in fig. 7 (a), when the feeding frequency is 2.45GHz, the working mode of the first cavity antenna (i.e. the low-frequency cavity antenna) is the fundamental mode TE _0.501 A mode, and a low frequency electric field is confined in the first sub-cavity A1 (the range of the white dotted frame shown in fig. 7 (a)). It can be seen that by loading the first filtering structure 251, a low-frequency electric field can be confined in the first sub-cavity A1, and the high-efficiency fundamental mode TE is excited _0.501 And a mode, wherein the first subcavity A1 forms a low-frequency resonant cavity.

As shown in fig. 7 (b), when the feeding frequency is 5.5GHz, the operation mode of the high frequency cavity antenna is the fundamental mode TE _1.501 The mode, and the high frequency electric field can normally pass through the first filtering structure 251 and be distributed throughout the cavity structure 211. It can be seen that loading the first filter structure 251 does not block the high frequency electric field, and the entire cavity structure 211 forms a high frequency resonant cavity.

As can be seen from the electric field distribution simulation diagrams shown in fig. 7 (a) and 7 (b), the first filtering structure 251 functions as a low-resistance high-pass filtering structure, which blocks the low-frequency electric field but does not block the high-frequency electric field.

It will be appreciated thatThe resonant frequency of the cavity antenna is related to the shape and physical dimensions of the antenna cavity, so that the first cavity antenna can be changed to operate in the fundamental mode TE by adjusting the spacing between the first filtering structure 251 and the slot 212, e.g. by adjusting the position of the metal post, without changing the overall shape and physical dimensions of the cavity structure 211 _0.501 Mode resonant frequency.

The antenna performance of the dual-frequency resonant cavity antenna 20 loaded with only the first filtering structure 251 is analyzed as follows in connection with fig. 8 (a) -9.

In order to facilitate comparative analysis of the antenna performance of the first cavity antenna, as shown in fig. 8 (a), the embodiment of the present application constructs a first reference antenna 31, where the shape and physical dimensions of the first reference antenna 31 shown in fig. 8 (a) are the same as those of the first sub-cavity A1 shown in fig. 5, that is, the antenna cavity of the first reference antenna 31 and the first sub-cavity A1 are both in a rectangular parallelepiped shape, the lengths in the Y-axis direction are all L0, the widths in the X-axis direction are all L1, and the heights in the Z-axis direction are the same. The width of the cavity structure 211 in the X-axis direction shown in fig. 5 is L2, where L2> L1. The first reference antenna 31 is a conventional half-mode waveguide resonant cavity antenna, and is not loaded with any filtering structure.

Fig. 8 (b) is a schematic diagram of a simulation curve of the reflection coefficient S11 and the antenna efficiency of the first reference antenna 31 shown in fig. 8 (a). In fig. 8 (b), reference numeral S11 is used to indicate the reflection coefficient curve of the first reference antenna 31, reference numeral rad_10 is used to indicate the radiation efficiency curve of the first reference antenna 31, and reference numeral tot_10 is used to indicate the system efficiency curve of the first reference antenna 31. As shown in fig. 8 (b), the direct use of different radiation modes of a conventional half-mode resonant cavity antenna (i.e., the first reference antenna 31) to cover multiple frequency bands may result in the effects that the resonant frequencies of the different modes are limited, cannot be freely controlled, and the mode with lower radiation efficiency appears in the required frequency band, which may result in poor antenna performance. For example, the radiation efficiency of the first reference antenna 31 has a radiation efficiency pit at 4.8GHz, which reduces the radiation efficiency of the WiFi-5G band, where the operation mode isFor higher order modes TE with low radiation efficiency _0.503 And (5) molding. It can be seen that the conventional resonant cavity antenna (i.e., the first reference antenna 31) cannot meet the antenna performance requirements of WiFi-2.4G/5G simultaneously.

Fig. 9 is a schematic diagram comparing the antenna performance of the dual-frequency resonant cavity antenna 20 shown in fig. 5 with the antenna performance of the first reference antenna 31 shown in fig. 8 (a) when only the first filtering structure 251 is loaded. In fig. 9, the reference numeral rad_10 is used to indicate the radiation efficiency curve of the first reference antenna 31, the reference numeral rad_11 is used to indicate the radiation efficiency curve of the dual-frequency resonant cavity antenna 20, the reference numeral tot_10 is used to indicate the system efficiency curve of the first reference antenna 31, and the reference numeral tot_11 is used to indicate the system efficiency curve of the dual-frequency resonant cavity antenna 20.

As shown in fig. 9, the radiation efficiency of the low frequency cavity antenna (i.e., the first cavity antenna) of the present application is improved by about 0.4dB as compared with the radiation efficiency of the first reference antenna 31 at a resonance frequency around 2.4 GHz. And in the frequency range below 5GHz, the efficiency curves of the low-frequency cavity antenna and the first reference antenna 31 of the present application are basically consistent, which indicates that the performance of the low-frequency cavity antenna and the first reference antenna 31 of the present application are similar.

According to the electric field distribution diagram, the first reference antenna 31 generates two electric field ranges at the mark 8 (6.1 GHz) and the high-frequency cavity antenna generates two electric field ranges at the mark 7 (5.5 GHz), and the working modes are the fundamental mode TE _1.501 And (5) molding.

In the frequency band above 5GHz, the TE of the first reference antenna 31 is not loaded with the first filtering structure 251 (e.g. metal pillar) _1.501 The resonance point of the mode is at the position of Mark 8 (6.1 GHz). Since the width L2 of the cavity structure 211 of the present application is greater than the width L1 of the antenna cavities of the first subcavities A1 and the first reference antenna 31, as described above, the high-frequency electric field can normally pass through the first filtering structure 251, and the entire cavity structure 211 forms a high-frequency resonant cavity, so that the width of the high-frequency resonant cavity of the present application is wider than the high-frequency resonant cavity of the first reference antenna 31. As shown in fig. 9, in loading In the case of the first filtering structure 251 (e.g. a metal pillar), the TE of the high frequency cavity antenna of the present application _1.501 The fact that the resonance point of the mode is shifted from the position of mark 8 (6.1 GHz) to the position of mark 7 (5.5 GHz), i.e. the high frequency resonance point is shifted into the frequency band of 5G and closer to the center frequency point of the 5G frequency band, indicates that the high frequency electric field can indeed pass through the metal pillar and is not blocked by the metal pillar, the cavity width of the cavity structure 211 is effectively utilized such that the high frequency cavity is wider than when the first filtering structure 251 (e.g. the metal pillar) is not loaded.

