Cavity antenna assembly and terminal

Abstract

The invention relates to a cavity antenna assembly and a terminal. The cavity antenna assembly comprises a cavity antenna; one end of the adjustable coupling branch knot is grounded; the tuning switch is provided with a plurality of common terminals and a plurality of throw terminals; a plurality of common ends of the tuning switch are selectively connected with the adjustable coupling branches; a plurality of first ends of the tuning module are respectively connected with the throwing positions one by one, and a second end of the tuning module is grounded; wherein the number of the first ends of the tuning module is the same as that of the throw ends of the tuning switch; wherein the tuning switch is used for being matched with the tuning module and adjusting the electrical length of the adjustable coupling branch knot so as to meet the requirement for switching between a fundamental frequency mode and a low frequency mode. Therefore, the efficiency of debugging the iterative cavity antenna can be improved.

Description

Technical Field

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

[0002] With the continuous evolution of mobile communication devices, especially smartphones, industrial design is trending towards higher screen-to-body ratios and an integrated aesthetic. Users are increasingly demanding seamless device ID (industrial design), which has led to a significant reduction or even complete elimination of the traditional antenna clearance area. To effectively address antenna radiation issues in metal backplanes or all-metal bodies, full-metal cavity antenna technology has emerged.

[0003] The related cavity antenna technology has become one of the mainstream solutions for achieving high-performance antenna design by utilizing specific metal enclosed / semi-enclosed cavity structures inside or on the edge of the device as a radiator or radiation environment.

[0004] However, during the implementation process, it was found that the current cavity antenna technology has at least the problem of low efficiency in debugging and iterating the cavity antenna. Summary of the Invention

[0005] Based on this, the purpose of this application is to solve at least one of the above-mentioned technical defects, especially the technical defect of low efficiency of debugging iterative cavity antennas in the prior art. This application provides a cavity antenna assembly and terminal.

[0006] In a first aspect, the present application provides a cavity antenna assembly, the cavity antenna assembly comprising:

[0007] Cavity antenna;

[0008] Adjustable coupling branch, one end of which is used for grounding;

[0009] The tuning switch has a plurality of common terminals and a plurality of throw terminals; the plurality of common terminals of the tuning switch are selectively connected to the adjustable coupling branches;

[0010] A tuning module, wherein the plurality of first ends are connected to the respective throw terminals one by one, and the second end of the tuning module is grounded; wherein the number of the first ends of the tuning module is the same as the number of the throw terminals of the tuning switch;

[0011] The tuning switch is used to cooperate with the tuning module to adjust the electrical length of the adjustable coupling branch to meet the switchability between multiple tuning modes.

[0012] In one embodiment, the assembly further comprises:

[0013] Multiple adjustable connectors, one end of each adjustable connector is connected to each preset position of the adjustable coupling branch;

[0014] The plurality of common terminals of the tuning switch are selectively connected to the second terminals of the adjustment connecting members.

[0015] In one embodiment, the cavity antenna is provided with an adjustable feed point position; the assembly further comprises:

[0016] Multiple cavity grounding members, one end of each cavity grounding member is connected to different positions of the cavity antenna, and the other end is used for grounding;

[0017] Among them, the adjustable feed point position is used to cooperate with the cavity grounding piece to meet the switchability between multiple tuning modes; the cavity grounding piece is used to cooperate with the adjustable coupling branch for tuning to reduce the antenna frequency mode.

[0018] In one embodiment, the cavity antenna is a rectangular parallelepiped, and an adjustable feed point position is set on a preset plane of the cavity antenna, wherein when the adjustable feed point position is at the center point of the preset plane, it is in a low-frequency mode; when the adjustable feed point position is close to the long side and short side of the preset plane, the antenna coverage frequency gradually increases.

[0019] In one embodiment, the distance between the adjustable coupling branch and the cavity antenna is a first distance, and the distance between the position where the tuning switch selectively connects the adjustable coupling branch and the ground is a second distance;

[0020] Among them, the larger the first distance, the smaller the coupling equivalent capacitance; the smaller the second distance, the higher the frequency is tuned, and the larger the second distance, the lower the frequency is tuned. The second distance is close to a quarter wavelength, and has the highest bandwidth and the most resonant modes.

[0021] In one embodiment, the tuning switch includes a single-pole multi-throw switch, and the number of the single-pole multi-throw switches includes 2, 3, or 4.

[0022] In one embodiment, the first single-pole multi-throw switch is disposed near the starting end of the adjustable coupling branch;

[0023] The second single-pole multi-throw switch is disposed adjacent to the end of the adjustable coupling branch.

[0024] In one embodiment, the tuning switch comprises a double-pole multi-throw switch.

[0025] In one embodiment, the shape of the adjustable coupling branch includes a straight shape or a U shape.

[0026] In a second aspect, the present application also provides a terminal comprising the above-mentioned cavity antenna assembly.

[0027] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0028] The cavity antenna assembly and terminal provided in this application adjust the electrical length of the adjustable coupling branch by cooperating with the tuning switch and the tuning module to achieve flexible switching between the baseband mode and the low-frequency mode. At the same time, the switching between the baseband mode and the multiplier mode is achieved by cooperating with the adjustable feed point position and the cavity grounding piece, thereby improving the antenna performance tuning efficiency, shortening the debugging cycle and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 A schematic diagram of a cavity antenna terminal provided in an embodiment of the present application

[0031] Figure 2 A schematic structural diagram of another cavity antenna terminal provided in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of the planar structure of a cavity antenna assembly provided in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of the three-dimensional structure of a cavity antenna assembly provided in an embodiment of the present application;

[0034] Figure 5 Schematic diagram of antenna S11 of a cavity antenna provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0037] It will be understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0038] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if there is transmission of electrical signals or data between the connected circuits, modules, units, etc.

