Tightly coupled antenna array and method thereof

Abstract

A tightly coupled antenna array includes a plurality of tightly coupled antenna oscillators for transmitting or receiving electromagnetic waves. The plurality of antenna oscillators comprise a plurality of active antenna oscillators excited by a plurality of excitation sources and a plurality of passive antenna oscillators. And each active antenna oscillator is used for being excited by a corresponding excitation source in the plurality of excitation sources. And each passive antenna oscillator is terminated by a limited passive impedance. Each antenna oscillator of the array is adjacent to a plurality of other antenna oscillators of the array, and the distance between each antenna oscillator of the plurality of other antenna oscillators does not exceed half of the wavelength of the electromagnetic wave.

Description

Technical Field

[0001] The present invention relates to the fields of wireless communications and radar systems, and in particular to tightly coupled antenna arrays. Background Art

[0002] The rapid development of mobile network technology has led to the need for multi-band or ultra-wideband phased array antennas that can cover all required frequency ranges. In order to provide greater capacity, the 5G frequency band has been extended to millimeter wave frequencies above 20GHz, up to 71GHz. In addition, due to the relatively high transmission loss at these frequencies, both base stations and mobile terminals may require ultra-wideband phased array antennas with fairly high directivity and adaptive beam scanning capabilities.

[0003] The applications of UWB antennas are not limited to broadband 5G communications technology. For example, another rapidly growing application area for such antenna arrays is automotive radar. For any multi-function antenna system, low-profile UWB antenna arrays with wide scan capability and high polarization purity are required. Integrating multiple antennas into a single UWB or multi-band radiating aperture that meets all requirements is challenging, but can make antenna equipment smaller and less expensive.

[0004] Tightly-coupled arrays (TCAs) are typically planar, ultra-wideband antenna arrays that are ideal for broadband applications where the available space for antennas is limited but the required gain is not too high. Unlike ordinary antenna arrays that are isolated with half-wavelength spacing, TCA elements are closely spaced or tightly coupled. The strong capacitive mutual coupling between adjacent elements makes TCAs ideal for extremely wide voltage standing wave ratio bandwidths, while their low profile is sufficient for use in mobile devices, etc. In addition, TCAs can steer beams over a wide scan range with low cross-polarization levels because the basic unit size is less than half a wavelength at the array's highest operating frequency.

[0005] The most challenging and costly part of designing and manufacturing any phased array antenna, including TCAs, is the design of the feed network and the integration of the active and passive circuit components required to excite each individual element. These tasks become more challenging and costly in the case of TCAs because more elements must be accommodated within the same aperture area compared to traditional narrowband phased array antennas. Summary of the invention

[0006] According to one aspect of the present invention, there is provided a tightly coupled antenna array, comprising: a plurality of tightly coupled antenna elements for transmitting or receiving electromagnetic waves, the plurality of antenna elements comprising: a plurality of active antenna elements, each active antenna element being excited by an excitation source; a plurality of passive antenna elements, each passive antenna element being terminated by a finite passive impedance; each antenna element of the array being adjacent to a plurality of other antenna elements of the array, and being spaced apart from each of the plurality of other antenna elements by no more than half the wavelength of the electromagnetic wave.

[0007] In some embodiments, the excitation source comprises a transmitter, a receiver, or a transceiver.

[0008] In some embodiments, the antenna elements of the array are used to send or receive electromagnetic waves of different wavelengths, and among the different wavelengths, the spacing does not exceed half of the minimum wavelength of the electromagnetic waves.

[0009] In some embodiments, the antenna elements of the array comprise patch antennas.

[0010] In some embodiments, the antenna elements of the array comprise linear dipole antennas.

[0011] In some embodiments, the antenna elements of the array include bow-tie antennas.

[0012] In some embodiments, the bow-tie antenna includes: a first conductive layer having one or more slots formed in the first conductive layer; and a second parasitic conductive layer having one or more slots formed in the second parasitic conductive layer and separated from the first conductive layer by a medium.

[0013] In some embodiments, the antenna elements of the array are used to send or receive electromagnetic waves with a frequency of 20 GHz to 80 GHz.

[0014] In some embodiments, each active antenna element of the array is configured to transmit or receive the electromagnetic wave according to a first polarization and a second polarization orthogonal to the first polarization.

[0015] In some embodiments, each active antenna element is configured to be excited by a corresponding excitation source through a corresponding impedance matching circuit.

[0016] According to one aspect of the present invention, a method is provided, comprising: determining a radiation pattern to be generated by a tightly coupled antenna array; determining, based on the radiation pattern, an excitation voltage of an excitation source of each of a plurality of active antenna elements of the antenna array, and a finite passive impedance of each of a plurality of passive antenna elements of the antenna array; manufacturing the antenna array so that: each passive antenna element is terminated by the finite passive impedance determined for the passive antenna element; each antenna element of the antenna array is adjacent to a plurality of other antenna elements of the antenna array, and the spacing between each antenna element of the plurality of other antenna elements is no more than half the wavelength of the electromagnetic wave.

