Cavity antenna and terminal equipment

Abstract

The embodiment of the invention provides a cavity antenna and terminal equipment. The cavity antenna comprises a resonant cavity, the resonant cavity comprises an all-metal surface, a radiation opening surface and a hollow-out metal surface which are not coplanar with one another, the hollow-out metal surface comprises a hollow-out area, and the hollow-out area comprises a plurality of connecting wires which are spaced from one another. The plurality of connecting lines respectively extend to the edge, which is not adjacent to the radiation port surface, of the hollow-out metal surface, and are connected with the all-metal surface. According to the technical scheme of the embodiment of the invention, the performance improvement and the miniaturization design of the cavity antenna can be considered.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of antenna technology, and in particular to a cavity antenna and a terminal device. Background Art

[0002] As terminal devices become increasingly lightweight, internal space becomes increasingly limited, and miniaturization of internal components is becoming an inevitable trend. Antennas are essential components for wireless communication in terminal devices, and their performance directly impacts their communication capabilities. Balancing antenna performance improvements with miniaturization is crucial for building competitive terminal products. Summary of the Invention

[0003] The embodiments of the present application provide a cavity antenna and a terminal device to achieve both performance improvement and miniaturization of the cavity antenna.

[0004] According to one aspect of the present application, a cavity antenna is provided, which includes a resonant cavity, which includes a full metal surface, a radiation port surface and a hollow metal surface that are not coplanar with each other, wherein the hollow metal surface includes a hollow area, and the hollow area includes a plurality of connecting lines spaced apart from each other, and the plurality of connecting lines respectively extend to edges of the hollow metal surface that are not adjacent to the radiation port surface and are connected to the full metal surface.

[0005] According to the technical solution of the embodiment of the present application, the path length of the current flowing through the surface of the resonant cavity can be flexibly adjusted by designing multiple connecting lines, thereby meeting the path length requirements of the cavity antenna for the surface current. In this way, under the premise that the fundamental mode resonant frequency remains unchanged, the cavity antenna can be designed to be smaller in size. In addition, compared with some related technologies that use the method of loading dielectric materials or lumped capacitors in the resonant cavity, the design of the cavity antenna of the embodiment of the present application can obtain higher radiation efficiency and bandwidth values, and can realize multi-frequency design. Therefore, the design of the cavity antenna of the embodiment of the present application can take into account both the performance improvement of the cavity antenna and its miniaturized design.

[0006] In some embodiments, the hollow metal surface further includes a non-hollow region, wherein a portion of an edge of the non-hollow region is adjacent to the radiation port surface, and the remaining edges of the non-hollow region are not adjacent to the radiation port surface, wherein the plurality of connecting lines are further connected to the remaining edges of the non-hollow region. In some embodiments, the hollow metal surface may be a hollow metal top surface of a resonant cavity, and the hollow region is provided along an edge of the non-hollow region that is not adjacent to the radiation port surface.

[0007] In some embodiments, the resonant cavity is a rectangular resonant cavity, the all-metal surface includes an all-metal bottom surface, a first all-metal side surface, a second all-metal side surface and a third all-metal side surface, the hollow metal surface is a hollow metal top surface, and the radiation port surface is a radiation port side surface, wherein the first all-metal side surface is parallel to the second all-metal side surface, and the radiation port side surface is parallel to the third all-metal side surface; the non-hollow area includes a first edge, a second edge, a third edge and a fourth edge, wherein the first edge is parallel to the second edge, the third edge is parallel to the fourth edge, and the fourth edge is adjacent to the radiation port side surface; multiple connecting lines include multiple first connecting lines connected between the first all-metal side surface and the first edge, multiple second connecting lines connected between the second all-metal side surface and the second edge, and multiple third connecting lines connected between the third all-metal side surface and the third edge.

[0008] While maintaining the same fundamental mode resonant frequency, the cavity antenna of this embodiment can achieve a dual-band design, achieving relatively high radiation efficiency and bandwidth, thereby balancing improved antenna performance with miniaturization. For example, compared to the comparative example of this application, the volume of the cavity antenna can be reduced by approximately 62.5%.

[0009] In some embodiments, the resonant cavity is a rectangular resonant cavity, the all-metal surface includes an all-metal bottom surface, a first all-metal side surface and a second all-metal side surface, the hollow metal surface is a hollow metal top surface, and the radiation port surface includes a first radiation port side surface and a second radiation port side surface, wherein the first all-metal side surface is orthogonal to the second all-metal side surface, the first radiation port side surface is parallel to the first all-metal side surface, and the second radiation port side surface is parallel to the second all-metal side surface; the non-hollow area includes a first edge, a second edge, a third edge and a fourth edge, wherein the first edge is parallel to the second edge, the third edge is parallel to the fourth edge, the second edge is adjacent to the first radiation port side surface, and the fourth edge is adjacent to the second radiation port side surface; multiple connecting lines include multiple first connecting lines connected between the first all-metal side surface and the first edge, and multiple second connecting lines connected between the second all-metal side surface and the third edge.

[0010] While maintaining the same fundamental mode resonant frequency, the cavity antenna of this embodiment can achieve a dual-band design, resulting in relatively high radiation efficiency, thereby balancing improved antenna performance with miniaturization. For example, compared to the comparative example of this application, the volume of the cavity antenna can be reduced by approximately 74.4%.

[0011] In some embodiments, the full metal surface includes a full metal bottom surface and a full metal top surface, and the hollow metal surface is a hollow metal side surface, and multiple connecting lines are connected between the full metal bottom surface and the full metal top surface. In some embodiments, the hollow metal surface can be a hollow metal side surface of a resonant cavity.

[0012] In some embodiments, the resonant cavity is a rectangular resonant cavity, and the radiation port surface includes a first radiation port side surface, a second radiation port side surface, and a third radiation port side surface, wherein the first radiation port side surface is parallel to the hollow metal side surface, and the second radiation port side surface and the third radiation port side surface are both orthogonal to the hollow metal side surface.

[0013] The cavity antenna of this embodiment can realize single-frequency design. Compared with the relevant comparative example of this application, the radiation efficiency of the cavity antenna is basically the same, but the volume can be reduced by about 86.7%.

[0014] In some embodiments, the full metal surface and / or the hollow metal surface has a recessed structure adjacent to the radiating aperture, which is used to adjust the equivalent capacitance of the radiating aperture. This embodiment allows capacitance adjustment without loading a lumped capacitor, thereby enabling flexible adjustment of the resonant frequencies of the cavity antenna in multiple resonant modes. For example, by specifically designing the recessed structure, the resonant frequencies of the cavity antenna's fundamental mode and higher-order modes can be more easily adjusted to fall within the 2.4 GHz and 5 GHz frequency bands.

[0015] In some embodiments, the plurality of connecting lines are respectively in the shape of curves or broken lines. The path length requirement of the cavity antenna for the surface current can be met by appropriately designing the specific line shape, size, and distribution interval of the plurality of connecting lines.

[0016] In some embodiments, the resonant cavity is filled with air or a dielectric material. Since the design of the cavity antenna in the above-mentioned embodiment of the present application can take into account both antenna performance improvement and miniaturization, the resonant cavity can be filled with air or a suitable dielectric material, which provides high design flexibility for the cavity antenna.

[0017] In some embodiments, the resonant cavity is filled with air and provided with an insulating support structure, which is supported between the top and bottom surfaces of the resonant cavity. When manufacturing a cavity antenna, an insulating support structure can be first provided. Then, using this insulating support structure as a foundation, full metal surfaces and hollow metal surfaces can be fabricated thereon, thereby forming the resonant cavity structure. This manufacturing process is simple and easy to implement.

[0018] In some embodiments, the cavity antenna transmits and receives signals in multiple operating frequency bands. Thus, the cavity antenna can combine the technical advantages of multiple operating frequency bands and has a wider range of applications.