[0039] It is understood that “at least one” may refer to one or more, “a plurality” may refer to two or more, and “at least a portion of an element” may refer to a portion or all of an element.

[0040] As used herein, the singular forms "a", "an", and "the" may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the stated features, integers, steps, operations, components, parts or combinations thereof.

[0041] The present invention relates to a method for carrying out the present invention and / or the method of claim 1, wherein the present invention comprises one or more other features, integral features, steps, operations, components, parts or combinations thereof. The present invention relates to a method for carrying out the present invention and / or the method of claim 1, wherein the present invention comprises one or more other features, integral features, steps, operations, components, parts or combinations thereof.

[0042] As mobile terminals develop towards an all-metal integrated design, traditional antenna clearance area design faces major challenges. Although the all-metal cavity antenna solves the radiation problem under the seamless design, there are obvious technical bottlenecks in actual application. In the existing technology, the debugging process of the metal cavity antenna requires repeated modification of the cavity structure model, and each mold modification cycle is as long as about two weeks, resulting in low efficiency in antenna performance optimization and seriously restricting the progress of product development. Especially in terms of multi-band support, traditional cavity antennas are difficult to quickly and flexibly switch between baseband mode, low-frequency mode, and multiplier mode, and cannot meet the needs of modern mobile communications for multi-band support. In addition, the existing technology lacks an effective electrical length adjustment mechanism, which makes the antenna performance tuning process complicated and time-consuming. These problems not only increase R&D costs, but also affect the market competitiveness of products.

[0043] Based on this, the present application provides a cavity antenna assembly and terminal. The electrical length of the adjustable coupling branch can be adjusted by using a tuning switch in conjunction with a tuning module, enabling flexible switching between fundamental and low-frequency modes. Furthermore, the switching between fundamental and multiplier modes can be achieved by using an adjustable feed point position in conjunction with a cavity grounding member. This improves antenna performance tuning efficiency, shortens the debugging cycle, and ultimately increases efficiency.

[0044] In an exemplary embodiment, Figure 1 A schematic structural diagram of a terminal with a cavity antenna 110 provided in an embodiment of the present application; Figure 2 This is a schematic structural diagram of another terminal with a cavity antenna 110 provided in an embodiment of the present application; Figure 1 、 Figure 2 As shown, cavity antennas 110 may be provided at opposite ends of the terminal.

[0045] Figure 3 A schematic diagram of the planar structure of a cavity antenna 110 component provided in an embodiment of the present application; Figure 4 A schematic diagram of the three-dimensional structure of a cavity antenna 110 component provided in an embodiment of the present application is shown as follows: Figure 3 、 Figure 4 As shown, the cavity antenna 110 assembly includes:

[0046] Cavity antenna 110;

[0047] Adjustable coupling branch B, one end of which is used for grounding;

[0048] The tuning switch 140 has a plurality of common terminals and a plurality of throw terminals; the plurality of common terminals of the tuning switch 140 are selectively connected to the adjustable coupling branch B;

[0049] The tuning module 120 has a plurality of first terminals connected to the respective throw terminals one by one, and a second terminal of the tuning module 120 is grounded; wherein the number of the first terminals of the tuning module 120 is the same as the number of the throw terminals of the tuning switch 140;

[0050] The tuning switch 140 is used to cooperate with the tuning module 120 to adjust the electrical length of the adjustable coupling branch B to meet the switchability between multiple tuning modes.

[0051] Among them, the adjustable coupling branch B refers to a conductor structure with a variable electrical path, which can be implemented by a segmented metal strip, the end of which is grounded to form a current loop. The tuning switch 140 refers to an electronic component with a multi-channel switching function, such as a radio frequency switch chip, which selects the conduction path through a control signal. The tuning module 120 can include an impedance matching circuit, which can be implemented by an LC network to optimize the signal transmission efficiency under different working conditions. These features work together to achieve resonant mode switching through circuit reconstruction without changing the physical size of the cavity.

[0052] Exemplarily, the coupling branch forms an electromagnetic coupling with the cavity antenna 110, and its equivalent electrical length determines the resonant frequency range. The common end of the tuning switch 140 is connected to different positions of the coupling branch, and the throw end is connected to the matching circuit of the tuning module 120. When the switch switches the conduction path, the effective electrical length of the coupling branch changes, causing the equivalent field distribution parameters of the cavity antenna 110 to change. The tuning module 120 adjusts the impedance matching according to the current working mode to ensure signal transmission efficiency. For example, this dynamic adjustment mechanism enables the same physical cavity to support rapid switching between baseband and low-frequency modes.

[0053] Compared to existing technologies, this embodiment avoids the inherent need for mechanical structural adjustments. While traditional methods require adjusting the field distribution parameters by modifying the mold and changing the cavity dimensions, this embodiment directly changes the equivalent electrical parameters through circuit reconstruction. This electronic tuning approach reduces the debugging cycle from two weeks to a few hours and supports dynamic mode switching. It also avoids material waste caused by repeated mold adjustments, significantly reducing production costs.

[0054] This embodiment achieves rapid switching and precise control of the cavity antenna 110's operating modes. Performance optimization can be achieved through circuit parameter adjustment without modifying the cavity's physical structure during debugging. This effectively addresses the low debugging efficiency and poor adaptability of traditional methods, and has significant application value in multi-band communication equipment.

