Antenna structure and communication device

Abstract

The embodiment of the invention provides an antenna structure and a communication device, and belongs to the technical field of antennae, and the antenna structure comprises a feed structure, a grounding layer group, a partial reflection layer group and a frequency selection layer, the grounding layer group is used for reflecting signals, and the partial reflecting layer group is used for enabling partial signals to pass through and reflecting the rest of the signals. The frequency selection layer comprises a hollow part and a reflection part, the hollow part is used for allowing a signal to pass through, and the reflection part is used for reflecting the signal. Phase delay can occur between signals radiated outwards through the hollow-out part and signals radiated outwards after being reflected by the reflection part, the signals can be reflected for multiple times among the grounding layer group, the partial reflection layer group and the frequency selection layer, phase delay for multiple times can occur, phase change of the whole signals can be amplified, and the frequency selection effect is improved. And phase tuning in a larger range can be obtained, so that the antenna structure realizes beam scanning in a larger range.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to an antenna structure and a communication device. Background Art

[0002] Antenna is a device that performs energy conversion and directional radiation or reception of electromagnetic waves in wireless communication. It is widely used in engineering systems such as radio communication, broadcasting, radar, navigation, remote sensing, etc. For example, antennas are used in mobile phones, laptops, tablet computers, netbooks, wearable devices, and other electronic devices. Electronic devices can use antennas to transmit signals. Among them, reconfigurable leaky wave antennas can achieve fixed-frequency beam scanning, which can effectively increase the radiation range of the antenna and are also widely used in the field of antenna technology.

[0003] In the related art, a reconfigurable leaky wave antenna usually includes an alternating high dielectric constant layer and a low dielectric constant liquid crystal layer. A control circuit is provided on the liquid crystal layer. The control circuit can apply a bias voltage to the liquid crystal layer to change the relative dielectric constant of the liquid crystal layer, thereby changing the electromagnetic parameters such as the phase and radiation pattern of the antenna, thereby realizing the reconfigurable characteristics of the leaky wave antenna, enabling the antenna to achieve fixed-frequency beam scanning, and reducing the antenna scanning's dependence on a wider frequency band.

[0004] However, in the above antenna, the fixed-frequency beam scanning of the antenna is realized by liquid crystal material, and its scanning range is often small, which reduces the reconfigurable characteristics of the antenna. Summary of the invention

[0005] The present application provides an antenna structure and a communication device, which can effectively increase the fixed-frequency beam scanning range of the antenna structure and enhance the reconfigurable characteristics of the antenna.

[0006] A first aspect of the present application provides an antenna structure, comprising a feeding structure, and a ground layer group, a partial reflection layer group and a frequency selection layer that are stacked;

[0007] The feeding structure is electrically connected to the ground layer group, and the partial reflection layer group is located between the ground layer group and the frequency selection layer;

[0008] The ground layer group is used to reflect signals, and the partial reflection layer group is used to allow part of the signals to pass through and reflect the rest of the signals;

[0009] The frequency selection layer includes a hollow portion and a reflection portion, the hollow portion is used for allowing the signal to pass through, and the reflection portion is used for reflecting the signal.

[0010] In the present application, a frequency selective layer is set up, and a phase delay can occur between the signal radiated outward through the hollow part of the frequency selective layer and the signal radiated outward through the hollow part after being reflected by the reflective part and the partial reflective layer group. The signal can be reflected multiple times between the ground layer group, the partial reflective layer group and the frequency selective layer, and multiple phase delays can occur. In this way, the phase change of the entire signal can be amplified, and a larger range of phase tuning can be obtained, so that the antenna structure can achieve a larger range of beam scanning, thereby improving the reconfigurable characteristics of the antenna structure.

[0011] In a possible implementation, the partial reflection layer group includes a first dielectric layer, a tuning layer, and a second dielectric layer stacked in sequence, the frequency selection layer is located on the first dielectric layer; the relative dielectric constants of the first dielectric layer and the second dielectric layer are both greater than the relative dielectric constant of the tuning layer under a bias voltage; the tuning layer is used to change the relative dielectric constant under the action of the bias voltage. The stacked first dielectric layer, the tuning layer, and the second dielectric layer can form a distributed Bragg reflector, which can radiate a stronger signal wave when the signal passes through the partial reflection layer group, which helps to improve the signal strength.

[0012] In a possible implementation, the frequency selective layer includes a plurality of metal patches arranged in an array, and there is a gap between two adjacent metal patches; the metal patches form the reflective portion, and the gap forms the hollow portion. When the signal propagates from the partial reflection layer group to the frequency selective layer, a portion of the signal can be radiated outward through the gap between the metal patches, while another portion of the signal can be reflected by the metal patches to the partial reflection layer group, and then reflected again into the gap through the partial reflection layer group, so as to radiate outward through the gap, thereby amplifying the phase change of the signal radiation.

[0013] In a possible implementation, the frequency selective layer includes a metal layer, and a plurality of through holes arranged in an array are provided on the metal layer; the through holes form the hollow portion, and the metal layer outside the through holes forms the reflective portion. When the signal propagates from the partial reflection layer group to the frequency selective layer, a portion of the signal can be radiated outward through the through holes on the metal layer, while another portion of the signal can be reflected to the partial reflection layer group through the metal layer outside the through holes, and then reflected again into the through holes through the partial reflection layer group, so as to be radiated outward through the through holes, thereby amplifying the phase change of the signal radiation.

[0014] In a possible implementation, the grounding layer group includes a metal floor and a third dielectric layer disposed on the metal floor; the feeding structure is electrically connected to the metal floor, and the partial reflection layer group is disposed on the third dielectric layer. The metal floor can reflect the signal so as to reflect all the signals fed by the feeding structure into the partial reflection layer group, which can effectively reduce or avoid the signal being projected toward the outside of the metal floor (that is, the side of the metal floor facing away from the partial reflection layer group), thereby causing signal loss, and helping to improve the signal radiation efficiency of the antenna structure.

[0015] In a possible implementation, the partial reflection layer group includes a plurality of the tuning layers and a plurality of the second dielectric layers; the plurality of the tuning layers and the plurality of the second dielectric layers are staggered between the first dielectric layer and the ground layer group. By increasing the number of tuning layers and second dielectric layers, the tuning layer's ability to regulate the beam scanning range can be effectively improved, so that the antenna structure can achieve a wider range of phase regulation, thereby enabling the antenna structure to achieve a wider range of beam scanning, effectively improving the antenna structure's beam scanning range.

