A highly directional antenna array design method and system

Abstract

The present invention belongs to the field of communication technology, and discloses a method and system for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium. By designing an aluminum waveguide with a half-wavelength height and adjusting the operating frequency to be the cutoff frequency of the waveguide, the TE10 mode wave is fed into an ENZ waveguide. Furthermore, aluminum blocks are filled in the waveguide to form an EMNZ structure, and slits are made on the side walls of the waveguide to form a radiation cavity to construct an antenna array. This method optimizes the electric field distribution and impedance matching by precisely designing the aluminum block filling and waveguide slits, and simulates and verifies the antenna performance. Based on this method, a ten-element antenna array with equal spacing and unequal spacing, as well as a 7-element planar antenna array, are designed to achieve highly directional radiation, effectively improving system performance and stability.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a design method and system for a highly directional antenna array based on a metal bandgap structure EMNZ medium. Background Art

[0002] Strong directional antenna arrays generally have the characteristics of high gain, low side lobes, and narrow main lobe width, which can minimize the interference of the external environment and have important applications in many fields such as radar, satellite communications, and remote sensing. In the current existing technology, the feeding of antenna arrays is usually based on parallel feeding networks or series feeding networks, but the amplitude and phase required by each array element must be accurately configured through a power divider or phase shifter. The feeding structure is complex and the feeding network occupies a large space. Some antennas are also usually designed to feed antenna array elements using resonant cavity excitation in high-order waveguide mode, which can simplify the feeding network to a certain extent, but there are still certain defects, or there are too many parameters to consider in the design, the structure is complex, or it is necessary to calculate complex impedance matching to ensure effective radiation, or the indicators of strong directional antennas such as radiation efficiency and half-power beam width are low, which greatly limits the development of antenna technology. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a design method for a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0004] The present invention is achieved by a method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium, the method comprising:

[0005] S1: An aluminum waveguide with a height of half a wavelength and a total length of 5 is designed. The operating frequency is adjusted to the cutoff frequency of the waveguide so that it can be equivalent to an ENZ waveguide when the TE10 mode wave is fed into it.

[0006] S2: On the basis of forming ENZ by cutoff waveguide, aluminum blocks are filled in the waveguide to form EMNZ, and the size and shape of the filled aluminum blocks are reasonably designed. At the same time, slits are opened on the side wall of the waveguide to form a radiation cavity to realize the antenna array;

[0007] S3: Based on the previous cavity, the electric field distribution inside the waveguide after the slot is opened and the impedance matching formula with the external environment are derived, and simulation verification is carried out. The influence of the array element spacing and the number of array elements on the antenna performance is discussed, and based on this, an equidistant ten-element antenna array is designed;

[0008] S4: Based on the equidistant ten-element antenna array, a unequal-spacing ten-element antenna array was designed, and the antenna performance was further improved;

[0009] S5: A 7-element planar antenna array is designed with an equally spaced 10-element antenna array as the basic array element, which effectively forms a highly directional antenna beam.

[0010] Further including the following technical features:

[0011] In order to optimize the derivation of electric field distribution and impedance matching, the present invention proposes an adaptive electric field distribution optimization algorithm, which iteratively calculates the electric field distribution inside the waveguide and dynamically adjusts the geometric parameters of the waveguide, such as the size, shape and position of the slit, to achieve the uniformity of the electric field distribution and the best matching of the impedance. In each iteration, the algorithm uses electromagnetic simulation software to simulate and verify the electric field distribution and impedance matching of the adjusted waveguide until the preset optimization goal is reached, such as the uniformity of the electric field distribution reaches a preset threshold or the impedance matching error is lower than a preset value. Through this optimization algorithm, the energy radiation efficiency of the antenna can be significantly improved.

[0012] Further including the following technical features:

[0013] In order to further optimize the design of unequal spacing arrays, the present invention proposes a method for designing unequal spacing arrays based on an intelligent optimization algorithm. The method first sets the optimization goals of the array design, such as suppressing side lobes, improving gain and directivity, etc., and then uses intelligent optimization algorithms, such as genetic algorithms and particle swarm optimization algorithms, to search for array element spacing combinations that meet the optimization goals. During the search process, the algorithm simulates and verifies different array element spacing combinations through electromagnetic simulation software, evaluates their performance, and iterates and optimizes according to the optimization goals until the optimal array element spacing combination is found. Through this optimization method, the performance of unequal spacing arrays can be further improved, and more precise beam control and higher gain can be achieved.

[0014] Further, the S1 specifically includes: first, when the doping medium is not considered, for the working state of TE 10 The waveguide with a cutoff frequency of the mode can be equivalent to a plasma material in the microwave frequency range, and its effective relative dielectric constant ε eff It can be expressed by the Drude dispersion model:

[0015]

[0016] Here, ε r is the relative dielectric constant of the medium in the waveguide, f is the incident frequency, and f p is the cutoff frequency of the waveguide, and:

[0017]

[0018] Therefore, the effective relative dielectric constant ε eff can be calculated as:

[0019]

[0020] Therefore, when the waveguide height h is 0.5λ, it is filled with air ε r ≈1, the structure is equivalent to a cross-sectional area of ​​S0 with a relative magnetic permeability μ r0 A uniform ENZ medium, in which the magnetic field H0 is uniformly distributed; at this time, the cross-sectional area S1 is doped in the ENZ region, and the relative magnetic permeability is μ r1 The effective relative magnetic permeability μ of the entire structure is eff can be calculated as:

[0021]

[0022] Among them, H a is the magnetic field in the waveguide after the medium is doped, and H a =H0;H d is the magnetic field in the doped medium and can be expressed as

[0023] H d =H0ψ n (r) (5)

[0024] Here, ψ n (r) is the scalar Helmholtz solution, representing H d The magnetic field distribution in the doped medium, when the doped medium is PEC, ψ n (r) = 0, so equation (4) can be written as

[0025]

[0026] At this time, the medium filled in the waveguide cavity is air, μ r0 ≈1; this means that by simply adjusting the ratio of the cross-sectional area of ​​the doped PEC medium to the cross-sectional area of ​​the ENZ structure, μ eff It is expressed as the required size rather than through complex parameter calculation; therefore, when S1 is close enough to S0, an EMNZ medium with a metallic bandgap structure that can operate at high power can be obtained.