[0055] In an exemplary embodiment, Figure 3 、 Figure 4 As shown, the components also include:

[0056] Multiple adjustable connectors, one end of each adjustable connector is connected to each preset position of the adjustable coupling branch B;

[0057] The common terminals of the tuning switch 140 are selectively connected to the second terminals of the adjustment connectors.

[0058] Among them, the adjustment connector may refer to a metal conductor used to establish an electrical connection between the adjustable coupling branch B and the tuning switch 140. For example, it may be implemented by a conductive column or a metal spring. Its function is to transmit the electrical characteristics of different branch positions to the tuning switch 140.

[0059] Among them, the preset position may refer to a pre-set electrical node on the adjustable coupling branch B. For example, it can be achieved by determining a specific coordinate point on the surface or inside of the branch through simulation or experiment to match the current distribution requirements under different resonant modes.

[0060] Among them, selective connection may refer to the operation of the tuning switch 140 connecting the common end to a specific adjustment connector according to a control signal, for example, it can be achieved through mechanical contacts or semiconductor switching circuits to dynamically change the equivalent electrical length of the branch.

[0061] Exemplarily, a plurality of preset positions are set on the surface or inside of the adjustable coupling branch B, and each position is led to the common end of the tuning switch 140 through an independent adjustment connector. When the tuning switch 140 selects a different adjustment connector to be turned on, the current path of the adjustable coupling branch B is changed, and the equivalent electrical length is adjusted accordingly. For example, when the tuning switch 140 connects the adjustment connector near the starting end of the branch to the circuit, the electrical length of the branch is shortened and the resonant frequency is increased; conversely, when the end adjustment connector is selected, the electrical length is extended and the resonant frequency is reduced. This dynamic adjustment method allows the cavity antenna 110 to switch between different frequency band modes without modifying the physical structure.

[0062] This embodiment directly changes the equivalent parameters of the coupling branches by dynamically switching the electrical connection points, avoiding repeated iterations of the physical structure. This embodiment can also achieve more precise resonant mode control through discrete preset positions and switch selection mechanisms.

[0063] In this embodiment, the electrical length of the coupling branches can be quickly adjusted without changing the physical dimensions of cavity antenna 110, allowing for flexible switching between fundamental and low-frequency modes. This significantly reduces the need for modifications to the metal cavity structure during antenna commissioning, shortens the performance optimization cycle, and improves the stability and repeatability of resonant mode switching.

[0064] In an exemplary embodiment, Figure 4 As shown, the cavity antenna 110 is provided with an adjustable feed point position M; the components further include:

[0065] Multiple cavity grounding members 130 , one end of each cavity grounding member 130 is connected to a different position of the cavity antenna 110 , and the other end is used for grounding;

[0066] The adjustable feed point position M is used to cooperate with the cavity grounding member 130 to satisfy the switchability between multiple tuning modes; the cavity grounding member is used to cooperate with the adjustable coupling branch for tuning to reduce the antenna frequency mode.

[0067] The adjustable feed point position M may refer to a feed access point that can be adjusted along the surface of the cavity antenna 110. For example, this can be achieved by connecting the matching network 150 to the transceiver module of the terminal. By changing the feed point position, the electromagnetic field distribution pattern inside the cavity antenna 110 can be adjusted. It is understood that in this application, the feed point is equivalent to the feed point, and can also be equivalent to the feed.

[0068] Among them, the cavity grounding member 130 may refer to a component used to establish an electrical connection between the cavity antenna 110 and the ground. For example, it may be implemented by using conductive foam or shrapnel. By arranging the grounding member at different positions, the current path distribution of the cavity antenna 110 may be changed.

[0069] Exemplarily, the cavity grounding member can be used to reduce the resonant mode of the antenna, that is, multiple frequency bands of the antenna can be integrated into the same resonant mode to reduce interference between the antenna frequency bands. In this way, frequency band tuning can be achieved after the frequency bands are integrated. At the same time, adding adjustable coupling branches can further reduce the resonant mode of the antenna and adjust the fundamental mode resonant frequency to the target frequency.

[0070] Optionally, when switching between fundamental frequency mode and harmonic frequency mode is required, the adjustable feed point position M is adjusted to the target area of ​​the cavity antenna 110, while the cavity grounding members 130 at different positions are selectively enabled. The change in the feed point position directly affects the electric field intensity distribution inside the cavity antenna 110, while the connection position of the grounding member controls the flow path of the current on the cavity surface. The synergistic effect of the two can change the equivalent electrical length of the cavity antenna 110, thereby achieving switching between fundamental frequency resonance and harmonic frequency resonance under fixed cavity size conditions by adjusting the combination of the electromagnetic field parameters m, n, and p.

[0071] This embodiment replaces mechanical structure modification with electrical parameter tuning and implements multi-mode switching without changing the cavity size through multi-position grounding arrangement.

[0072] In this embodiment, flexible switching between the baseband mode and the multiplier mode can be achieved without repeated mold modification, which significantly shortens the antenna debugging cycle and reduces manufacturing costs.

[0073] In an exemplary embodiment, Figure 4 As shown, the adjustable feed point position M is used to connect to the transceiver module of the terminal through the matching network 150.

[0074] Among them, the adjustable feed point position M may refer to an area on the cavity antenna 110 where the connection point can be changed, which can be specifically implemented by using a sliding contact or a segmented conductive structure, and the electromagnetic field distribution can be adjusted by changing the contact position between the feed point and the cavity antenna 110.