As can be seen from the above, the first cavity antenna corresponding to the first sub-cavity A1 (i.e. the low-frequency sub-cavity) constructed by loading the first filtering structure 251 in the cavity structure 211 can maintain the antenna performance of the low-frequency cavity antenna, and does not form a blocking effect on the high-frequency electric field of the high-frequency cavity antenna.

In addition, the radiation efficiency of the high-frequency cavity antenna and the first reference antenna 31 of the present application are concave at Mark 9 (4.78 GHz), because excitation at the frequency point of 4.78GHz results in a higher order mode TE with relatively low efficiency _0.503 And (5) molding. Because the frequency point of 4.78GHz is positioned near the frequency band of WiFi-5G, the antenna efficiency of the high-frequency cavity antenna is subjected to a high-order mode TE _0.503 The influence of the mode is pulled low. Wherein a relatively inefficient higher order mode TE is used as to how to reduce or avoid appearance at the Mark 9 (4.78 GHz) location _0.503 The low high frequency antenna efficiency is mode-pulled, see description below.

Referring to fig. 10 (a) -10 (h), the filter structure 25 further includes a second filter structure 252, the second filter structure 252 and the metal body 21 together form the second sub-cavity B1 (the range of the dashed box S1 shown in fig. 10 (a) -10 (h)) including at least a partial area of the slit 212 and other sub-cavities located on one side or both sides of the second sub-cavity B1 in the cavity structure 211, and the sum of the volumes of the second sub-cavity B1 and the other sub-cavities is equal to the volume of the cavity structure 211.

In this embodiment, the second filtering structure 252 is a low-pass high-resistance filtering structure, and the second filtering structure 252 is further configured to bind an electric field of a second resonant frequency band generated by the second cavity antenna in the second sub-cavity B1, so that the second cavity antenna can exert the antenna performance of the corresponding high-frequency cavity antenna. Specifically, the second filtering structure 252 includes a plurality of second filtering units 2520 disposed at intervals, where a distance between two adjacent second filtering units 2520 at a junction between the second sub-cavity B1 and the other sub-cavity is smaller than one quarter of an electromagnetic wave wavelength of the second resonant frequency band (e.g., 5.5 GHz). In this embodiment, the second filtering structure 252 is a band-stop structure that only resonates in the second resonant frequency band, so that a filtering effect of low-frequency pass and high-frequency resistance can be achieved, the second cavity antenna can perform the antenna performance of the high-frequency cavity antenna, and the blocking effect is not formed on the low-frequency electric field of the low-frequency cavity antenna.

It should be noted that reference to "constructing" a subchamber in embodiments of the present application refers to electrically dividing the chamber structure 211 into two or more separate subchambers, each subchamber forming an amorphous "wall" therebetween, and not to a physical separation. For example, the sub-cavities within the cavity structure 211 are all physically connected, but due to the presence of the first filter structure 251, the low frequency electric field generated in the first sub-cavity A1 is substantially unable to pass through the first filter structure 251 into the remaining area of the cavity structure 211. Similarly, due to the presence of the second filter structure 252, the high frequency electric field generated in the second sub-cavity B1 is substantially unable to pass through the second filter structure 252 into the remaining area of the cavity structure 211.

In this embodiment, the second filtering unit 2520 is disposed on a surface of the metal body 21 (e.g., an inner surface or an outer surface of the first metal panel 213 or the second metal panel 214). The second filtering unit 2520 adopts an SRR DGS (SplitRing Resonator Defected Ground Structure, open resonator ring defected ground structure) structure. For example, a slit may be etched in an outer surface of the second metal panel 214 to form the SRR DGS structure. The SRR DGS structure is a band-stop structure and is equivalent to LC series resonance at a resonance frequency point.

As shown in fig. 10 (a), in the present embodiment, each of the second filtering units 2520 includes two annular first slit structures 2521 and second slit structures 2522 formed on a surface of the metal body 21 (for example, an inner surface or an outer surface of the first metal panel 213 or the second metal panel 214), wherein a side length a1 of the first slit structure 2521 is smaller than a side length a2 of the second slit structure 2522, and the second slit structures 2522 are enclosed outside the first slit structures 2521. It should be noted that, in the thickness direction of the second metal panel 214, neither the first slit structure 2521 nor the second slit structure 2522 penetrates the inner surface and the outer surface of the first metal panel 213 or the second metal panel 214 where they are located. In other embodiments, the second filtering unit 2520 may be a slot structure or a metal structure in a U-shape, an L-shape, a C-shape, etc. The form of the second filtering structure 252 is not particularly limited in the embodiments of the present application, as long as the second filtering structure 252 can form a high-frequency resonant structure, and a corresponding low-pass high-resistance filtering effect can be generated.

In the first embodiment, as shown in fig. 10 (a), a plurality of the second filtering units 2520 are arranged in two L-shaped structures on the surface of the first metal panel 213 or the second metal panel 214, and the positions of orthographic projections of the slits 212 on the first metal panel 213 and the second metal panel 214 are offset from the positions of the two L-shaped structures. The two L-shaped structures and the metal body 21 together construct the second sub-cavity B1 (as shown by the range of a dashed line frame S1 in fig. 10 (a)) containing the whole area of the gap 212, and the fourth sub-cavity B2 and the fifth sub-cavity B3 located at two sides of the second sub-cavity B1 and not containing the area where the gap 212 is located, in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is T-shaped, and the sum of the volumes of the second sub-cavity B1, the fourth sub-cavity B2, and the fifth sub-cavity B3 is equal to the volume of the cavity structure 211.