[0027] Furthermore, the working mechanism of the EMNZ antenna array is as follows:

[0028] The antenna array is fed by coaxial waveguide. type air gap, propagates to each array element for excitation; forms a The purpose of the air gap is to reduce the reflection of the incident electromagnetic wave and reduce the S11 of the antenna; The type gap forms an EMNZ electromagnetic tunnel. When the wave passes through the tunnel, there is an energy reflection coefficient R at both ends of the tunnel, which can be calculated as:

[0029]

[0030] Among them, l1 and l2 are the widths of the tunnel at a and b respectively, k0 is the wave number in free space, and A represents the area of ​​the tunnel. When a1 and a2 are equal, R=0, and the electromagnetic wave can pass through the tunnel without loss, realizing the EMNZ supercoupling effect, so that the wave can perfectly tunnel from the feeding end to the radiation end inside the waveguide cavity; the air gap at the other end allows the wave to be transmitted from the middle to both sides, exciting each radiation cavity; it has been mentioned before that the electromagnetic wave in the ENNZ medium remains dynamic in the time domain and appears as a static field in space, with uniform phase and amplitude distribution; that is, for the EMNZ medium, there is

[0031]

[0032] Therefore, there is a constant electric field amplitude E0 and magnetic field amplitude H0 in the medium, which will not change due to changes in the spatial state; but in fact, when the wave is excited to enter the EMNZ medium, although it has infinite phase velocity and wavelength at this time, it still follows the causal principle in the theory of relativity, and it takes a certain amount of time to build a steady-state spatial static field. During this period of time, the wave will still propagate along the air gap in the cavity. When it reaches the b end of the tunnel, the amplitude of the wave has not changed. After it propagates to both ends of the antenna, the amplitude will continue to decrease when radiating outward through the cavity. The phase will only fluctuate within a small range due to the infinite phase velocity of the EMNZ material, but it can still be approximately considered the same, thus eventually forming a spatial static field with the same phase and a cone-shaped amplitude distribution in the air gap at the b end of the tunnel;

[0033] Setting E i , H i Represents ±x i The electric field and magnetic field of the radiation cavity at (i = 1, 2, N), and the field inside the cavity is assumed to be uniform. Since the parameters of the cavity are the same, its input impedance E i / H i , remains unchanged, proving that the attenuation amplitude of the electric and magnetic fields in each cavity compared with the initial value is the same; according to previous studies,

[60] , the tangential electric field at the boundary of the closed cavity wrapped by PEC is 0, so the loop integral of the electric field along the metal boundary is 0; for the antenna, the effective electric field loop integral is only contributed by the electric field at the feeding waveguide port and the radiating cavity; set the electric field E0 and the magnetic field H0 to be the electric field and magnetic field at the port respectively, and apply Faraday's law of electromagnetic induction along the boundary of the air gap in the waveguide cavity, we can get:

[0034]

[0035] Among them, H x It represents the value of the magnetic field when the position changes in the air gap at the b end in the x-axis direction. eff , the area difference S0-S1-h0l and h0 are both small enough, then the right side of equation (10) can be ignored, resulting in

[0036]

[0037] This shows that the total electric field in the radiation cavity is only related to the initial field strength, the feeding waveguide and the cavity width, and has nothing to do with the length and width of the EMNZ medium in the xy direction, which provides an important reference for designing effective strong directional antennas. x To x (x1<l x <x2) and set E x is the electric field at x (x1<x<x2), and the electric field value at -x is also E x , then

[0038]

[0039] ω is the operating frequency of the antenna array, since μ eff ≈0 and Then E x can be calculated as Similarly, when 0<x<x1, Faraday's electromagnetic induction theorem can be used to obtain When x>x N When E x =0; Next, E when x1<x<x2 x Expand to x i <x<x i+1 When calculating, we can approximate the E x The piecewise function expression at x>0 is:

[0040]

[0041] Since the radiation cavity is symmetric about x = 0, equation (12) is also applicable when x < 0, and it shows that E x The value of will decrease with the increase of i, that is, the increase of the number of cavities passed by the wave during propagation. However, the value of the electric field component of the wave in the waveguide cavity is constant when it is between the two radiating cavities, revealing the stepped distribution of the electric field in the air gap at the b end of the tunnel in the designed antenna array, indicating that the antenna array can excite each array element with a conical amplitude distribution.

[0042] Furthermore, the impedance matching formula in S3 specifically includes:

[0043] First, when no groove is formed on the waveguide sidewall to form a radiation cavity, the input impedance Z of the closed EMNZ medium formed by the doped medium is in can be calculated as

[0044]

[0045] d0 is the width of the feed waveguide. As mentioned above, S0-S1≈0, ψ n (r) = 0, so the input impedance of the closed EMNZ system can be approximated to 0; then, a groove is made on the side wall of the EMNZ medium, and the existence of the cavity does not affect Z in Next, we analyze the influence of the impedance of the radiating cavity and the feeding waveguide on the antenna performance separately; for each radiating cavity, let its impedance be composed of real and imaginary parts, then Z i =E i / H i =R i +jX i , we can know that the Z of the cavity at different positions i The same; for a general electrically large-aperture antenna, the field within the aperture is continuous in space, similar to free space, so the ratio of the electric field to the magnetic field within the aperture can be approximately equal to the intrinsic impedance of free space η0 = 377Ω; however, for the designed EMNZ antenna array, there are multiple aperture lengths l i The metal conductor side walls between the cavities will cause the continuity of the field between them to be broken in space, and will generate an imaginary impedance X when radiating. i However, the infinite wavelength in the EMNZ medium makes the whole connected by the gap between the cavities be regarded as a compressed point with extremely small electrical size. This small electrode point can be equivalent to a free space that is actually large enough. There is still a continuous field everywhere in this space. Therefore, the real part of the internal impedance of the cavity can still be approximately equal to R e [E i / H i ]=η0; at the same time, each cavity can be regarded as a small rectangular waveguide, propagating electromagnetic waves from the gap to free space, then the total cavity real radiation resistance can be calculated as The unit is Ω; the imaginary impedance is X i The existence of will cause the resonant frequency to shift when the cavity spacing of the antenna array changes, and requires additional tuning inductance when considering the impedance matching between the antenna and the external environment; but the ENZ cutoff waveguide of the main part is at f p When working, reactance X will also be generatedENZ , can be calculated as:

[0046] X ENZ =ωμ0μ eff S0 (14)

[0047] μ0 is the magnetic permeability in vacuum, so μ can be controlled eff The value of makes the ENZ waveguide behave as an inductor in the circuit (μ eff <0) or capacitance (μ eff >0) element; due to the radiation cavity generated by the X i It is usually a negative value, which is usually an inductor in the circuit. The μ calculated by the designed EMNZ antenna array is eff > 0, by adjusting the designed antenna size, the reactance of the ENZ main cutoff waveguide in the antenna can be made to behave as a capacitive element in the circuit at the operating frequency, thereby eliminating the influence of the cavity inductance, that is, X ENZ +∑ i X i =0, at this time there is a waveguide cutoff frequency f p =2πω; usually, due to the μ of the designed antenna eff Close to 0, X ENZ and∑ i X i The values ​​of are small, so the reactance generated by the radiation cavity can generally be ignored; for the feeding waveguide filled with PTFE, the effective relative dielectric constant ε can be calculated according to formula (3): p ≈1, relative magnetic permeability μ p =μ r0 ≈1, which is approximately equivalent to free space. Since the EMNZ medium and free space have good wave impedance matching characteristics, there is no need to consider impedance matching between the feeding waveguide and the EMNZ antenna array separately, and lossless transmission of waves from the antenna excitation point to the internal cavity of the radiation waveguide can be achieved. Considering the transmission line of the feeding waveguide filled with PTFE, the transmission TE 10 The wave impedance of the wave, according to formula (2), at this time its cut-off frequency

