A tightly coupled ultra-wideband antenna element and antenna array

Abstract

This application belongs to the field of antenna technology, and discloses a tightly coupled ultra-wideband antenna element and an antenna array. The ultra-wideband antenna element includes a dielectric substrate and a plurality of microstrip patches. The plurality of microstrip patches are divided into two groups and are respectively laid flat on the upper surface and the lower surface of the dielectric substrate. Two adjacent microstrip patches on the upper surface form an excitation driving unit, and all the remaining microstrip patches among the plurality of microstrip patches except the excitation driving unit are used as parasitic units of the excitation driving unit. The microstrip patches on the lower surface are all arranged below the gaps between at least one group of adjacent microstrip patches on the upper surface. Impedance matching is satisfied between the excitation driving unit and the parasitic unit. The excitation driving unit is fed, and the parasitic unit is driven in a tightly coupled manner. The spacing between the excitation antenna and the parasitic antenna in this application is small, and it is easy to be placed on the top, around of a vehicle or on devices such as drones for realizing communication or data transmission, and has the characteristics of simple structure, low profile, easy to manufacture, multi-band operation, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of antennas, and particularly relates to a tightly coupled ultra-wideband antenna element and an antenna array. Background Art

[0002] Ultra-wideband technology directly modulates impulse pulses with very steep rise and fall times, enabling signals to have a bandwidth on the order of GHz. It solves major problems related to propagation that have plagued traditional wireless technologies for many years. It has advantages such as being insensitive to channel fading, having a low transmit signal power spectral density, low interceptability, low system complexity, and being able to provide a positioning accuracy of several centimeters. Ultra-wideband technology also has many advantages such as high transmission rate, strong anti-interference ability, extremely wide bandwidth, large system capacity, good confidentiality, being easy to miniaturize and convenient to carry, and low cost.

[0003] With the broadening of the mobile spectrum, there are more and more scenarios where communication devices need to be applied. Using multiple antennas to cover multiple frequency bands will inevitably cause problems of mutual coupling between devices, which will seriously affect the efficiency of antenna operation. At the same time, the size of the antenna must also be taken into consideration. In daily life, a large-sized and high-profile antenna is undoubtedly inconvenient and unaesthetic. Therefore, the actual application demand for stable antenna elements and antenna arrays with low profiles for ultra-wideband is very urgent.

[0004] For traditional microstrip patch broadband antennas, an antenna is placed on one side while a metal ground is usually placed on the other side to achieve the desired bandwidth, matching, and other corresponding indicators. Using the tightly coupled method can not only effectively reduce the profile of the antenna, but also achieve a higher degree of compactness and utilization rate of the substrate. The tightly coupled design is not limited by the floor. Its principle is to bring the feeding unit and parasitic unit of the antenna close to each other to form a capacitive coupling effect, thereby generating a broadband effect to achieve the purpose of broadening the bandwidth. The arrangement distance between each microstrip patch is very small and very close, making full use of the capacitive coupling enhancement effect. Tightly coupled antennas and their arrays, as a new type of ultra-wideband antennas, have advantages such as low profile, wide operating frequency band, and high space utilization rate. Summary of the Invention

[0005] Aiming at the technical problems pointed out in the background art, the technical problem to be solved by the present invention is: to propose a low-profile ultra-wideband antenna implemented based on tightly coupled technology.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] A tightly coupled ultra-wideband antenna unit includes a dielectric substrate and several microstrip patches. The several microstrip patches are divided into two groups and are respectively laid flat on the upper surface and the lower surface of the dielectric substrate; two adjacent microstrip patches on the upper surface form an excitation driving unit, and the remaining microstrip patches among the several microstrip patches, except for the excitation driving unit, are all used as parasitic units of the excitation driving unit. The microstrip patches on the lower surface are all arranged below the gaps between at least one group of adjacent microstrip patches on the upper surface; impedance matching is satisfied between the excitation driving unit and the parasitic units; the excitation driving unit is fed, and the parasitic units are driven in a tightly coupled manner to achieve effective radiation of electromagnetic waves and expand the working bandwidth.