[0019] In some embodiments, the multiple operating frequency bands include at least one of the 2.4 GHz band and the 5 GHz band. The cavity antenna can function as a dual-band WiFi antenna, combining the technical advantages of both 2.4 GHz and 5 GHz, offering improved communication performance and a wider range of applications.

[0020] According to one aspect of the present application, a terminal device is provided, comprising a radio frequency processing module and a cavity antenna according to any of the aforementioned embodiments, wherein the radio frequency processing module is connected to the cavity antenna via a transmission line. Because the design of the cavity antenna can balance performance improvement with miniaturization, the terminal device, based on the cavity antenna, has better communication performance and a more optimized internal structural layout.

[0021] In some embodiments, the terminal device further includes a back shell and a display screen, wherein the back shell includes a back panel portion and a frame portion, the display screen is located on the front side of the back shell and includes a display area and a non-display area surrounding the display area, the cavity antenna is located between the back shell and the display screen, the radiation port faces the frame portion, and the orthographic projection of the radiation port on the display screen falls into the non-display area. Product types of the terminal device include, but are not limited to, mobile phones, tablet computers, or personal computers with display screens. The cavity antenna is hidden inside the terminal device, making the terminal device relatively simple and beautiful in appearance.

[0022] In some embodiments, the back cover is a metal back cover. Since metal plates have a blocking effect on electromagnetic waves, the radiation port of the cavity antenna can be positioned in an area close to the frame and opposite the non-display area. This allows electromagnetic waves to be radiated to the outside of the terminal device through the non-display area, or electromagnetic waves to be received from the outside of the terminal device, thereby meeting the communication needs of the terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1A is a schematic diagram of a three-dimensional structure of a cavity antenna according to some embodiments of the present application;

[0024] Figure 1B 1 is a schematic diagram of a top view of a cavity antenna according to some embodiments of the present application;

[0025] Figure 1C Schematic diagram of a curve showing the radiation efficiency, total efficiency, and reflection coefficient |S11| of the cavity antenna during operation as a function of the resonant frequency according to some embodiments of the present application;

[0026] Figure 2A Schematic diagram of the three-dimensional structure of a cavity antenna according to a comparative example of the present application;

[0027] Figure 2B Schematic diagram of the internal electric field distribution of a cavity antenna according to a comparative example of the present application during operation;

[0028] Figure 2C Schematic diagram of surface current distribution of a cavity antenna according to a comparative example of the present application during operation;

[0029] Figure 3A Schematic diagram of the three-dimensional structure of a rectangular resonant cavity in the related art;

[0030] Figure 3B Schematic diagram of the three-dimensional structure of a cavity antenna according to a comparative example of the present application;

[0031] Figure 3C Schematic diagram of the curve showing the radiation efficiency and reflection coefficient |S11| of a cavity antenna according to a comparative example of the present application when working as a function of the resonant frequency (with Figure 2A The proportions shown are for comparison);

[0032] Figure 4A A schematic diagram of the structure, equivalent circuit model, and equivalent radiation model of a cavity antenna in the related art;

[0033] Figure 4B Schematic diagram of the three-dimensional structure of a cavity antenna according to a comparative example of the present application;

[0034] Figure 4C Schematic diagram of the curve showing the radiation efficiency and reflection coefficient |S11| of a cavity antenna according to a comparative example of the present application when working as a function of the resonant frequency (with Figure 2A The proportions shown are for comparison);

[0035] Figure 5A is a schematic diagram of a three-dimensional structure of a cavity antenna according to some embodiments of the present application;

[0036] Figure 5B 1 is a schematic diagram of a top view of a cavity antenna according to some embodiments of the present application;

[0037] Figure 5C Schematic diagram of a curve showing the radiation efficiency, total efficiency, and reflection coefficient |S11| of the cavity antenna during operation as a function of the resonant frequency according to some embodiments of the present application;

[0038] Figure 6A is a schematic diagram of a three-dimensional structure of a cavity antenna according to some embodiments of the present application;

[0039] Figure 6B 1 is a schematic diagram of a top view of a cavity antenna according to some embodiments of the present application;

[0040] Figure 6C is a schematic side view of the structure of a cavity antenna according to some embodiments of the present application;

[0041] Figure 6D Schematic diagram of a curve showing the radiation efficiency, total efficiency, and reflection coefficient |S11| of the cavity antenna during operation as a function of the resonant frequency according to some embodiments of the present application;

[0042] Figure 7A is a schematic diagram of a three-dimensional structure of a cavity antenna according to some embodiments of the present application;

[0043] Figure 7B 1 is a schematic diagram of a top view of a cavity antenna according to some embodiments of the present application;

[0044] Figure 7C Schematic diagram of a curve showing the radiation efficiency, total efficiency, and reflection coefficient |S11| of the cavity antenna during operation as a function of the resonant frequency according to some embodiments of the present application;

[0045] Figure 8A This is a schematic diagram of the main structure of a terminal device according to some embodiments of the present application;

[0046] Figure 8B Schematic diagram of the cross-sectional structure of a terminal device according to some embodiments of the present application.

[0047] Reference numerals:

[0048] The accompanying drawings of the embodiments of the present application are as follows:

[0049] 500-terminal device; 510-back shell; 511-back panel; 512-frame; 520-display; 521-display area; 5211-metal back panel;

[0050] 522 - non-display area; 100 - cavity antenna; 10 - rectangular resonant cavity; 11 - full metal surface; 12 - radiation port surface; 13 - hollow metal surface;

[0051] 132-hollow area; 1311-connecting line; 133-non-hollow area; 312-full metal top surface; 111, 211, 311-full metal bottom surface;

[0052] 112,212-first full metal side; 113,213-second full metal side; 114-third full metal side; 131,231-hollow metal top;

[0053] 331-hollow metal side; 121-radiation port side; 221, 321-first radiation port side; 222, 322-second radiation port side;

[0054] 323 - side of the third radiation port; 1331, 2331 - first edge; 1332, 2332 - second edge; 1333, 2333 - third edge;

[0055] 1334, 2334 - fourth edge; 1311a, 2311a - first connecting line; 1311b, 2311b - second connecting line; 1311c - third connecting line;

[0056] 134-depressed structure.

[0057] The accompanying drawings of the comparative examples cited in this application are as follows:

[0058] 001, 002, 003 - Cavity antenna; 010, 020, 030 - Rectangular resonant cavity; 021 - Dielectric material; 011 - All-metal surface; 012 Radiating port;

[0059] 0312-full metal bottom; 0111-full metal top; 0112-first full metal side; 0113-second full metal side;

[0060] 0114-Third all-metal side; 040-Equivalent circuit model; 050-Equivalent radiation model; 031-Transmission line; 032 Lumped capacitance. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0062] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the", and "this" are intended to also include expressions such as "one or more", unless the context clearly indicates otherwise.

[0063] References in this specification to "one embodiment" or "a specific embodiment" mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. The terms "including," "comprising," "having," and their variations all mean "including but not limited to," unless otherwise specifically stated.

[0064] 2.4G is a wireless technology that operates in the 2.4GHz frequency range, for example, between 2.400GHz and 2.4835GHz. 2.4G technology has a wide range of applications, including wireless connectivity scenarios such as WiFi (wireless fidelity) and Bluetooth. 2.4G technology can be applied to a wide range of products, such as mobile phones, tablets, personal computers, smart wearables, wireless keyboards, and wireless mice.

[0065] The antenna is an essential component for terminal devices to implement wireless communication functions. In some related technologies, the WiFi antenna of the terminal device adopts a cavity antenna, which is an antenna that radiates and receives electromagnetic waves through a resonant cavity. The cavity antenna can include a single or multiple resonant modes, among which the fundamental mode is the resonant mode with the lowest resonant frequency (the resonant frequency refers to the frequency in a physical system that can produce the maximum amplitude when the system is stimulated by external factors). The resonant wavelength of the fundamental mode is the key to determining the size of the cavity antenna. In the WiFi antenna of the terminal device, the fundamental mode with an operating frequency range of around 2.4 GHz (such as between 2.400 GHz and 2.4835 GHz) is usually called the fundamental mode 2.4 GHz.

