3D vertical super-directivity antenna and optimization method thereof

Abstract

This invention describes a 3D stereoscopic hyperdirectional antenna and its optimization method. It includes: a multilayer substrate, several radiating elements, and an excitation module; the radiating elements are mounted on the multilayer substrate to form a 3D stereoscopic radiating element array; the excitation module includes an excitation circuit and a computing unit; it records the radiation field generated when the 3D stereoscopic radiating element array is uncoupled and the uniquely excited radiation field of different radiating elements when coupling exists; it expands the radiation fields before and after coupling using spherical wave coefficients to establish the connection between the coupled and uncoupled electromagnetic fields, obtaining a coupling matrix; it calculates and generates a hyperdirectional excitation vector based on the coupling matrix, thereby exciting the radiating elements through the excitation circuit to achieve hyperdirectional beam generation. Compared with existing antenna technologies, the hyperdirectional array excitation vector proposed in this invention can dynamically realize hyperdirectional beams with aligned directions, exhibiting excellent performance in both directivity and achievable gain.

Description

Technical Field

[0001] This invention relates to stereo array antennas, including a 3D stereo hyperdirectional antenna and its optimization method. Background Technology

[0002] With the development of wireless communication, Multiple-Input Multiple-Output (MIMO) technology has demonstrated powerful capabilities in improving spectral efficiency and wireless communication system capacity, becoming a key technology for enhancing 5G communication speeds. However, the theoretical capacity analysis of traditional MIMO arrays is based on the condition that there is no coupling between antennas. The physical implementation of this mathematical condition requires at least half a wavelength between the antenna elements of the MIMO array. The spacing between MIMO arrays is large, so the required spatial aperture area for large-scale MIMO array deployment is also large. However, when deploying antennas in actual base stations, the total array area is often limited by factors such as scenario and cost. Therefore, the number of available antennas in MIMO arrays is also limited in actual use.

[0003] Based on the above practical background, a natural direction for technological exploration is to arrange more antenna elements within a given total antenna aperture area and explore whether there is any gain compared to traditional MIMO antenna arrays. Furthermore, due to advancements in antenna manufacturing processes, antenna arrays are no longer limited to planar arrays. Because the spacing between elements in emerging 3D hyperdirectional antennas is narrower, electromagnetic coupling occurs between the elements. Therefore, the beam vector generated by traditional beamforming methods will be distorted after antenna coupling, failing to achieve the desired alignment with the user. In addition, traditional beamforming methods do not consider the radiation pattern of antenna elements, assuming that the radiation of a single antenna element is isotropic. This radiation mode is difficult to generate in practical antenna elements. Commonly used practical antenna elements (such as dipole antennas) have non-uniform energy radiation in space. This inherent non-uniform distribution of antenna radiation energy in space is not considered in current beamforming algorithms. In summary, how to perform low-complexity beamforming while simultaneously considering the antenna's own radiation pattern and the coupling between antenna elements makes the beam alignment of 3D hyperdirectional antennas with the user a significant challenge.

[0004] Furthermore, existing research indicates that when the spacing between antenna elements is less than half a wavelength, hyperdirectional beams can be generated by appropriately setting the excitation vector. However, in the case of linear arrays, hyperdirectional beams can only be generated in the end-fire direction, and the antenna's radiation efficiency suffers a significant loss in this direction. Therefore, existing research has demonstrated that the effect of hyperdirectional beams is limited for linear arrays. Improving the practicality of hyperdirectional beams through heterogeneous antenna array design, and converting directivity gain into actual power gain, not only places demands on the excitation vector algorithm but also on optimizing the radiation efficiency of the antenna array. Summary of the Invention

[0005] Based on the above problems, in order to improve the beamforming gain and radiation efficiency of 3D stereo hyperdirectional antennas, and at the same time extend the applicable scenarios to more general and practical multi-directional hyperdirectional multi-user communication models, a design and implementation method for 3D stereo hyperdirectional antennas is proposed.

[0006] This invention describes a 3D stereoscopic hyperdirectional antenna, comprising: a multilayer substrate, several radiating elements, and an excitation module;

[0007] The plurality of radiating units are mounted on a multilayer substrate to form a 3D stereoscopic radiating unit array.

[0008] The excitation module includes an excitation circuit and a calculation unit; it is used to record the radiation field generated when the 3D stereo radiating element array is uncoupled and the unique excitation field of different radiating elements when coupling exists; it expands the radiation field before and after coupling using spherical wave coefficients to establish the connection between the coupled electromagnetic field and the uncoupled electromagnetic field, thus obtaining the coupling matrix; it calculates and generates a hyperdirectional excitation vector based on the coupling matrix, thereby exciting the radiating elements through the excitation circuit to achieve hyperdirectional beam generation.

[0009] Furthermore, the radiating element is a dipole element, and its spatial distribution must ensure that the radiated electric field intensity generated by the antenna along the Z-axis follows... Distribution pattern.

[0010] Furthermore, the recording of the radiation field generated when the recording array is uncoupled and the uniquely excited radiation field of different antenna elements when coupling exists are specifically as follows: The radiation field generated when coupling is uncoupled is recorded using actual spatial positions. The elevation and horizontal angles of the spherical coordinates are uniformly divided, discretizing the space into P directions, and the radiation field in each direction is recorded. direction and The electric field strength in the direction is used as the radiation field of the current antenna element being solved. Specifically, when setting the array excitation, only the antenna element to be solved is given a unit excitation to generate electromagnetic radiation. Other antenna elements are connected to a matching impedance network as a load. Similarly, the space is discretized into P directions, and the electric field strength in each direction is recorded. direction and The electric field strength in the direction is used as the radiation field of the current array element being solved.