[0048]

[0049] ε r1 =2.1, which is the relative dielectric constant of PTFE. Then the wave impedance Z of the feeding waveguide is p It can be calculated as

[0050]

[0051] μ0, ε0 magnetic permeability and dielectric constant in vacuum; Based on the above analysis, the antenna array system is equivalent to a transmission line model of a series circuit;

[0052] Therefore, when the entire EMNZ antenna array is impedance matched with the external environment, since the overall input resistance of the EMNZ medium and the imaginary reactance of the radiation cavity are close to 0 and can be ignored, only the total real resistance R of the radiation cavity needs to be considered. N And the wave impedance Z of the feeding waveguide p Determine the antenna load resistance Z L ; For R N With Z p , it can be easily matched with the external environment by using a λ / 4 impedance transformer, which greatly simplifies the complex impedance matching problem of array antennas in actual engineering applications. At this time, it can be observed and calculated that when the antenna is working, the reflection coefficient of the antenna array when looking from the feed power supply to the entire antenna array is:

[0053]

[0054] The above formula shows that the characteristic impedance Z0 of the transmission line can be adjusted so that Z0 = R N +Z p , effectively making the reflection coefficient Γ approach 0, so that the antenna array has extremely high radiation efficiency at the operating frequency, which can maximize the power absorbed from the matching source and effectively radiate the waves entering the free space, thereby obtaining a high-gain directivity pattern; at the same time, the metal material selected for the main structure and the doped medium enables the antenna array to operate at high power, improving the difficulty of EMNZ media previously realized by doping media in working at high power.

[0055] Furthermore, the total field pattern of the antenna array is only affected by the array factor pattern function S(θ). By studying S(θ), the radiation characteristics of the antenna array can be analyzed, including:

[0056] Consider 2N midpoints located at The radiating element of the EMNZ medium antenna array has a phase difference of 0, and the unit feeding amplitude of each element is obtained through the previous analysis of the electric field and magnetic field distribution inside the EMNZ medium antenna array.

[0057]

[0058] Where I0 represents the initial excitation amplitude of the antenna array when x=0, k is the attenuation coefficient when the excitation is transmitted between the array elements, and x i =(1 / 2+i)d; Obviously, k is a function of the spacing d between array elements and the number of array elements N, so

[0059] k=f(d,N) (19)

[0060] Then, the array factor pattern function can be derived as:

[0061]

[0062] Here, k0 represents the wave number in free space, and θ is the angle between the ray radiated by the array element and the x-axis direction; therefore, equation (20) shows that the array factor pattern function of the proposed EMNZ highly directional antenna array can be controlled by adjusting the array element spacing d and the number of array elements N, thereby optimizing the total field pattern of the antenna and designing an antenna array with good performance.

[0063] Another object of the present invention is to provide a strong directional antenna array design system based on a metal bandgap structure EMNZ medium for implementing the strong directional antenna array design method based on a metal bandgap structure EMNZ medium, the system comprising:

[0064] Aluminum waveguide design module, used to design an aluminum waveguide with a height of half a wavelength and a total length of 5 wavelengths, and adjust the operating frequency to the cutoff frequency of the waveguide so that it can be equivalent to an ENZ waveguide when the TE10 mode wave is fed;

[0065] The antenna array realization module is connected to the aluminum waveguide design module. On the basis of forming ENZ by cutting off the waveguide, aluminum blocks are filled in the waveguide to form EMNZ. The size and shape of the filled aluminum blocks are reasonably designed. At the same time, slits are opened on the side wall of the waveguide to form a radiation cavity to realize the antenna array.

[0066] The equidistant ten-element antenna array design module is connected to the antenna array realization module. Based on the previous cavity, the electric field distribution inside the waveguide after the slot is opened and the impedance matching formula with the external environment are derived, and simulation verification is carried out. The influence of the array element spacing and the number of array elements on the antenna performance is discussed, and based on this, an equidistant ten-element antenna array is designed;

[0067] The unequal spacing ten-element antenna array design module is connected to the equal spacing ten-element antenna array design module. Based on the equal spacing ten-element antenna array, an unequal spacing ten-element antenna array is designed, and the antenna performance is further improved;

[0068] The 7-element planar antenna array design module is connected to the unequal-spacing 10-element antenna array design module. A 7-element planar antenna array is designed with the equidistant 10-element antenna array as the basic array element, which effectively forms a strong directional antenna beam.

[0069] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0070] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0071] Another object of the present invention is to provide an information data processing terminal, which is used to implement the highly directional antenna array design system based on the metal bandgap structure EMNZ medium.

[0072] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0073] First, in view of the technical problems existing in the above-mentioned prior art, some creative technical effects are brought about after solving the problems. The specific description is as follows:

[0074] 1. Excellent directivity: The designed EMNZ medium antenna array has extremely strong directivity. By optimizing the array element spacing and the number of array elements, it is possible to increase the main lobe peak gain, narrow the half-power lobe width, and reduce the side lobe level. This makes the radiation of the antenna array in a specific direction more concentrated and effective, which is conducive to improving the reliability and stability of signal transmission.

[0075] 2. Excellent impedance matching: By designing the appropriate array element spacing and number of array elements, the antenna array can have good impedance matching with the external environment, minimize the reflected power, and improve energy utilization. This helps to reduce the loss during signal transmission and improve system performance.

[0076] 3. Simple process implementation: The antenna array has a relatively simple structural design, with a linear array element layout, and coupling between the elements is achieved through a simple feeding network and waveguide connection. This makes the antenna manufacturing and debugging process simpler and more cost-effective, making it suitable for large-scale production and application.

[0077] 4. Multiple design options: In addition to the equally spaced antenna array design, unequally spaced and planar antenna array designs are also proposed. These different design options can be flexibly selected according to specific application requirements and scenario characteristics, further meeting the needs of different users and having wider applicability and scalability.

[0078] The EMNZ medium antenna array of the present invention has broad application prospects in the fields of communications, radar, wireless sensor networks, aerospace, etc., can improve the performance and stability of the system, and promote technological progress and application innovation in related fields.

[0079] Second, in the field of communications: the EMNZ medium antenna array proposed in the present invention has good directivity and impedance matching characteristics, and is suitable for antenna design in communication systems. Its excellent main lobe peak gain and low side lobe level make it have broad application prospects in the fields of wireless communication base stations, satellite communications, mobile communications and wireless networks, and can improve the transmission efficiency and coverage of communication systems.

[0080] Radar application: The high directivity and superior performance of antenna arrays make them have important application prospects in radar systems. The EMNZ medium antenna array proposed in this invention can achieve higher main lobe gain and lower side lobe level, which helps to improve the target detection and tracking capabilities of radar systems and is suitable for military, aerospace, meteorological monitoring and other fields.

[0081] Wireless sensor network: In wireless sensor networks, the performance of antenna arrays is crucial to the reliability and coverage of signal transmission. The EMNZ medium antenna array designed in this invention has excellent directivity and impedance matching characteristics, and can be used to build various wireless sensor networks, including environmental monitoring, smart Internet of Things, smart transportation and other fields, to improve the coverage and data transmission quality of sensor networks.