[0075] The matching network 150 may refer to an impedance conversion circuit composed of an inductor, a capacitor or a transmission line, and may be implemented in an L-type, T-type or π-type topology to eliminate the impedance mismatch between the transceiver module and the antenna.

[0076] Exemplarily, the adjustable feed point position M can form a signal transmission link with the transceiver module through the matching network 150. When the feed point position is switched, the matching network 150 dynamically adjusts the impedance parameters to maintain signal transmission efficiency. For example, in the process of switching from the baseband mode to the multiplier mode, the feed point moves along the edge of the cavity to the target coordinate, and the variable capacitor or adjustable inductor in the matching network 150 synchronously changes the capacitive reactance or inductive reactance value, so that the antenna input impedance and the RF front-end output impedance maintain a conjugate matching state. This embodiment cooperates with the cavity grounding member 130 to change the electromagnetic field mode distribution in the cavity by adjusting the feed point position, thereby realizing the radiation switching of signals in different frequency bands.

[0077] This embodiment introduces the synergistic effect of the adjustable feed point and the matching network 150 to achieve multi-band compatibility through electrical parameter adjustment while keeping the cavity structure fixed, thereby avoiding the debugging process of repeatedly modifying the physical dimensions of the cavity.

[0078] In this embodiment, the impedance matching characteristics of the signal transmission path are effectively optimized, and the signal reflection loss caused by the change of the feeding point position is reduced. At the same time, electrical tuning is replaced by mechanical structure adjustment, which significantly shortens the antenna performance debugging cycle.

[0079] In an exemplary embodiment, the distance between the adjustable coupling branch and the cavity antenna is a first distance, and the distance between the position where the tuning switch selectively connects the adjustable coupling branch and the ground is a second distance;

[0080] Among them, the larger the first distance, the smaller the coupling equivalent capacitance; the smaller the second distance, the higher the frequency is tuned, and the larger the second distance, the lower the frequency is tuned. The second distance is close to a quarter wavelength, and has the highest bandwidth and the most resonant modes.

[0081] In an exemplary embodiment, the cavity antenna is a rectangular parallelepiped, and an adjustable feed point position is set on a preset plane of the cavity antenna, wherein when the adjustable feed point position is at the center point of the preset plane, it is in a low-frequency mode; when the adjustable feed point position is close to the long side and short side of the preset plane, the antenna coverage frequency gradually increases.

[0082] The rectangular parallelepiped may refer to a cavity having a rectangular parallelepiped structure. The predetermined surface may refer to the upper surface or radiation surface of the cavity. The center point may refer to the geometric center of the rectangle.

[0083] For example, when the feed point is located at the geometric center of a preset plane, the fundamental frequency mode of the cavity is excited. When the feed point is moved toward the long side, higher-order modes along the long side are excited. When the feed point is moved toward the short side, higher-order modes along the short side are excited. When the feed point is close to the corners of both the long and short sides, the highest frequency is excited. In this way, by moving a single feed point, a single antenna can cover multiple frequency bands. Different feed point positions can excite independent resonant modes, avoiding frequency band interference.

[0084] In this embodiment, the resonance mode switching is achieved by adjusting the position of the adjustable feed point without changing the physical size of the cavity, thereby improving the test efficiency of the cavity antenna.

[0085] In an exemplary embodiment, the cavity grounding member includes conductive foam or spring.

[0086] Among them, the conductive foam may refer to an elastic filling material with conductive properties, for example, it can be realized by using a foamed polymer with a metal layer plated on the surface, and its elastic deformation ability can adapt to the change of the gap between the cavity antenna 110 and the ground end to ensure contact stability.

[0087] Among them, the spring refers to a metal contact component with elastic deformation capability, for example, it can be realized by a sheet structure stamped from copper alloy, which forms a detachable electrical connection with the preset position of the cavity antenna 110 through elastic pressure to achieve dynamic adjustment of the grounding path.

[0088] Exemplarily, the conductive foam or shrapnel is arranged at different positions of the cavity antenna 110, such as the edge of the side wall or the corner of the bottom surface. When it is necessary to switch between the fundamental frequency mode and the frequency doubling mode, the current distribution path can be changed by selectively crimping the conductive foam or shrapnel to a specific area of ​​the cavity antenna 110. The compression deformation characteristics of the conductive foam enable it to automatically fill the gap caused by mechanical tolerances during the assembly process, while the elastic contact method of the shrapnel allows it to maintain a low-impedance grounding state after multiple adjustments. This design does not require modifying the physical dimensions of the cavity antenna 110, and the resonant mode can be adjusted only by selecting the location of the grounding point.

[0089] In this embodiment, the resonant mode switching is achieved by quickly adjusting the position of the elastic grounding member without changing the physical size of the cavity, while avoiding the risk of grounding failure caused by mechanical assembly errors.

[0090] In an exemplary embodiment, Figure 3 、 Figure 4As shown, the tuning switch 140 includes a single-pole multi-throw switch, and the number of the single-pole multi-throw switches includes 2, 3, and 4.

[0091] The term "SPMT switch" may refer to an electronic switch having a common terminal and multiple throw terminals. Specifically, it may be implemented as a mechanical contact switch or a semiconductor switch, and is used to change the circuit path by switching the connection between the common terminal and different throw terminals. The number of "two" may refer to the use of two independently controlled SPMT switches, each located at a different position on the adjustable coupling branch B, to work together to expand the electrical length adjustment range.