[0011] Furthermore, establishing the connection between coupled and uncoupled electromagnetic fields specifically involves: representing the coupled radiated electric field of a single element as a linear combination of the uncoupled radiated electric fields of multiple elements. If the total number of transmitting antennas is... Uncoupled radiation field is The coupled radiation field is denoted as Linear representation:

[0012]

[0013]

[0014]

[0015]

[0016] The electric field coefficient The substitution methods include substituting the actually recorded radiated electric field parameters or the spherical wave expansion coefficients, adjusting the number of expansion terms according to the required accuracy; linear combination coefficients. The physical meaning is that when there is coupling, the first The radiation field of the first antenna element affects the first... The influence of the radiation field of each antenna;

[0017] Representing the coupled field as a linear combination of several uncoupled fields, the above formula can be simplified in matrix form as follows:

[0018]

[0019] in For recording the coupled electric field, To record the uncoupled electric field, It is due to the above coupling coefficients The coupling matrix is ​​formed; obtained through simulation recording. and In the case of a matrix, The formula for calculating a matrix is:

[0020]

[0021] Furthermore, the step of calculating the hyperdirectional excitation vector based on the coupling matrix includes: designing the excitation vector and the actual equivalent vector through the coupling matrix. To establish a connection, and therefore ensure that the radiation field with the coupling matrix conforms to the radiation field designed by traditional beamforming theory, the excitation vector of the coupled array is the excitation vector of the uncoupled array multiplied by... For a given array, let the aligned user beam excitation vector designed using traditional beamforming methods be... Then the excitation vector of the 3D stereoscopic hyperdirectional antenna is ;in , This is the energy normalization coefficient. Vector sum The matrix expression is as follows:

[0022]

[0023]

[0024] in The vector is the array response vector from the transmitting end. The matrix is ​​defined as the self-impedance matrix of the antenna array, derived from the ideal radiation pattern of a single radiating element. and the geometric position of the antenna array radiating elements ,… Decide

[0025] Furthermore, the beamforming module of the transmitting end is calculated as follows: in a multi-user receiving communication scenario, the array response vector is the array response vector of the transmitting end corresponding to multiple receiving users, which is equal to the sum of the array response vectors obtained by independently calculating each single user.

[0026] According to another aspect provided in this specification, a method for optimizing a 3D stereo hyperdirectional antenna is provided. This method includes array structure optimization and radiation efficiency optimization. The array structure optimization includes finding the optimal antenna element spacing that best balances the radiation efficiency and directivity of the 3D stereo hyperdirectional antenna through simulation. The radiation efficiency optimization specifically involves further improving the antenna radiation efficiency by iteratively optimizing and adjusting the impedance matching.

[0027] Furthermore, in the radiation efficiency optimization, the iterative optimization specifically involves: firstly, obtaining the input impedance of different radiating elements in the 3D stereoscopic hyperdirectional antenna through simulation; for each radiating element, setting the corresponding excitation end pure resistance input impedance to be conjugate matched with the measured radiating element impedance in amplitude; then, exciting the 3D stereoscopic hyperdirectional antenna to obtain a new input impedance and repeating this process until the radiation efficiency of the radiating element array exceeds a preset threshold or the number of iterations reaches a preset maximum number of optimizations.

[0028] The beneficial effects of this invention are as follows: The 3D stereoscopic hyperdirectional antenna, considering the antenna radiation pattern and electromagnetic coupling characteristics, and the simulated excitation vector method, comprehensively consider electromagnetic characteristics compared to traditional methods, combining communication information theory with the actual physical transmission environment. Furthermore, by utilizing the hyperdirectional beam generated by electromagnetic coupling, the antenna radiated energy is more focused at the user, improving the communication quality for individual users while reducing signal interference between different users.

[0029] For hyperdirectional beam generation in single-user scenarios using 3D stereo hyperdirectional antennas, it is possible to achieve high-directivity beam alignment in a single direction. As the user's position changes, no calculations related to the antenna array are required; only the user's azimuth angle needs to be estimated to generate the optimal hyperdirectional beam aligned with the user's azimuth.

[0030] For beam generation in multi-user scenarios using 3D stereo hyperdirectional antennas, the proposed stereo 3D antenna structure and array excitation vector enable the simultaneous generation of multiple hyperdirectional beams aimed at multiple users, thereby improving energy efficiency and communication quality while reducing interference between users.

[0031] To address the issue of low radiation efficiency in 3D hyperdirectional antenna arrays with electromagnetic coupling, radiation efficiency was optimized from two aspects: antenna array structure design and matching impedance optimization. A trade-off was struck between theoretical directional gain and practically achievable gain, resulting in a 3D hyperdirectional antenna with actual energy gain. Attached Figure Description

[0032] Figure 1 This is a communication scenario diagram of the problem studied in this invention and a schematic diagram of the hardware composition of the 3D stereoscopic hyperdirectional antenna.

[0033] Figure 2 This is a schematic diagram of the single-layer 3D stereoscopic superdirectional antenna of the present invention;

[0034] Figure 3 This is a schematic diagram of the multi-layer 3D stereoscopic hyperdirectional antenna of the present invention;

[0035] Figure 4 This is a conceptual diagram of the 3D stereoscopic hyperdirectional antenna of the present invention;

[0036] Figure 5 This is a schematic diagram of the unidirectional superdirectional beam generated by the present invention;

[0037] Figure 6 This is a schematic diagram of the multidirectional superdirectional beam generated by the present invention;

[0038] Figure 7This is a schematic diagram showing the radiation efficiency before and after the array structure design optimization of the present invention;

[0039] Figure 8 This is a schematic diagram illustrating the variation of the directivity and radiation efficiency of the 3D stereoscopic hyperdirectional antenna of the present invention with the spacing of antenna elements.

[0040] Figure 9 This is a schematic diagram illustrating how the gain and radiation efficiency of the 3D stereoscopic hyperdirectional antenna of this invention change with the spacing of antenna elements.

[0041] Figure 10 This is a schematic diagram illustrating the variation of the directivity and radiation efficiency of the multilayer 3D stereoscopic hyperdirectional antenna of the present invention with the spacing of antenna elements.

[0042] Figure 11 This is a schematic diagram illustrating how the gain and radiation efficiency of the multi-layer 3D stereoscopic hyperdirectional antenna of the present invention vary with the spacing of antenna elements. Detailed Implementation

[0043] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0044] This invention discloses a 3D stereoscopic super-directional antenna, comprising: a multilayer substrate, several radiating elements, and an excitation module;

[0045] The plurality of radiating elements are mounted on a multilayer substrate to form a 3D stereoscopic radiating element array. The array includes at least one column with multiple radiating elements, and is used to generate a radiation field. The excitation module includes an excitation circuit and a beamforming module. The beamforming module generates a hyperdirectional excitation vector (simulated excitation coefficient), which excites the radiating element array through the excitation circuit, thereby achieving hyperdirectionality between the actual spatial beam of the 3D stereoscopic hyperdirectional antenna and the theoretical radiation field beam of the array. In any of the above aspects / embodiments, the plurality of radiating elements may include dual-polarized radiating elements.

[0046] In any of the above aspects / embodies, each dual-polarized radiating element can provide isolation in the range of about 40 dB to about 50 dB between the transmit port and the receive port.

[0047] In any of the above aspects / embodies, the plurality of radiation elements may include single-polarized radiation elements.

[0048] In any of the above aspects / embodies, in the 3D stereoscopic hyperdirectional antenna, each excitation output of the excitation module is matched to a corresponding radiating element.