[0016] In one possible implementation, the tuning layer is a liquid crystal layer, a vanadium dioxide layer, a ferrite layer, a graphene layer or a diode layer. The above materials and devices can present different relative dielectric constants after applying a bias voltage, and can change the electromagnetic parameters such as the phase and directional pattern of the antenna structure, thereby realizing the reconfigurable characteristics of the antenna structure.

[0017] In a possible implementation, the first dielectric layer and the second dielectric layer are formed of aluminum oxide. Aluminum oxide has a relatively high relative dielectric constant, and can be stacked with a tuning layer with a relatively low relative dielectric constant to form a distributed Bragg reflector, which can enable the signal to obtain a stronger reflected signal after passing through a partial reflection group layer, thereby helping to improve the signal strength.

[0018] In a possible implementation, the reflective portion is made of at least one of gold, copper, and aluminum.

[0019] In a possible implementation, the third dielectric layer is formed of a cycloolefin copolymer. Cycloolefin copolymer has a relatively low relative dielectric constant, which is close to the relative dielectric constant of the tuning layer. In this way, when the signal is radiated from the third dielectric layer to the tuning layer, the signal loss can be reduced, which is beneficial to improving the radiation efficiency of the antenna structure.

[0020] In one possible implementation, the shape of the metal patch is at least one of a rectangle, a circle, a triangle or a trapezoid. By flexibly setting the shape and arrangement of the metal patch, different structural forms of reflective parts and hollow parts can be obtained, which helps to optimize the structural parameters of the frequency selection layer and helps to improve the beam scanning range of the antenna structure.

[0021] In a possible implementation, the through hole has a shape of at least one of a rectangle, a circle, a triangle or a trapezoid.

[0022] In a possible implementation, the thickness of the tuning layer is an odd multiple of one quarter of the medium wavelength of the tuning layer, and the medium wavelength of the tuning layer is the wavelength of the signal propagating in the tuning layer. In this way, the signal can have a higher propagation efficiency when propagating in the tuning layer, which can reduce the loss of the signal and help improve the radiation efficiency of the antenna structure as a whole to the signal.

[0023] In one possible implementation, the thickness of the first dielectric layer is an odd multiple of one quarter of the dielectric wavelength of the first dielectric layer, and the dielectric wavelength of the first dielectric layer is the wavelength of the signal propagating in the first dielectric layer; this can enable the signal to have a higher propagation efficiency in the first dielectric layer, help reduce the loss of the signal in the first dielectric layer, thereby effectively improving the radiation efficiency of the antenna structure.

[0024] The thickness of the second dielectric layer is an odd multiple of one quarter of the dielectric wavelength of the second dielectric layer, and the dielectric wavelength of the second dielectric layer is the wavelength of the signal propagating in the second dielectric layer. In this way, the signal can have a higher propagation efficiency in the second dielectric layer, which helps to reduce the loss of the signal in the second dielectric layer, thereby effectively improving the radiation efficiency of the antenna structure.

[0025] The second aspect of the present application provides a communication device, including any of the above-mentioned antenna structures. By making the communication device include the above-mentioned antenna structure, the space occupied by the antenna structure in the communication device can be effectively reduced, the rationality of the layout of the antenna structure in the communication device can be improved, and it is helpful to improve the miniaturization design of the communication device. Moreover, it is also helpful to reduce the difficulty and cost of production of the communication device.

[0026] In one possible implementation, the communication device further includes a control circuit, which is electrically connected to a tuning layer in the antenna structure; and the control circuit is used to apply a bias voltage to the tuning layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of an antenna structure provided in an embodiment of the present application;

[0028] Figure 2A schematic diagram of the structure of a frequency selection layer provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of the structure of another frequency selection layer provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of another antenna structure provided in an embodiment of the present application;

[0031] Figure 5 A transmission line model diagram of an antenna structure provided in an embodiment of the present application;

[0032] Figure 6 A simulation diagram of the dispersion characteristics of an antenna structure provided in an embodiment of the present application;

[0033] Figure 7 It is a dispersion simulation diagram of the antenna structure when no frequency selection layer is provided in the related art;

[0034] Figure 8 Directional diagrams of the antenna structure provided in the embodiments of the present application and the antenna structure in the related art;

[0035] Fig. 9 Another antenna structure provided in an embodiment of the present application and a directional diagram of an antenna structure in the related art.

[0036] Description of reference numerals:

[0037] 100-antenna structure;

[0038] 110-feeding structure;

[0039] 120 - ground layer group; 121 - metal floor; 122 - third dielectric layer;

[0040] 130-partial reflection layer group; 131-first dielectric layer; 132-tuning layer; 133-second dielectric layer;

[0041] 140 - frequency selection layer; 141 - hollow portion; 142 - reflection portion. DETAILED DESCRIPTION

[0042] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0043] A leaky wave antenna is a structure that continuously radiates electromagnetic waves along a traveling wave structure when the electromagnetic wave propagates along the structure. The radiated waves are called leaky waves. This structure that generates leaky waves is called a leaky wave antenna. By changing the frequency, the leaky wave antenna can achieve beam scanning, which enables the antenna to achieve a wider range of signal coverage. Generally speaking, a leaky wave antenna usually requires a wider spectrum bandwidth to achieve complete beam scanning. With the continuous development of antenna technology, by introducing tunable materials (such as liquid crystal) into the leaky wave antenna, the leaky wave antenna can achieve beam scanning at a fixed frequency, thereby effectively improving the propagation range of the leaky wave antenna.

[0044] In the related art, a reconfigurable leaky wave antenna is provided, which includes a high dielectric constant layer and a low dielectric constant liquid crystal layer stacked in layers, and a control circuit is arranged on the liquid crystal layer, and the control circuit can apply a bias voltage to the liquid crystal layer to change the relative dielectric constant of the liquid crystal layer, thereby changing the electromagnetic parameters of the antenna and realizing the reconfigurable characteristics of the leaky wave antenna. However, due to the limited tuning range of the relative dielectric constant of the liquid crystal material, the fixed frequency beam scanning range of the leaky wave antenna realized by the liquid crystal material is often small, which reduces the reconfigurable characteristics of the antenna.