Specifically, the cavity structure 211 has a rectangular structure and includes a first end C1 and a second end C2 opposite to each other, and a third end C3 and a fourth end C4 opposite to each other, where the third end C3 is far from the slit 212, and the fourth end C4 is near to the slit 212. Each L-shaped structure comprises two arms perpendicular to each other, one of which extends in a first direction and the other of which extends in a second direction. Wherein the first direction is parallel to the length direction of the slit 212, i.e. the first direction is the Y-axis direction; the second direction is perpendicular to the length direction of the slit 212, i.e. the second direction is the X-axis direction.

For one of the L-shaped structures, the end of one arm is near the first end C1 of the cavity structure 211 and the end of the other arm is near the third end C3 of the cavity structure 211. Similarly, for another L-shaped structure, the end of one arm is near the second end C2 of the cavity structure 211 and the end of the other arm is near the third end C3 of the cavity structure 211. The region between the two L-shaped structures constitutes the second sub-cavity B1. By adjusting the length and the setting position of the two arms of the two L-shaped structures, the size of the second sub-cavity B1 and the resonant frequency of the second cavity antenna can be adjusted.

In a second embodiment, as shown in fig. 10 (b), a plurality of second filtering units 2520 are arranged along the second direction (i.e. the X-axis direction) on the surface of the second metal panel 214, and are arranged in two rows along the first direction (i.e. the Y-axis direction), so as to form a "|" shape structure, and the front projection of the slit 212 on the second metal panel 214 covers part of the structures of the two "|" shapes structure. The "|" structure and the metal body 21 together construct the second sub-cavity B1 (the range of the dashed line frame S1 shown in fig. 10 (B)) containing the partial region of the gap 212 and the fourth sub-cavity B2 and the fifth sub-cavity B3 located at two sides of the second sub-cavity B1 in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is rectangular, and the sum of the volumes of the second sub-cavity B1, the fourth sub-cavity B2 and the fifth sub-cavity B3 is equal to the volume of the cavity structure 211.

Specifically, the "|" shape structure includes two arms parallel to each other, each arm extending along the second direction (i.e., the X-axis direction), and two ends of each arm being respectively adjacent to opposite ends of the cavity structure 211. The region between the two arms of the "|" shaped structure constitutes the second subcavity B1. By adjusting the arrangement positions of the two arms of the "|" shaped structure in the first direction (i.e. the Y-axis direction), the size of the second sub-cavity B1 and the resonant frequency of the second cavity antenna can be adjusted.

In the third embodiment, as shown in fig. 10 (c), a plurality of the second filtering units 2520 are arranged along the second direction (i.e., the X-axis direction) on the surface of the second metal panel 214, and the front projection of the slit 212 on the second metal panel 214 covers at least one of the second filtering units 2520. The plurality of second filter units 2520 together with the metal body 21 construct the second sub-cavity B1 (the range of the dashed frame S1 shown in fig. 10 (c)) including the partial region of the slit 212 and the fourth sub-cavity B2 located at one side of the second sub-cavity B1 in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is rectangular, and the sum of the volumes of the second sub-cavity B1 and the fourth sub-cavity B2 is equal to the volume of the cavity structure 211.

Specifically, the second filtering units 2520 are arranged in a row along the second direction (i.e. the X-axis direction), and the second filtering units 2520 at the end are respectively near to opposite ends of the cavity structure 211. By adjusting the arrangement positions of the plurality of second filter units 2520 in the first direction (i.e., the Y-axis direction), the size of the second sub-cavity B1 and the resonant frequency of the second cavity antenna may be adjusted.

In the fourth embodiment, as shown in fig. 10 (d), a plurality of second filtering units 2520 are arranged in an L-shaped structure on the surface of the first metal panel 213 or the second metal panel 214, and the positions of orthographic projections of the slits 212 on the first metal panel 213 and the second metal panel 214 are offset from the positions of the L-shaped structure. The L-shaped structure and the metal body 21 together construct the second sub-cavity B1 (as shown by the range of a dashed line frame S1 in fig. 10 (d)) containing the whole area of the gap 212 and the fourth sub-cavity B2 located at one side of the second sub-cavity B1 and not containing the area where the gap 212 is located in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is L-shaped, and the sum of the volumes of the second sub-cavity B1 and the fourth sub-cavity B2 is equal to the volume of the cavity structure 211.

The shape and arrangement of the L-shaped structure shown in fig. 10 (d) are similar to those of any one of the L-shaped structures shown in fig. 10 (a), and detailed descriptions thereof are omitted herein. By adjusting the length and the setting position of the two arms of the L-shaped structure, the size of the second subchamber B1 and the resonant frequency of the second cavity antenna can be adjusted.

In the fifth embodiment, as shown in fig. 10 (e), a plurality of the second filtering units 2520 are arranged in an L-shaped structure on the surface of the second metal panel 214, and the orthographic projection of the slit 212 on the second metal panel 214 covers a part of the L-shaped structure. The L-shaped structure and the metal body 21 together form the second sub-cavity B1 (the range of the dashed line frame S1 shown in fig. 10 (e)) containing the partial region of the gap 212 and the fourth sub-cavity B2 located at one side of the second sub-cavity B1 in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is rectangular, and the sum of the volumes of the second sub-cavity B1 and the fourth sub-cavity B2 is equal to the volume of the cavity structure 211.

Specifically, the L-shaped structure includes two arms perpendicular to each other, wherein one arm extends along the second direction (i.e. the X-axis direction) and has an end near the fourth end C4 of the cavity structure 211; the other arm extends in the first direction (i.e., the Y-axis direction) and terminates near the second end C2 of the cavity structure 211. The feed structure 24 is located near the second end C2 of the cavity structure 211. By adjusting the length and the setting position of the two arms of the L-shaped structure, the size of the second subchamber B1 and the resonant frequency of the second cavity antenna can be adjusted.