[0049] In any of the above aspects / embodies, the plurality of radiating elements are arranged at intervals of less than half a wavelength.

[0050] In any of the above aspects / embodiments, there is a mutual coupling effect between the radiating elements.

[0051] In any of the above aspects / embodiments, the array comprises a single column having radiating elements.

[0052] In any of the above aspects / embodiments, the array comprises multiple columns in the same plane.

[0053] In any of the above aspects / embodiments, the array comprises multiple columns in different planes.

[0054] The excitation module includes an excitation circuit and a calculation unit; it is used to record the radiation field generated when the 3D stereo radiating element array is uncoupled and the unique excitation field of different radiating elements when coupling exists; it expands the radiation field before and after coupling using spherical wave coefficients to establish the connection between the coupled electromagnetic field and the uncoupled electromagnetic field, thus obtaining the coupling matrix; it calculates and generates a hyperdirectional excitation vector based on the coupling matrix, thereby exciting the radiating elements through the excitation circuit to achieve hyperdirectional beam generation.

[0055] In any of the above aspects / embodiments, the radiation element may have an arbitrary radiation pattern;

[0056] In any of the above aspects / embodiments, the spherical wave expansion is a spatially complete orthogonal basis function that can completely describe any electric field distribution;

[0057] In any of the above aspects / embodiments, the radiating element array has arbitrary antenna spacing;

[0058] In any of the above aspects / embodiments, the hyperdirectional array can be aligned in any direction in space.

[0059] The 3D stereoscopic hyperdirectional antenna of the present invention is implemented through a base station, the base station including the 3D stereoscopic hyperdirectional antenna for transmitting and receiving in wireless communication. The 3D stereoscopic hyperdirectional antenna includes an array of multiple radiating elements, wherein the array includes at least one column having multiple radiating elements, the array being used to generate a radiating field. The excitation module further includes an excitation circuit for providing excitation to the radiating element array, wherein the excitation circuit provides the required excitation to the radiating elements, thereby causing the 3D stereoscopic hyperdirectional antenna to generate a hyperdirectional beam. The base station also includes a transmitter coupled to the 3D stereoscopic hyperdirectional antenna for providing a transmitted signal; the base station also includes a receiver coupled to the 3D stereoscopic hyperdirectional antenna for receiving a received signal.

[0060] Example 1: The specific implementation steps of the excitation vector scheme of the present invention in the single-user reception communication scenario of the 3D stereoscopic hyperdirectional antenna transmission are as follows:

[0061] 3D stereoscopic hyperdirectional antenna transmission and single-user reception communication scenario modeling: such as Figure 1 As shown, this invention studies a downlink communication system with a transmitting end equipped with the aforementioned 3D stereo hyperdirectional antenna array and a single-user receiving end. The base station (BS) deploys one of the aforementioned 3D stereo hyperdirectional antennas to generate a hyperdirectional beam for the user, improving transmission quality. The 3D stereo hyperdirectional antenna consists of... Composed of a densely packed antenna array, we assume that the 3D stereoscopic hyperdirectional antenna and the target user are in a random scattering environment. There may be direct links between the base station and the user, as well as reflected links via reflectors. Since the base station's location is fixed, for simplicity, we assume that the azimuth angles (elevation and horizontal angles) of the scatterer relative to the base station in the communication environment can be obtained by the base station through environmental sensing or channel estimation methods. Assuming there are... If there are scatterers, then this The channel coefficients between a scatterer and the target user can be used as follows: The channel vector representation.

[0062] Hyperdirectional Beamforming: Existing beamforming algorithms do not consider the electromagnetic coupling effect between transmitting antennas. When applied to the 3D hyperdirectional antenna, the resulting spatial beam is affected by coupling distortion and cannot be aligned with the user. The 3D hyperdirectional antenna excitation vector proposed in this paper not only improves the beam alignment problem but also generates a hyperdirectional beam using coupling.

[0063] The 3D hyperdirectional antenna modeling process involves: first, modeling dipole elements in commercial electromagnetic simulation software and placing a suitably sized substrate beneath them to meet actual manufacturing requirements. Electromagnetism provides a complete analytical expression for the electromagnetic radiation of dipole antennas. The radiation pattern of a single dipole antenna is simulated using software and compared with the analytical expression in existing electromagnetic theory to confirm the modeling's correctness. The radiated electric field intensity generated by the modeled dipole antenna along the Z-axis follows... The distribution pattern conforms to the results of the analytical expression. Then, the modeled dipole array is unfolded at equal intervals (intervals less than half a wavelength) in a plane to form a linear HMIMO array (e.g., ...). Figure 2 As shown in the figure, the antenna is finally unfolded in the vertical plane to form a 3D array. Each antenna element theoretically has the same radiation pattern, but due to coupling effects, the actual radiation pattern of each antenna element needs to be obtained through simulation. The actual manufacturing model of the 3D antenna is shown in the figure. Figure 4 As shown, dipole antenna elements are arranged on each substrate layer.

[0064] Spherical wave expansion of the radiation pattern: After modeling the densely packed 3D hyperdirectional antenna, it is necessary to calculate the electromagnetic coupling between its array elements. First, the radiation patterns generated by all arrays without coupling need to be recorded. Since different antenna elements have different spatial coordinates, even if their radiation patterns are the same without coupling, the electromagnetic radiation intensity and phase received from different transmitting antennas at the same receiving point will differ during near-field observation. Therefore, it is necessary to record the uncoupled radiation modes according to the actual spatial positions of the antenna array elements after modeling the 3D hyperdirectional antenna. This is achieved by setting the array factor for individual dipole elements. In the array factor setting, by specifying the coordinate differences between different array elements and the excitation coefficients of the antenna elements, a linear superposition of the radiation fields after individual excitation of different elements can be generated in space. The electric field generated by different elements in this way is only related to their spatial position and excitation coefficient, naturally not including the coupling effect of other radiating elements. The space is discretized into P directions (the elevation and horizontal angles of the spherical coordinates are uniformly divided), and the electromagnetic coupling of each direction is recorded. direction and The electric field strength in the direction is used as the radiation field of the current array element being solved.

[0065] Secondly, it is necessary to calculate the radiation patterns of different antenna elements when coupling exists. The simulation method involves modeling all the antenna elements of the 3D hyperdirectional antenna in simulation software. When setting the array excitation, only the antenna elements to be solved are given a unit excitation to generate electromagnetic radiation. Other antenna elements are connected to a matching impedance network as a load. Similarly, the space is discretized into P directions, and the radiation patterns in each direction are recorded. direction and The electric field strength in the direction. Further, this process is repeated for all modeled antenna elements, and the radiation field generated when each element is uniquely excited is recorded.