[0045] In order to solve the above problems, the researchers thought of improving the structure of the antenna by setting a frequency selective layer in the antenna structure. The frequency selective layer includes a hollow part and a reflective part. A phase delay can occur between the signal radiated outward through the hollow part and the signal radiated outward after being reflected by the reflective part. By amplifying the phase change of the signal, a wider range of phase tuning can be obtained, so that the antenna structure can achieve a wider range of beam scanning and enhance the reconfigurable characteristics of the antenna structure.

[0046] The antenna structure and communication device provided in the present application are described in detail below in conjunction with the accompanying drawings.

[0047] Figure 1 A schematic diagram of the structure of an antenna provided in an embodiment of the present application.

[0048] The embodiment of the present application provides an antenna structure and a communication device including the antenna structure. The antenna structure can be a high-frequency leaky wave antenna. For example, the antenna structure can radiate electromagnetic wave signals in the microwave, millimeter wave, and terahertz frequency bands. The antenna structure can be applied to communication base station platform antenna feed systems, millimeter wave radars, smart homes and other communication devices.

[0049] See also Figure 1As shown, the antenna structure 100 may include a feeding structure 110 and a stacked ground layer group 120, a partial reflection layer group 130 and a frequency selection layer 140. The feeding structure 110 may be electrically connected to the ground layer group 120, and the partial reflection layer group 130 may be located between the ground layer group 120 and the frequency selection layer 140. The feeding structure 110 may feed or input power to the antenna structure 100, so that a signal may be fed into the antenna structure 100 through the feeding structure 110. For example, the feeding structure 110 may be a waveguide structure, for example, the waveguide structure may be a rectangular waveguide. The feeding structure 110 may be electrically connected to the ground layer group 120 by welding or metal springs, so that the feeding structure 110 may feed the ground layer group 120. Alternatively, the feeding structure 110 and the ground layer group 120 may also feed the ground layer group 120 by gap coupling. Specifically, the specific structural form and feeding method of the feeding structure 110 can be selected and set according to the specific application scenario. The embodiment of the present application does not limit the feeding method and electrical connection method of the feeding structure 110.

[0050] Among them, the partial reflection layer group 130 can be used to realize the reconfigurable characteristics of the antenna structure 100. For example, a tuning device can be provided in the partial reflection layer group 130. When a bias voltage is applied to the partial reflection layer group 130, the dielectric constant in the partial reflection layer group 130 can change to change the overall electromagnetic parameters of the antenna structure 100, so that the phase and radiation pattern of the antenna structure 100 change, thereby realizing the reconfigurable characteristics of the antenna structure 100.

[0051] The frequency selective layer 140 may include a hollow portion 141 and a reflective portion 142, wherein the hollow portion 141 may be used for allowing the signal to pass through, and the reflective portion 142 may be used for reflecting the signal. For example, the reflective portion 142 may be a metal layer. When the signal is projected onto the metal layer, the metal layer may reflect the signal to change the propagation direction of the signal. For example, when the signal is transmitted from the partial reflection layer group 130 to the frequency selective layer 140, a portion of the signal may radiate outward through the hollow portion 141, and another portion may be reflected again to the partial reflection layer group 130 through the reflective portion 142. Then, the signal reflected to the partial reflection layer group 130 may be reflected to the hollow portion 141 through the partial reflection layer group 130, and radiate outward through the hollow portion 141 to form a leaky wave mode.

[0052] For example, in a specific working process, after the feeding structure 110 feeds the signal into the ground layer group 120, the signal can reach the partial reflection layer group 130 through the ground layer group 120, and a part of the signal reaching the partial reflection layer group 130 can pass through the partial reflection layer group 130, and the other part can be reflected by the partial reflection layer group 130 to the ground layer group 120. At this time, the ground layer group 120 can reflect all the signals reflected back from the partial reflection layer group 130 to the partial reflection layer group 130 again, and after multiple repeated reflections between the partial reflection layer group 130 and the ground layer group 120, the signal finally passes through the partial reflection layer group 130 and propagates to the frequency selection layer 140. Among them, after the signal passes through the partial reflection layer group 130, a part of it can be radiated outward through the hollow portion 141 of the frequency selection layer 140. Outward radiation means that the signal is radiated through the hollow portion 141 toward the side of the frequency selection layer 140 that is back to the partial reflection layer group 130, and the other part can be reflected on the partial reflection layer group 130 through the reflection portion 142, and after multiple reflections between the reflection portion 142 and the partial reflection layer group 130, it is finally reflected by the partial reflection layer group 130 and then radiated outward through the hollow portion 141.

[0053] Compared with the fixed-frequency beam scanning scheme of the antenna achieved by liquid crystal materials in the related art, the embodiment of the present application sets a frequency selection layer 140 on the partial reflection layer group 130. A phase delay may occur between the signal radiated outward through the hollow portion 141 of the frequency selection layer 140 and the signal radiated outward through the hollow portion 141 after being reflected by the reflection portion 142 and the partial reflection layer group 130. The signal may be reflected multiple times between the ground layer group 120, the partial reflection layer group 130 and the frequency selection layer 140, and multiple phase delays may occur. In this way, the phase change of the entire signal can be amplified, and a wider range of phase tuning can be obtained, so that the antenna structure 100 can achieve a wider range of beam scanning, thereby improving the reconfigurable characteristics of the antenna structure 100.

[0054] Continue to see Figure 1 As shown, the partial reflection layer group 130 may include a first dielectric layer 131, a tuning layer 132, and a second dielectric layer 133 that are stacked. For example, the first dielectric layer 131 may be disposed on a side of the tuning layer 132 that faces the frequency selection layer 140, and the second dielectric layer 133 may be disposed on a side of the tuning layer 132 that faces the ground layer group 120. The frequency selection layer 140 may be disposed on the first dielectric layer 131.

[0055] The relative dielectric constants of the first dielectric layer 131 and the second dielectric layer 133 may both be greater than the relative dielectric constant of the tuning layer 132 under the bias voltage. The relative dielectric constant is a physical parameter that characterizes the dielectric properties or polarization properties of a dielectric material. Its value is equal to the ratio of the dielectric constant of the dielectric material to the dielectric constant of a vacuum.

[0056] For example, a bias voltage may be applied to the tuning layer 132 , and the relative dielectric constant of the tuning layer 132 may change under the action of the bias voltage to change the overall electromagnetic parameters of the antenna structure 100 , thereby changing the phase and radiation pattern of the antenna structure 100 , thereby realizing the reconfigurable characteristics of the antenna structure 100 .