[0092] For example, the common terminals of two single-pole, multi-throw (SPMT) switches are connected to the starting and ending terminals of the adjustable coupling branch B, respectively, while their throw terminals are connected to different nodes of the tuning module 120. When the switches are switched, the connection point between the coupling branch and the tuning module 120 changes, thereby altering the effective electrical length of the branch. For example, the first switch controls the grounding path selection at the starting terminal of the branch, while the second switch controls the grounding path selection at the ending terminal of the branch. By combining different paths, switching between baseband mode and low-frequency mode is achieved.

[0093] In this embodiment, the combined use of two single-pole multi-throw switches improves adjustment flexibility, enables the same cavity structure to adapt to multiple resonance modes, shortens the debugging cycle and reduces development costs.

[0094] In an exemplary embodiment, Figure 3 、 Figure 4 As shown, the first single-pole multi-throw switch is arranged near the starting end of the adjustable coupling branch B;

[0095] The second single-pole multi-throw switch is disposed near the end of the adjustable coupling branch B.

[0096] The starting end may refer to the initial connection area where the adjustable coupling branch B is electromagnetically coupled to the cavity antenna 110. For example, this can be achieved by placing a switch near the connection point between the branch and the cavity antenna 110. This position directly affects the starting path of the current distribution. The ending end may refer to the end area of ​​the adjustable coupling branch B away from the cavity antenna 110. For example, this can be achieved by placing a switch near the connection point between the end of the branch and the ground path. This position controls the terminal impedance matching of the branch.

[0097] For example, a switch at the starting end modifies the current distribution in the initial segment of the branch by selecting different connection paths, while a switch at the end adjusts the impedance characteristics of the end segment by switching the grounding path. When the two switches work together, the switch at the starting end adjusts the field distribution of the fundamental frequency mode, while the switch at the end adjusts the resonant length of the low-frequency mode. This allows for dual-band switching through segmented electrical length tuning without changing the physical dimensions of the cavity.

[0098] In this embodiment, the electrical connection status between the starting end and the end of the branch is controlled in sections, so that the same cavity structure can adapt to different frequency band requirements, avoiding repeated model modification while improving the reliability of antenna mode switching.

[0099] In an exemplary embodiment, the tuning switch 140 comprises a double-pole, multi-throw switch.

[0100] A double-pole, multi-throw (DPMT) switch refers to an electronic switching device with two independent common terminals and multiple throw terminals. For example, it can be implemented using a mechanical contact switch or a semiconductor switching circuit. The two common terminals are connected to different positions of an adjustable coupling branch B. By switching the conductive state of the two common terminals and the throw terminals, the electrical connection paths at both ends of the coupling branch are synchronously adjusted. This structure achieves multi-path control with a single switch, reducing the number of independent switches in the component.

[0101] Exemplarily, the two common terminals of the double-pole multi-throw switch are respectively connected to the starting end and the end of the adjustable coupling branch B, and the multiple throw terminals are connected to different grounding points of the tuning module 120. When the switch is switched, the starting end and the end are simultaneously switched to the ground path corresponding to the tuning module 120, thereby changing the equivalent electrical length of the coupling branch. For example, when the switch is switched to the first group of throw terminals, the coupling branch forms a first electrical length, corresponding to the fundamental frequency mode; when it is switched to the second group of throw terminals, the coupling branch forms a second electrical length, corresponding to the low-frequency mode. By synchronously switching the two groups of common terminals, the layout redundancy problem caused by the need to configure single-pole switches in pairs can be avoided.

[0102] In this embodiment, within a fixed cavity size, the ground paths at both ends of the coupling branch can be synchronously adjusted by switching a single switch, achieving rapid adjustment of the electrical length. This design effectively reduces the number of switching components in the assembly, optimizes the compactness of the antenna structure, and ensures stability and consistency in switching between different operating modes.

[0103] In an exemplary embodiment, Figure 3 、 Figure 4 As shown, the shape of the adjustable coupling branch B includes a straight shape or a U shape.

[0104] Among them, the straight-line shape may refer to a geometric shape in which branches extend in a straight line. For example, it can be realized by using a single straight metal strip or a conductive pattern of straight lines. The straight line shape keeps the current path uniform, which is convenient for layout in a compact space.

[0105] Among them, the U-shape may refer to a geometric form in which the branches are bent in a U shape. For example, it can be realized by using a metal structure in which two parallel conductors are connected by an arc or right-angle bend. The U-shaped bend can increase the length of the current path and enhance the coupling with the cavity antenna 110 through the bending area.

[0106] For example, within the constraints of a fixed cavity size, the equivalent electrical length of the coupling branch can be varied by selecting a straight or U-shaped branch configuration. When the straight configuration is adopted, the current flows along a straight path, resulting in a shorter electrical length, suitable for fundamental mode tuning. When the U-shape is adopted, the current path is extended due to the zigzag structure, increasing the equivalent electrical length and expanding the tuning range of the low-frequency mode. These two configurations are switched via tuning switch 140, allowing the same cavity antenna 110 to flexibly switch between different frequency bands without modifying the physical dimensions of the cavity.

[0107] In some embodiments, straight-line branches can be arranged along the cavity sidewalls to save space, while U-shaped branches can be arranged around the cavity edge to enhance coupling. Furthermore, the U-shaped bend angle can be set to 90 degrees or an arc, and the bend spacing can be adjusted according to frequency band requirements.