[0066] Finally, after obtaining the radiation fields under coupled and uncoupled conditions, the radiation fields can be expanded using spherical wave coefficients:

[0067]

[0068] in Let be the wave number, where The wavelength of the electromagnetic wave at the operating frequency. For free space impedance, For spherical coordinate system coordinate parameters, The three parameters represent the electromagnetic wave mode (TE / TM wave), the electromagnetic wave expansion dimension, and the electromagnetic wave expansion order, respectively. The spherical wave expansion coefficient, Let be a spherical wave function, which serves as a complete set of basis functions in space and can be used to describe any spatial radiation field. Its specific expression is as follows:

[0069]

[0070] The spherical wave function is a complete set of basis functions in space, which can be used to describe any spatial radiation field; It is an nth-order first-kind spherical Hankel function. For the normalized correlation Legendre function, The unit vector pointing to the user in the spherical coordinate system. and They are direction and A unit vector in direction.

[0071] Coupling matrix calculation:

[0072] After obtaining the radiation modes of the 3D stereoscopic hyperdirectional antenna under both uncoupled and coupled conditions, we can represent the coupled radiation electric field of a single element as a linear combination of the uncoupled radiation electric fields of multiple elements. If the total number of transmitting antennas is... Uncoupled radiation field is The coupled radiation field is denoted as Linear representation:

[0073]

[0074]

[0075]

[0076]

[0077] The electric field coefficient Either the actually recorded radiation electric field parameters can be substituted, or the spherical wave expansion coefficients can be substituted. Substituting the spherical wave expansion coefficients offers greater flexibility, allowing adjustment of the number of expansion terms to suit the required precision. Linear combination coefficients. The physical meaning is that when there is coupling, the first The radiation field of the first antenna element affects the first... The influence of the radiation field of each antenna. From the above definitions, it can be seen that through the coupling matrix, we have established the relationship between coupled and uncoupled electromagnetic fields, representing the coupled field as a linear combination of multiple uncoupled fields. Since the above formulas can be simplified to matrix form:

[0078]

[0079] in For recording the coupled electric field, To record the uncoupled electric field, It is due to the above coupling coefficients The coupling matrix is ​​formed by simulation records. and In the case of a matrix, The formula for calculating a matrix is:

[0080]

[0081] The coupling matrix can be derived from the simulation results based on the above process.

[0082] Superdirectional excitation vector

[0083] First, consider traditional beamforming design. Since traditional communication models do not consider the influence of coupling effects, the excitation vector after traditional beamforming design in the 3D hyperdirectional antenna is not equal to the equivalent excitation vector of the actual antenna array. The designed excitation vector and the actual equivalent vector are obtained through the aforementioned coupling matrix. To establish a connection, and therefore ensure that the radiation field with the coupling matrix conforms to the radiation field designed by traditional beamforming theory, the excitation vector of the coupled array is the excitation vector of the uncoupled array multiplied by... For a given array, let the aligned user beam excitation vector designed using traditional beamforming methods be... Then the excitation vector of the 3D stereoscopic hyperdirectional antenna is ;in , This is the energy normalization coefficient. Vector sum The matrix expression is as follows:

[0084]

[0085]

[0086] in The vector is the array response vector from the transmitting end. The matrix is ​​defined as the self-impedance matrix of the antenna array, derived from the ideal radiation pattern of a single radiating element. and the geometric position of the antenna array radiating elements ,… The excitation circuit, consisting of a power divider and a phase shifter, adjusts the power distribution and phase of the excitation for each antenna to achieve the excitation vector calculated by the beamforming module. The excitation circuit generates a single-user scene spatial hyperdirectional beam, such as... Figure 5 As shown.

[0087] Superdirectional array radiation efficiency optimization

[0088] Array structure optimization: Although theoretical analysis shows that the directivity achievable by the array increases as the spacing between antenna elements decreases, for A linear antenna array with multiple antenna elements, at element spacing The maximum directionality that can be achieved at that time is However, simulation experiments revealed that as the component spacing... As the antenna shrinks, the coupling effect strengthens, reducing its radiation efficiency. There exists a skip edge region in the radiation efficiency range (where the antenna radiation efficiency drops sharply). This decrease in antenna radiation efficiency means that an increase in directivity does not necessarily translate into an increase in actual energy efficiency, because the actual realized antenna energy gain (…) ) When the antenna spacing is too large, the radiation efficiency is high but the achievable directivity is low; when the antenna spacing is too small, the directivity is high but the radiation efficiency is too low. Both will result in too small an achievable energy gain. Therefore, the design of the array geometry must be optimized. Figure 9 The figure shows the energy gain achievable with different array spacings. It can be seen from the figure that when the array spacing is... When viewed from the left and right, the maximum achievable gain is achieved for the single-layer 3D stereoscopic hyperdirectional antenna, that is, the optimal trade-off is achieved between radiation efficiency and directivity.

[0089] Radiation efficiency optimization

[0090] After selecting the optimal geometry of the 3D hyperdirectional antenna, the input impedance of the antenna array feed circuit and the input impedance of the antenna may not be equal, resulting in an impedance mismatch problem. Adjusting the impedance matching can further improve the antenna's radiation efficiency. Circuit theory shows that for antennas with complex input impedance... The optimal input impedance value of the feed terminal of the aforementioned radiating element. The optimal input impedance at the feed end is the conjugate of the complex input impedance of the antenna. Since dynamically adjusting arbitrary complex impedances in practical circuits is very complex, we consider improving the radiation efficiency of the 3D hyperdirectional antenna by achieving impedance matching only in amplitude. Simulations show that changing the input impedance at the feed end does not significantly change the beam pattern generated by the 3D hyperdirectional antenna (i.e., the directivity does not change significantly), but the input impedance of the radiating element changes considerably. Therefore, impedance matching is an iterative optimization process. In each iteration, we first obtain the input impedance of different radiating elements through simulation. Then, we set the pure resistive input impedance at the excitation end to be equal to the input impedance of the antenna element in amplitude. We then excite the 3D hyperdirectional antenna to obtain a new antenna element input impedance and repeat this process. The radiation efficiency optimization results achieved through amplitude impedance matching are as follows. Figure 7 As shown, it can be seen that at least a 10% improvement in radiation efficiency can be achieved.