[0066] Limited by the fundamental mode's resonant wavelength, naturally resonant air-filled cavity antennas typically have large dimensions, making them unsuitable for compact devices with limited internal space. While some related technologies can reduce the size of cavity antennas by loading the resonant cavity with dielectric materials or using lumped capacitors, this can lead to increased losses and narrower bandwidth.

[0067] Therefore, in terminal equipment products with increasingly compact spatial layouts, how to balance the performance improvement of cavity antennas and their miniaturized design is a key and difficult issue for technical personnel in this field to study.

[0068] In view of this, an embodiment of the present application provides a cavity antenna and a terminal device to take into account both the performance improvement of the cavity antenna and its miniaturized design.

[0069] The terminal device of the embodiment of the present application may include, but is not limited to, a mobile phone, a tablet computer, a personal computer, a smart wearable, a wireless keyboard, or a wireless mouse.

[0070] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0071] like Figure 1A and Figure 1B As shown, they are respectively a schematic diagram of the three-dimensional structure and a schematic diagram of the top view structure of the cavity antenna 100 according to some embodiments of the present application. In the embodiment of the present application, the cavity antenna 100 includes a resonant cavity, such as the rectangular resonant cavity 10 shown in the figure, which includes a full metal surface 11, a radiation port surface 12 and a hollow metal surface 13 that are not coplanar with each other, wherein the hollow metal surface 13 includes a hollow area 132, and the hollow area 132 includes a plurality of connecting lines 1311 spaced apart from each other, and the plurality of connecting lines 1311 respectively extend to the edges of the hollow metal surface 13 that are not adjacent to the radiation port surface 12, and are connected to the full metal surface 11.

[0072] The resonant cavity is a metal cavity used to allow high-frequency electromagnetic fields to continuously oscillate within it. The specific shape of the resonant cavity is not limited, for example Figure 1A and Figure 1B As shown, in some embodiments, the resonant cavity may be a rectangular resonant cavity 10 in the shape of a cuboid. In other embodiments of the present application, the resonant cavity may also be in other shapes, such as a trapezoidal shape that is narrow at the top and wide at the bottom.

[0073] In the embodiment of the present application, the full metal surface 11, the radiation port surface 12 and the hollow metal surface 13 are not coplanar with each other, so that an intersection line is formed at the intersection. Any part of the full metal surface 11 is metal. The full metal surface 11 can be arranged on one or more geometric surfaces of the multiple geometric surfaces of the resonant cavity, for example, on one or more geometric surfaces of the six geometric surfaces (i.e., the top surface, the bottom surface and the four side surfaces) of the rectangular resonant cavity 10. For example Figure 1A and Figure 1B As shown, in this embodiment, the full metal surface 11 includes a full metal bottom surface 111, a first full metal side surface 112, a second full metal side surface 113 and a third full metal side surface 114, that is, the full metal surface 11 is arranged on the bottom surface and three side surfaces of the six geometric surfaces of the rectangular resonant cavity 10.

[0074] In the embodiment of the present application, the radiation aperture 12 is the opening surface of the resonant cavity. On the one hand, electromagnetic waves in the resonant cavity can be radiated outward through the radiation aperture 12, and on the other hand, electromagnetic waves outside the resonant cavity can enter the resonant cavity through the radiation aperture 12. The radiation aperture 12 can be arranged on one or more geometric surfaces of the resonant cavity. For example Figure 1A and Figure 1B As shown, in this embodiment, the radiation port surface 12 is a radiation port side surface 121 , which is arranged on one of the six geometric surfaces of the rectangular resonant cavity 10 .

[0075] In some embodiments of the present application, the “edge” of the hollow metal surface 13 that is not adjacent to the radiation port surface 12 may have a certain width, such as Figure 1B In other embodiments, the “edge” of the hollow metal surface 13 that is not adjacent to the radiation port surface 12 may also be the intersection of the hollow metal surface 13 and the full metal surface 11, that is, Figure 1B The case where the size d=0.

[0076] At least a portion of the hollow metal surface 13 is a hollow area 132, which can be composed of a plurality of connecting lines 1311 and transparent spaces between the plurality of connecting lines 1311. The hollow metal surface 13 can be arranged on one or more geometric surfaces of the resonant cavity. For example Figure 1A and Figure 1BAs shown, in this embodiment, the hollow metal surface 13 is a hollow metal top surface 131, which is arranged on the top surface of the six geometric surfaces of the rectangular resonant cavity 10. In addition to the hollow area 132, the hollow metal surface 13 may also include a non-hollow area 133, wherein any part of the non-hollow area 133 is metal, and a portion of the edge of the non-hollow area 133 is adjacent to the radiation port surface 12, while the remaining edges of the non-hollow area 133 are not adjacent to the radiation port surface 12. Multiple connecting lines 1311 can also be respectively connected to the remaining edges of the non-hollow area 133. In some embodiments, the hollow metal surface 13 may also include only the hollow area 132 and not the non-hollow area 133.

[0077] The embodiment of the present application does not specifically limit the number, shape, size, arrangement interval, etc. of the connecting wires 1311, which can be flexibly designed according to the performance parameter requirements of the cavity antenna 100. Figure 1A and Figure 1B In the embodiment shown, the connection line 1311 may be in the shape of a broken line. In other embodiments, the connection line 1311 may also be in the shape of a curve or an oblique line (not shown in the drawings).

[0078] In the embodiment of the present application, the interior of the resonant cavity may be filled with air or dielectric material.

[0079] In some embodiments, the interior of the resonant cavity is filled with air. In order to meet the structural strength requirements of the cavity antenna 100, an insulating support structure (not shown in the figure) can also be provided in the resonant cavity. The insulating support structure is supported between the bottom and top surfaces of the resonant cavity. The specific structural form of the insulating support structure is not limited, and includes but is not limited to an insulating dielectric support plate, or an insulating dielectric bracket, etc. In some embodiments, when making the cavity antenna 100, an insulating support structure can be provided first, and then, with the insulating support structure as the support base, a full metal surface 11 and a hollow metal surface 13 are made thereon, thereby forming the structure of a rectangular resonant cavity 10. The manufacturing process is simple and easy to implement.

[0080] The cavity antenna 100 may include other elements and related circuits in addition to the resonant cavity. The other elements include but are not limited to matching elements such as capacitors, inductors, or transformers, which are not shown in the figure.

[0081] Figure 1CThe figure shows a curve diagram of the radiation efficiency, total efficiency and reflection coefficient |S11| of the cavity antenna 100 according to some embodiments of the present application during operation as a function of the resonant frequency. S11 is also commonly referred to as the reflection coefficient, which can be understood as the ratio of the reflected power at the port of the cavity antenna to the incident power. S11 generally contains amplitude information and phase information, wherein the amplitude information is often used to reflect the matching status of the port, usually represented by |S11|. In communication engineering, |S11| is usually expressed in dB, such as dB(|S11|) = 10×log10(|S11|). |S11| is usually a negative value. The larger the absolute value of the negative value, the smaller the proportion of the reflected signal and the smaller the loss of the port mismatch. The radiation efficiency of the cavity antenna can be understood as the ratio of the radiation power of the cavity antenna to the input power. The radiation efficiency is usually expressed in dB and is usually a negative value. The smaller the absolute value of the negative value, the higher the radiation efficiency. The total efficiency of the cavity antenna is η = ηA * ML, where ηA is the radiation efficiency and ML is the loss of the cavity antenna due to impedance mismatch. ML is mainly determined by the matching of the cavity antenna.