[0082] Aerospace: In the aerospace field, the performance of the antenna system is of vital importance for the communication, navigation and monitoring of aircraft. The EMNZ medium antenna array proposed in this invention has excellent directivity and stability, and can be used for applications such as communication, radar monitoring, navigation and positioning of aerospace, thereby improving the communication quality and navigation accuracy of aerospace.

[0083] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0084] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0085] The expected benefits and commercial value of the EMNZ medium antenna array design method based on the metal bandgap structure of the present invention are mainly reflected in the following aspects:

[0086] 1. High-gain and strong directivity antenna: The antenna array designed with EMNZ medium has strong directivity and high gain, which can significantly improve the radiation efficiency and performance of the antenna and meet the needs of modern communication systems for high-performance antennas.

[0087] 2. Wide application: This technology can be widely used in wireless communications, radar, satellite communications and other fields to improve the signal transmission quality and reliability of these systems and enhance market competitiveness.

[0088] 3. High-power operation: The designed antenna array is capable of operating at high power, overcoming the limitation that traditional EMNZ medium antennas are difficult to operate stably at high power, and meeting high-power demand scenarios such as military and aerospace.

[0089] 4. Cost-effectiveness: Utilizing common materials such as aluminum waveguide and filled PTFE, the manufacturing cost is relatively low, which facilitates mass production and market promotion.

[0090] 5. Simplified design and debugging: Through effective impedance matching and array design, the antenna design and debugging process is simplified, the R&D cycle and cost are reduced, and the market competitiveness is improved.

[0091] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0092] The present invention fills the technical gaps at home and abroad in the following aspects:

[0093] 1. High-power application of EMNZ media: Traditional EMNZ media antennas have significant limitations in high-power applications, but the present invention achieves stable operation of EMNZ media under high-power conditions by optimizing design and material selection.

[0094] 2. Innovative antenna structure design: The present invention proposes a design method of filling aluminum blocks in the waveguide to form an EMNZ, and opening slits on the side walls of the waveguide to form a radiation cavity, which significantly improves the directivity and gain of the antenna.

[0095] 3. Combination of theory and simulation verification: The present invention not only derives the electric field distribution and impedance matching formulas theoretically, but also verifies the effectiveness of the design through simulation, providing a solid theoretical foundation and technical support for subsequent practical applications.

[0096] (3) Whether the technical solution of the present invention solves the technical problems that people have been eager to solve but have not been able to solve successfully:

[0097] The present invention solves the following problems that have always troubled technicians:

[0098] 1. Design of EMNZ antenna under high power: Traditional EMNZ medium antennas are difficult to work stably under high power, but the present invention successfully achieves stable operation under high power conditions by optimizing the design of waveguide and filling materials.

[0099] 2. High directivity and high gain: While achieving high directivity, high gain of the antenna is ensured, which is difficult to achieve in traditional designs. The present invention successfully achieves both through innovative structural design and material selection.

[0100] 3. Simplified impedance matching: Impedance matching between the antenna and the external environment is an important problem in antenna design. The present invention achieves good matching between the antenna and the external environment through reasonable design, and significantly improves the radiation efficiency of the antenna.

[0101] (4) Whether the technical solution of the present invention overcomes technical prejudice:

[0102] 1. Limitations of the application of EMNZ media: Traditionally, it is believed that EMNZ media are difficult to apply under high-power conditions. The present invention overcomes this prejudice through innovative design and experimental verification, demonstrating the great potential of EMNZ media in high-power antenna design.

[0103] 2. Dependence on complex structural design: It is generally believed that high-performance antennas require complex structural design and high-precision manufacturing processes. The present invention breaks this prejudice by achieving high-performance antennas through simplified structural design and the application of common materials.

[0104] 3. Traditional understanding of impedance matching: In traditional antenna design, impedance matching is a complex and critical issue. The present invention simplifies the impedance matching process and overcomes this technical difficulty through an innovative design method.

[0105] Fourth, the present invention proposes innovative solutions to several key technical problems existing in the prior art and has achieved significant technical progress.

[0106] First, the present invention solves the problem of low efficiency of existing technologies in specific application scenarios. Due to design limitations, traditional technologies are often unable to cope with complex tasks, resulting in low efficiency. However, the present invention introduces new design concepts and technical means to make the task processing process more efficient, greatly improve work efficiency, and meet the fast-paced needs of modern society.

[0107] Secondly, the present invention overcomes the shortcomings of the prior art in terms of stability and reliability. Due to limitations in materials, processes, and other aspects, traditional technologies often have problems of poor stability and low reliability, which affects the normal operation and service life of the equipment. The present invention significantly improves the stability and reliability of the equipment by optimizing material selection, improving manufacturing processes, and other methods, reduces the possibility of failure, and provides users with more stable and reliable products.

[0108] Thirdly, the present invention has made significant technological progress in energy conservation and emission reduction. Traditional technologies often generate a large amount of energy consumption and emissions during operation, causing serious pollution to the environment. However, the present invention effectively reduces energy consumption and emissions by introducing advanced energy-saving technologies and environmentally friendly materials, realizes a green and low-carbon production method, and makes positive contributions to protecting the environment and achieving sustainable development.

[0109] Finally, the present invention has significantly improved the level of intelligence and automation. With the continuous advancement of science and technology, intelligence and automation have become important development trends in modern industry. By integrating advanced sensors, controllers and algorithms, the present invention realizes intelligent control and automated operation of equipment, improves production efficiency and product quality, reduces labor costs and error rates, and provides new ideas and methods for the development of industrial automation and intelligence. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 It is a flow chart of a method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium provided by an embodiment of the present invention;

[0111] Figure 2 is a two-dimensional conceptual schematic diagram of an EMNZ antenna array provided by an embodiment of the present invention;

[0112] Figure 3 is an equivalent circuit diagram of the antenna array structure provided by an embodiment of the present invention;

[0113] Figure 4 Schematic diagram of the structure of the antenna array provided by an embodiment of the present invention: (a) 3D structure view (b) front view (c) two-dimensional xy plane cross-sectional view;

[0114] Figure 5 The embodiments of the present invention provide (a) the magnetic field distribution inside the antenna and in the near field region; (b) the reflection coefficient S11 of the two-dimensional EMNZ antenna array; and (c) the gain pattern of the two-dimensional EMNZ antenna array.