[0008] In a tightly coupled ultra-wideband antenna unit of the present application, two adjacent microstrip patches on the upper surface form an excitation driving unit, and the remaining microstrip patches are used as coupled radiation parasitic units of the excitation driving unit. The excitation driving unit excites the surrounding and other microstrip patches on the lower surface. The microstrip patches on the lower surface serving as coupled radiation parasitics are placed below the middle seams of two segments of microstrip patches on the upper surface. When the low-profile tightly coupled ultra-wideband antenna unit of the present invention is in use, the excitation signal source is set at the gap between two adjacent microstrip patches forming the excitation driving unit. The excitation signal source excites the excitation driving unit, causing the microstrip patches forming the excitation driving unit to generate high-frequency resonance. The microstrip patches serving as parasitic units receive the electromagnetic waves generated by the high-frequency resonance of the microstrip patches of the excitation driving unit through coupled radiation; through the tightly coupled manner, the microstrip patches not directly fed generate surface currents because they receive the electromagnetic waves generated by the high-frequency resonance of the microstrip patches of the excitation driving unit.

[0009] A method characterized by current, voltage, and impedance is adopted to describe the influence between each coupled microstrip patch and the interaction relationship between microstrip patches. When the antenna unit is in use, a feeder is set on the excitation driving unit, and the excitation signal is input into the excitation driving unit through the feeder. The excitation driving unit with the feeder set can be regarded as the network port of the entire antenna unit, and an electromagnetic wave coupling network is formed between each radiation patch.

[0010] For the coupled influence between the microstrip patches for excitation driving and the parasitic microstrip patches in the tightly coupled ultra-wideband antenna unit, it can be equivalently understood as the mutual coupling influence between multiple ports. The voltage of the i-th port between the corresponding different microstrip patches is Then it is expressed as

[0011]

[0012] Among them represents the input impedance of the microstrip patch h i and represents the mutual impedance between the microstrip patch i and the microstrip patch j. represents the current of the i-th port between the corresponding different microstrip patches, represents the current of the j-th port between the corresponding different microstrip patches.

[0013] Based on the tightly coupled ultra-wideband antenna unit of the present invention, the coupling effect between microstrip patches is utilized to form continuous current distribution and electric field distribution. Without a ground plane for the antenna and with extremely small intervals between each microstrip patch and being very compact, the purpose of expanding the antenna bandwidth is achieved.

[0014] The S-parameters of the overall tightly coupled ultra-wideband antenna unit are described by the ratio of the output input voltage of the overall antenna normalized. For the radiated electromagnetic waves between the respective microstrip patches on the microstrip patch and the incident electromagnetic waves on the corresponding microstrip patch, after normalization, they can be expressed as:

[0015]

[0016] For the reflected electromagnetic waves of the corresponding microstrip patch on the microstrip patch, after normalization, they are expressed as:

[0017]

[0018] Therefore, the ratio of the output to the input voltage of the matching network of the tightly coupled ultra-wideband antenna at the port is expressed as:

[0019]

[0020] The overall S-parameter matrix of the matching network of the tightly coupled ultra-wideband antenna in the system is expressed as follows:

[0021]

[0022] In the formula, a 1 , a 2 , ……, a n are used to represent the incident waves of N ports, b 1 , b 2 , ……, b n are used to represent their reflected waves, and S ij represents that when using the incident wave a j to connect the corresponding device port j, all other ports except the device port j are terminated with matching loads. Therefore, as long as the magnitude of the reflected wave at port i is measured, the corresponding S-parameter can be measured. Based on the analysis of the formula of the matching network, for the tightly coupled ultra-wideband antenna array, in the scattering parameters, S ij . Characterizes the impedance matching characteristics of the microstrip patches of different tightly coupled ultra-wideband antenna arrays, and S ijCharacterize the coupling characteristics between different microstrip patches. Therefore, the coupling situation between microstrip patches is usually characterized by means of S-parameters. Wherein, the values of i and j range from 1 to n, and n is the total number of several microstrip patches.

[0023] For each microstrip patch of the tightly coupled antenna, its overall characteristics can be obtained through analysis, such as the impedance bandwidth, surface current distribution, radiation pattern, gain, polarization, etc. of the antenna. Since the overall characteristics of the antenna are not a simple linear superposition of the characteristics of each microstrip patch, the arrangement and spacing of the microstrip patches of the antenna are used to generate a completely comprehensive overall antenna radiation effect. In the present invention, the mutual coupling and interference phenomena between the microstrip patches of the tightly coupled ultra-wideband antenna are utilized to eliminate the mutual interference of electromagnetic waves between the microstrip patches, so as to achieve performance index effects that are difficult for ordinary antennas such as low profile and ultra-wideband to achieve.