[0057] It should be noted that the value of the bias voltage can be greater than or equal to 0V. When the bias voltage is 0V, it can be understood that no bias voltage is applied to the tuning layer 132. When the bias voltage is greater than 0V, it can be understood that a bias voltage is applied to the tuning layer 132. That is, in the partial reflection layer group 130, the relative dielectric constant of the tuning layer 132 changes under the bias voltage, but its relative dielectric constant value is always smaller than the relative dielectric constants of the first dielectric layer 131 and the second dielectric layer 133.

[0058] For example, a control circuit may be provided in the communication device, and the control circuit may be electrically connected to the tuning element to apply a bias voltage to the tuning layer 132 to change the relative dielectric constant of the tuning layer 132 .

[0059] The stacked first dielectric layer 131, tuning layer 132 and second dielectric layer 133 can form a distributed Bragg reflector (DBR). The distributed Bragg reflector is composed of periodically arranged basic reflection units. By adjusting the relevant parameters of the basic reflection units, such as the material, structure thickness and refractive index of the reflection units, the reflection of the corresponding frequency can be enhanced to obtain a stronger reflection signal. Specifically, when electromagnetic waves pass through different media, they will be reflected at the interface, and the magnitude of the reflectivity will be related to the dielectric constant between the media. Therefore, if films with different dielectric constants are stacked together periodically, when the electromagnetic waves pass through these films with different dielectric constants, the electromagnetic waves reflected from each layer will constructively interfere due to the change in phase angle, and then combine with each other to obtain a strong reflected electromagnetic wave. In this way, when the signal is fed from the feeding structure 110 and enters the partial reflection layer group 130 formed by the first dielectric layer 131, the tuning layer 132 and the second dielectric layer 133, the partial reflection layer group 130 can reflect or radiate a stronger signal wave outward, which helps to improve the signal strength.

[0060] An asymmetric Fabry-Perot cavity (FPC) may be formed between the partial reflection layer group 130 and the frequency selection layer 140. At this time, the first dielectric layer 131 may be regarded as a resonant cavity, and the DBR composed of the frequency selection layer 140, the tuning layer 132 and the second dielectric layer 133 is an asymmetric structure with respect to the first dielectric layer 131. The asymmetric FPC structure has an overcoupling effect, which can make the incident light (or electromagnetic wave signal) reflected back with a very strong phase delay, thereby realizing the amplification of the phase change.

[0061] Continue to see Figure 1 As shown, the ground layer group 120 may include a metal floor 121 and a third dielectric layer 122 disposed on the metal floor 121, the feed structure 110 may be electrically connected to the metal floor 121, and the partial reflection layer group 130 may be disposed on the third dielectric layer 122. The metal floor 121 may reflect the signal to reflect all the signals fed by the feed structure 110 into the partial reflection layer group 130, and after the partial reflection layer group 130 reflects part of the signal back, the metal floor 121 may continue to reflect the reflected signal into the partial reflection layer group 130 again, which can effectively reduce or avoid the signal being projected toward the outside of the metal floor 121 (that is, the side of the metal floor 121 facing away from the partial reflection layer group 130), thereby causing signal loss, and helping to improve the signal radiation efficiency of the antenna structure 100.

[0062] The third dielectric layer 122 can provide space for signal reflection between the partial reflection side and the metal floor 121. At this time, the third dielectric layer 122 can also be understood as a resonant cavity, and the metal floor 121 is a full-transmitting surface. Through the mirror theory, the resonant cavity formed between the partial reflection layer group 130 and the metal floor 121 can be equivalent to a symmetrical FPC resonant cavity.

[0063] In the embodiments of this application, see Figure 1 As shown, the thickness of the tuning layer 132 may be L1, and the value of L1 may be an odd multiple of one quarter of the medium wavelength of the tuning layer 132. The medium wavelength of the tuning layer 132 refers to the wavelength of the signal propagating in the tuning layer 132. For the same electromagnetic wave, the frequency of its propagation in different media remains unchanged, while the propagation speed and wavelength will change. Taking the propagation of electromagnetic waves in a vacuum as a comparison, the wavelength of the wave propagating in the medium can be obtained by the following formula:

[0064]

[0065] In the formula, λ is the wavelength of the wave propagating in the medium, λ0 is the wavelength of the wave propagating in a vacuum, and n is the refractive index of the medium material. From the above formula, it can be concluded that the medium wavelength of the signal propagating in the tuning layer 132 can be calculated by the refractive index of the tuning layer 132 material and the wavelength of the wave in a vacuum.

[0066] When the thickness of the tuning layer 132 is an odd multiple of one quarter of the dielectric wavelength, the signal can have a higher propagation efficiency when propagating in the tuning layer 132 , which can reduce signal loss and help improve the overall radiation efficiency of the antenna structure 100 for signals.

[0067] Continue to see Figure 1 As shown, the thickness of the first dielectric layer 131 may be L2, and the value of L2 may be an odd multiple of one quarter of the dielectric wavelength of the first dielectric layer 131, wherein the dielectric wavelength of the first dielectric layer 131 is the wavelength of the signal propagating in the first dielectric layer 131. In this way, the signal can have a higher propagation efficiency in the first dielectric layer 131, which helps to reduce the loss of the signal in the first dielectric layer 131, thereby effectively improving the radiation efficiency of the antenna structure 100.

[0068] Continue to see Figure 1 As shown, the thickness of the second dielectric layer 133 may be L3, and the value of L3 may be an odd multiple of one quarter of the dielectric wavelength of the second dielectric layer 133, wherein the dielectric wavelength of the second dielectric layer 133 is the wavelength of the signal propagating in the second dielectric layer 133. In this way, the signal can have a higher propagation efficiency in the second dielectric layer 133, which helps to reduce the loss of the signal in the second dielectric layer 133, thereby effectively improving the radiation efficiency of the antenna structure 100.

[0069] In an embodiment of the present application, the tuning layer 132 can be a liquid crystal layer, a vanadium dioxide layer, a ferrite layer, a graphene layer or a diode. The above materials and devices can exhibit different relative dielectric constants after applying a bias voltage, and can change the electromagnetic parameters such as the phase and radiation pattern of the antenna structure 100, thereby realizing the reconfigurable characteristics of the antenna structure 100.