[0115] Figure 6 It is the field distribution of the equally spaced antenna array provided by the embodiment of the present invention: (a) contour map of the electric field distribution in the air gap of the equally spaced EMNZ antenna array (b) the electric field amplitude distribution in the radiation cavity (c) the electric field phase distribution in the radiation cavity;

[0116] Figure 7 : is a comparison of the reflection coefficient and radiation pattern of the unequal spacing antenna array and the equal spacing antenna array provided by the embodiment of the present invention: (a) The reflection coefficient S of the antenna array under the two array element spacing configurations 11 (b) E-plane radiation pattern of the antenna array under two element spacing configurations (c) Radiation efficiency of the antenna array under two element spacing configurations

[0117] Figure 8 The field distribution of the unequally spaced antenna array provided by the embodiment of the present invention is as follows: (a) contour map of the electric field distribution in the air gap of the unequally spaced EMNZ antenna array (b) the electric field amplitude distribution in the radiation cavity (c) the electric field phase distribution in the radiation cavity;

[0118] Fig. 9 Schematic diagram of the structure of the planar antenna array provided by the embodiment of the present invention and related simulation results: (a) front and side schematic diagram of the planar antenna array structure (b) reflection coefficient S 11 (c) E-plane radiation pattern (d) H-plane radiation pattern (e) Stereo far-field radiation pattern. DETAILED DESCRIPTION

[0119] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0120] The embodiment of the present invention provides a method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium, the method comprising:

[0121] S1: An aluminum waveguide with a height of half a wavelength and a total length of 5 wavelengths was designed. The operating frequency was adjusted to the cutoff frequency of the waveguide so that it could be equivalent to an ENZ waveguide when the TE10 mode wave was fed into it.

[0122] S2: On the basis of forming ENZ by cutoff waveguide, aluminum blocks are filled in the waveguide to form EMNZ, and the size and shape of the filled aluminum blocks are reasonably designed. At the same time, slits are opened on the side wall of the waveguide to form a radiation cavity to realize the antenna array;

[0123] S3: Based on the previous cavity, the electric field distribution inside the waveguide after the slot is opened and the impedance matching formula with the external environment are derived, and simulation verification is carried out. The influence of the array element spacing and the number of array elements on the antenna performance is discussed, and based on this, an equidistant ten-element antenna array is designed;

[0124] S4: Based on the equidistant ten-element antenna array, a unequal-spacing ten-element antenna array was designed, and the antenna performance was further improved;

[0125] S5: A 7-element planar antenna array is designed with an equally spaced 10-element antenna array as the basic array element, which effectively forms a highly directional antenna beam.

[0126] The following is a detailed description of the design method of a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0127] Working principle:

[0128] 1. Formation of ENZ waveguide (S1)

[0129] Cutoff waveguide: Design an aluminum waveguide with a height of half a wavelength and a length of 5 wavelengths. By adjusting the operating frequency to the cutoff frequency of the waveguide, the propagation of all modes above the cutoff frequency can be suppressed, allowing only the lowest-order TE10 mode to propagate in the waveguide.

[0130] ENZ equivalent: In the cutoff state, the propagation constant of the TE10 mode wave in the waveguide approaches zero. At this time, the effective dielectric constant of the waveguide also approaches zero, making the waveguide equivalent to ENZ (Epsilon-Near-Zero) medium. ENZ medium has special electromagnetic properties and can achieve functions such as beam compression and impedance matching.

[0131] 2. EMNZ structure and radiation cavity (S2)

[0132] EMNZ formation: Aluminum blocks are filled in the ENZ waveguide to form an EMNZ (Epsilon-and-Mu-Near-Zero) structure. The EMNZ structure has both near-zero dielectric constant and permeability, which can further enhance the beam compression effect and improve the radiation efficiency of the antenna.

[0133] Radiating cavity: Slots are made in the sidewalls of the waveguide to form radiating cavities. These slots act as the radiating elements of the antenna, coupling the electromagnetic energy in the waveguide into free space. By properly designing the size, shape, and position of the slots, the radiation pattern and gain of the antenna can be controlled.

[0134] 3. Electric field distribution and impedance matching (S3)

[0135] Derivation of electric field distribution: Based on the theoretical model of slotted waveguide, the mathematical expression of the electric field distribution inside the waveguide is derived. This helps to understand the propagation characteristics of electromagnetic waves in the waveguide and provides a theoretical basis for the design of antenna arrays.

[0136] Impedance matching formula: By analyzing the boundary conditions between the waveguide and free space, the impedance matching formula is derived. This enables the antenna to efficiently radiate energy into free space and reduce reflection losses.

[0137] Simulation verification: Use electromagnetic simulation software to simulate and verify the electric field distribution and impedance matching of the slotted waveguide. By comparing with the theoretical calculation results, verify the accuracy of the model and optimize the antenna design.

[0138] Influence of array parameters: Study the influence of array element spacing and number of array elements on antenna performance. Through simulation analysis, determine the optimal array element spacing and number of array elements to achieve high gain and narrow beam radiation characteristics.

[0139] Equidistant 10-element array: Based on the above analysis, an equidistant 10-element antenna array is designed. This array has high gain and narrow beam width, and is suitable for application scenarios that require directional radiation.

[0140] 4. Unequally spaced 10-element array (S4)

[0141] Optimization design: Based on the equidistant ten-element array, the element spacing is further optimized to form an unequal-spacing ten-element array. By adjusting the element spacing, the side lobes can be suppressed and the gain and directivity of the antenna can be improved.

[0142] 5. Seven-element planar array (S5)

[0143] Array element expansion: A seven-element planar antenna array is designed with an equally spaced ten-element array as the basic array element. By arranging multiple basic array elements into a planar array, the gain and directivity of the antenna can be further improved to form a narrower beam.

[0144] The design method of highly directional antenna array based on metal bandgap structure EMNZ medium achieves high gain and narrow beam radiation effect by cleverly utilizing the special electromagnetic characteristics of ENZ and EMNZ structures. This method has the advantages of flexible design and easy implementation, and has broad application prospects in wireless communication, radar detection and other fields.

[0145] Further, the S1 specifically includes: first, when the doping medium is not considered, for the working state of TE 10 The waveguide with a cutoff frequency of the mode can be equivalent to a plasma material in the microwave frequency range, and its effective relative dielectric constant ε eff It can be expressed by the Drude dispersion model:

[0146]

[0147] Here, ε r is the relative dielectric constant of the medium in the waveguide, f is the incident frequency, and f p is the cutoff frequency of the waveguide, and:

[0148]

[0149] Therefore, the effective relative dielectric constant ε eff can be calculated as:

[0150]

[0151] Therefore, when the waveguide height h is 0.5λ, it is filled with air ε r ≈1, the structure is equivalent to a cross-sectional area of ​​S0 with a relative magnetic permeability μ r0A uniform ENZ medium, in which the magnetic field H0 is uniformly distributed; at this time, the cross-sectional area S1 is doped in the ENZ region, and the relative magnetic permeability is μ r1 The effective relative magnetic permeability μ of the entire structure is eff can be calculated as:

[0152]

[0153] Among them, H a is the magnetic field in the waveguide after the medium is doped, and H a =H0;H d is the magnetic field in the doped medium and can be expressed as

[0154] H d =H0ψ n (r) (5)

[0155] Here, ψ n (r) is the scalar Helmholtz solution, representing H d The magnetic field distribution in the doped medium, when the doped medium is PEC, ψ n (r) = 0, so equation (4) can be written as

[0156]

[0157] At this time, the medium filled in the waveguide cavity is air, μ r0 ≈1; this means that by simply adjusting the ratio of the cross-sectional area of ​​the doped PEC medium to the cross-sectional area of ​​the ENZ structure, μ eff It is expressed as the required size rather than through complex parameter calculation; therefore, when S1 is close enough to S0, an EMNZ medium with a metallic bandgap structure that can operate at high power can be obtained.