In the sixth embodiment, as shown in fig. 10 (f), the arrangement structure of a plurality of the second filter units 2520 is similar to the L-shaped structure shown in fig. 10 (e), except that: whereas the feeding structure 24 shown in fig. 10 (f) is located near the first end C1 of the cavity structure 211, the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is L-shaped.

In the seventh embodiment, as shown in fig. 10 (g), a plurality of the second filtering units 2520 are arranged in a Z-shaped structure on the surface of the first metal panel 213 or the second metal panel 214, and the positions of orthographic projections of the slits 212 on the first metal panel 213 and the second metal panel 214 are offset from the positions of the Z-shaped structure. The Z-shaped structure and the metal body 21 together construct the second sub-cavity B1 (as shown by a dashed line frame S1 in fig. 10 (g)) including the entire area of the slit 212 and the fourth sub-cavity B2 located at one side of the second sub-cavity B1 and not including the area where the slit 212 is located in the cavity structure 211, wherein an orthographic projection of the second sub-cavity B1 on the second metal panel 214 is L-shaped, and a sum of volumes of the second sub-cavity B1 and the fourth sub-cavity B2 is equal to a volume of the cavity structure 211.

Specifically, the two ends of the Z-shaped structure are respectively near the first end C1 and the second end C2 of the cavity structure 211, and the Z-shaped structure includes three arms, one of which extends along the second direction (i.e., the X-axis direction), and the other two of which extend along the first direction (i.e., the Y-axis direction). By adjusting the length and the setting position of the three arms of the Z-shaped structure, the size of the second sub-cavity B1 and the resonant frequency of the second cavity antenna can be adjusted.

In the eighth embodiment, as shown in fig. 10 (h), a plurality of the second filtering units 2520 are arranged on the surface of the first metal panel 213 or the second metal panel 214 along the first direction (i.e., the Y-axis direction), and the positions of the orthographic projections of the slits 212 on the first metal panel 213 and the second metal panel 214 are offset from the positions of the plurality of the second filtering units 2520. The plurality of second filter units 2520 together with the metal body 21 construct the second sub-cavity B1 (as shown by the range of the dashed frame S1 in fig. 10 (h)) including the entire area of the slit 212 and the fourth sub-cavity B2 located at one side of the second sub-cavity B1 and far from the slit 212 in the cavity structure 211, wherein the orthographic projection of the second sub-cavity B1 on the second metal panel 214 is rectangular, and the sum of the volumes of the second sub-cavity B1 and the fourth sub-cavity B2 is equal to the volume of the cavity structure 211.

Specifically, the second filtering units 2520 are arranged in a row along the first direction (i.e., the Y-axis direction), and the second filtering units 2520 at the end are respectively near opposite ends of the cavity structure 211. By adjusting the arrangement positions of the plurality of second filter units 2520 in the second direction (i.e., the X-axis direction), the size of the second sub-cavity B1 and the resonant frequency of the second cavity antenna may be adjusted.

It should be noted that the above-mentioned overall arrangement shape of the second filter structure 252 is only an exemplary illustration, and the overall arrangement shape of the second filter structure 252 is not limited to the above-mentioned arrangement shape, and those skilled in the art may modify or adjust the arrangement shape of the second filter structure 252 according to actual design requirements. All technical variations made according to the technical scheme of the application are covered in the protection scope of the application.

In addition, since the resonant frequency of the cavity antenna is related to the physical size of the antenna cavity, the larger the physical size of the antenna cavity is, the lower the resonant frequency of the corresponding cavity antenna is, and therefore, the volume of the first sub-cavity A1 is larger than the volume of the second sub-cavity B1. In order to reduce the volume of the cavity structure 211, in other embodiments, when the width of the second sub-cavity B1 is greater than the width L1 of the first sub-cavity A1 and less than the width L2 of the cavity structure 211 in the second direction (i.e., the X-axis direction), the width of the cavity structure 211 may be reduced to be equal to the width of the second sub-cavity B1; when the width of the second sub-cavity B1 is smaller than the width of the first sub-cavity A1, the width L2 of the cavity structure 211 may be shortened to be equal to the width L1 of the first sub-cavity A1.

Taking the configuration shown in fig. 10 (a) as an example of the second filtering structure 252, the electric field distribution in the cavity structure 211 of the dual-frequency resonant cavity antenna 20 loaded with only the second filtering structure 252 is analyzed in conjunction with fig. 11 (a) -11 (b).

Fig. 11 (a) -11 (b) are simulation graphs of the distribution of the electric field generated in the cavity structure 211 at the feeding frequencies of 2.45GHz and 5.5GHz of the dual-frequency resonant cavity antenna 20 loaded with only the second filtering structure 252 (SRR DGS structure).

As shown in fig. 11 (a), when the feeding frequency is 2.45GHz, the working mode of the low-frequency cavity antenna is the fundamental mode TE _0.501 The mode and low frequency electric field can normally pass through the second filtering structure 252 and be distributed throughout the cavity structure 211. It can be seen that loading the second filter structure 252 does not block the low frequency electric field, and the entire cavity structure 211 forms a low frequency resonant cavity.

As shown in fig. 11 (b), when the feeding frequency is 5.5GHz, the working mode of the second cavity antenna (i.e. the high-frequency cavity antenna) is the fundamental mode TE _1.501 A mode, and a high-frequency electric field is confined in the second sub-cavity B1 (a range of a white dotted frame as shown in fig. 11 (B)). It can be seen that by loading the second filter structure 252, the high-frequency electric field can be confined in the second sub-cavity B1, and the high-efficiency fundamental mode TE can be excited _1.501 And a mode, wherein the second subcavity B1 forms a high-frequency resonant cavity.

As can be seen from the electric field distribution simulation diagrams shown in fig. 11 (a) and 11 (b), the second filter structure 252 functions as a low-pass high-resistance filter structure that blocks the high-frequency electric field but does not block the low-frequency electric field.