[0070] For example, when the tuning layer 132 is a liquid crystal layer and a vanadium dioxide layer, the bias voltage can be applied to the upper and lower surfaces of the tuning layer 132. When the magnitude of the bias voltage is changed, the relative dielectric constant of the tuning layer 132 can be changed under the action of the bias voltage. When the tuning layer 132 is a ferrite layer, a graphene layer or a diode, the bias voltage can be applied to the tuning layer 132 in other ways to change the relative dielectric constant of the tuning layer 132. Specifically, the bias voltage application method can be selected and set according to the setting form of the tuning layer 132.

[0071] The first dielectric layer 131 and the second dielectric layer 133 may be formed of alumina, which has a relatively high relative dielectric constant. By stacking with the tuning layer 132 having a lower relative dielectric constant, a distributed Bragg reflector can be formed, which enables the signal to obtain a stronger reflected signal after passing through the partial reflection layer, thereby helping to improve the signal strength.

[0072] It should be noted that, depending on the different forms of the tuning layer 132, the materials of the first dielectric layer 131 and the second dielectric layer 133 may be different, and the relative dielectric constants of the first dielectric layer 131 and the second dielectric layer 133 are both greater than the relative dielectric constant of the tuning layer 132 under the bias voltage. In the specific application process, the molding materials of the first dielectric layer 131 and the second dielectric layer 133 can be selected and set according to the setting mode of the tuning layer 132 or the specific application scenario.

[0073] The third dielectric layer 122 may be formed of a cycloolefin copolymer (Zeonor). Cyclic olefin copolymer has a relatively low relative dielectric constant, which is close to the relative dielectric constant of the tuning layer 132. In this way, when the signal is radiated from the third dielectric layer 122 to the tuning layer 132, the signal loss can be reduced, which is beneficial to improving the radiation efficiency of the antenna structure 100.

[0074] It should be noted that, depending on the different settings of the tuning layer 132, the molding material of the third dielectric layer 122 may also be different, as long as the relative dielectric constant of the third dielectric layer 122 is close to the relative dielectric constant of the tuning layer 132, so as to reduce signal loss and improve the radiation efficiency of the antenna structure 100.

[0075] Figure 2 A schematic diagram of the structure of a frequency selection layer provided in an embodiment of the present application.

[0076] See also Figure 2As shown, in a possible implementation, the frequency selection layer 140 may include a plurality of metal patches arranged in an array, and there is a gap between two adjacent metal patches. Among them, the metal patch can form a reflective portion 142 of the frequency selection layer 140, and the gap can form a hollow portion 141 of the frequency selection layer 140. For example, the metal patch can be attached to the first dielectric layer 131 of the partial reflection layer group 130 by bonding, snapping or buckling. For example, the metal patches can be arranged in a rectangular array in the form of M rows × N columns, where the values ​​of M and N can both be greater than or equal to 2. Alternatively, in some examples, the metal patches can also be arranged in other arrays, for example, the metal patches can be arranged in an array in the form of a circle, a triangle, etc. Specifically, the arrangement of the metal patches can be selected and set according to the shape of the antenna structure 100, the shape of the metal patch, and the specific application scenario.

[0077] When the signal propagates from the partial reflection layer group 130 to the frequency selection layer 140, part of the signal can radiate outward through the gap between the metal patches, while another part of the signal can be reflected by the metal patches to the partial reflection layer group 130, and reflected again into the gap through the partial reflection layer group 130 to radiate outward through the gap, thereby amplifying the phase change of the signal radiation.

[0078] The shape of the metal patch may be at least one of a rectangle, a circle, a triangle or a trapezoid. For example, the shapes of the plurality of metal patches may all be the same, such as a rectangle, a circle, a triangle or a trapezoid. Alternatively, in some examples, the shapes of the metal patches may be different. For example, the shape of some metal patches may be one shape, and the shape of another part of the metal patches may be another different shape.

[0079] By flexibly setting the shape and arrangement of the metal patch, it is possible to obtain reflective portions 142 and hollow portions 141 of different structural forms, which helps to optimize the structural parameters of the frequency selection layer 140, effectively improve the intensity of the overcoupling effect of the asymmetric FPC structure, and enhance the influence of the phase change of the tuning layer 132 under different bias voltages, thereby effectively improving the beam scanning range of the antenna structure 100.

[0080] Figure 3 A schematic diagram of the structure of another frequency selection layer provided in an embodiment of the present application.

[0081] Or, in another possible implementation, see Figure 3 As shown, the frequency selection layer 140 may include a metal layer, and a plurality of through holes arranged in an array may be opened on the metal layer, wherein the through holes may form a hollow portion 141, and the metal layer outside the through holes may form a reflective portion 142. For example, the through holes may be formed on the metal layer by laser cutting or the like.

[0082] For example, the through holes may also be arranged in a rectangular array in the form of M rows × N columns, where the values ​​of M and N may both be greater than or equal to 2. Alternatively, in some examples, depending on the shape of the metal layer, the through holes may also be arranged in other arrays, for example, the through holes may be arranged in an array in the form of a circle, a triangle, etc. Specifically, the arrangement of the through holes may be selected and set according to the shape of the antenna structure 100, the shape of the metal layer, and a specific application scenario.

[0083] When the signal propagates from the partial reflection layer group 130 to the frequency selection layer 140, part of the signal can be radiated outward through the through hole, while another part of the signal can be reflected by the metal layer outside the through hole to the partial reflection layer group 130, and then reflected again into the through hole through the partial reflection layer group 130 to radiate outward through the through hole, thereby amplifying the phase change of the signal radiation.

[0084] Among them, the shape of the through hole can also be at least one of a rectangle, a circle, a triangle or a trapezoid. For example, through holes of the same shape can be provided on the metal layer, and each through hole can be arranged in a rectangular array, a circular array or a triangular array. Alternatively, in some examples, each through hole can also be combined in different shapes, for example, the shape of a part of the through holes can be rectangular, and the shape of another part of the through holes can be circular. Alternatively, the shape of a part of the through holes can be circular, and the shape of another part of the through holes can be triangular. Specifically, the shape of each through hole can be selected and set according to the specific application scenario.

[0085] By opening through holes of different shapes and sizes on the metal layer, hollow portions 141 and reflective portions 142 of different structural forms can be obtained, so that the structural parameters of the frequency selection layer 140 can be optimized to increase the intensity of the overcoupling effect of the asymmetric FPC structure and enhance the influence of the phase change produced by the tuning layer 132 under different bias voltages, thereby effectively improving the beam scanning range of the antenna structure 100.