[0091] Example 2: The specific implementation steps of the excitation vector scheme of the present invention in the 3D stereoscopic hyperdirectional antenna transmit-receive multi-user communication scenario are as follows:

[0092] The 3D stereoscopic hyperdirectional antenna transmission and multi-user reception communication scenario system modeling is as follows: Figure 1 As shown, this invention studies a downlink communication system where the transmitting end is equipped with the aforementioned 3D stereo hyperdirectional antenna and the receiving end is a user receiving signal. Specifically, the base station (BS) deploys the aforementioned 3D stereo hyperdirectional antenna to generate a hyperdirectional beam targeting the user, improving transmission quality. The 3D stereo hyperdirectional antenna is composed of... Composed of a densely packed antenna array, we assume that the 3D stereoscopic hyperdirectional antenna and the target user are in a random scattering environment. There may be direct links between the base station and the user, as well as reflected links via reflectors. Since the base station's location is fixed, for simplicity, we assume that the azimuth angles (elevation and horizontal angles) of the scatterer relative to the base station in the communication environment can be obtained by the base station through environmental sensing or channel estimation methods. Assuming there are... If there are scatterers, then this The channel coefficients between a scatterer and the target user can be used as follows: The channel vector representation.

[0093] 3D stereo antenna design

[0094] For a single-plane linear 3D hyperdirectional antenna and an arbitrary excitation vector, the electromagnetic radiation generated by all antenna elements on the plane perpendicular to the linear array is symmetrical about the plane where the linear 3D hyperdirectional antenna is located. Therefore, when there is a focused beam in a direction other than the end-fire direction, there must also be a focused beam in its symmetrical direction with respect to the plane. Thus, energy cannot form a hyperdirectional focused beam in a single direction.

[0095] However, in multi-user communication scenarios, the 3D stereoscopic hyperdirectional antenna at the transmitting end needs to simultaneously generate multiple hyperdirectional beams pointing towards the users. To achieve this goal, this invention proposes constructing the 3D stereoscopic hyperdirectional antenna. Compared to the existing two-dimensional structure of xy-plane arrays, this application further arranges multiple antenna layers along the z-axis, thereby enabling the generation of hyperdirectional beams in any direction. For the 3D stereoscopic hyperdirectional antenna (e.g. HMIMO arrays, such as Figure 3 As shown in the figure, this array has a structure similar to a linear array from multiple perspectives. Therefore, theoretically, it is possible to generate multiple hyperdirectional focusing beams independently and simultaneously in different directions by designing beamforming excitation vectors, which provides a physical basis for realizing spatial multi-hyperdirectional beams that can be simultaneously aligned with multiple user positions.

[0096] As can be seen from the above principles, the essence of multi-directional hyperdirectional design is still achieved through the design method of linear array end-fire hyperdirectional antenna. Therefore, the 3D stereoscopic hyperdirectional antenna should also have a certain degree of spatial symmetry, and this idea has been verified in simulations. The example 3D stereoscopic hyperdirectional antenna proposed in this invention is... Structure, such as Figure 3 As shown, a larger-scale expansion in spatial structure can then be carried out.

[0097] Multi-directional hyperdirectional beamforming: Existing beamforming algorithms do not consider the electromagnetic coupling effect between transmitting antennas. When using the 3D hyperdirectional antenna, the resulting spatial beam is affected by coupling distortion and cannot be aligned with the user. The heterogeneous antenna 3D hyperdirectional antenna excitation vector construction proposed in this application not only improves the beam alignment problem but also generates hyperdirectional beams using coupling. In particular, the stacked heterogeneous antenna array can simultaneously generate multi-directional hyperdirectional focusing beams aligned with multiple users. Due to the narrow spatial beam achieved, it can improve user communication quality while maintaining very low inter-user interference.

[0098] The 3D hyperdirectional antenna modeling process involves: first, modeling dipole elements in commercial electromagnetic simulation software and placing a suitably sized substrate beneath them to meet actual manufacturing requirements. Electromagnetism provides a complete analytical expression for the electromagnetic radiation of dipole antennas. The radiation pattern of a single dipole antenna is simulated using software and compared with the analytical expression in existing electromagnetic theory to confirm the modeling's correctness. The radiated electric field intensity generated by the modeled dipole antenna along the Z-axis follows... distributed

[0099] The pattern matches the result of the analytical expression; The angle of elevation in spherical coordinates. This is the horizontal azimuth angle in spherical coordinates. The modeled dipole array is then unfolded at equal intervals in a plane to form a linear HMIMO array (e.g., ...). Figure 2 As shown), it is finally unfolded in the vertical plane to form a 3D array (as shown). Figure 3 (As shown). Each antenna element theoretically has the same radiation pattern, but due to coupling effects, the actual radiation pattern of each antenna element needs to be obtained through simulation. The actual manufacturing model of the 3D antenna is shown below. Figure 4 As shown.

[0100] Spherical wave expansion of the radiation pattern: After modeling the densely packed 3D hyperdirectional antenna, it is necessary to calculate the electromagnetic coupling between its array elements. First, the radiation patterns generated by all arrays without coupling need to be recorded. Since different antenna elements have different spatial coordinates, even if their radiation patterns are the same without coupling, the electromagnetic radiation intensity and phase received from different transmitting antennas at the same receiving point will differ during near-field observation. Therefore, it is necessary to record the uncoupled radiation modes according to the actual spatial positions of the antenna array elements after modeling the 3D hyperdirectional antenna. This is achieved by setting the array factor for individual dipole elements. In the array factor setting, by specifying the coordinate differences between different array elements and the excitation coefficients of the antenna elements, a linear superposition of the radiation fields after individual excitation of different elements can be generated in space. The electric field generated by different elements in this way is only related to their spatial position and excitation coefficient, naturally not including the coupling effect of other radiating elements. The space is discretized into P directions (the elevation and horizontal angles of the spherical coordinates are uniformly divided), and the electromagnetic coupling of each direction is recorded. direction and The electric field strength in the direction is used as the radiation field of the current array element being solved.

[0101] Secondly, it is necessary to calculate the radiation patterns of different antenna elements when coupling exists. The simulation method involves modeling all the antenna elements of the 3D hyperdirectional antenna in simulation software. When setting the array excitation, only the antenna elements to be solved are given a unit excitation to generate electromagnetic radiation. Other antenna elements are connected to a matching impedance network as a load. Similarly, the space is discretized into P directions, and the radiation patterns in each direction are recorded. direction and The electric field strength in the direction. Further, this process is repeated for all modeled antenna elements, and the radiation field generated when each element is uniquely excited is recorded.