[0024] The principle of eliminating the influence between antennas through multi-antenna mutual coupling is as follows: simultaneously adjust the shape, size and distance of each radiation patch to achieve different degrees of coupling between each patch. Realize inconsistent voltages, currents and peripheral field strengths on the antenna patches, so as to form patches with corresponding impedance characteristics and achieve coupling matching between the patches. In this way, the influence of the electromagnetic waves radiated by the antenna patches is formed into a favorable coupling effect to achieve effective radiation of the antenna.

[0025] Multiple tightly coupled ultra-wideband antenna elements are arranged in an array according to certain rules. The isolation degree refers to the mutual coupling that occurs between each antenna element due to surface waves or space waves when the antenna receives and transmits electromagnetic waves. When the distance between antenna elements is greater than half of the wavelength, the mutual coupling will be very weak and can be ignored; when it is less than half of the wavelength, the antenna elements will interfere with each other and affect the normal channel transmission. The isolation degree is one of the most commonly used methods, that is, the coupling coefficient. Analyze an N-element antenna array through the scattering matrix, as shown in the following formula:

[0026]

[0027] It is obtained that the scattering matrix of the N-element antenna array is:

[0028]

[0029] In the above formula, x 1 , x 2 , ……, x n are used to represent the incident waves of N ports, and y 1 , y 2 , ……, y n are used to represent its reflected waves, |Sp ij|$\mathrm{S}_{ij}$ is the coupling coefficient of the tightly coupled ultra-wideband antenna array. Generally, the isolation is with absolute value. The so-called isolation refers to the ratio of the radiation power generated by the signal source of other antenna ports to the original port to its own radiation power. If the value of the isolation is larger, it means that the coherence between each antenna port is lower. It is expressed by the formula:

[0030]

[0031] In the above formula, $\mathrm{S}_{ij}$ ij represents the $\mathrm{S}$ parameter of the coupling generated on port $i$ when port $j$ is excited, $v_i$ i represents the voltage value at port $i$, $v_j$ j represents the voltage value at port $j$.

[0032] Preferably, the microstrip patches laid on both sides of the dielectric substrate are evenly distributed on the circumference.

[0033] Preferably, the dielectric substrate is configured as a PCB board; the several microstrip patches are divided into two groups and printed on both side surfaces of the PCB board respectively. The PCB board as the dielectric substrate is beneficial to the preparation of this antenna unit by printing, and the preparation process is simple and easy to be prepared in batches.

[0034] Preferably, the shapes of the several microstrip patches include any one of fan-shaped ring, arc, square, circle, and triangle. Preferably it is fan-shaped ring. The antenna structure realized by this tight coupling method can effectively control the height of the antenna. Compared with the traditional antenna design method, the antenna thickness is greatly reduced.

[0035] The fan-shaped ring microstrip patch can be slit at different positions of the fan-shaped ring to control the size of the slit, realize the distance interval between different patches, and thus realize the coupling between different radiation patches. By adjusting the distance between the upper and lower groups of patches of the fan-shaped ring antenna, the coupling between the upper and lower groups of patches is realized. This structural fan-shaped ring structure method can realize the design of a circular structure antenna. The fan-shaped ring antenna designed by this tight coupling method has a small height and is convenient for installation.

[0036] The radiation unit can be an arc structure, a circle or a square. By placing the upper and lower layers of arc-shaped, circular or square metal radiation patches, the coupling between the upper and lower layers of metal patches is realized. At the same time, holes or slits are respectively made in the upper patch and the lower patch to realize the coupling at different positions. The metal patches at different positions above or below are separated by slits or holes, and the metal at different positions forms radiation to achieve the mutual coupling effect. Thus, a low-profile tightly coupled antenna is formed.

[0037] Preferably, the size of the microstrip patch, the distance between the parasitic microstrip patch and the driving microstrip patch for excitation are configured in an adjustable manner. The size of the microstrip patch includes width, angle, and length. By adjusting the distance between the parasitic microstrip patch and the driving microstrip patch, the size of the parasitic microstrip patch itself, and the interleaving angle between the parasitic microstrip patch and the excitation unit, it can operate in a wide frequency band. It can also achieve operation at multiple frequency points, that is, a multi-frequency antenna, by pulling the distance apart, adjusting its own size and angle, and even by adding stubs. In addition, by adjusting the distance between the parasitic microstrip patch and the driving unit to change the coupling amount, such as the farther the distance, the smaller the coupling amount, the contribution to the bandwidth and radiation pattern will be smaller.