It will be appreciated that the resonant frequency of a cavity antenna is related to the shape and physical dimensions of the antenna cavity at which it is bondedThe overall shape and physical dimensions of the structure 211 may be unchanged, so that the second cavity antenna may be changed to operate in the fundamental mode TE by adjusting the overall dimensions and/or the arrangement position of the second filtering structure 252 _1.501 Mode resonant frequency.

The antenna performance of the dual-band resonant cavity antenna 20 of the present application will be analyzed with reference to fig. 12 to 14 by taking the configuration shown in fig. 10 (a) as an example of the second filtering structure 252.

As shown in fig. 12, the dual-band resonant cavity antenna 20 may construct a first sub-cavity A1 covering the WiFi-2.4G band and a second sub-cavity B1 covering the WiFi-5G band in the cavity structure 211 by loading the first filtering structure 251 (e.g., a metal pillar) and the second filtering structure 252 (e.g., an SRR DGS structure). Wherein the partial areas of the first sub-cavity A1 and the second sub-cavity B1 overlap and share the same feeding structure 24 for feeding and the slot 212 for radiating and receiving electromagnetic wave energy with the same slot 212.

As can be seen from the electric field distribution simulation diagram shown in fig. 12, the dual-frequency resonant cavity antenna 20 operates in the fundamental mode TE at a resonant frequency of 2.45GHz _0.501 Mode, operating in fundamental mode TE at a resonant frequency of 5.5GHz _1.501 The mode, it can be seen that the dual-frequency resonant cavity antenna 20 operates in the basic mode TE with relatively high radiation efficiency in both WiFi-2.4G/5G dual-frequency bands _m01 And (5) molding.

For the purpose of comparison and analysis of the antenna performance of the dual-frequency resonant cavity antenna 20 of the present application, as shown in fig. 13 (a), the embodiment of the present application further constructs a second reference antenna 32, where the shape and physical dimensions of the second reference antenna 32 shown in fig. 13 (a) are the same as those of the dual-frequency resonant cavity antenna 20 shown in fig. 10 (a), the lengths of the two are L0 in the Y-axis direction, the widths of the two are L2 in the X-axis direction, and the heights of the two are the same in the Z-axis direction. Wherein the second reference antenna 32 is a conventional half-mode waveguide resonant cavity antenna, and is not loaded with any filtering structure.

Fig. 13 (b) is a simulation diagram of the distribution of the electric field generated by the second reference antenna 32 at a resonant frequency of 5.5 GHz. From FIG. 13 (b)The second reference antenna 32 is operated in a mixed mode at a resonant frequency of 5.5GHz, and the application can fix the mixed mode at 5.5GHz to TE with relatively high radiation efficiency by loading the second filtering structure 252 (e.g., SRR DGS structure) _1.501 And (5) molding.

Fig. 14 is a schematic diagram showing the comparison between the antenna performance of the dual-frequency resonant cavity antenna 20 shown in fig. 12 and the simulation result of the antenna performance of the second reference antenna 32 shown in fig. 13 (a). In fig. 14, the reference numeral rad_20 is used to indicate the radiation efficiency curve of the second reference antenna 32, the reference numeral rad_21 is used to indicate the radiation efficiency curve of the dual-frequency resonant cavity antenna 20, the reference numeral tot_20 is used to indicate the system efficiency curve of the second reference antenna 32, and the reference numeral tot_21 is used to indicate the system efficiency curve of the dual-frequency resonant cavity antenna 20.

As shown in fig. 14, in the WiFi-2.4G band, the TE of the second reference antenna 32 is not loaded with the first filtering structure 251 (e.g., a metal pillar) _0.501 The resonant frequency of the mode is 2GHz. Whereas, in case of loading the first filtering structure 251 (e.g. a metal pillar), the TE of the dual-frequency resonant cavity antenna 20 of the present application _0.501 The resonant frequency of the mode is 2.45GHz. The dual-frequency resonant cavity antenna 20 of the present application is capable of loading a TE after loading the first filtering structure 251 with respect to a second reference antenna 32 that is not loaded with the first filtering structure 251 (e.g., a metal post) _0.501 The mode resonance point is shifted from 2GHz to 2.45GHz, i.e., the low frequency resonance point is shifted into the 2.4G band, closer to the center frequency point of the WiFi-2.4G band, and a radiation efficiency of-3.1 dB is obtained in the WiFi-2.4G band, which is improved by about 1.6dB compared with the original cavity antenna (i.e., the second reference antenna 32).

In the WiFi-5G band, without loading the second filtering structure 252 (e.g., SRR DGS structure), the radiation efficiency of the second reference antenna 32 has a radiation efficiency pit at the location of 4.78 GHz. As analyzed above, this is due to excitation at the frequency of 4.78GHz, which results in a relatively inefficient higher order mode TE _0.503 And (5) molding. Since the frequency point of 4.78GHz is located at 5GHzIn the vicinity of the frequency band of (2), i.e. from TE, at the time of mode transition _0.503 Transfer to TE _1.501 When in mode, the electric field exhibits different modes in different states, e.g. TE when the phase is 0 _0.503 A mode of TE at a phase of 90 _0.503 The mode, that is, the second reference antenna 32 operates in a hybrid mode at a resonant frequency of 5.5 GHz. Therefore, the high frequency radiation efficiency of the second reference antenna 32 is subjected to the higher order mode TE _0.503 The influence of the mode is pulled low.

In addition, without loading the first filtering structure 251 (e.g., metal posts) and the second filtering structure 252 (e.g., SRR DGS structure), the TE of the second reference antenna 32 _1.501 The resonance point of the mode is at 6.1 GHz.

In the case where the second filtering structure 252 (e.g., SRR DGS structure) is loaded, the dual-band resonant cavity antenna 20 of the present application can provide a higher order mode TE with relatively low efficiency in the vicinity of the second resonant frequency band _0.503 The mode (i.e., mode 2 shown in FIG. 14) is shifted in the low frequency direction, e.g., to around 3.4 GHz-3.5 GHz, resulting in a relatively inefficient higher order mode TE _0.503 The mode is far away from the high-frequency band of WiFi-5G, so that the radiation efficiency of the WiFi-5G frequency band can be prevented from being affected by the relatively low-efficiency high-order mode TE _0.503 The die pull was low.