[0102] Finally, after obtaining the radiation fields under coupled and uncoupled conditions, the radiation fields can be expanded using spherical wave coefficients:

[0103]

[0104] in Let be the wave number, where The wavelength of the electromagnetic wave at the operating frequency. For free space impedance, For spherical coordinate system coordinate parameters, The three parameters represent the electromagnetic wave mode (TE / TM wave), the electromagnetic wave expansion dimension, and the electromagnetic wave expansion order, respectively. The spherical wave expansion coefficient, Let be a spherical wave function, which serves as a complete set of basis functions in space and can be used to describe any spatial radiation field. Its specific expression is as follows:

[0105]

[0106] The spherical wave function is a complete set of basis functions in space, which can be used to describe any spatial radiation field; It is an nth-order first-kind spherical Hankel function. For the normalized correlation Legendre function, The unit vector pointing to the user in the spherical coordinate system. and They are direction and unit vector of direction

[0107] Coupling matrix calculation:

[0108] After obtaining the radiation modes of the 3D stereoscopic hyperdirectional antenna under both uncoupled and coupled conditions, we can represent the coupled radiation electric field of a single element as a linear combination of the uncoupled radiation electric fields of multiple elements. If the total number of transmitting antennas is... Uncoupled radiation field is The coupled radiation field is denoted as Linear representation:

[0109]

[0110]

[0111]

[0112]

[0113] The electric field coefficient Either the actually recorded radiation electric field parameters can be substituted, or the spherical wave expansion coefficients can be substituted. Substituting the spherical wave expansion coefficients offers greater flexibility, allowing adjustment of the number of expansion terms to suit the required precision. Linear combination coefficients. The physical meaning is that when there is coupling, the first The radiation field of the first antenna element affects the first... The influence of the radiation field of each antenna. From the above definitions, it can be seen that through the coupling matrix, we have established the relationship between coupled and uncoupled electromagnetic fields, representing the coupled field as a linear combination of multiple uncoupled fields. Since the above formulas can be simplified to matrix form:

[0114]

[0115] in For recording the coupled electric field, To record the uncoupled electric field, It is due to the above coupling coefficients The coupling matrix is ​​formed by simulation records. and In the case of a matrix, The formula for calculating a matrix is:

[0116]

[0117] The coupling matrix can be derived from the simulation results based on the above process.

[0118] Superdirectional beam array excitation vector:

[0119] First, consider traditional beamforming design. Since traditional communication models do not consider the influence of coupling effects, the excitation vector after traditional beamforming design in the 3D hyperdirectional antenna is not equal to the equivalent excitation vector of the actual antenna array. The designed excitation vector and the actual equivalent vector are obtained through the aforementioned coupling matrix. To establish a connection, and therefore ensure that the radiation field with the coupling matrix conforms to the radiation field designed by traditional beamforming theory, the excitation vector of the coupled array is the excitation vector of the uncoupled array multiplied by... For a given array, let the aligned user beam excitation vector designed using traditional beamforming methods be... Then the excitation vector of the 3D stereoscopic hyperdirectional antenna is ;in , This is the energy normalization coefficient. Vector sum The matrix expression is as follows:

[0120]

[0121]

[0122] in The vector is the array response vector from the transmitting end. The matrix is ​​defined as the self-impedance matrix of the antenna array, derived from the ideal radiation pattern of a single radiating element. and the geometric position of the antenna array radiating elements ,… The excitation circuit, consisting of a power divider and a phase shifter, adjusts the power distribution and phase of the excitation for each antenna to achieve the excitation vector calculated by the beamforming module. The resulting multi-user scene spatial hyperdirectional beam is as follows: Figure 6 As shown.

[0123] Multidirectional superdirectional radiation efficiency optimization:

[0124] Array structure optimization: Although theoretical analysis shows that the directivity achievable by the array increases as the spacing between antenna elements decreases, for A linear antenna array with multiple antenna elements, at element spacing The maximum directionality that can be achieved at that time is However, simulation experiments revealed that as the component spacing... As the antenna shrinks, the coupling effect strengthens, reducing its radiation efficiency. There exists a skip edge region in the radiation efficiency range (where the antenna radiation efficiency drops sharply). This decrease in antenna radiation efficiency means that an increase in directivity does not necessarily translate into an increase in actual energy efficiency, because the actual realized antenna energy gain (…) ) When the antenna spacing is too large, the radiation efficiency is high but the achievable directivity is low; when the antenna spacing is too small, the directivity is high but the radiation efficiency is too low. Both will result in too small an achievable energy gain. Therefore, the design of the array geometry must be optimized. Figure 11 The figure shows the energy gain achievable with different array spacings of stacked heterogeneous antennas. It can be seen from the figure that when the array spacing is... When viewed from the left and right, the 3D stereoscopic hyperdirectional antenna array achieves the maximum achievable gain, that is, it achieves the best trade-off between radiation efficiency and directivity.

[0125] Radiation efficiency optimization: After determining the optimal geometry of the 3D stereoscopic hyperdirectional antenna, the input impedance of the antenna array feed circuit and the input impedance of the antenna may not be equal, resulting in an impedance mismatch problem. Adjusting the impedance matching can further improve the antenna's radiation efficiency. As circuit theory shows, for antennas with complex input impedance... The optimal input impedance value at the feed end of the aforementioned 3D stereoscopic hyperdirectional antenna. The optimal input impedance at the feed end is the conjugate of the complex input impedance of the antenna. Since dynamically adjusting arbitrary complex impedances in practical circuits is very complex, we consider improving the radiation efficiency of the 3D hyperdirectional antenna by achieving impedance matching only in amplitude. Simulations show that changing the input impedance at the feed end does not significantly change the beam pattern (i.e., the directivity), but it does significantly change the input impedance of the radiating elements. Therefore, impedance matching is an iterative optimization process. In each iteration, we first obtain the input impedances of different radiating elements of the 3D hyperdirectional antenna through simulation. Then, we set the pure resistive input impedance at the excitation end to be equal to the input impedance of the antenna elements in amplitude. We then excite the 3D hyperdirectional antenna to obtain new antenna element input impedances and repeat this process. The loop ends when the array's radiation efficiency exceeds a pre-set threshold or the number of iterations reaches a pre-set maximum optimization number. The radiation efficiency optimization results achieved through amplitude impedance matching are as follows. Figure 7 As shown, it can be seen that at least a 10% improvement in radiation efficiency can be achieved, realizing a practical hyperdirectional array.

[0126] The functions and effects of this invention are further illustrated and demonstrated through the following simulation experiments:

[0127] (1) Single-user scenario of the 3D stereoscopic hyperdirectional antenna described in the single layer:

[0128] (1.1) Simulation conditions:

[0129] Set the number of users to The antenna array operates at a frequency of 1.6 GHz and consists of microstrip dipole antennas. For simplicity, for the heterogeneous HMIMO array, we consider a set of antenna arrays deployed in the xy plane, with antenna elements arranged along the x-axis and multiple layers of antennas arranged along the y-axis. In the simulation, we consider two cases of the 3D stereoscopic hyperdirectional antenna: the array aperture area remains constant, and the number of antennas is inversely proportional to the antenna spacing; the total number of antennas remains constant, and the array aperture is directly proportional to the antenna spacing. Furthermore, the simulation assumes that the user is located on the extension of the positive x-axis, therefore the elevation angle from the 3D stereoscopic hyperdirectional antenna to each user is... Horizontal azimuth at The excitation energy of the antenna array is set to 1W in the simulation.