[0038] Preferably, multiple excitation driving units composed of two adjacent microstrip patches are provided. Setting multiple driving units according to design requirements is beneficial to realizing multi-frequency mode radiation.

[0039] Preferably, stubs are provided on the microstrip patch used as a parasitic unit. By adding stubs to the microstrip patch, the effect of broadening the width of the low-frequency band can be achieved.

[0040] Beneficial technical effects

[0041] The solution of this application enables the entire antenna structure to operate in a relatively wide frequency band; the microstrip patch antenna has the characteristics of low cost, low profile, easy manufacturing, multi-band operation, etc. The interval between the excitation antenna and the parasitic antenna is small, and it is easy to be placed on the top, around the car, or on devices such as drones for communication or data transmission. By setting multiple excitation driving units composed of two adjacent microstrip patches, it is easy to realize the antenna from the dual-frequency radiation mode. Description of the drawings

[0042] Figure 1 It is a schematic diagram of a tightly coupled ultra-wideband antenna unit;

[0043] Figure 2 It is a top view of the tightly coupled ultra-wideband antenna;

[0044] Figure 3 It is a bottom view of the tightly coupled ultra-wideband antenna;

[0045] Figure 4 It is a schematic diagram of the parasitic patch being deformed and adding an L-shaped stub;

[0046] Figure 5 It is a schematic diagram of the upper surface of the three-layer tightly coupled ultra-wideband antenna unit;

[0047] Figure 6 It is a schematic diagram of the lower surface of the three-layer tightly coupled ultra-wideband antenna unit;

[0048] Figure 7 It is the impedance bandwidth diagram of the tightly coupled ultra-wideband antenna unit;

[0049] Figure 8 It is the impedance bandwidth diagram of the tightly coupled ultra-wideband millimeter-wave antenna element;

[0050] Figure 9 It is the schematic diagram of a 3×3 equally spaced antenna array;

[0051] Wherein: 1 is the first microstrip patch, 2 is the second microstrip patch, 3 is the third microstrip patch, 4 is the fourth microstrip patch, 5 is the fifth microstrip patch, 6 is the sixth microstrip patch, 7 is the seventh microstrip patch, 8 is the eighth microstrip patch, 9 is the ninth microstrip patch, 10 is the tenth microstrip patch, 11 is the eleventh microstrip patch, 12 is the twelfth microstrip patch, 13 is the dielectric substrate, 14 is the first additional microstrip patch, 15 is the second additional microstrip patch, 16 is the third additional microstrip patch, 17 is the additional dielectric substrate. Detailed implementation mode

[0052] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. Hereinafter, terms such as "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a number of" is two or more.

[0053] Embodiment 1

[0054] A low-profile tightly coupled ultra-wideband antenna element, as Figures 1 to 3 shown, the plurality of microstrip patches are configured as the first microstrip patch 1 to the twelfth microstrip patch 12 in a fan-shaped ring; wherein the first microstrip patch 1 to the seventh microstrip patch 7 are coplanar and evenly arranged on a circumference on the upper surface of the dielectric substrate 13; the first microstrip patch 1 and the second microstrip patch 2 are adjacent to each other and form an excitation driving unit; the third microstrip patch 3 and the fourth microstrip patch 4 are adjacent to each other and form an excitation driving unit; the eighth microstrip patch 8 to the twelfth microstrip patch 12 are coplanar and arranged on the lower surface of the dielectric substrate.