[0082] The following takes the resonant cavity as a rectangular resonant cavity 10 as an example. Figure 1C The beneficial effects of the embodiments of the present application are analyzed and explained in detail with reference to some related technologies and comparative examples.

[0083] like Figure 2A , which is a schematic diagram of the three-dimensional structure of a cavity antenna 001 according to a comparative example of the present application. In this comparative example, cavity antenna 001 includes a rectangular resonant cavity 010, whose length a, width b, and height h are: a = 88 mm, b = 44 mm, and h = 3 mm, respectively. Rectangular resonant cavity 010 includes a full metal surface 011 and a radiation port surface 012, but does not include the hollow metal surface 13 described above. Full metal surface 011 includes a full metal bottom surface 0312, a full metal top surface 0111, a first full metal side surface 0112, a second full metal side surface 0113, and a third full metal side surface 0114. That is, full metal surface 011 is arranged on the bottom, top, and three side surfaces of the six geometric surfaces of rectangular resonant cavity 010. The interior of rectangular resonant cavity 010 is filled with air.

[0084] like Figure 2B As shown, it is a schematic diagram of the internal electric field distribution of the comparative cavity antenna 001 when it is working, wherein the rectangular resonant cavity 010 works in the fundamental mode 1 / 2TM 110 , the unit of internal electric field is dB(V / m). Figure 2B It can be seen that the internal electric field presents a full wavelength distribution trend along the X direction, and the electric field intensity first increases and then decreases along the X direction. The internal electric field presents a half wavelength distribution trend along the -Y direction, and the electric field intensity gradually decreases along the -Y direction. Figure 2CAs shown, it is a schematic diagram of the surface current distribution of the comparative cavity antenna 001 when it is working, wherein the rectangular resonant cavity 010 works in the fundamental mode 1 / 2TM 110 , the unit of surface current is dB(A / m). Figure 2C It can be seen that the surface current presents a full wavelength distribution along the X direction, and the current intensity first decreases and then increases along the X direction. The surface current presents a half wavelength distribution along the -Y direction, and the current intensity gradually increases along the -Y direction. Figure 2B and Figure 2C It can be concluded that the electric field intensity of the rectangular resonant cavity 010 in the areas close to the first full-metal side surface 0112 , the second full-metal side surface 0113 , and the third full-metal side surface 0114 is relatively small, and the surface current is relatively large.

[0085] Based on the analysis of the above comparative example, the present embodiment improves the structure of the rectangular resonant cavity. Figure 1A and Figure 1B As shown, in an embodiment of the present application, the rectangular resonant cavity 10 is composed of a full metal surface 11, a radiation port surface 12 and a hollow metal surface 13, wherein the hollow area 132 of the hollow metal surface 13 includes a plurality of connecting lines 1311 spaced apart from each other, each connecting line 1311 extends to an edge of the hollow metal surface 13 that is not adjacent to the radiation port surface 12, and each connecting line 1311 is connected to the full metal surface 11.

[0086] Under the premise of keeping the length, width and height of the rectangular resonant cavity 10 unchanged, the path of the current flowing on the surface of the rectangular resonant cavity 10 can be appropriately extended by properly designing the line type, size and distribution interval of the multiple connecting lines 1311, so that the multiple resonant modes of the rectangular resonant cavity 10 (such as the fundamental mode 1 / 2TM 110 , high order mold 1 / 2TM 210 , high order mold 1 / 2TM 130 The resonant wavelengths of the plurality of resonant modes (e.g., the wavelengths of the plurality of resonant modes) increase, and accordingly, the resonant frequencies of the plurality of resonant modes of the rectangular resonant cavity 10 decrease. That is, while maintaining the length, width, and height of the rectangular resonant cavity 10, the resonant frequencies of the plurality of resonant modes of the rectangular resonant cavity 10 can be reduced by appropriately designing the line shape, size, and distribution spacing of the plurality of connecting lines 1311.

[0087] Based on the above analysis, from another perspective, if the fundamental mode 1 / 2TM is maintained 110 The resonant frequency remains unchanged, such as making the fundamental mode 1 / 2TM 110Working in the frequency range of 2.4 GHz, the path length of the current flowing through the surface of the resonant cavity can be flexibly adjusted by appropriately designing the line type, size and distribution interval of the multiple connecting lines 1311, thereby meeting the path length requirement of the cavity antenna 100 for the surface current. In this way, the rectangular resonant cavity 10 is Figure 2A The comparative example shown can be designed with a smaller size, that is, at least one of the length, width and height can be reduced.

[0088] Absolute bandwidth is one way to express the bandwidth of a cavity antenna. It can be understood as the frequency range within which the cavity antenna effectively operates, that is, the difference between the upper and lower frequency limits within which the cavity antenna effectively operates. Under appropriate feeding schemes, the cavity antenna 100 of the present embodiment can transmit and receive signals in multiple operating frequency bands, that is, it can operate in multiple resonant modes. These multiple operating frequency bands may include, but are not limited to, at least one of the 2.4 GHz band and the 5 GHz band.

[0089] As described above, the 2.4GHz band has a frequency range near 2.4GHz, for example, between 2.400GHz and 2.4835GHz. The 5GHz band has a frequency range near 5GHz, for example, between 4.9GHz and 5.9GHz. Because the two have different frequency ranges and are based on different standards, they each have their own advantages and disadvantages. For example, in terms of speed, 5GHz is stable and faster, while 2.4GHz is slightly slower; in terms of coverage, 2.4GHz has a wider range, while 5GHz has a relatively smaller range; and in terms of wall penetration, 2.4GHz is stronger than 5GHz, providing a more stable connection.

[0090] In some embodiments of the present application, by properly designing the line type, size, and distribution interval of the plurality of connecting lines 1311, the fundamental mode TM of the cavity antenna 100 can be made 110 Working in the frequency range of 2.4 GHz, the high-order mode 1 / 2TM of the cavity antenna 100 210 , high order mold 1 / 2TM 130 Working in the frequency range of 5 GHz, the cavity antenna 100 can realize a dual-band design, and can have the technical advantages of both 2.4 GHz and 5 GHz, with better communication performance and a wider range of applications.

[0091] Therefore, the design of the cavity antenna 100 according to the embodiment of the present application can take into account both the performance improvement and the miniaturization of the antenna.

[0092] In the embodiment of the present application, the specific structure of the resonant cavity is not limited. Figure 1A and Figure 1BAs shown, in some embodiments of the present application, the resonant cavity is a rectangular resonant cavity 10, the full metal surface 11 includes a full metal bottom surface 111, a first full metal side surface 112, a second full metal side surface 113, and a third full metal side surface 114, the hollow metal surface 13 is a hollow metal top surface 131, and the radiation port surface 12 is a radiation port side surface 121, wherein the first full metal side surface 112 is parallel to the second full metal side surface 113, and the radiation port side surface 121 is parallel to the third full metal side surface 114. The non-hollow area 133 includes a first edge 1331, a second edge 1332, a third edge 1333, and a fourth edge 1334, wherein the first edge 1331 is parallel to the second edge 1332, the third edge 1333 is parallel to the fourth edge 1334, and the fourth edge 1334 is adjacent to the radiation port side surface 121. The multiple connecting lines 1311 include multiple first connecting lines 1311a connected between the first full metal side 112 and the first edge 1331, multiple second connecting lines 1311b connected between the second full metal side 113 and the second edge 1332, and multiple third connecting lines 1311c connected between the third full metal side 114 and the third edge 1333.