[0108] In this example, the coupling branch shape can be quickly switched based on the target frequency band requirements, optimizing the electrical length adjustment range while maintaining a compact cavity antenna layout. The complementary I-shaped and U-shaped designs address both high- and low-frequency tuning requirements, improving the reliability and efficiency of antenna mode switching and avoiding the extended development cycle caused by repeated adjustments to the cavity size.

[0109] In an exemplary embodiment, Figure 1 、 Figure 2 As shown, the present application also provides a terminal, including the above-mentioned cavity antenna assembly.

[0110] Among them, the terminal may refer to an electronic device with wireless communication function, for example, it can be implemented by a mobile phone, tablet computer or Internet of Things device, which has an integrated cavity antenna component to realize multi-band signal receiving and transmitting function.

[0111] Among them, the cavity antenna component may refer to a radiation structure formed by a metal cavity, which can be realized by stamping or CNC machining, and the antenna resonance characteristics can be changed by adjusting the electrical length of the coupling branch.

[0112] Exemplarily, the cavity antenna assembly provided inside the terminal cooperates with the tuning module through a tuning switch. When it is necessary to switch between the baseband mode and the low-frequency mode, the tuning switch switches the common end to the target throw end, so that the corresponding impedance element in the tuning module is connected to the circuit, thereby changing the equivalent electrical length of the adjustable coupling branch. For example, when the tuning switch is switched to the first throw end, the first capacitor in the tuning module is connected to the circuit, shortening the electrical length of the coupling branch to support the high-frequency mode; when switched to the second throw end, the inductor element in the tuning module is connected to the circuit, extending the electrical length to support the low-frequency mode. This process does not require modifying the physical dimensions of the cavity antenna, and mode conversion is achieved only through circuit switching.

[0113] This embodiment enables the terminal to quickly switch the operating modes of different communication frequency bands while maintaining a fixed size of the cavity antenna, significantly shortening the antenna performance debugging cycle and reducing the manufacturing costs caused by repeated mold repairs.

[0114] In an exemplary embodiment, there are many solutions for cavity antenna implementation, and a seat radiator such as a sound cavity BOX or a shielding cover can be used. The radiation mode resonant frequency f of the cavity antenna is mnp The following expression (1):

[0115] (1);

[0116] in, represents the resonant frequency of the TE mode in the cavity (Hz), represents the angular frequency (rad / s), represents the wave number, μ represents the magnetic permeability (H / m), ε represents the dielectric constant (F / m), and m, n, and p represent the mode index (representing the half-wave number).

[0117] like Figure 4 As shown, the cavity antenna's length * width * height = a * b * h. The antenna radiation window is located within the shaded area. One end of the RF cable is soldered to point M on the cavity surface for radiation connection. The other end is connected to the cable socket on the RF front end, providing signal transmission between the RF and antenna. g1, g2, ..., gn are the grounding posts for the cavity antenna.

[0118] Conventional electromagnetic model simulations can quickly derive the values ​​of a, b, and h. This antenna covers Wi-Fi 2.4G / 5G and cellular 2 / 3 / 4 / 5G 600MHz-6GHz bands. The overall solution follows a main cavity design of 600MHz-3GHz and a sub-cavity design of 3GHz-6GHz.

[0119] Among them, g1 and g2 are split into the main cavity and sub-cavity, and the boundary conditions of the excitation mode are transformed according to the electric field strength point to stimulate high-order resonant modes. For example, in medium and low frequencies: TE 0.5,1,0 ,TE 1,0.5,0 ,TM 1,0.5,0 ,TE 1,1,0 ,TE 1,2,0 ,TE 2,2,0 Equal modes; medium and high frequency TM 1,1,0 ,TM 2,1,0 ,TM 2,2,0 , HE 1,2,0 The other modes support high-frequency radiation.

[0120] The main radiation mode is half-wave radiation mode, fundamental mode T 0.5,0,0: A 1 / 4 wavelength standing wave along the length direction (a axis), with the electric field maximum at the center and one end grounded. 0.5,0,0 : A 1 / 4 wavelength standing wave along the width direction (b-axis), with the magnetic field surrounding the electric field distribution.

[0121] According to the requirements of the working frequency band, the filling dielectric constant ε of the cavity r =3.8 medium, the antenna design goals and detailed indicators are shown in Table 1 below. Through model simulation, the low-frequency basic cavity model is determined, and the medium and high frequencies are realized through the sub-resonant cavity or the frequency doubling mode of the base membrane. The design goals are shown in Table 1 below.

[0122] Table 1 Full-band antenna design objectives

[0123]

[0124] Based on the simulation, the actual size of the cavity steel sheet is 60mm*35mm*5mm. The initial resonance mode is sorted out through simulation calculation as shown in Table 2 below.

[0125] Table 2 Initial radiation pattern based on cavity antenna

[0126]

[0127] In order to quickly adapt and debug the resonant frequency in Table 2 to the target frequency band, the mode of the ground column molecular cavity is set, that is, Figure 4 The grounding posts g1, g2, ..., gn, etc., were confirmed through simulation and debugging, as shown in Table 3 below. The configuration of the grounding posts effectively reduces the resonant frequency mode. The grounding posts can be grounded using conductive foam, shrapnel, or other grounding methods, with no specific restrictions.

[0128] Table 3 Cavity antenna grounding column solution

[0129]

[0130] After adding the grounding post, the antenna still has many resonance modes (7 types). At the same time, due to the frequency adaptation bandwidth and redundant tuning scheme, coupling branches are conveniently added near the board edge and the long side of the cavity antenna to widen the antenna bandwidth, further reduce the antenna resonance mode, and improve the antenna efficiency. Figure 4 As shown in the figure, the fundamental mode resonant frequency is adjusted to the target frequency by coupling the branches. This is easy to calculate, and by adjusting the coupling equivalent C, the fundamental mode of the cavity antenna is migrated to the target frequency.