[0086] The material of the reflector 142 may be at least one of gold, copper or aluminum. For example, the reflector 142 may be a structural member made of any one of the above materials, or the radiator may be a structural member mixed with any two or more of the above materials. The above materials have good electrical conductivity, which helps to improve the reflection efficiency of the frequency selection layer 140 for signals and improve the radiation efficiency of the antenna structure 100 for signals.

[0087] Figure 4 A schematic diagram of the structure of another antenna structure provided in an embodiment of the present application.

[0088] In one possible implementation, see Figure 4As shown, the partial reflection layer group 130 may include a plurality of tuning layers 132 and a plurality of second dielectric layers 133, and the plurality of tuning layers 132 and the plurality of second dielectric layers 133 may be alternately arranged between the first dielectric layer 131 and the ground layer group 120. For example, see Figure 4 As shown, the number of the tuning layer 132 and the second dielectric layer 133 can both be three layers, and the three tuning layers 132 and the three second dielectric layers 133 can be alternately stacked and arranged between the first dielectric layer 131 and the ground layer group 120. By increasing the number of the tuning layer 132 and the second dielectric layer 133, the ability of the tuning layer 132 to control the beam scanning range can be effectively improved, so that the antenna structure 100 can achieve a wider range of phase control, thereby enabling the antenna structure 100 to achieve a wider range of beam scanning, and effectively improving the beam scanning range of the antenna structure 100.

[0089] The following is a test of the beam scanning performance of the antenna structure 100 provided in the embodiment of the present application in conjunction with the accompanying drawings. Figure 1 Take the structure in () as an example for experiment.

[0090] Figure 5 A transmission line model diagram of an antenna structure provided in an embodiment of the present application.

[0091] First, the antenna structure 100 is equivalent to Figure 5 The transmission line model shown in . Then, the dispersion characteristics of the antenna structure 100 are calculated and analyzed, and the following dispersion equation can be obtained:

[0092] Y0+Y FSS +Y TL (Y H ,Y LC ,Y sub )=0

[0093] Where Y0 is the admittance corresponding to the free space wave, and its value is usually 1 / 377, Y FSS is the admittance corresponding to the frequency selective layer 140, Y H is the admittance corresponding to the second dielectric layer 133, Y LC is the admittance corresponding to the tuning layer 132, Y sub The admittance corresponding to the ground layer group 120 is related to the propagation constant of the antenna structure 100 in the leaky wave mode. TL (Y H , Y LC , Y sub ) is the admittance corresponding to the short-circuited transmission line, and its value can be calculated using transmission line theory.

[0094] The above equation is a transcendental equation with the propagation constant of the leaky wave mode generated by the antenna structure 100 as an unknown variable. It can be iteratively solved according to the Muller root finding or Pade root finding method to obtain the admittance value of the frequency selective layer 140, so as to obtain good impedance matching. According to the admittance value of the frequency selective layer 140, the structure of the frequency selective layer 140 that meets the admittance value can be designed. For example, after the admittance value of the frequency selective layer 140 is obtained, the size of the reflective portion 142 and the hollow portion 141 in the frequency selective layer 140 can be calculated according to the admittance value. In this example, the reflective portion 142 is selected as a square metal patch as an example, and the following parameters are selected for testing after calculation.

[0095]

[0096] The total height of the antenna is L (refer to Figure 1 The thickness L4 of the ground layer group 120 (see Figure 1 The width d1 of the reflective portion 142 (see Figure 2 The width d2 of the hollow portion 141 (see Figure 2 ) is the gap width between two adjacent square metal patches. By inputting the above parameters into the simulation software, a dispersion characteristic simulation curve of the antenna structure 100 can be obtained.

[0097] Figure 6 A simulation diagram of the dispersion characteristics of an antenna structure provided in an embodiment of the present application.

[0098] See also Figure 6 As shown, Figure 6 The antenna structure 100 is Figure 1 , that is, a dispersion characteristic simulation curve diagram after the frequency selective layer 140 is set in the antenna structure 100. Figure 6 The horizontal axis in the figure is the normalized frequency f / f0, and the vertical axis is α / k0 or β / k0, where α is the attenuation constant, β is the phase constant, and k0 is the free space wave number. For ease of comparison, the horizontal axis in the figure is normalized, f is the operating frequency, and f0 is the optimal operating frequency when the bias voltage is 0V so that the phase constant β is equal to the attenuation constant α. At this time, the antenna has the maximum gain. Figure 6Curve 1 in the figure is the ratio of the phase constant β to the free space wave number k0 (i.e., β / k0) when the bias voltage is 0. Curve 2 is the ratio of the attenuation constant α to the free space wave number k0 (i.e., α / k0) when the bias voltage is 0. Curve 3 is the ratio of the phase constant β to the free space wave number k0 when the bias voltage is 15V. Curve 4 is the ratio of the attenuation constant α to the free space wave number k0 when the bias voltage is 15V.

[0099] from Figure 6 It can be concluded from curve 1 and curve 2 that when the normalized frequency is 1 and the bias voltage on the tuning layer 132 is 0, as mentioned above, the two curves α / k0 and β / k0 intersect, and the values ​​of α / k0 and β / k0 are equal, that is, the attenuation constant α is equal to the phase constant β. At this time, it can be known from the leaky wave antenna theory that the beam pointing angle θ of the antenna structure 100 is 0 degrees.

[0100] from Figure 6 It can be seen from curves 3 and 4 in that when the normalized frequency is 1 and the bias voltage on the tuning layer 132 is 15V, the values ​​of the two curves α / k0 and β / k0 on the horizontal axis are very different, and the value of β / k0 is much larger than the value of α / k0, that is, β>>α. At this time, it can be known from the leaky wave antenna theory that the beam pointing angle θ satisfies the following formula:

[0101] sinθ=β / k0

[0102] According to the inverse trigonometric function, we can conclude that: θ = sin -1 β / k0

[0103] From curve 3 in the figure, it can be concluded that the value of β / k0 is about 0.46, so it can be concluded that the beam pointing angle θ is about 27.5 degrees. Therefore, it can be seen that when the bias voltage increases from 0V to 15V, the beam pointing θ of the antenna structure 100 changes from 0 degrees to 27.5 degrees, that is, the beam scanning range of the antenna structure 100 is 27.5 degrees.