[0158] Furthermore, the working mechanism of the EMNZ antenna array is as follows:

[0159] The antenna array is fed by coaxial waveguide. type air gap, propagates to each array element for excitation; forms a The purpose of the air gap is to reduce the reflection of the incident electromagnetic wave and reduce the S11 of the antenna; The type gap forms an EMNZ electromagnetic tunnel. When the wave passes through the tunnel, there is an energy reflection coefficient R at both ends of the tunnel, which can be calculated as:

[0160]

[0161] Among them, l1 and l2 are the widths of the tunnel at a and b respectively, k0 is the wave number in free space, and A represents the area of ​​the tunnel. When a1 and a2 are equal, R=0, and the electromagnetic wave can pass through the tunnel without loss, realizing the EMNZ supercoupling effect, so that the wave can perfectly tunnel from the feeding end to the radiation end inside the waveguide cavity; the air gap at the other end allows the wave to be transmitted from the middle to both sides, exciting each radiation cavity; it has been mentioned before that the electromagnetic wave in the ENNZ medium remains dynamic in the time domain and appears as a static field in space, with uniform phase and amplitude distribution; that is, for the EMNZ medium, there is

[0162]

[0163] Therefore, there is a constant electric field amplitude E0 and magnetic field amplitude H0 in the medium, which will not change due to changes in the spatial state; but in fact, when the wave is excited to enter the EMNZ medium, although it has infinite phase velocity and wavelength at this time, it still follows the causal principle in the theory of relativity, and it takes a certain amount of time to build a steady-state spatial static field. During this period of time, the wave will still propagate along the air gap in the cavity. When it reaches the b end of the tunnel, the amplitude of the wave has not changed. After it propagates to both ends of the antenna, the amplitude will continue to decrease when radiating outward through the cavity. The phase will only fluctuate within a small range due to the infinite phase velocity of the EMNZ material, but it can still be approximately considered the same, thus eventually forming a spatial static field with the same phase and a cone-shaped amplitude distribution in the air gap at the b end of the tunnel;

[0164] Setting E i , H i Represents ±x i The electric field and magnetic field of the radiation cavity at (i = 1, 2, N), and the field inside the cavity is assumed to be uniform. Since the parameters of the cavity are the same, its input impedance E i / H i , remains unchanged, proving that the attenuation amplitude of the electric and magnetic fields in each cavity compared with the initial value is the same; according to previous studies,

[60] , the tangential electric field at the boundary of the closed cavity wrapped by PEC is 0, so the loop integral of the electric field along the metal boundary is 0; for the antenna, the effective electric field loop integral is only contributed by the electric field at the feeding waveguide port and the radiating cavity; set the electric field E0 and the magnetic field H0 to be the electric field and magnetic field at the port respectively, and apply Faraday's law of electromagnetic induction along the boundary of the air gap in the waveguide cavity, we can get:

[0165]

[0166] Among them, H x It represents the value of the magnetic field when the position changes in the air gap at the b end in the x-axis direction. eff, the area difference S0-S1-h0l and h0 are both small enough, then the right side of equation (10) can be ignored, resulting in

[0167]

[0168] This shows that the total electric field in the radiation cavity is only related to the initial field strength, the feeding waveguide and the cavity width, and has nothing to do with the length and width of the EMNZ medium in the xy direction, which provides an important reference for designing effective strong directional antennas. x To x (x1<l x <x2) and set E x is the electric field at x (x1<x<x2), and the electric field value at -x is also E x , then

[0169]

[0170] ω is the operating frequency of the antenna array, since μ eff ≈0 and Then E x can be calculated as Similarly, when 0<x<x1, Faraday's electromagnetic induction theorem can be used to obtain When x>x N When E x =0; Next, E when x1<x<x2 x Expand to x i <x<x i+1 When calculating, we can approximate the E x The piecewise function expression at x>0 is:

[0171]

[0172] Since the radiation cavity is symmetric about x = 0, equation (12) is also applicable when x < 0, and it shows that E x The value of will decrease with the increase of i, that is, the increase of the number of cavities passed by the wave during propagation. However, the value of the electric field component of the wave in the waveguide cavity is constant when it is between the two radiating cavities, revealing the stepped distribution of the electric field in the air gap at the b end of the tunnel in the designed antenna array, indicating that the antenna array can excite each array element with a conical amplitude distribution.

[0173] Furthermore, the impedance matching formula in S3 specifically includes:

[0174] First, when no groove is formed on the waveguide sidewall to form a radiation cavity, the input impedance Z of the closed EMNZ medium formed by the doped medium isin can be calculated as

[0175]

[0176] d0 is the width of the feed waveguide. As mentioned above, S0-S1≈0, ψ n (r) = 0, so the input impedance of the closed EMNZ system can be approximated to 0; then, a groove is made on the side wall of the EMNZ medium, and the existence of the cavity does not affect Z in Next, we analyze the influence of the impedance of the radiating cavity and the feeding waveguide on the antenna performance separately; for each radiating cavity, let its impedance be composed of real and imaginary parts, then Z i =E i / H i =R i +jX i , we can know that the Z of the cavity at different positions i The same; for a general electrically large-aperture antenna, the field within the aperture is continuous in space, similar to free space, so the ratio of the electric field to the magnetic field within the aperture can be approximately equal to the intrinsic impedance of free space η0 = 377Ω; however, for the designed EMNZ antenna array, there are multiple aperture lengths l i The metal conductor side walls between the cavities will cause the continuity of the field between them to be broken in space, and will generate an imaginary impedance X when radiating. i However, the infinite wavelength in the EMNZ medium makes the whole connected by the gap between the cavities be regarded as a compressed point with extremely small electrical size. This small electrode point can be equivalent to a free space that is actually large enough. There is still a continuous field everywhere in this space. Therefore, the real part of the internal impedance of the cavity can still be approximately equal to R e [E i / H i ]=η0; at the same time, each cavity can be regarded as a small rectangular waveguide, propagating electromagnetic waves from the gap to free space, then the total cavity real radiation resistance can be calculated as The unit is Ω; the imaginary impedance is X i The existence of will cause the resonant frequency to shift when the cavity spacing of the antenna array changes, and requires additional tuning inductance when considering the impedance matching between the antenna and the external environment; but the ENZ cutoff waveguide of the main part is at f p When working, reactance X will also be generated ENZ , can be calculated as:

[0177] X ENZ =ωμ0μ eff S0 (14)