[0055] More specific scheme: The microstrip patch on the upper surface has a total of 7 segments, among which 4 segments are the excitation-driven patches and 3 segments are the parasitic microstrip patches. The inner diameter of the fan-shaped ring is 21 mm, the outer diameter is 31 mm, the width is 10 mm, and the central angle of the fan-shaped ring is 45 degrees. The first microstrip patch 1 and the second microstrip patch 2 form a driving unit, and the coaxial cable feeding method is selected for feeding. The third microstrip patch 3 and the fourth microstrip patch 4 also adopt the coaxial cable feeding method to form another pair of excitation-driven units. They are coplanar with the fifth microstrip patch 5, the sixth microstrip patch 6, and the seventh microstrip patch 7 and are placed on the upper surface of the dielectric substrate. The parasitic microstrip patches on the lower surface have a total of 5 segments. The inner diameter of the fan-shaped ring is 21 mm, the outer diameter is 31 mm, the width is 10 mm, and the central angle of the fan-shaped ring is 45 degrees. The five microstrip patches 8, 9, 10, 11, and 12 for coupling parasitics are all coplanar; the eighth microstrip patch 8 is placed directly below the gap between the second microstrip patch 2 and the fifth microstrip patch 5, the ninth microstrip patch 9 is placed directly below the gap between the third microstrip patch 3 and the fifth microstrip patch 5, the tenth microstrip patch 10 is placed directly below the gap between the first microstrip patch 1 and the sixth microstrip patch 6, the eleventh microstrip patch 11 is placed directly below the gap between the sixth microstrip patch 6 and the seventh microstrip patch 7, and the twelfth microstrip patch 12 is correspondingly placed directly below the gap between the fourth microstrip patch 4 and the seventh microstrip patch 7.

[0056] Example 2

[0057] A tightly coupled ultra-wideband antenna unit based on Example 1, as Figure 4 shown, L-shaped stubs are added to the sixth microstrip patch 6 and the ninth microstrip patch 9. The addition of the L-shaped stubs not only changes the current distribution on the microstrip patches but also changes the coupling path between the microstrip patches, broadening the low-frequency bandwidth of the entire antenna and forming three operating frequency bands to achieve a multi-band antenna.

[0058] Example 3

[0059] Based on Example 1, the microstrip patches used as the excitation unit and the parasitic unit are set to be multi-layered, and dielectric substrates are filled between the layers; the microstrip patches of each layer are distributed in a uniform or non-uniform manner; two adjacent units in any layer of the microstrip patches are used as an excitation unit, and the remaining microstrip patches are used as driving units to realize the radiation of electromagnetic waves. The microstrip patches are located on the upper surface of the uppermost dielectric substrate, the lower surface of the lowermost dielectric substrate, and between adjacent dielectric substrates respectively.

[0060] As Figure 5As shown, an additional dielectric substrate 17 is added to the lower surface of the antenna. The first additional microstrip patch 14, the second additional microstrip patch 15, and the third additional microstrip patch 16 are arranged in a flat manner at the bottom of the additional dielectric substrate. The first additional microstrip patch 14, the second additional microstrip patch 15, and the third additional microstrip patch 16 are respectively disposed directly below the gaps between at least one set of adjacent microstrip patches among the eighth microstrip patch 8 to the twelfth microstrip patch 12.

[0061] Figure 7 As shown in the impedance bandwidth diagram of the broadband antenna in this embodiment, the antenna bandwidth is defined as the frequency range where a certain electrical parameter of the antenna is outside the intolerable range. These electrical parameters can be the voltage standing wave ratio at the antenna input port, antenna gain, circular polarization axial ratio, far-field radiation beam width, etc. The antenna bandwidth also has an absolute bandwidth and a relative bandwidth, and the calculation formulas are respectively:

[0062] B = f h - f l

[0063] B r =(f h - f l ) / f 0 × 100%

[0064] Where f h , f l and f 0 are respectively the highest frequency, the lowest frequency, and the center frequency within the frequency band.

[0065] From Figure 7 it can be seen that by adjusting the angles of the microstrip patches 16, 17, and 18, a bandwidth of -6 dB can be maintained within the ultra-wideband range of 2 GHz - 13 GHz.

[0066] Embodiment 4

[0067] A 5G millimeter-wave antenna using a tightly coupled ultra-wideband antenna element. On the basis of Embodiment 1, the low-profile tightly coupled ultra-wideband antenna is scaled down proportionally. As Figure 8 shown in the impedance bandwidth diagram of the broadband antenna in this embodiment, it can be seen from the figure that the antenna in this embodiment is below -8.68 dB bandwidth within the ultra-wideband range of 27 GHz - 52 GHz, achieving full coverage of the FR2 frequency band of 5G.

[0068] Embodiment 5

[0069] A tightly coupled ultra-wideband antenna element array. On the basis of Embodiment 1, the low-profile tightly coupled ultra-wideband antenna elements of the present invention are combined into a stable ultra-wideband communication tightly coupled antenna array. As Figure 9As shown, nine antenna elements are used to form a 3×3 equally spaced antenna array in a coplanar form. It can also be expanded into other array forms according to the usage scenario, such as linear arrays, non-equally spaced arrays, etc., so that the antenna array can obtain higher gain. In this embodiment, the same unit array is adopted, but the actual array design is not limited to the same unit array form.