[0104] Figure 7 This is a dispersion simulation diagram of the antenna structure when no frequency selection layer is provided in the related art.

[0105] See also Figure 7 As shown, Figure 7 is a dispersion characteristic simulation curve diagram when the antenna structure is not provided with the frequency selection layer 140, Figure 7 Curve 1 in the figure is the ratio of the phase constant β to the free space wave number k0 (i.e., β / k0) when the bias voltage is 0. Curve 2 is the ratio of the attenuation constant α to the free space wave number k0 (i.e., α / k0) when the bias voltage is 0. Curve 3 is the ratio of the phase constant β to the free space wave number k0 when the bias voltage is 15V. Curve 4 is the ratio of the attenuation constant α to the free space wave number k0 when the bias voltage is 15V.

[0106] from Figure 7 It can be concluded from curve 1 and curve 2 that when the normalized frequency is 1 and the bias voltage on the tuning layer 132 is 0, the two curves α / k0 and β / k0 intersect, and the values ​​of α / k0 and β / k0 are equal, that is, the attenuation constant α is equal to the phase constant β. At this time, according to the leaky wave antenna theory, it can be seen that the beam pointing angle θ of the antenna structure 100 is 0 degrees.

[0107] From curves 3 and 4 in the figure, it can be concluded that when the frequency is 1 and the bias voltage on the tuning layer 132 is 15V, the values ​​of the two curves α / k0 and β / k0 on the horizontal axis are very different, and the value of β / k0 is much larger than the value of α / k0, that is, β>>α. At this time, according to the leaky wave antenna theory, it can be known that the beam pointing angle θ satisfies the following formula:

[0108] sinθ=β / k0

[0109] At this time, the value of the beam pointing angle θ can be obtained according to the inverse trigonometric function, and from the curve 3 in the figure, it can be obtained that the value of β / k0 is about 0.33, so it can be obtained that the beam pointing angle θ is about 19.5 degrees. Therefore, it can be known that when the bias voltage increases from 0V to 15V, the beam pointing θ of the antenna structure 100 changes from 0 degrees to 19.5 degrees when the frequency selective layer 140 is not set, that is, the beam scanning range of the antenna structure 100 when the frequency selective layer 140 is not set is 19.5 degrees.

[0110] It can be concluded from the experimental results that, compared with the antenna structure without a frequency selection layer, after the frequency selection layer 140 is set in the antenna structure 100, the beam scanning range of the antenna structure 100 is increased from 19.5 degrees to 27.5 degrees, that is, the beam scanning range of the antenna structure 100 is increased by 8 degrees. The beam scanning range has a significant increase, which effectively increases the beam scanning effect of the antenna structure 100.

[0111] In conjunction with the accompanying drawings, a simulation experiment is performed on the directional pattern of the antenna structure 100.

[0112] Figure 8 The directional diagram of the antenna structure provided in the embodiment of the present application and the antenna structure in the related art.

[0113] See also Figure 8 As shown, Figure 8 The horizontal axis is the beam pointing angle, and the vertical axis is the directivity coefficient. Figure 8Curve 1 is a directional pattern curve when the bias voltage is 0V when the frequency selective layer 140 is provided in the antenna structure 100. Curve 2 is a directional pattern curve when the bias voltage is 15V when the frequency selective layer 140 is provided in the antenna structure 100. Curve 3 is a directional pattern curve when the bias voltage is 0V when the frequency selective layer 140 is not provided in the antenna structure 100. Curve 4 is a directional pattern curve when the bias voltage is 15V when the frequency selective layer 140 is not provided in the antenna structure 100.

[0114] When the directivity coefficient reaches the maximum value, the value corresponding to the horizontal axis is the beam pointing angle of the antenna structure 100. Figure 8 From the curves 1 and 2 in FIG. 1 , it can be concluded that when the frequency selective layer 140 is provided in the antenna structure 100, when the bias voltage is 0 V, the beam pointing angle of the antenna structure 100 is 0 degrees, and when the bias voltage is 15 V, the beam pointing angle of the antenna structure 100 is about 27.7 degrees, which is consistent with the above dispersion simulation diagram (i.e. Figure 6 ) is closer to the beam pointing angle of 27.5 degrees obtained by the experiment. It can be concluded from curves 3 and 4 that when the antenna structure 100 is not provided with the frequency selective layer 140, when the bias voltage is 0V, the beam pointing angle of the antenna structure 100 is 0 degrees, and when the bias voltage is 15V, the beam pointing angle of the antenna structure 100 is about 20.8 degrees, which is consistent with the above dispersion simulation diagram (that is, Figure 7 ) experiment, the beam pointing angle of 19.5 degrees is closer.

[0115] It can be concluded from the experimental results that, compared with the antenna structure 100 without the frequency selective layer 140, after the frequency selective layer 140 is set in the antenna structure 100, the beam scanning range of the antenna structure 100 is increased from 20.8 degrees to 27.7 degrees, that is, the beam scanning range of the antenna structure 100 is increased by 6.9 degrees. The beam scanning range has been significantly increased, which effectively increases the beam scanning effect of the antenna structure 100, which is consistent with the conclusion drawn from the dispersion simulation diagram test.

[0116] In conjunction with the accompanying drawings, a simulation experiment is performed on the directional patterns when both the tuning layer 132 and the second dielectric layer 133 in the antenna structure 100 are three layers.

[0117] Fig. 9 Another antenna structure provided in an embodiment of the present application and a directional diagram of an antenna structure in the related art.

[0118] See also Fig. 9 As shown, Fig. 9Curve 1 is a directional diagram when the bias voltage is 0V when the frequency selective layer 140 is provided in the antenna structure 100. Curve 2 is a directional diagram when the bias voltage is 15V when the frequency selective layer 140 is provided in the antenna structure 100. Curve 3 is a directional diagram when the bias voltage is 0V when the frequency selective layer 140 is not provided in the antenna structure 100. Curve 4 is a directional diagram when the bias voltage is 15V when the frequency selective layer 140 is not provided in the antenna structure 100.