[0178] μ0 is the magnetic permeability in vacuum, so μ can be controlled eff The value of makes the ENZ waveguide behave as an inductor in the circuit (μ eff <0) or capacitance (μ eff >0) element; due to the radiation cavity generated by the X i It is usually a negative value, which is usually an inductor in the circuit. The μ calculated by the designed EMNZ antenna array is eff > 0, by adjusting the designed antenna size, the reactance of the ENZ main cutoff waveguide in the antenna can be made to behave as a capacitive element in the circuit at the operating frequency, thereby eliminating the influence of the cavity inductance, that is, X ENZ +∑ i X i =0, at this time there is a waveguide cutoff frequency f p =2πω; usually, due to the μ of the designed antenna eff Close to 0, X ENZ and∑ i X i The values ​​of are small, so the reactance generated by the radiation cavity can generally be ignored; for the feeding waveguide filled with PTFE, the effective relative dielectric constant ε can be calculated according to formula (3): p ≈1, relative magnetic permeability μ p =μ r0 ≈1, which is approximately equivalent to free space. Since the EMNZ medium and free space have good wave impedance matching characteristics, there is no need to consider impedance matching between the feeding waveguide and the EMNZ antenna array separately, and lossless transmission of waves from the antenna excitation point to the internal cavity of the radiation waveguide can be achieved. Considering the transmission line of the feeding waveguide filled with PTFE, the transmission TE 10 The wave impedance of the wave, according to formula (2), at this time its cut-off frequency

[0179]

[0180] ε r1 =2.1, which is the relative dielectric constant of PTFE. Then the wave impedance Z of the feeding waveguide is p It can be calculated as

[0181]

[0182] μ0, ε0 magnetic permeability and dielectric constant in vacuum; Based on the above analysis, the antenna array system is equivalent to a transmission line model of a series circuit;

[0183] Therefore, when the entire EMNZ antenna array is impedance matched with the external environment, since the overall input resistance of the EMNZ medium and the imaginary reactance of the radiation cavity are close to 0 and can be ignored, only the total real resistance R of the radiation cavity needs to be considered. NAnd the wave impedance Z of the feeding waveguide p Determine the antenna load resistance Z L ; For R N With Z p , it can be easily matched with the external environment by using a λ / 4 impedance transformer, which greatly simplifies the complex impedance matching problem of array antennas in actual engineering applications. At this time, it can be observed and calculated that when the antenna is working, the reflection coefficient of the antenna array when looking from the feed power supply to the entire antenna array is:

[0184]

[0185] The above formula shows that the characteristic impedance Z0 of the transmission line can be adjusted so that Z0 = R N +Z p , effectively making the reflection coefficient Γ approach 0, so that the antenna array has extremely high radiation efficiency at the operating frequency, which can maximize the power absorbed from the matching source and effectively radiate the waves entering the free space, thereby obtaining a high-gain directivity pattern; at the same time, the metal material selected for the main structure and the doped medium enables the antenna array to operate at high power, improving the difficulty of EMNZ media previously realized by doping media in working at high power.

[0186] Furthermore, the total field pattern of the antenna array is only affected by the array factor pattern function S(θ). By studying S(θ), the radiation characteristics of the antenna array can be analyzed, including:

[0187] Consider 2N midpoints located at The radiating element of the EMNZ medium antenna array has a phase difference of 0, and the unit feeding amplitude of each element is obtained through the previous analysis of the electric field and magnetic field distribution inside the EMNZ medium antenna array.

[0188]

[0189] Where I0 represents the initial excitation amplitude of the antenna array when x=0, k is the attenuation coefficient when the excitation is transmitted between the array elements, and x i =(1 / 2+i)d; Obviously, k is a function of the spacing d between array elements and the number of array elements N, so

[0190] k=f(d,N) (19)

[0191] Then, the array factor pattern function can be derived as:

[0192]

[0193] Here, k0 represents the wave number in free space, and θ is the angle between the ray radiated by the array element and the x-axis direction; therefore, equation (20) shows that the array factor pattern function of the proposed EMNZ highly directional antenna array can be controlled by adjusting the array element spacing d and the number of array elements N, thereby optimizing the total field pattern of the antenna and designing an antenna array with good performance.

[0194] The embodiment of the present invention provides a highly directional antenna array design system based on a metal bandgap structure EMNZ medium for implementing the highly directional antenna array design method based on a metal bandgap structure EMNZ medium, the system comprising:

[0195] Aluminum waveguide design module, used to design an aluminum waveguide with a height of half wavelength and a total length of 5, and adjust the operating frequency to the cutoff frequency of the waveguide so that it can be equivalent to an ENZ waveguide when the TE10 mode wave is fed;

[0196] The antenna array realization module is connected to the aluminum waveguide design module. On the basis of forming ENZ by cutting off the waveguide, aluminum blocks are filled in the waveguide to form EMNZ. The size and shape of the filled aluminum blocks are reasonably designed. At the same time, slits are opened on the side wall of the waveguide to form a radiation cavity to realize the antenna array.

[0197] The equidistant ten-element antenna array design module is connected to the antenna array realization module. Based on the previous cavity, the electric field distribution inside the waveguide after the slot is opened and the impedance matching formula with the external environment are derived, and simulation verification is carried out. The influence of the array element spacing and the number of array elements on the antenna performance is discussed, and based on this, an equidistant ten-element antenna array is designed;

[0198] The unequal spacing ten-element antenna array design module is connected to the equal spacing ten-element antenna array design module. Based on the equal spacing ten-element antenna array, an unequal spacing ten-element antenna array is designed, and the antenna performance is further improved;

[0199] The 7-element planar antenna array design module is connected to the unequal-spacing 10-element antenna array design module. A 7-element planar antenna array is designed with the equidistant 10-element antenna array as the basic array element, which effectively forms a strong directional antenna beam.

[0200] An embodiment of the invention provides a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0201] An embodiment of the present invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium.

[0202] An embodiment of the present invention provides an information data processing terminal, which is used to implement the highly directional antenna array design system based on the metal bandgap structure EMNZ medium.

[0203] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0204] 3. Evidence of the effects of the embodiments. The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with the data, charts, etc. of the test process.

[0205] The method provided in the embodiment of the present invention uses full-wave electromagnetic simulation software to simulate the antenna array model proposed above, and the following experimental results are obtained:

[0206] 1. Equally spaced ten-element antenna array

[0207] The reflection coefficient S11 of the antenna array under the equal spacing configuration is as follows: Figure 7 (a) shows the E-plane radiation pattern of the antenna array under the equal spacing configuration. Figure 7 As shown in (a), the radiation efficiency of the antenna array under the equal spacing configuration is Figure 7 (a) as shown; Figure 6 As shown, Figure 6 (b) is the electric field amplitude distribution in the radiation cavity, Figure 6 (c) is the electric field phase distribution in the radiation cavity.

[0208] The equidistant ten-element antenna array designed by the present invention is modeled and run in professional electromagnetic simulation software, and the reflection coefficient S11 is measured to be -20.47dB at the operating frequency, the main lobe peak gain is 12.9dBi, the half-power lobe width is 18.6°, and the side lobe level is -21.1dB, which has strong directivity and good radiation efficiency. At the same time, the electric field amplitude of the array element is conical and the phase is approximately the same, which verifies the theoretical correctness of the proposed antenna array design method.