[0130] During the simulation, we compared the 3D antenna simulation excitation vector method of this invention with the existing maximizing directional beamforming method in MIMO arrays that does not consider coupling, in terms of the directivity and gain achieved by the array.

[0131] (1.2) Simulation results:

[0132] Figures 8-9 The effects of antenna element spacing on array directivity, achievable gain, and radiation efficiency with a fixed antenna array aperture area were plotted. Under the same simulation scenario settings, the simulation results show that the achievable hyperdirectivity gradually increases as the antenna element spacing decreases. This is because the hyperdirectivity simulation excitation vector method proposed in this invention is based on the coupling effect between the radiating elements of the 3D hyperdirectivity antenna. When the element spacing decreases, the array coupling effect also increases accordingly, and the corresponding hyperdirectivity is improved. The leftmost directivity shows a decreasing trend because the actual radiation pattern of the array cannot be represented by a linear combination of the ideal radiation patterns of the array elements, indicating insufficient application of coupling. However, as can be seen from the radiation efficiency curve, the coupling effect leads to a decrease in the radiation efficiency of the antenna array, which in turn reduces the proportion of directional gain converted into actual energy gain transmitted by the antenna. Therefore, there is a trade-off between directivity and radiation efficiency. The result of this trade-off is that the achievable gain curve shows a trend of first increasing and then decreasing: in the small-spaced part, the achievable gain is not high due to the low radiation efficiency; in the large-spaced part, the superdirectivity is not obvious due to the weak coupling effect of the antenna elements. However, in the region where the radiation efficiency is high and the coupling effect is strong, the application of this heterogeneous antenna structure and the proposed 3D superdirective antenna excitation vector construction achieves a high antenna energy gain, which can effectively reduce communication energy loss or improve communication rate.

[0133] (2) Multi-user scenario of the 3D stereoscopic hyperdirectional antenna

[0134] (2.1) Simulation conditions

[0135] Set the number of users to The antenna array operates at a frequency of 1.6 GHz and consists of microstrip dipole antennas. For simplicity, for the 3D hyperdirectional antenna, we consider an antenna array deployed in the xy plane, with antenna elements arranged along the x-axis and multiple antenna layers arranged along the y-axis. In the simulation, we consider two scenarios for the 3D hyperdirectional antenna: the array aperture area remains constant, and the number of antennas is inversely proportional to the antenna spacing; the total number of antennas remains constant, and the array aperture is directly proportional to the antenna spacing. Furthermore, the simulation assumes that users are uniformly distributed in the xy plane; therefore, the elevation angle from the 3D hyperdirectional antenna to each user is... Horizontal azimuth at The antenna array is randomly distributed among the components. The excitation energy for the antenna array is set to 1W in the simulation.

[0136] During the simulation, we compared the 3D antenna simulation excitation vector method of this invention with the existing maximizing directional beamforming method in MIMO arrays that does not consider coupling, in terms of the directivity and gain achieved by the array.

[0137] (2.2) Simulation results

[0138] Figures 10-11The simulation results of the 3D stereo hyperdirectional antenna for single-user and multi-user applications are described. The influence of antenna element spacing on array directivity, achievable gain, and radiation efficiency with a fixed antenna array aperture area is plotted. Simulation results show that the proposed 3D stereo hyperdirectional antenna array and multi-user excitation vector method can simultaneously generate multiple non-interfering hyperdirectional beams in space, improving the communication rate of each user while ensuring minimal mutual interference through high directivity. Similarly, the achievable hyperdirectionality gradually increases as the antenna element spacing decreases. This is because the proposed hyperdirectional simulation excitation vector method is based on the coupling effect between the radiating elements. When the element spacing decreases, the array coupling effect also strengthens, resulting in improved hyperdirectionality. The decreasing directivity on the far left is because the actual radiation pattern of the array cannot be represented by a linear combination of the ideal radiation patterns of the array elements, indicating insufficient application of coupling. However, as can be seen from the radiation efficiency curve, the coupling effect leads to a decrease in the radiation efficiency of the antenna array, which in turn reduces the proportion of directional gain converted into actual energy gain transmitted by the antenna. Therefore, there is a trade-off between directivity and radiation efficiency. The result of this trade-off is that the achievable gain curve shows a trend of first increasing and then decreasing: in the small-spaced part, the achievable gain is not high due to the low radiation efficiency; in the large-spaced part, the superdirectivity is not obvious due to the weak coupling effect of the antenna elements. However, in the region where the radiation efficiency is high and the coupling effect is strong, the application of this heterogeneous antenna structure and the proposed 3D superdirective antenna excitation vector method achieves a higher antenna energy gain, which can effectively reduce communication energy loss or improve communication rate.

[0139] The results above show that the present invention not only has the high directivity of super-directional beamforming, but also has the characteristics of low computational load and low delay.

[0140] In some examples, this invention describes a design and implementation method for a 3D hyperdirectional antenna, which is also applicable to massive MIMO communication in 5G networks. In various examples, the disclosed 3D hyperdirectional antenna can use multiple dual-polarized or single-polarized radiating elements arranged in a single or multi-row array, and generates a more ideal spatial radiation pattern and hyperdirectional beam by utilizing coupling effects to modulate the simulated excitation coefficients.

[0141] The disclosed 3D hyperdirectional antenna simulation excitation vector design algorithm can utilize the mutual coupling effect between radiating elements to realize a practical hyperdirectional beam.

[0142] The various examples in the disclosed antenna arrays can be applied to beam focusing at any location in space, and the superdirectional beam direction can be adjusted in real time in practical applications.

[0143] This invention describes an example of a 3D stereo hyperdirectional antenna capable of generating hyperdirectional beams in arbitrary directions. The disclosed 3D stereo hyperdirectional antenna includes a densely packed array of radiating elements and an excitation module. The coupling between the radiating elements causes a distortion between the theoretical and actual radiation patterns of the 3D stereo antenna. The excitation vector of the disclosed 3D stereo hyperdirectional antenna array can utilize coupling to generate hyperdirectional beams in arbitrary spatial directions, focusing energy towards the target user. The disclosed 3D stereo hyperdirectional antenna can be used in massive MIMO communication, incorporating previously unconsidered antenna RF characteristics and electromagnetic coupling effects into the communication system, improving communication speed, and achieving hyperdirectional beams with practical gain.