[0070] To simplify the complex coupling problem in the antenna, from the perspective of "circuit", the scattering parameters (Sp matrix) in microwave network theory can be used to analyze the antenna array. By giving the reflected wave and incident wave outside the reference plane, the external characteristics of the antenna system can be determined. For a 3×3 antenna array, the scattering matrix Sp can be expressed as

[0071]

[0072] In the formula, Sp ii is the reflection coefficient, where i is 1, 2, 3, indicating the voltage reflection situation at port i when port i is excited and other ports are load-matched; Sp ij is the transmission coefficient, where i is 1, 2, 3 and j is 1, 2, 3, indicating the voltage transmission situation from port j to port i when port j is excited and other ports are load-matched. When the Sp parameters satisfy specific relationships, they can be divided into the following several types of networks: reciprocal network (Sp ij = Sp ji ); symmetric network (Sp ii = Sp jj ) and lossless network (|Sp ii | 2 +|Sp jj | 2 = 1), etc. |Sp ii | and |Sp ij | respectively represent the return loss of port i and the isolation between port i and port j. The smaller the value of Sp ii , the greater the return loss of antenna port i and the better the impedance matching; the smaller the value of Sp ij , the higher the isolation between antenna port i and port j and the weaker the coupling degree.

[0073] The above is the preferred embodiment of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present application, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A tightly coupled ultra-wideband antenna element, comprising a dielectric substrate and a plurality of microstrip patches, Characterized in that: The plurality of microstrip patches are divided into two groups and are respectively laid flat on the upper surface and the lower surface of the dielectric substrate; two adjacent microstrip patches on the upper surface form an excitation driving unit, and all the remaining microstrip patches among the plurality of microstrip patches except the excitation driving unit are used as parasitic units of the excitation driving unit, and the microstrip patches on the lower surface are all arranged below the gaps between at least one group of adjacent microstrip patches on the upper surface; impedance matching is satisfied between the excitation driving unit and the parasitic unit; the excitation driving unit is fed, and the parasitic unit is driven in a tightly coupled manner to realize effective radiation of electromagnetic waves and expand the working bandwidth.

2. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: The microstrip patches laid flat on both sides of the dielectric substrate are evenly distributed on the circumference.

3. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: The shapes of the plurality of microstrip patches include any one of fan-shaped, arc-shaped, square, circular, and triangular.

4. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: The dielectric substrate is configured as a PCB board; the plurality of microstrip patches are divided into two groups and are respectively printed on both side surfaces of the PCB board.

5. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: The sizes of the plurality of microstrip patches, the thickness of the dielectric substrate, and the distances between the microstrip patches are all configured in an adjustable manner.

6. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: The microstrip patches used as the excitation unit and the parasitic unit are arranged in multiple layers, and dielectric substrates are filled between the layers; the microstrip patches in each layer are distributed in a uniform or non-uniform manner; two adjacent units among the microstrip patches on any one layer are used as an excitation unit, and the remaining microstrip patches are used as driving units to realize the radiation of electromagnetic waves.

7. The tightly coupled ultra-wideband antenna element according to claim 1 or 6, Characterized in that: The excitation driving units composed of two adjacent microstrip patches are provided in multiple numbers.

8. The tightly coupled ultra-wideband antenna element according to claim 1, Characterized in that: Stub branches are provided on the microstrip patches used as parasitic units.

9. The tightly coupled ultra-wideband antenna element according to claim 3, Characterized in that: The plurality of microstrip patches are configured as the first microstrip patch to the twelfth microstrip patch; among them, the first microstrip patch to the seventh microstrip patch are coplanar and are evenly distributed on a circumference on the upper surface of the dielectric substrate; the first microstrip patch is adjacent to the second microstrip patch, and two adjacent microstrip patches form an excitation driving unit; the third microstrip patch is adjacent to the fourth microstrip patch, and two adjacent microstrip patches form an excitation driving unit; the eighth microstrip patch to the twelfth microstrip patch are coplanar and are arranged on the lower surface of the dielectric substrate.

10. An antenna array, Characterized in that: It includes the tightly coupled ultra-wideband antenna element according to any one of claims 1-9.

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