Meanwhile, the dual-frequency resonant cavity antenna 20 can also be used for TE _1.501 The resonance point of the mode is shifted from 6.1GHz to 5.5GHz, i.e. the high-frequency resonance point is shifted into the WiFi-5G frequency band and closer to the center frequency point of the WiFi-5G frequency band.

In addition, the dual-band cavity antenna 20 is also capable of exciting a new, relatively efficient resonance at a location between mode 2 and mode 4 (e.g., at 4.78 GHz), namely mode 3 shown in FIG. 14, which mode 3 is also a higher order mode TE _0.503 The efficiency of the higher order modes at this location is not the lowest. Therefore, the whole bandwidth of the WiFi-5G frequency band can be widened, and the whole bandwidth can be covered to 5.15 GHz-5.85 GHz, so that the high-frequency radiation efficiency of Wi-Fi5G is improved.

As shown in fig. 14, the dual-band resonant cavity antenna 20 of the present application obtains a radiation efficiency of about-2 dB in the WiFi-5G frequency band, and the radiation efficiency of WiFi-5G is improved by about 1.8-2.2dB compared to the original cavity antenna (i.e., the second reference antenna 32).

As can be seen from the above, the dual-band resonant cavity antenna 20 of the present application can construct two TEs with high radiation efficiency in the same cavity structure 211 by loading the first filtering structure and the second filtering structure _m01 A subcavity of the mold; in addition, by loading the first filtering structure, TE can also be added _0.501 The resonance point of the mode (i.e., the low frequency resonance point) moves into the frequency band of 2.4G; by loading the second filtering structure, TE can also be applied _1.501 Higher order mode TE with relatively low efficiency near the mode _0.503 The mode (i.e., mode 2 shown in FIG. 14) moves in the low frequency direction, moving TE _1.501 The resonance point of the mode shifts into the frequency band of WiFi-5G and at TE _1.501 The excitation near the mode produces a relatively efficient higher order mode TE _0.503 The module is used for widening the whole bandwidth of the WiFi-5G frequency band, so that the antenna efficiency can be effectively improved.

The relationship between the physical parameters b, a1, a2 of the second filter structure 252 and the antenna performance of the dual-frequency resonant cavity antenna 20 is analyzed by taking the configuration of the second filter structure 252 as shown in fig. 10 (a) as an example. As shown in fig. 10 (a), the physical parameter b is a distance between two L-shaped structures formed by the second filtering structure 252, the physical parameter a1 is a side length of a first slit structure 2521 of the SRR DGS structure, and the physical parameter a2 is a side length of a second slit structure 2522 of the SRR DGS structure. Illustratively, the values of the respective physical parameters are: l0=60 mm, l1=21 mm, l2=30 mm.

Fig. 15 (a) is a graph showing the relationship between the antenna efficiency of the dual-frequency resonant cavity antenna 20 shown in fig. 12 and the physical parameter b. In fig. 15 (a), reference numerals rad_b=10, rad_b=14, rad_b=16 are used to indicate radiation efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter b is 10mm, 14mm, or 16mm, and reference numerals tot_b=10, tot_b=14, and tot_b=16 are used to indicate system efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter b is 10mm, 14mm, or 16 mm.

As shown in fig. 15 (a), the operation modes of the dual-frequency resonant cavity antenna 20 include at least mode 1 (fundamental mode TE _0.501 Mode), mode 2 (higher order mode TE _0.503 Mode), mode 3 (higher order mode TE _0.503 Mode), mode 4 (fundamental mode TE _1.501 And (5) a mould). The dual-band resonant cavity antenna 20 operates in mode 1 in the WiFi-2.4G band and in mode 4 in the WiFi-5G band. Mode 2 (higher order mode TE) _0.503 Mode) is a higher order mode with relatively low radiation efficiency, while mode 3 (higher order mode TE) _0.503 Mode) is a higher order mode with relatively high radiation efficiency.

As can be seen from the graph shown in fig. 15 (a), mode 3 (higher order mode TE _0.503 Mode) changes significantly with different values of the physical parameter b, and the different values of the physical parameter b have less influence on other modes. It can be seen that mode 3 (higher order mode TE) can be adjusted by adjusting the value of the physical parameter b _0.503 Mode) such that the higher order mode TE is relatively efficient _0.503 The module is close to the frequency band of the WiFi-5G to widen the frequency band of the WiFi-5G, so that the radiation efficiency of the frequency band of the WiFi-5G can be improved.

Fig. 15 (b) is a graph showing the relationship between the antenna efficiency of the dual-frequency resonant cavity antenna 20 shown in fig. 12 and the physical parameter a 1. In fig. 15 (b), reference numerals rad_a1=4, rad_a1=4.5, rad_a1=5 are used to indicate radiation efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter a1 is 4mm, 4.5mm, 5mm, respectively, and reference numerals tot_a1=4, tot_a1=4.5, and tot_a1=5 are used to indicate system efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter a1 is 4mm, 4.5mm, and 5mm, respectively.

As can be seen from the graph shown in fig. 15 (b), mode 4 (fundamental mode TE _1.501 Mode) changes significantly with different values of the physical parameter a1, and the different values of the physical parameter a1 have less influence on other modes. It can be seen that by adjusting the value of the physical parameter a1, i.e. the side length of the first slit structure 2521 of the SRR DGS structure, mode 4 (fundamental mode TE _1.501 Mode) so that the high frequency resonance point can be shifted into the frequency band of WiFi-5G.

Fig. 15 (c) is a graph showing the relationship between the antenna efficiency of the dual-frequency resonant cavity antenna 20 shown in fig. 12 and the physical parameter a 2. In fig. 15 (c), reference numerals rad_a2=6, rad_a2=6.5, rad_a2=7 are used to indicate radiation efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter a2 is 6mm, 6.5mm, or 7mm, and reference numerals tot_a2=6, tot_a2=6.5, or tot_a2=7 are used to indicate system efficiency curves of the dual-frequency resonant cavity antenna 20 when the physical parameter a2 is 6mm, 6.5mm, or 7 mm.