[0131] exist Figure 4After adding the coupling branch, the coupling equivalent circuit model is Ccoupling = 0.27pF, Larm = 2.8 nH, and the branch equivalent inductance; the calculated g = 3.2mm.

[0132] Among them, in the low frequency band (600-1500MHz): branches act as parasitic radiators; in the medium frequency band (1.5-2.7GHz): cavity-branch hybrid resonance; in the high frequency band (3-6GHz): branches are coupled by surface waves.

[0133] Regarding branch B, one end is open and the other end is grounded. The electrical length generally covers λ / 4 in the target frequency band (the specific calculation method is not repeated here). As for the specific shape, it can be straight, U-shaped or other shapes without limitation.

[0134] The key parameters of the cavity antenna are shown in Table 4 below. The cavity antenna is migrated to the target operating frequency band, and the number of resonant modes is reduced to four. At the same time, the antenna performance can be effectively improved. The detailed key parameters are shown in Table 5 below.

[0135] Table 4 Cavity ground post + coupled direct antenna hybrid mode

[0136]

[0137] Among them, Hybrid is a mixed resonance mode of TE and TM.

[0138] Furthermore, the present application targets the resonant cavity and introduces resonant tuning of the coupled resonant cavity antenna based on the fundamental resonant mode to stimulate the resonant frequency deviation, thereby realizing a solution that does not require repeated model modification. Through circuit tuning, the antenna performance can be quickly debugged to achieve the target design.

[0139] like Figure 3As shown, by introducing an adjustable coupling branch, the fundamental mode can be effectively shifted to the target low frequency. Hybrid mode can be used to achieve antenna isolation and performance. Furthermore, by adjusting the adjustable feed point M and the grounding points g1, g2, ...gn (the figure shows that the grounding points can be multiple), the fundamental mode can be extended to multiple frequencies. Furthermore, by adjusting the positions of contacts P1 and P2, the antenna switch and coupling, the antenna's resonant modes can be tuned for low, medium, and high frequency bands. P1 and P2 can be extended to multiple contact points. Furthermore, by switching the antenna tuning switch, multi-band expansion is achieved. C1 and C2, one near the beginning and one near the end of the branch, can be extended to multiple switches. P1 and P2 are the direct contact points between the switch and the coupling. C1 and C2 are antenna switches. This number can be expanded to more than two. Because they are similar models, this patent focuses on the two contact points and two antenna switch models. Ultimately, antenna design goals can be quickly achieved without adding or modifying models. Greatly improves the efficiency and redundancy of the design.

[0140] like Figure 4 As shown, the frame antenna assembly includes:

[0141] Cavity antenna A, where the shaded area is the cavity antenna radiation surface.

[0142] The cavity antenna is coupled with the branch B, and g is the distance between the coupling branch and the cavity antenna.

[0143] Antenna tuning switches C1, C2 (can be DPXT, SPXT, where X = 2, 3, 4, ...);

[0144] Among them, P1, P2, P3, ... are the positions where several PCB springs and coupling branches are connected, corresponding to Figure 4 P1 and P2 adjustable arrow tuning positions, i.e. "slide" tuning.

[0145] Figure 4 P1, P2, P3, ... belong to a specific implementation of sliding. By setting the positions P1, P2, P3, ... of different springs, "sliding" tuning of the switch and the coupling branch is achieved.

[0146] Based on simulations, these locations can be pre-reserved on the PCB for spring-clip debugging. The debugging position circuit can be connected to the tuning switch C1 or C2 to achieve final "position tuning" of the tuning switch. Ultimately, based on actual OTA (over the air) verification (measuring antenna radiation performance), the optimal antenna switch position (Pm) is selected (where m∈(1,2,3,...)). t is the coordinate of the Pm contact point.

[0147] The terminal includes a PCB motherboard D. The coupling environment of the entire cavity antenna provided in this example is not a key factor, so the 3D environment of the entire device is not shown in the figure. The tunable positions and parameters are given, such as Figure 4 shown.

[0148] Point M is located at the same position as the RF Cable feeding the cavity, where (s, r) is the coordinate of point M.

[0149] In some specific embodiments, the coupling node location analysis generally involves tuning the coupling distance g and the switch position t. A larger g indicates a smaller coupling equivalent capacitance; g is determined during the simulation phase. t = 0, grounded; a larger t indicates a closer approach to the end. Generally speaking, closer to the ground point, a greater impact on low frequencies, and closer to the end, a greater impact on high frequencies. A value near λ / 4 exhibits a higher bandwidth and more resonant modes.

[0150] Regarding the analysis of the feeding position, generally speaking, center feeding excites the base film, has moderate coupling strength, good impedance matching, and small radiation loss. The closer to the edge, the easier it is to excite high-frequency modes. Asymmetric excitation leads to mode distortion, increased impedance mismatch, and longer surface current paths. Corner feeding easily excites TE+TM mixed modes, strong coupling introduces multi-mode interference, complex current distribution, and increased ohmic loss and radiation loss. 1 / 4 wavelength offset feeding couples part of the energy to the high-order mode, but the main mode is still dominant, and impedance matching can be optimized through tuning. For example Figure 4 As shown, the RF cable is fed using a 1 / 4 wavelength offset. The M-point position coordinate parameter is introduced, meaning two parameters are tuned: s and r represent the position of the RF cable feed point. This position is determined based on simulation and field verification. Generally speaking, the smaller the s*r area, the easier it is to excite higher-order modes.