[0209] 2. Unequally spaced ten-element antenna array

[0210] The reflection coefficient S11 of the antenna array under unequal spacing configuration is as follows: Figure 7 As shown in (a), the E-plane radiation pattern of the antenna array under unequal spacing configuration is as follows Figure 7 As shown in (a), the radiation efficiency of the antenna array under unequal spacing configuration is Figure 7 (a) as shown; Figure 8 As shown, Figure 8 (b) is the electric field amplitude distribution in the radiation cavity, Figure 8 (c) is the electric field phase distribution in the radiation cavity.

[0211] The unequally spaced ten-element antenna array designed by the present invention is modeled and run in professional electromagnetic simulation software, and the reflection coefficient S11 is measured to be -25.64dB at the operating frequency, the main lobe peak gain is 14.0dBi, the half-power lobe width is 15.0°, and the side lobe level is -21.4dB, which has extremely strong directivity and radiation efficiency. At the same time, the electric field amplitude of the array element is conical and the phase is approximately the same, which verifies the theoretical correctness of the proposed antenna array design method.

[0212] 3. 7-element planar antenna array

[0213] like Fig. 9 As shown, the structural schematic diagram of the planar antenna array provided by the embodiment of the present invention and the related simulation results: (a) the front and side schematic diagrams of the planar antenna array structure, (b) the reflection coefficient S 11 , (c) E-plane radiation pattern, (d) H-plane radiation pattern, (e) stereo far-field radiation pattern.

[0214] The 7-element planar antenna array designed in the present invention is modeled and run in professional electromagnetic simulation software, and the reflection coefficient S11 is measured to be -31.81dB at the operating frequency, the main lobe peak gain is 21.3dBi, the half-power lobe width is 17.2° and 12.4° on the E plane and the H plane and the side lobe level is -25.5dB and -24.8dB respectively. It has extremely strong directivity and radiation efficiency, as well as a simplified feeding structure.

[0215] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium, characterized in that: The method includes: S1, forming an ENZ waveguide: using a metal waveguide to adjust the operating frequency to the cutoff frequency of the waveguide to suppress the propagation of modes higher than the cutoff frequency, allowing only the lowest-order TE10 mode to propagate in the waveguide, so that the effective dielectric constant in the waveguide approaches zero in the cutoff state, forming an ENZ waveguide; S2, constructing the EMNZ structure and radiation cavity: filling metal blocks in the ENZ waveguide to form an EMNZ structure with both near-zero dielectric constant and permeability, so as to further enhance the beam compression effect and improve the radiation efficiency of the antenna; opening slits in the side wall of the waveguide to form a radiation cavity, which serves as the radiation unit of the antenna and couples the electromagnetic energy in the waveguide into the free space; S3, Derivation of electric field distribution and impedance matching: Based on the theoretical model of slotted waveguide, the mathematical expression of the electric field distribution inside the waveguide is derived, and the boundary conditions between the waveguide and free space are analyzed to derive the impedance matching formula to achieve efficient energy radiation of the antenna; the electric field distribution and impedance matching are simulated and verified by electromagnetic simulation software, and the influence of array element spacing and number of array elements on antenna performance is studied to optimize the antenna design; S4, unequal spacing array design: Based on the equal spacing antenna array, the array element spacing is optimized to form an unequal spacing array to suppress side lobes and improve the gain and directivity of the antenna; S5, planar array expansion: using the optimized unequally spaced antenna array as the basic array element, a planar antenna array is designed. By arranging multiple basic array elements to form a planar array, the gain and directivity of the antenna are improved to form a narrower beam. Forming an ENZ waveguide: designing a metal waveguide with a height of half a wavelength and a length of at least 5 wavelengths, wherein the effective relative dielectric constant of the ENZ waveguide can be represented by the Drude dispersion model and is realized by filling with air or doped media; The antenna array is fed by a coaxial rotary feeding waveguide, and the wave propagates to each array element through the "H"-shaped air gap for excitation; a "│"-shaped air gap is formed at one end of the antenna feeding network; the "I"-shaped gap in the middle forms an EMNZ electromagnetic tunnel, and the wave can tunnel from the feeding end to the radiation end inside the waveguide cavity; the air gap at the other end allows the wave to transmit from the middle to both sides, exciting each radiation cavity.

2. The method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium according to claim 1, characterized in that: The formation of the ENZ waveguide in S1 is specifically as follows: by adjusting the waveguide height, internal filling medium and operating frequency, the waveguide is made equivalent to a plasma material in the microwave frequency range, and its effective relative dielectric constant approaches zero, thereby forming an ENZ waveguide; and metal medium is doped in the ENZ region to further form an EMNZ structure.

3. The method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium according to claim 1, characterized in that: The impedance matching formula in S3 is specifically as follows: by calculating the input impedance of the closed EMNZ medium and analyzing the influence of the impedance of the radiation cavity and the feeding waveguide on the antenna performance, the reactance of the ENZ waveguide is adjusted to eliminate the inductance influence of the cavity, and the impedance matching between the antenna and the feeding waveguide is achieved, thereby improving the radiation efficiency of the antenna.

4. The method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium according to claim 1, characterized in that: The total field pattern of the antenna array is optimized by regulating the array element spacing and the number of array elements. Specifically, the array factor pattern function is regulated by adjusting the array element spacing d and the number of array elements N, thereby optimizing the total field pattern of the antenna and designing an antenna array with good performance.

5. A system for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium, which implements the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium as claimed in any one of claims 1 to 4, characterized in that: The system includes: Aluminum waveguide design module, used to design an aluminum waveguide with a height of half a wavelength and a total length of 5 wavelengths, and adjust the operating frequency to the cutoff frequency of the waveguide so that it can be equivalent to an ENZ waveguide when the TE10 mode wave is fed; The antenna array realization module is connected to the aluminum waveguide design module. On the basis of forming ENZ by cutting off the waveguide, aluminum blocks are filled in the waveguide to form EMNZ. The size and shape of the filled aluminum blocks are reasonably designed. At the same time, slits are opened on the side wall of the waveguide to form a radiation cavity to realize the antenna array. The equidistant ten-element antenna array design module is connected to the antenna array realization module. Based on the previous cavity, the electric field distribution inside the waveguide after the slot is opened and the impedance matching formula with the external environment are derived, and simulation verification is carried out. The influence of the array element spacing and the number of array elements on the antenna performance is discussed, and based on this, an equidistant ten-element antenna array is designed; The unequal spacing ten-element antenna array design module is connected to the equal spacing ten-element antenna array design module. Based on the equal spacing ten-element antenna array, an unequal spacing ten-element antenna array is designed, and the antenna performance is further improved; The 7-element planar antenna array design module is connected to the unequal-spacing 10-element antenna array design module. A 7-element planar antenna array is designed with the equidistant 10-element antenna array as the basic array element, which effectively forms a strong directional antenna beam.

6. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium as described in any one of claims 1-4.

7. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the method for designing a highly directional antenna array based on a metal bandgap structure EMNZ medium as described in any one of claims 1 to 4.

8. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the highly directional antenna array design system based on the metal bandgap structure EMNZ medium as described in claim 5.

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