As can be seen from the graph shown in fig. 15 (c), mode 2 (higher order mode TE _0.503 Mode) changes significantly with different values of the physical parameter a2, and the different values of the physical parameter a2 have less influence on other modes. It can be seen that by adjusting the physical parameter a2, i.e. the side length of the second slit structure 2522 of the SRR DGS structure, mode 2 (higher order mode TE _0.503 Mode), thereby the resonance point of the mode 2 can be shifted towards the low frequency direction to be far away from the WiFi-5G frequency band, thereby the radiation efficiency of the WiFi-5G frequency band can be prevented from being higher-order mode TE with lower efficiency _0.503 The die pull was low.

As can be seen from the graphs of the relationship between the antenna efficiency and the physical parameters b, a1, a2 shown in fig. 15 (a), 15 (b), 15 (c), the positions of the resonance points in the

modes

3, 4, and 2 can be adjusted by adjusting the two physical parameters b, a1, and a2, respectively. In combination with the previous analysis, the radiation efficiency of the WiFi-5G frequency band can be improved by adjusting the positions of the resonance points of the mode 2, the mode 3 and the mode 4.

Fig. 15 (d) is a graph showing the relationship between the antenna efficiency of the dual-frequency resonant cavity antenna 20 shown in fig. 12 and the installation position of the feed structure 24. In fig. 15 (d), reference numerals rad_position 1 and rad_position 2 are used to indicate radiation efficiency curves of the dual-frequency resonant cavity antenna 20 when the feeding structure 24 is located at the

positions

1 and 2, and reference numerals tot_position 1 and tot_position 2 are used to indicate system efficiency curves of the dual-frequency resonant cavity antenna 20 when the feeding structure 24 is located at the

positions

1 and 2, respectively.

From the graph shown in fig. 15 (d), it can be seen that by adjusting the position of the feeding structure 24, the impedance bandwidth of WiFi-5G can be improved.

In summary, the dual-band resonant cavity antenna 20 according to the present application can construct two different antenna subcavities (the first subcavities A1 and the second subcavities B1) in the same cavity structure 211 by loading two filtering structures 25 on the metal body 21, thereby obtaining two cavity antennas covering different frequency bands. And, the partial areas of the two antenna subchambers overlap and are fed by the same feed structure 24, and the same slot 212 is used for radiating or receiving electromagnetic wave energy, so that the multiplexing of the same chamber structure 211 and the dual-frequency common chamber design of the two chamber antennas can be realized, the utilization rate of the chamber structure 211 is improved, the whole volume of the dual-frequency resonant chamber antenna 20 is reduced, and the dual-frequency resonant chamber antenna 20 is flexibly applied to the compact terminal equipment 100.

In addition, the dual-band resonant cavity antenna 20 can make the two cavity antennas respectively cover the WiFi-2.4G/5G frequency band by loading the first filtering structure 251 and the second filtering structure 252, so as to meet the antenna performance requirement of WiFi-2.4G/5G, and make the two cavity antennas work in TE with high radiation efficiency _m01 The mode makes the dual-frequency resonant cavity antenna 20 still have higher radiation efficiency when applied to the terminal device 100 adopting the all-metal structural design, and further can ensure the antenna performance.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that are easily conceivable by those skilled in the art within the technical scope of the present application should be covered in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A dual-frequency resonant cavity antenna, comprising:

the metal body is internally provided with a cavity structure, and the surface of the metal body is provided with a slit which is communicated with the cavity structure and takes a strip shape;

The first filtering structure is arranged on the metal body and constructs a first subchamber in the chamber structure together with the metal body;

the second filtering structure is arranged on the metal body and forms a second subchamber together with the metal body in the chamber structure; the first subcavity and the second subcavity respectively comprise at least partial areas of the gaps, and an overlapping area exists between the first subcavity and the second subcavity; and

a feed structure located in the overlap region;

the first cavity antenna utilizes the feed structure to feed and radiates or receives electromagnetic wave energy of a first resonant frequency band through the gap;

the feed structure, the gap and the second subchamber jointly form a second cavity antenna, and the second cavity antenna utilizes the feed structure to feed and radiate or receive electromagnetic wave energy of a second resonant frequency band through the gap.

2. The dual-frequency resonant cavity antenna of claim 1, wherein the first resonant frequency band is lower in frequency than the second resonant frequency band;

The first filtering structure adopts a low-resistance high-pass filtering structure and is also used for binding an electric field of a first resonant frequency band generated by the first cavity antenna in the first subchamber.

3. The dual-band resonant cavity antenna of claim 2, wherein the first filtering structure comprises a plurality of first filtering units arranged at intervals, wherein a distance between two adjacent first filtering units is smaller than one quarter of an electromagnetic wave wavelength of the first resonant frequency band and larger than one half of an electromagnetic wave wavelength of the second resonant frequency band.

4. A dual-frequency resonant cavity antenna according to claim 3, wherein a plurality of the first filter elements are arranged along a first direction, the first direction being parallel to a length direction of the slot;

the first filter structure and the metal body together construct the first subcavity containing all areas of the gap and a third subcavity far away from the gap in the cavity structure, and the sum of the volumes of the first subcavity and the third subcavity is equal to the volume of the cavity structure.

5. The dual-band resonant cavity antenna of claim 2, wherein the second filtering structure is a low-pass high-resistance filtering structure, and the second filtering structure is further configured to bind an electric field in a second resonant frequency band generated by the second cavity antenna in the second sub-cavity.

6. The dual-frequency resonant cavity antenna of claim 5, wherein the second filtering structure and the metal body together construct in the cavity structure the second subchamber containing at least a partial region of the slot and other subchambers located on one or both sides of the second subchamber, and a sum of volumes of the second subchamber and the other subchambers is equal to a volume of the cavity structure.