[0151] Table 5 below is the tuning status table of the feeding position M point, and the corresponding efficiency tuning table is completed according to the actual debugging. According to the table, the optimal s op and r op .

[0152] Table 5 Feeding position efficiency tuning state table

[0153]

[0154] Table 6 below is the efficiency tuning table for tuning the antenna switch connection coupling branch position. The optimal t is determined based on the debugging value. op1 (P1) and t op1 (P2), where the coupling distance g can be determined through simulation and passive fixture.

[0155]

[0156] Based on the above confirmation of point M and points P1 and P2, the antenna switches C1 and C2 have several switch states. i (i∈(1,2,…,u), where u represents the state of the antenna switch L and C). If the switch is double-throw, then there are 2 2 = 4 states. If the switch is u-throw, then there are 2 u In different frequency bands, C1 and C2 switch to different states, respectively, using State 1 and State 2 By implementing a software-based antenna switch solution, we can achieve antenna performance switching between different operating frequency bands, achieving efficiency targets for each operating frequency band within the 0.6 GHz to 6 GHz passband. This is shown in Table 7 below. This table was confirmed through debugging and then mapped to the code for implementation.

[0157] Among them, Coden (n=1, 2) is the code mode corresponding to two certain switch states.

[0158] Table 7 Antenna switch state switching diagram

[0159]

[0160] According to different antenna states, different code control logic is called to achieve tuning of the corresponding working frequency band. The solution is relatively mature and will not be described in detail here.

[0161] According to the initial cavity antenna design a*b*h=60mm*35mm*5mm, g=3.2mm, after one-time mold forming, through debugging and optimization, s=12mm, r=9.5mm, t=15mm, the corresponding antenna switch LC matrix switching, the antenna design goal can be quickly achieved and the expected goal is achieved. The detailed antenna S11 is as follows Figure 5 As shown, through this practical application, the OTA indicators of each frequency band can reach the expected level by only adjusting the feed point position and the switch tuning state.

[0162] In the description of this specification, the reference terms "some embodiments," "other embodiments," "specific implementation," "another implementation," etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0163] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, article, or device comprising the element.

[0164] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referenced to each other.

[0165] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cavity antenna assembly, characterized in that: The components include: Cavity antenna; Adjustable coupling branch, one end of which is used for grounding; A tuning switch having a plurality of common terminals and a plurality of throw terminals; the plurality of common terminals of the tuning switch are selectively connected to the adjustable coupling branch; A tuning module, wherein the plurality of first ends are respectively connected to the throw ends one by one, and the second end of the tuning module is grounded; wherein the number of the first ends of the tuning module is the same as the number of the throw ends of the tuning switch; The tuning switch is used to cooperate with the tuning module to adjust the electrical length of the adjustable coupling branch to meet the switchability between multiple tuning modes.

2. The assembly according to claim 1, characterized in that The components also include: A plurality of adjustable connectors, one end of each of the adjustable connectors being connected to respective preset positions of the adjustable coupling branches; The plurality of common ends of the tuning switch are selectively connected to the second end of each of the adjustment connecting members.

3. The assembly according to claim 1, characterized in that The cavity antenna is provided with an adjustable feed point position; the component further comprises: a plurality of cavity grounding members, one end of each cavity grounding member being connected to a different position of the cavity antenna and the other end being used for grounding; The adjustable feed point position is used to cooperate with the cavity grounding piece to satisfy the switchability between multiple tuning modes; the cavity grounding piece is used to cooperate with the adjustable coupling branch to tune, so as to reduce the antenna frequency mode.

4. The assembly according to claim 3, characterized in that The cavity antenna is a rectangular parallelepiped, and the adjustable feed point position is set on the preset plane of the cavity antenna. When the adjustable feed point position is at the center point of the preset plane, it is in a low-frequency mode; when the adjustable feed point position is close to the long side and short side of the preset plane, the antenna coverage frequency gradually increases.

5. The assembly according to claim 3, characterized in that The adjustable feed point position is used to connect to the transceiver module of the terminal through a matching network.

6. Assembly according to any one of claims 1 to 5, characterized in that The distance between the adjustable coupling branch and the cavity antenna is a first distance, and the distance between the position where the tuning switch selectively connects the adjustable coupling branch and the ground is a second distance; Among them, the larger the first distance is, the smaller the coupling equivalent capacitance is; the smaller the second distance is, the high frequency is tuned, and the larger the second distance is, the low frequency is tuned. The second distance is close to a quarter wavelength, and has the highest bandwidth and the most resonant modes.

7. Assembly according to any one of claims 1 to 5, characterized in that The tuning switch includes a single-pole multi-throw switch, and the number of the single-pole multi-throw switches includes 2, 3 or 4.

8. The assembly according to claim 6, characterized in that The first single-pole multi-throw switch is arranged near the starting end of the adjustable coupling branch; The second single-pole multi-throw switch is arranged near the end of the adjustable coupling branch.

9. Assembly according to any one of claims 1 to 5, characterized in that The tuning switch includes a double-pole multi-throw switch.

10. The assembly according to claim 1, characterized in that The shape of the adjustable coupling branch includes a straight shape or a U shape.

11. A terminal, characterized in that: The invention comprises a cavity antenna assembly as claimed in any one of claims 1 to 9.

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