[0093] As mentioned above about Figure 2A According to the analysis of the comparative example shown, the surface current of the rectangular resonant cavity 010 is relatively large in the area close to the first full metal side 0112, the second full metal side 0113 and the third full metal side 0114 (see Figure 2C As shown), therefore, in the embodiment of the present application, Figure 1A and Figure 1B As shown, the hollow metal surface 13 can be set on the top surface of the rectangular resonant cavity 10, and the hollow area 132 can be arranged as close as possible to the first full metal side 112, the second full metal side 113 and the third full metal side 114. In this way, while maintaining the fundamental mode 1 / 2TM 110 Under the premise that the resonant frequency remains unchanged, the path length requirement of the cavity antenna 100 for the surface current can be met by properly designing the line type, size and distribution interval of the multiple connecting lines 1311. Therefore, the cavity antenna 100 of the embodiment of the present application is Figure 2A The cavity antenna 001 of the comparative example shown can be designed with a smaller cavity size. Moreover, under an appropriate feeding scheme, the cavity antenna 100 of the embodiment of the present application can operate in multiple operating frequency bands.

[0094] In some embodiments of the present application, the connecting line 1311 can be designed as Figure 1A and Figure 1B The rectangular resonant cavity 10 may be filled with air. The embodiment of the present application does not limit the specific size parameters of the cavity antenna 100. Figure 1A and Figure 1BAs shown, in this embodiment, some relevant parameters of the cavity antenna 100 can be designed as: h=3mm, l=44mm, w=33mm, d=1mm, dx=10mm, dy=9.4mm, w_slot=4mm, lx=4.5mm, ly=4.2mm, fx=11mm, fy=12mm, the width of the connecting line 1311 (not shown in the figure) is 0.4mm, where F represents the feeding position of the cavity antenna 100.

[0095] like Figure 1C As shown, the |S11| curve presents troughs in the above frequency ranges of the 2.4 GHz band and the 5 GHz band, respectively. Thus, the cavity antenna 100 can operate in the 2.4 GHz band and the 5 GHz band, wherein the resonant mode of the 2.4 GHz band is the fundamental mode 1 / 2TM. 110 , the resonant modes in the 5GHz band include the high-order mode 1 / 2TM 210 and higher order mode 1 / 2TM 130 .

[0096] The beneficial effects of the cavity antenna 100 according to the embodiment of the present application will be further described in detail below through a rectangular resonant cavity in the related art and two other comparative examples.

[0097] like Figure 3A As shown in FIG. 1 , it is a schematic diagram of the structure of a rectangular resonant cavity 020 in the related art. The rectangular resonant cavity 020 includes six closed all-metal surfaces and a dielectric material filled therein (not shown). In the rectangular resonant cavity 020, the electromagnetic field can oscillate at a series of resonant frequencies, and the magnitude of the resonant frequency is related to the shape, geometric dimensions, and resonant waveform of the resonant cavity. In the rectangular resonant cavity 020, TM mnp The resonant frequency f(TM mnp ) can be expressed as follows:

[0098]

[0099] Among them, c is the propagation speed of electromagnetic waves in vacuum, which is a physical constant; ε r is the relative dielectric constant of the dielectric material; μ r is the relative magnetic permeability of the dielectric material; a, b, and h are the length, width, and height of the rectangular resonant cavity 020, respectively; m, n, and p are the number of half-standing waves of the electromagnetic field in the X, Y, and Z directions, respectively. (A standing wave is a distribution along a transmission line formed by two waves of the same frequency traveling in opposite directions.) TM electromagnetic waves have an electric field component but no magnetic field component in the direction of propagation and are therefore also called transverse magnetic waves or P waves.

[0100] According to the above expression, the resonant frequency f(TM mnp ) decreases with the increase of any of the size parameters a, b, and h, and, with the relative dielectric constant ε r Since dielectric materials are usually non-magnetic materials, the relative magnetic permeability μ of different dielectric materials is r For the resonant frequency f(TM mnp ) can be neglected.

[0101] The side of the rectangular resonant cavity 020 is opened to serve as a radiation port, so that the basic structure of the cavity antenna can be obtained. Thus, the resonant frequency of the cavity antenna also basically conforms to the above-mentioned variation law, that is, it decreases with the increase of any parameter of the size parameters a, b, and h. Moreover, as the relative dielectric constant ε increases, the resonant frequency of the cavity antenna decreases. r decreases with the increase of .

[0102] According to the above description, the resonant frequency of the fundamental mode is the key to determining the size of the rectangular resonant cavity 020. Therefore, in a comparative example of the present application, under the premise that the resonant frequency of the fundamental mode remains unchanged, an appropriate dielectric material is selected to increase the relative dielectric constant ε. r , which can achieve the purpose of reducing some of the size parameters a, b, and h.

[0103] Reference Figure 2A In the comparative example shown, for the cavity antenna 001 with a side opening, it can include multiple resonant modes. In the order of the resonant frequencies from small to large, the resonant frequencies of the first four resonant modes are f(1 / 2TM 110 )=2.4GHz、f(1 / 2TM 210 )=3.8GHz、f(1 / 2TM 220 )=4.8GHz、f(1 / 2TM 310 )=5.4GHz, where the fundamental mode frequency is f(1 / 2TM 110 )=2.4GHz. If the rectangular resonant cavity 010 is filled with air (the relative dielectric constant of air is ε r It is generally considered to be 1), so the size parameters of the cavity antenna 001 need to be designed as a=88mm, b=44mm, and h=3mm.

[0104] like Figure 3B As shown, under the premise that the fundamental mode frequency remains unchanged, if the interior of the rectangular resonant cavity 020 is composed of a relative dielectric constant ε r =3, dielectric loss tangent angle tanδ = 0.01, the size parameters of the cavity antenna 002 can be designed as a = 54mm, b = 25mm, h = 3mm, thus, compared with Figure 2AThe air-filled cavity antenna 001 has an overall volume reduced by approximately 65%.

[0105] like Figure 3C As shown, it is a curve diagram of the radiation efficiency and reflection coefficient |S11| of the cavity antenna 002 of the comparative example changing with the resonant frequency when working (with Figure 2A As shown in the figure, the |S11| curves of the two cavity antennas 001 and 002 are basically the same, but the radiation efficiency of the cavity antenna 002 is lower than that of the cavity antenna 001. For example, the fundamental mode 1 / 2TM 110 The radiation efficiency of the CMOS device decreases from -0.2dB to below -3dB. r While this approach can achieve the goal of reducing dimensional parameters, it will also reduce radiation efficiency to a certain extent, resulting in greater losses in cavity antenna 002. Furthermore, in practical applications, the thickness and relative permittivity of dielectric material 021 are difficult to flexibly adjust based on design requirements, leading to a lack of design flexibility in cavity antenna 002. Furthermore, the weight of dielectric material 021 also increases the weight of cavity antenna 002.

[0106] Another comparative example of the present application adopts a solution that reduces some of the dimensional parameters a, b, and h by loading a lumped capacitor in a rectangular resonant cavity while keeping the fundamental mode resonant frequency unchanged.

[0107] Reference Figure 4A , which are schematic diagrams of the structure, equivalent circuit model 040, and equivalent radiation model 050 of a cavity antenna 003 in the related art, wherein (a) shows a schematic diagram of the structure of a cavity antenna 003 with side openings and dimensional parameters a, b, and h, (b) shows a schematic diagram of the equivalent circuit model 040 of the cavity antenna 003, and (c) shows a schematic diagram of the equivalent radiation model 050 of the fundamental mode of the cavity antenna 003. As shown in (a) and (b), the metal surface of the cavity antenna 003 can be equivalent to a transmission line 031 of length b, and the side opening of the cavity antenna 003 can be equivalent to a capacitor C. As shown in Figures (b) and (c), when b < λ / 4 (λ is the fundamental mode resonant wavelength, and the fundamental mode resonant frequency range is, for example, 2.4 GHz), the equivalent radiation model 050 of the fundamental mode of the cavity antenna 003 can be obtained, where the arrow F indicates feeding the cavity antenna 003, and the equivalent inductance of the transmission line 031 is X L , the radiation resistance of the cavity antenna 003 is R, and the equivalent capacitance of the electric field coupling generated by the side opening of the cavity antenna 003 is X C .