7. The dual-band resonant cavity antenna of claim 6, wherein the second filtering structure comprises a plurality of second filtering units arranged at intervals, and wherein a distance between two adjacent second filtering units at a junction of the second sub-cavity and the other sub-cavity is smaller than a quarter of an electromagnetic wave wavelength of the second resonant frequency band.

8. The dual-band resonant cavity antenna of claim 7, wherein the second filtering unit is disposed on a surface of the metal body, the second filtering unit adopts an SRR DGS structure, and the SRR DGS structure resonates in the second resonant frequency band.

9. The dual-band resonant cavity antenna of claim 8, wherein each of the second filtering units comprises two annular first slot structures and second slot structures formed on the surface of the metal body, wherein a side length of the first slot structure is smaller than a side length of the second slot structure, and the second slot structures are surrounded outside the first slot structures.

10. The dual-band resonant cavity antenna of claim 9, wherein the metal body is integrally in a rectangular parallelepiped shape, and comprises a first metal panel, a second metal panel and a connecting portion, wherein the first metal panel, the second metal panel and the connecting portion jointly enclose the cavity structure, and the slit is formed in the first metal panel.

11. The dual-band resonant cavity antenna according to claim 9, wherein the metal body is L-shaped as a whole, and includes a flat plate portion and an extension portion bent and extended from one end of the flat plate portion, the flat plate portion and the inside of the extension portion together forming the cavity structure, and the extension portion forms the slit away from one end surface of the flat plate portion;

the metal body comprises a first metal panel, a second metal panel, a bending part and a connecting part, wherein the first metal panel and the second metal panel are oppositely arranged, the bending part bends and extends out from one end of the first metal panel, the connecting part is arranged between the first metal panel and the second metal panel, and the first metal panel, the second metal panel, the bending part and the connecting part jointly enclose into a cavity structure; the first metal panel, the second metal panel and the connecting part are partially structured to form the flat plate part, and the bending part and the connecting part are partially structured to form the extending part.

12. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged in two L-shaped structures on the surface of the first metal panel or the second metal panel, and the orthographic projection positions of the slits on the first metal panel and the second metal panel are staggered from the positions of the two L-shaped structures;

the two L-shaped structures and the metal body together construct the second subcavities containing all areas of the gaps, and fourth subcavities and fifth subcavities which are positioned at two sides of the second subcavities and do not contain the areas where the gaps are positioned in the cavity structures; the orthographic projection of the second subchamber on the second metal panel is in a T shape, and the sum of the volumes of the second subchamber, the fourth subchamber and the fifth subchamber is equal to the volume of the cavity structure.

13. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged on the surface of the second metal panel in a direction perpendicular to the length direction of the slot and are arranged in two rows in a direction parallel to the length direction of the slot to form a "|" shape structure, and the orthographic projection of the slot on the second metal panel covers part of the structures of the two "|" shapes structure;

The second subcavity, the fourth subcavity and the fifth subcavity which are positioned on two sides of the second subcavity are constructed in the cavity structure together with the metal body, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity, the fourth subcavity and the fifth subcavity is equal to the volume of the cavity structure.

14. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged on a surface of the second metal panel in a direction perpendicular to a length direction of the slit, and an orthographic projection of the slit on the second metal panel covers at least one of the second filter units;

the second filter units and the metal bodies together construct a second subcavity containing a partial area of the gap and a fourth subcavity positioned at one side of the second subcavity in the cavity structure, wherein orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

15. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged in an L-shaped structure on the surface of the first metal panel or the second metal panel, and the orthographic projection positions of the slits on the first metal panel and the second metal panel are staggered from the L-shaped structure;

the L-shaped structure and the metal body together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned at one side of the second subcavity and does not contain the area where the gap is located in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is L-shaped, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

16. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged in an L-shaped structure on the surface of the second metal panel, and the orthographic projection of the slit on the second metal panel covers part of the L-shaped structure;

the L-shaped structure and the metal body together construct the second subcavity of the partial area containing the gap and a fourth subcavity positioned at one side of the second subcavity in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, or the orthographic projection of the second subcavity on the second metal panel is L-shaped; the sum of the volumes of the second subchamber and the fourth subchamber is equal to the volume of the chamber structure.

17. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged in a Z-shaped structure on the surface of the first metal panel or the second metal panel, and the orthographic projection positions of the slits on the first metal panel and the second metal panel are staggered from the Z-shaped structure;

the Z-shaped structure and the metal body together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned at one side of the second subcavity and does not contain the area where the gap is located in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is L-shaped, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

18. The dual-frequency resonant cavity antenna according to claim 10 or 11, wherein a plurality of the second filter units are arranged on the surface of the first metal panel or the second metal panel in a direction parallel to the length direction of the slit, and the positions of orthographic projections of the slit on the first metal panel and the second metal panel are staggered from the positions of the plurality of the second filter units;

The second filter units and the metal bodies together construct a second subcavity containing all areas of the gap and a fourth subcavity which is positioned on one side of the second subcavity and far away from the gap in the cavity structure, wherein the orthographic projection of the second subcavity on the second metal panel is rectangular, and the sum of the volumes of the second subcavity and the fourth subcavity is equal to the volume of the cavity structure.

19. The dual-frequency resonant cavity antenna of claim 1, wherein the cavity structure and the slot are both filled with a medium;

the feed structure comprises a feed branch and a feed port arranged on the feed branch, the feed branch is arranged in the gap through the medium and extends along the length direction of the gap, and the feed branch is arranged at intervals with the metal structure of the metal body; the feed port is used for feeding the feed branch knot, and the feed branch knot is used for coupling excitation of the metal body.

20. A terminal device, comprising:

the shell and the display screen jointly enclose a containing cavity; and

The dual-frequency resonant cavity antenna as claimed in any one of claims 1-19, wherein the dual-frequency resonant cavity antenna is arranged in the accommodating cavity, and a gap formed on the surface of the metal body of the dual-frequency resonant cavity antenna is opposite to the joint between the edge of the shell and the edge of the display screen.