[0144] This disclosure may be embodied in other specific forms without departing from the subject matter of the claims. The exemplary embodiments described are merely illustrative in all respects and not restrictive. Selected features from one or more of the foregoing embodiments may be combined to create alternative embodiments not explicitly described, and features suitable for such combinations are to be understood to fall within the scope of the invention. For example, although a certain size and shape of the disclosed antenna is shown, other sizes and shapes may be used.

[0145] Furthermore, all values ​​and sub-ranges within the scope of the disclosure are also disclosed. Additionally, while the systems, devices, and processes disclosed and illustrated herein may include a specific number of elements / components, these systems, devices, and components may be modified to include more or fewer such elements / components. For example, although any disclosed radiating elements may be of a fixed number, the embodiments disclosed herein may be modified to include more or fewer such elements / components. The subject matter described herein is intended to cover and encompass all appropriate technical modifications.

Claims

1. A 3D stereoscopic hyperdirectional antenna, characterized in that, include: Multilayer substrate, several radiating units and excitation module; The plurality of radiating units are mounted on a multilayer substrate to form a 3D stereoscopic radiating unit array. The excitation module includes an excitation circuit and a beamforming module; the beamforming module is used to record the radiation field generated when the 3D stereo radiating unit array is not coupled and the radiation field that is uniquely excited by different radiating units when there is coupling; the radiation fields before and after coupling are expanded by spherical wave coefficients to establish the relationship between the coupled electromagnetic field and the uncoupled electromagnetic field, and the coupling matrix is ​​obtained. The hyperdirectional excitation vector is calculated based on the coupling matrix, and then the radiating element is excited by the excitation circuit to achieve hyperdirectional beam generation. The establishment of the connection between the coupled and uncoupled electromagnetic fields specifically involves: representing the coupled radiating electric field of a single element as a linear combination of the uncoupled radiating electric fields of multiple elements. If the total number of transmitting antennas is... Uncoupled radiation field is The coupled radiation field is denoted as Linear representation: The electric field coefficient The substitution methods include substituting the actually recorded radiated electric field parameters or the spherical wave expansion coefficients, adjusting the number of expansion terms according to the required accuracy; linear combination coefficients. The physical meaning is the influence of the radiation field of the nth radiating element on the radiation field of the mth antenna when there is coupling; Representing the coupled field as a linear combination of several uncoupled fields, the above formula can be simplified in matrix form as follows: in For recording the coupled electric field, To record the uncoupled electric field, It is composed of the above linear combination coefficients The coupling matrix is ​​formed; obtained through simulation recording. and In the case of a matrix, The formula for calculating a matrix is: 。 2. The 3D stereoscopic hyperdirectional antenna according to claim 1, characterized in that, The radiating elements are arranged at intervals less than half a wavelength, resulting in mutual coupling effects.

3. A 3D stereoscopic hyperdirectional antenna according to claim 1, characterized in that, The 3D stereoscopic radiation unit array includes a single column of radiation units, multiple columns on the same plane, or multiple columns on different planes.

4. A 3D stereoscopic hyperdirectional antenna according to claim 1, characterized in that, The radiating element includes a dipole element, and its spatial distribution must ensure that the radiated electric field intensity generated by the antenna along the Z-axis follows the sin(θ) distribution law, where θ is the horizontal elevation angle.

5. A 3D stereoscopic hyperdirectional antenna according to claim 1, characterized in that, The radiation field generated when the recording array is uncoupled and the uniquely excited radiation field of different radiation units when coupling exists are specifically described as follows: The radiation field generated when coupling is uncoupled is recorded using actual spatial positions. The spherical coordinates are uniformly divided into elevation and horizontal angles, discretizing the space into P directions, and recording the elevation angle of each direction. Direction and horizontal azimuth The electric field intensity in the direction is used as the radiation field of the current array element being solved. Specifically, when coupling exists, the uniquely excited radiation field of each radiation element is recorded as follows: when setting the array excitation, only the radiation element to be solved is given a unit excitation to generate electromagnetic radiation; other radiation elements are connected to a matching impedance network as a load. Similarly, the space is discretized into P directions, and the electric field intensity in each direction is recorded. direction and The electric field strength in the direction is used as the radiation field of the current array element being solved.

6. A 3D stereoscopic hyperdirectional antenna according to claim 1, characterized in that, The calculation of the hyperdirectional excitation vector based on the coupling matrix includes: designing the excitation vector and the actual equivalent vector through the coupling matrix. To establish a connection, and therefore ensure that the radiation field with the coupling matrix conforms to the radiation field designed by traditional beamforming theory, the excitation vector of the coupled array is the excitation vector of the uncoupled array multiplied by... For a given array, let the aligned user beam excitation vector designed using traditional beamforming methods be... Then the excitation vector of the 3D stereoscopic hyperdirectional antenna is ;in , This is the energy normalization coefficient. Vector sum The matrix expression is as follows: in The vector is the array response vector from the transmitting end. The matrix is ​​defined as the self-impedance matrix of the antenna array, derived from the ideal radiation pattern of a single radiating element. and the geometric position of the antenna array radiating elements ,… Decide, For wave number, The unit vector pointing to the user in the spherical coordinate system. The angle of elevation in spherical coordinates. is the horizontal azimuth angle in spherical coordinates.

7. A 3D stereoscopic hyperdirectional antenna according to claim 6, characterized in that, In a multi-user receiving communication scenario, the array response vector of the transmitting end is the array response vector corresponding to multiple receiving users, which is equal to the sum of the array response vectors calculated independently for each single user.

8. An optimization method based on the antenna according to any one of claims 1-7, characterized in that, The method includes array structure optimization and radiation efficiency optimization; the array structure optimization includes finding the optimal radiating element spacing that best balances the radiation efficiency and directivity of the 3D stereoscopic hyperdirectional antenna through simulation; the radiation efficiency optimization specifically involves further improving the antenna radiation efficiency by iteratively optimizing and adjusting the impedance matching.

9. The optimization method according to claim 8, characterized in that, In the radiation efficiency optimization, the iterative optimization is as follows: First, the input impedance of different radiating elements in the 3D stereo hyperdirectional antenna is obtained through simulation. For each radiating element, the corresponding excitation end pure resistance input impedance is set to be conjugate matched with the measured radiating element impedance in amplitude. Then, the 3D stereo hyperdirectional antenna is excited to obtain a new input impedance and this process is repeated until the radiation efficiency of the radiating element array exceeds the preset threshold or the number of iterations reaches the preset maximum number of optimizations.

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