[0108] The resonant frequency f0 of the cavity antenna 003 can be expressed by the following expression:

[0109]

[0110] Where L is the equivalent inductance X L The inductance value, C is the equivalent capacitance X C According to this expression, when the resonant frequency f0 remains unchanged, if the capacitance value C increases, the inductance value L decreases, because the equivalent inductance X L The capacitance C is generated by transmission line 031, which is equivalent to the metal surface of cavity antenna 003. Therefore, the length b of transmission line 031 can be reduced accordingly, and thus the size b of cavity antenna 003 can be reduced accordingly. Therefore, as an alternative, the size of cavity antenna 003 can be reduced by increasing the capacitance C.

[0111] like Figure 4B As shown, it is a schematic diagram of the three-dimensional structure of a cavity antenna 003 according to a comparative example of the present application. Figure 2A The comparative example shown in Figure 4B In the comparative example shown, under the premise of keeping the fundamental mode frequency unchanged, three 0.5pf (pf is the unit of capacitance) lumped capacitors 032 are connected in parallel at the side openings of the rectangular resonant cavity 030. Based on the above analysis, as the capacitance value C increases, the size parameters of the cavity antenna 003 can be designed to be reduced accordingly. Therefore, the size parameters of the cavity antenna 003 can be designed to be a=54mm, b=25mm, and h=3mm. Figure 2A The overall volume of the cavity antenna 001 shown is reduced by about 65%.

[0112] The Q value (quality factor) is a dimensionless physical quantity used to measure the performance of electronic devices or resonant circuits. According to the expression for the Q value of a cavity antenna, Q = 2πf0CR, it can be seen that, assuming other conditions remain unchanged, the larger the capacitance value C, the greater the Q value. Furthermore, according to the relationship between the Q value and the bandwidth (BW), Q = f0 / BW, it can be seen that, assuming f0 remains unchanged, as the Q value increases, the bandwidth (BW) decreases. Therefore, while the design of cavity antenna 003 can reduce its size parameters to a certain extent, it also brings about the problem of reduced bandwidth.

[0113] like Figure 4C As shown, it is a curve diagram of the radiation efficiency and reflection coefficient |S11| of the cavity antenna 003 according to a comparative example of the present application when working as a function of the resonant frequency (with Figure 2A The comparative examples are shown for comparison).

[0114] Comparing the reflection coefficient |S11| curves of the two cavity antennas 001 and 003, it can be seen that at the same |S11| value, for example -3dB, the difference between the upper and lower frequency limits of cavity antenna 003 is significantly smaller than that of cavity antenna 001. Therefore, the bandwidth of cavity antenna 003 is reduced compared to that of cavity antenna 001, resulting in that, in some application scenarios, cavity antenna 003 cannot meet the design requirements of broadband and multi-frequency. In addition, comparing the radiation efficiency curves of the two cavity antennas 001 and 003, it can be seen that under the premise of the same fundamental mode resonant frequency, the radiation efficiency of cavity antenna 003 is significantly lower than that of cavity antenna 001. For example, the fundamental mode 1 / 2TM 110 The radiation efficiency drops from -0.2dB to below -3dB.

[0115] In the embodiment of the present application, the comparison Figure 1C and Figure 4C It can be seen that under the premise of the same fundamental mode resonant frequency, the cavity antenna 100 of the embodiment of the present application can obtain higher radiation efficiency and bandwidth value, and, compared with Figure 2A In the comparative example shown, the volume of the cavity antenna 100 can be reduced by about 62.5%, and has a more compact size. Figure 1A and Figure 1B The cavity antenna 100 shown can take into account both the performance improvement of the antenna and its miniaturized design.

[0116] In the embodiment of the present application, as described above, the specific structural form of the resonant cavity is not limited. In addition to the rectangular resonant cavity 10 shown in the schematic diagram of the above embodiment, it can also present a variety of deformed structures.

[0117] like Figure 5A and Figure 5BAs shown, they are schematic diagrams of the main view structure and the top view structure of the cavity antenna 100 according to other embodiments of the present application. In this embodiment, the resonant cavity is a rectangular resonant cavity 10, the full metal surface 11 includes a full metal bottom surface 211, a first full metal side surface 212 and a second full metal side surface 213, the hollow metal surface 13 is a hollow metal top surface 231, and the radiation port surface 12 includes a first radiation port side surface 221 and a second radiation port side surface 222, wherein the first full metal side surface 212 and the second full metal side surface 213 are orthogonal, the first radiation port side surface 221 is parallel to the first full metal side surface 212, and the second radiation port side surface 222 is parallel to the second full metal side surface 213. The non-hollowed-out area 133 includes a first edge 2331, a second edge 2332, a third edge 2333, and a fourth edge 2334. The first edge 2331 is parallel to the second edge 2332, the third edge 2333 is parallel to the fourth edge 2334, the second edge 2332 is adjacent to the first radiation port side surface 221, and the fourth edge 2334 is adjacent to the second radiation port side surface 222. The plurality of connecting lines 1311 include a plurality of first connecting lines 2311a connected between the first all-metal side surface 212 and the first edge 2331, and a plurality of second connecting lines 2311b connected between the second all-metal side surface 213 and the third edge 2333.

[0118] In these embodiments, the connecting line 1311 can be designed as a broken line shape, and the interior of the rectangular resonant cavity 10 can be filled with air. The embodiments of the present application do not limit the specific size parameters of the cavity antenna 100. In some embodiments, refer to Figure 5A and Figure 5B As shown, some relevant parameters of the cavity antenna 100 can be designed as: h=3mm, l=30mm, w=33mm, d=1mm, dx=9.4mm, dy=9mm, w_slot=4mm, lx=4mm, ly=4mm, lf=4.65mm, wf=1.6mm, the width of the connecting line 1311 (not shown in the figure) is 0.4mm, where F represents the feeding position of the cavity antenna 100.

[0119] like Figure 5C As shown in FIG, which is a curve diagram of the radiation efficiency, total efficiency and reflection coefficient |S11| of the cavity antenna 100 of this embodiment when working as a function of the resonant frequency. As can be seen from the figure, the cavity antenna 100 can operate in the 2.4 GHz band and the 5 GHz band, wherein the resonant mode of the 2.4 GHz band is the fundamental mode 1 / 4TM 110 , the resonant modes in the 5GHz band include the high-order mode 1 / 4TM 310 and higher order mode 1 / 4TM 130 .

[0120] In addition, compared Figure 5C 、 Figure 3C and Figure 4C It can be seen that under the premise of the same fundamental mode resonant frequency, the cavity antenna 100 of the embodiment of the present application can obtain higher radiation efficiency, and, compared with Figure 2A In the comparative example shown, the overall volume of the cavity antenna 100 is reduced by about 74.4%, resulting in a more compact size. Therefore, the design of the cavity antenna 100 in this embodiment can achieve both improved antenna performance and miniaturization.

[0121] like Figure 6A 、 Figure 6B and Figure 6C As shown, they are schematic diagrams of the main view structure, top view structure and side view structure of the cavity antenna 100 according to other embodiments of the present application. In this embodiment, the resonant cavity is a rectangular resonant cavity 10, the full metal surface 11 includes a full metal bottom surface 311 and a full metal top surface 312, the hollow metal surface 13 is a hollow metal side surface 331, and multiple connecting wires 1311 are connected between the full metal bottom surface 311 and the full metal top surface 312. As mentioned above Figure 2A According to the analysis of the comparative example shown, the surface current of the rectangular resonant cavity 010 is relatively large in the area close to the first full metal side 0112, the second full metal side 0113 and the third full metal side 0114 (see Figure 2C As shown), therefore, in this embodiment of the present application, the hollow metal surface 13 can be arranged on the side surfaces of the six geometric surfaces of the rectangular resonant cavity 10.