[0119] When the directivity coefficient reaches the maximum value, the value corresponding to the horizontal axis is the beam pointing angle of the antenna structure 100. Fig. 9 It can be concluded from curves 1 and 2 that when the frequency selection layer 140 is provided in the antenna structure 100, when the bias voltage is 0V, the beam pointing angle of the antenna structure 100 is 0 degrees. When the bias voltage is 15V, the beam pointing angle of the antenna structure 100 is approximately 34.6 degrees. It can be concluded from curves 3 and 4 that when the frequency selection layer 140 is not provided in the antenna structure 100, when the bias voltage is 0V, the beam pointing angle of the antenna structure 100 is 0 degrees. When the bias voltage is 15V, the beam pointing angle of the antenna structure 100 is approximately 26.7 degrees.

[0120] It can be concluded from the experimental results that when the number of layers of the tuning layer 132 and the second dielectric layer 133 are both three, compared with the antenna structure 100 without the frequency selection layer 140, after the frequency selection layer 140 is set in the antenna structure 100, the beam scanning range of the antenna structure 100 is increased from 26.7 degrees to 34.6 degrees, and the beam scanning range of the antenna structure 100 is increased by 7.9 degrees. The beam scanning range has a significant increase, which effectively increases the beam scanning effect of the antenna structure 100.

[0121] In addition, Figure 8 and Fig. 9 By comparison, it can be seen that when the number of layers of the tuning layer 132 and the second dielectric layer 133 are both one layer, after the frequency selection layer 140 is added, the beam scanning range of the antenna structure 100 is 27.7 degrees. By increasing the number of layers of the tuning layer 132 and the second dielectric layer 133, when the frequency selection layer 140 is not set, the beam scanning range of the antenna structure 100 is 26.7 degrees. It is explained that the method of increasing the beam scanning range by setting the frequency selection layer 140 can increase the beam scanning range to a greater extent and has a better phase amplification effect compared to the method of increasing the beam scanning range by adding the tuning layer 132 and the second dielectric layer 133. Moreover, it can also effectively reduce the thickness of the antenna structure 100, which is conducive to the miniaturization design of the antenna structure 100.

[0122] The embodiment of the present application also provides a communication device, which may include the antenna structure 100 in any of the above scenarios. The communication device may be a communication base station platform antenna feed system, a millimeter wave radar, a smart home, etc. By making the communication device include the above antenna structure 100, the space occupied by the antenna structure 100 in the communication device can be effectively reduced, the rationality of the layout of the antenna structure 100 in the communication device can be improved, and it is helpful to improve the miniaturization design of the communication device. Moreover, it is also helpful to reduce the difficulty and cost of producing the communication device.

[0123] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances. The terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna structure, characterized in that: It includes a feeding structure, and a ground layer group, a partial reflection layer group and a frequency selection layer which are stacked; The feeding structure is electrically connected to the ground layer group, and the partial reflection layer group is located between the ground layer group and the frequency selection layer; The ground layer group is used to reflect signals, and the partial reflection layer group is used to allow part of the signals to pass through and reflect the rest of the signals; The frequency selection layer includes a hollow portion and a reflection portion, the hollow portion is used for allowing signals to pass through, and the reflection portion is used for reflecting the signals.

2. The antenna structure according to claim 1, characterized in that: The partial reflection layer group comprises a first dielectric layer, a tuning layer, and a second dielectric layer which are stacked in sequence, and the frequency selection layer is located on the first dielectric layer; The relative dielectric constants of the first dielectric layer and the second dielectric layer are both greater than the relative dielectric constant of the tuning layer under a bias voltage; The tuning layer is used to change the relative dielectric constant under the action of applied bias voltage.

3. The antenna structure according to claim 1 or 2, characterized in that: The frequency selection layer includes a plurality of metal patches arranged in an array, and there is a gap between two adjacent metal patches; The metal patch forms the reflecting portion, and the gap forms the hollow portion.

4. The antenna structure according to any one of claims 1 to 3, characterized in that: The frequency selection layer comprises a metal layer, and a plurality of through holes arranged in an array are provided on the metal layer; The through hole forms the hollow portion, and the metal layer outside the through hole forms the reflective portion.

5. The antenna structure according to any one of claims 1 to 4, characterized in that: The grounding layer group includes a metal floor and a third dielectric layer arranged on the metal floor; The feeding structure is electrically connected to the metal floor, and the partial reflection layer group is arranged on the third dielectric layer.

6. The antenna structure according to claim 2, characterized in that: The partial reflection layer group includes a plurality of the tuning layers and a plurality of the second dielectric layers; The plurality of tuning layers and the plurality of the second dielectric layers are alternately arranged between the first dielectric layer and the ground layer group.

7. The antenna structure according to claim 2 or 6, characterized in that: The tuning layer is a liquid crystal layer, a vanadium dioxide layer, a ferrite layer, a graphene layer or a diode layer.

8. The antenna structure according to any one of claims 2, 6 or 7, characterized in that: The first dielectric layer and the second dielectric layer are formed of aluminum oxide.

9. The antenna structure according to any one of claims 1 to 8, characterized in that: The reflecting part is formed of at least one of gold, copper and aluminum.

10. The antenna structure according to claim 5, characterized in that: The third dielectric layer is formed of cycloolefin copolymer.

11. The antenna structure according to claim 3, characterized in that: The shape of the metal patch is at least one of a rectangle, a circle, a triangle or a trapezoid.

12. The antenna structure according to claim 4, characterized in that: The through hole has a shape of at least one of a rectangle, a circle, a triangle or a trapezoid.

13. The antenna structure according to any one of claims 2, 6 to 8, characterized in that: The thickness of the tuning layer is an odd multiple of one quarter of a medium wavelength of the tuning layer, where the medium wavelength of the tuning layer is a wavelength of a signal propagating in the tuning layer.

14. The antenna structure according to any one of claims 2, 6 to 8, characterized in that: The thickness of the first dielectric layer is an odd multiple of one quarter of the dielectric wavelength of the first dielectric layer, and the dielectric wavelength of the first dielectric layer is the wavelength of the signal propagating in the first dielectric layer; The thickness of the second dielectric layer is an odd multiple of one quarter of a dielectric wavelength of the second dielectric layer, and the dielectric wavelength of the second dielectric layer is a wavelength of a signal propagating in the second dielectric layer.

15. A communication device, characterized in that: It comprises the antenna structure described in any one of claims 1 to 14.

16. The communication device according to claim 15, characterized in that: The communication device further comprises a control circuit, wherein the control circuit is electrically connected to the tuning layer in the antenna structure; The control circuit is used to apply a bias voltage to the tuning layer.

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