[0122] Reference Figure 6A As shown, in some embodiments, the radiation port surface 12 may include a first radiation port side surface 321, a second radiation port side surface 322 and a third radiation port side surface 323, wherein the first radiation port side surface 321 is parallel to the hollow metal side surface 331, and the second radiation port side surface 322 and the third radiation port side surface 323 are both orthogonal to the hollow metal side surface 331 and are both orthogonal to the full metal bottom surface 311.

[0123] In these embodiments, the connecting line 1311 can be designed as Figure 6C The interior of the rectangular resonant cavity 10 can be filled with dielectric material, air, or provided with an insulating support structure. The embodiment of the present application does not limit the specific size parameters of the cavity antenna 100. In some embodiments, the interior of the rectangular resonant cavity 10 is filled with a relative dielectric constant ε r =3, dielectric material (not shown) with dielectric loss tangent angle tanδ=0.01, refer to Figure 6B and Figure 6CAs shown, some relevant parameters of the cavity antenna 100 can be designed as: hc=3mm, l=38mm, w=13.5mm, fx=19mm, fy=2mm, dx=4.8mm, lx=2mm, the width of the connecting line 1311 (not shown in the figure) is 0.35mm, where F represents the feeding position of the cavity antenna 100.

[0124] like Figure 6D As shown in FIG, which is a curve diagram of the radiation efficiency, total efficiency and reflection coefficient |S11| of the cavity antenna 100 of this embodiment when working as a function of the resonant frequency. As can be seen from the figure, the cavity antenna 100 can be designed as a single-frequency antenna, which can operate in the 2.4 GHz frequency band, wherein the resonant mode of the 2.4 GHz frequency band is 1 / 2TM 110 .

[0125] compared to Figure 2A In the comparative example shown, the overall volume of the cavity antenna 100 of the embodiment of the present application is reduced by about 86.7%, and has a more compact size. Figure 3C and Figure 4C The comparative example shown in the figure shows that the fundamental mode 1 / 2TM of the cavity antenna 100 of the embodiment of the present application is 110 The radiation efficiency is basically the same, therefore, the design of the cavity antenna 100 in this embodiment can take into account both its performance improvement and its miniaturization design.

[0126] In some embodiments of the present application, Figure 7A and Figure 7B , which are schematic diagrams of the three-dimensional structure and the top view structure of the cavity antenna 100 according to some embodiments of the present application. In these embodiments, the full metal surface 11 and / or the hollow metal surface 13 may have a recessed structure 134 (as an example, in this embodiment, the recessed structure 134 is provided on the hollow metal surface 13). The recessed structure 134 is adjacent to the radiation aperture 12, so that the shape of the radiation aperture 12 is no longer rectangular as in the aforementioned embodiment, but presents a special shape, for example, it may present the "concave" shape shown in the figure.

[0127] Because the electric field coupling generated by the side openings of the cavity antenna 100 is equivalent to distributed capacitance, the capacitance value of which is primarily determined by the structural shape and dimensions of the radiating aperture 12. Therefore, the equivalent capacitance of the radiating aperture 12 can be adjusted by designing the recessed structure 134. This not only balances performance improvement and miniaturization of the cavity antenna 100, but also allows for capacitance adjustment without adding lumped capacitance, thereby enabling flexible adjustment of the resonant frequencies of the multiple resonant modes of the cavity antenna 100. For example, through the specific design of the recessed structure 134, the resonant frequencies of the fundamental mode and higher-order modes of the cavity antenna 100 can be more easily adjusted to fall within the 2.4 GHz and 5 GHz frequency bands.

[0128] The design of the recessed structure 134 can be applicable to the cavity antenna 100 of any of the above embodiments, and the embodiments of the present application do not specifically limit this.

[0129] like Figure 7A and Figure 7B As shown, this embodiment is Figure 1A 、 Figure 1B The illustrated embodiment is a structural variation, wherein the full metal surface 11 includes a full metal bottom surface 111, a first full metal side surface 112, a second full metal side surface 113, and a third full metal side surface 114. The hollow metal surface 13 is a hollow metal top surface 131, and the radiation port surface 12 is a radiation port side surface 121. The hollow metal top surface has a recessed structure 134. The first full metal side surface 112 is parallel to the second full metal side surface 113, and the radiation port side surface 121 is parallel to the third full metal side surface 114. The non-hollow area 133 includes a first edge 1331, a second edge 1332, a third edge 1333, and a fourth edge 1334. The first edge 1331 is parallel to the second edge 1332, the third edge 1333 is opposite to the fourth edge 1334, and the fourth edge 1334 is adjacent to the radiation port side surface 121. The multiple connecting lines 1311 include multiple first connecting lines 1311a connected between the first full metal side 112 and the first edge 1331, multiple second connecting lines 1311b connected between the second full metal side 113 and the second edge 1332, and multiple third connecting lines 1311c connected between the third full metal side 114 and the third edge 1333.

[0130] The specific structural form of the recessed structure 134 is not limited, for example, Figure 7A As shown in FIG, it includes a recessed bottom surface and three recessed side surfaces. The specific size and specific location of the recessed structure 134 can be flexibly adjusted according to design requirements. In some embodiments, a recessed structure can also be designed on the all-metal bottom surface 111, thereby also having the effect of adjusting the equivalent capacitance of the radiation aperture 12.

[0131] In these embodiments, the connecting line 1311 can be a broken line, and the interior of the rectangular resonant cavity 10 can be filled with air. The embodiment of the present application does not limit the specific size parameters of the cavity antenna 100. In some embodiments, refer to Figure 7A and Figure 7B As shown, some relevant parameters of the cavity antenna 100 can be designed as: h=3mm, l=44mm, w=32mm, d=1mm, dx=10mm, dy=9mm, w_slot=4mm, lx=3.8mm, ly=4mm, fx=11mm, fx=12mm, lc=5mm, wc=5mm, hc=2.6mm, the width of the connecting line 1311 (not shown in the figure) is 0.4mm, where F represents the feeding position of the cavity antenna 100.

[0132] like Figure 7C As shown in FIG, which is a curve diagram of the radiation efficiency, total efficiency and reflection coefficient |S11| of the cavity antenna 100 of this embodiment when working as a function of the resonant frequency. As can be seen from the figure, the cavity antenna 100 can operate in the 2.4 GHz band and the 5 GHz band, wherein the resonant mode of the 2.4 GHz band is the fundamental mode 1 / 2TM 110 , the resonant modes in the 5GHz band include the high-order mode 1 / 2TM 210 and higher order mode 1 / 2TM 130 .

[0133] In addition, compared Figure 7C 、 Figure 3C and Figure 4C It can be seen that under the premise of the same fundamental mode resonant frequency, the cavity antenna 100 of the embodiment of the present application can obtain higher radiation efficiency and bandwidth value, and, compared with Figure 2A In the comparative example shown, the overall volume of the cavity antenna 100 is reduced by approximately 62.5%, resulting in a more compact size. Therefore, the design of the cavity antenna 100 in this embodiment can achieve both improved antenna performance and miniaturization, and its resonant frequency can be adjusted more flexibly and easily.

[0134] In some embodiments of the present application, in order to further optimize the performance of the cavity antenna 100, corresponding matching elements (not shown in the figure), such as capacitor elements, inductor elements, or transformers, can be set at the feeding position F of the cavity antenna 100 on the basis of the structure of any of the above embodiments. In this way, the |S11| curve of the cavity antenna 100 can be further optimized and adjusted.

[0135] The present application also provides a terminal device, such as Figure 8A and Figure 8B, which are schematic diagrams of the main structure and cross-sectional structure of a terminal device 500 according to some embodiments of the present application, respectively. The terminal device 500 includes the cavity antenna 100 of any of the aforementioned embodiments. Specific product types of the terminal device 500 include, but are not limited to, mobile phones, tablet computers, personal computers, smart wearables, wireless keyboards, or wireless mice. In some embodiments, the terminal device 500 may further include a radio frequency processing module (not shown in the figure), which is connected to the cavity antenna 100 via a transmission line (not shown in the figure). The radio frequency processing module is used to perform relevant processing on the feed signal and the received signal of the cavity antenna 100, such as filtering, amplification, or frequency conversion.

[0136] Since the design of the cavity antenna 100 can take into account both performance improvement and miniaturization, the terminal device 500 has better communication performance based on the cavity antenna 100 and its internal structure layout can be further optimized.

[0137] like Figure 8A and Figure 8B As shown, in some embodiments of the present application, the terminal device 500 may further include a back shell 510 and a display screen 520, wherein the back shell 510 includes a back panel portion 511 and a frame portion 512, the back panel portion 511 and the frame portion 512 constitute a receiving space, the display screen 520 is located on the front side of the back shell 510, and includes a display area 521 and a non-display area 522 surrounding the display area 521, the cavity antenna 100 is located between the back shell 510 and the display screen 520, and its radiation port surface (such as the first radiation port side surface 221 and the second radiation port side surface 222) faces the frame portion 512, and the positive projection of the radiation port surface on the display screen 520 is located in the non-display area 522.

[0138] In these embodiments, the terminal device 500 may be a mobile phone, tablet computer, or personal computer with a display screen 520. The cavity antenna 100 is hidden inside the terminal device 500, making the terminal device 500 simple and beautiful in appearance.

[0139] Continue to refer to Figure 8A and Figure 8BAs shown, the non-display area 522 of the display screen 520 generally does not include a metal layer. The non-display area 522 can be provided with a light-shielding ink layer to block the structures that need to be hidden inside the terminal device 500 and the stray light that may be generated at the edge of the display area 521. Since the display area 521 of the display screen 520 needs to be provided with a display circuit, it generally includes a metal layer or a metal backplate 5211. In some embodiments of the present application, the back shell 510 can adopt a metal back shell or a non-metal back shell. Since the metal plate surface (such as the metal back shell, the metal backplate 5211, etc.) has a blocking effect on electromagnetic waves, the radiation port surface of the cavity antenna 100 can be set in an area close to the frame portion 512 and opposite to the non-display area 522. Thus, electromagnetic waves can be radiated to the outside of the terminal device 500 through the non-display area 522, or electromagnetic waves from the outside of the terminal device 500 can be received, thereby meeting the communication needs of the terminal device 500. The cavity antenna 100 of the embodiment of the present application is particularly suitable for terminal devices 500 using metal back shells.

[0140] like Figure 8A As shown, as an example, the cavity antenna 100 adopts Figure 5A and Figure 5B In the embodiment shown, the radiation port surface includes a first radiation port side surface 221 and a second radiation port side surface 222. The first radiation port side surface 221 and the second radiation port side surface 222 correspond to and are positioned as close to the narrow side and the wide side of the frame portion 512. This makes the internal space layout of the terminal device 500 more compact.

[0141] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A cavity antenna, characterized in that: The invention comprises a resonant cavity, wherein the resonant cavity comprises a full metal surface, a radiation port surface and a hollow metal surface which are not coplanar with each other, wherein the hollow metal surface comprises a hollow area, and the hollow area comprises a plurality of connecting lines spaced apart from each other, and the plurality of connecting lines respectively extend to edges of the hollow metal surface which are not adjacent to the radiation port surface and are connected to the full metal surface.

2. The cavity antenna according to claim 1, wherein: The hollow metal surface also includes a non-hollow area, a portion of the edges of the non-hollow area are adjacent to the radiation port surface, and the remaining edges of the non-hollow area are not adjacent to the radiation port surface, wherein the multiple connecting lines are also respectively connected to the remaining edges of the non-hollow area.

3. The cavity antenna according to claim 2, wherein: The resonant cavity is a rectangular resonant cavity, the full metal surface includes a full metal bottom surface, a first full metal side surface, a second full metal side surface and a third full metal side surface, the hollow metal surface is a hollow metal top surface, and the radiation port surface is a radiation port side surface, wherein the first full metal side surface is parallel to the second full metal side surface, and the radiation port side surface is parallel to the third full metal side surface; The non-hollow area includes a first edge, a second edge, a third edge, and a fourth edge, wherein the first edge is parallel to the second edge, the third edge is parallel to the fourth edge, and the fourth edge is adjacent to the side surface of the radiation port; The plurality of connection lines include a plurality of first connection lines connected between the first full metal side and the first edge, a plurality of second connection lines connected between the second full metal side and the second edge, and a plurality of third connection lines connected between the third full metal side and the third edge.

4. The cavity antenna according to claim 2, wherein: The resonant cavity is a rectangular resonant cavity, the full metal surface includes a full metal bottom surface, a first full metal side surface, and a second full metal side surface, the hollow metal surface is a hollow metal top surface, and the radiation port surface includes a first radiation port side surface and a second radiation port side surface, wherein the first full metal side surface is orthogonal to the second full metal side surface, the first radiation port side surface is parallel to the first full metal side surface, and the second radiation port side surface is parallel to the second full metal side surface; The non-hollow area includes a first edge, a second edge, a third edge, and a fourth edge, wherein the first edge is parallel to the second edge, the third edge is parallel to the fourth edge, the second edge is adjacent to the side surface of the first radiation port, and the fourth edge is adjacent to the side surface of the second radiation port; The plurality of connection lines include a plurality of first connection lines connected between the first full metal side surface and the first edge, and a plurality of second connection lines connected between the second full metal side surface and the third edge.

5. The cavity antenna according to claim 1, wherein: The full metal surface includes a full metal bottom surface and a full metal top surface, the hollow metal surface is a hollow metal side surface, and the multiple connecting lines are connected between the full metal bottom surface and the full metal top surface.

6. The cavity antenna according to claim 5, characterized in that: The resonant cavity is a rectangular resonant cavity, and the radiation port surface includes a first radiation port side surface, a second radiation port side surface and a third radiation port side surface, wherein the first radiation port side surface is parallel to the hollow metal side surface, and the second radiation port side surface and the third radiation port side surface are both orthogonal to the hollow metal side surface.

7. The cavity antenna according to claim 1, wherein: The full metal surface and / or the hollow metal surface has a concave structure, and the concave structure is adjacent to the radiation port surface and is used to adjust the equivalent capacitance of the radiation port surface.

8. The cavity antenna according to claim 1, wherein: The multiple connection lines are respectively in the shape of curves or broken lines.

9. The cavity antenna according to claim 1, wherein: The resonant cavity is filled with air or dielectric material.

10. The cavity antenna according to claim 1, wherein: The resonant cavity is filled with air, and an insulating support structure is provided in the resonant cavity. The insulating support structure is supported between the top surface and the bottom surface of the resonant cavity.

11. The cavity antenna according to any one of claims 1 to 10, characterized in that: The cavity antenna transmits and receives signals in multiple operating frequency bands.

12. The cavity antenna according to claim 11, wherein: The multiple operating frequency bands include at least one of a 2.4 GHz frequency band or a 5 GHz frequency band.

13. A terminal device, characterized in that: include: The cavity antenna according to any one of claims 1 to 12; as well as The radio frequency processing module is connected to the cavity antenna through a transmission line.

14. The terminal device according to claim 13, characterized in that Also includes: Back shell, including back plate part and frame part; as well as a display screen, located on the front side of the back shell, the display screen comprising a display area and a non-display area surrounding the display area; The cavity antenna is located between the back shell and the display screen, the radiation port faces the frame portion, and the orthographic projection of the radiation port on the display screen falls into the non-display area.

15. The terminal device according to claim 13, characterized in that The back shell is a metal back shell.

Images