[0017] In some embodiments, the excitation source comprises a transmitter, a receiver, or a transceiver.

[0018] In some embodiments, determining the excitation voltage of the excitation source for each of the multiple active antenna elements of the antenna array and the finite passive impedance of each of the multiple passive antenna elements of the antenna array includes: using one or more genetic algorithms to determine the excitation voltage of the excitation source for each of the multiple active antenna elements of the antenna array and the finite passive impedance of each of the multiple passive antenna elements of the antenna array.

[0019] In some embodiments, the method further comprises operating the antenna array by driving each active antenna element according to the excitation voltage of the corresponding excitation source determined for the active antenna element.

[0020] In some embodiments, the determining the excitation voltage of the excitation source for each of the multiple active antenna elements of the antenna array and the finite passive impedance of each of the multiple passive antenna elements of the antenna array comprises: for each of a plurality of frequencies to excite the active antenna element: for a side angle, determining the excitation voltage of the excitation source for each of the multiple active antenna elements of the antenna array and the finite passive impedance of each of the multiple passive antenna elements of the antenna array.

[0021] In some embodiments, determining the excitation voltage of the excitation source of each of the multiple active antenna elements of the antenna array includes: for each of the multiple frequencies to excite the active antenna element: for non-broadcast angles, by fixing the determined finite passive impedance, determining the excitation voltage of the excitation source of each of the multiple active antenna elements of the antenna array.

[0022] In some embodiments, each finite passive impedance of each passive antenna element includes one or more lumped or distributed circuit components; for each passive antenna element, the method further includes: determining the value of each lumped or distributed circuit component based on the finite passive impedance determined for the passive antenna element; the manufacturing of the antenna array includes: for each finite passive impedance, manufacturing the finite passive impedance according to each lumped or distributed circuit component and the value determined for each lumped or distributed circuit component.

[0023] In some embodiments, manufacturing the antenna array includes manufacturing each antenna element so that each antenna element is used to send or receive electromagnetic waves of different wavelengths; among the different wavelengths, the spacing does not exceed half of the minimum wavelength of the electromagnetic waves.

[0024] In some embodiments, manufacturing the antenna array includes manufacturing each antenna element such that each antenna element of the antenna array includes a patch antenna, a linear dipole antenna, or a bow-tie antenna.

[0025] In some embodiments, the bow-tie antenna includes: a first conductive layer having one or more slots formed in the first conductive layer; and a second parasitic conductive layer having one or more slots formed in the second parasitic conductive layer and separated from the first conductive layer by a medium.

[0026] In some embodiments, manufacturing the antenna array includes manufacturing each antenna element such that each active antenna element of the antenna array is used to transmit or receive the electromagnetic wave according to a first polarization and a second polarization orthogonal to the first polarization.

[0027] In some embodiments, manufacturing the antenna array includes manufacturing each antenna element such that: each active antenna element is configured to be excited by a corresponding one of the plurality of excitation sources through a corresponding impedance matching circuit.

[0028] The present summary does not necessarily describe the full scope of all aspects. Other aspects, features and advantages will be apparent to those of ordinary skill in the art after reviewing the following description of specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0030] Figure 1 is a schematic diagram of a tightly coupled antenna array according to an embodiment of the present invention;

[0031] Figure 2 is another schematic diagram of a tightly coupled antenna array according to an embodiment of the present invention;

[0032] Figure 3A and Figure 3B Two examples of RLC circuits for passive impedance of passive antenna elements of a tightly coupled antenna array according to an embodiment of the present invention are shown;

[0033] Figure 4A and Figure 4B Schematic diagrams of dual-polarized tightly coupled arrays with circular and square patch antenna elements according to embodiments of the present invention;

[0034] Figure 5A and Figure 5B A perspective view and a cross-sectional view of a bow-tie antenna element according to an embodiment of the present invention are respectively shown;

[0035] Figure 6 Shows Figure 5A and Figure 5B The upper and lower layers of the bow-tie antenna element;

[0036] Figure 7 is a flow chart of a method for manufacturing a tightly coupled antenna array according to an embodiment of the present invention;

[0037] Figure 8 An example of a pattern of a tightly coupled antenna array and a desired pattern of an idealized tightly coupled antenna array is shown;

[0038] Fig. 9 Examples of the directivity pattern of a tightly coupled antenna array according to an embodiment of the present invention and the expected directivity pattern of an idealized tightly coupled antenna array are shown. DETAILED DESCRIPTION

[0039] The present invention is directed to an improved tightly coupled antenna array that reduces cost and manufacturing complexity without unacceptable performance loss. Although various embodiments of the present invention are described below, the present invention is not limited to these embodiments, and variations of these embodiments are fully possible within the scope of the present invention, which is limited only by the appended claims.

[0040] In existing implementations of TCA, each antenna element is excited, so multiple circuit components (e.g., matching networks, phase shifters, amplifiers, and duplexers) are required to be excited. This requirement is difficult to meet due to the very small size of the basic unit inherent in TCA. This problem becomes more serious when the operating frequency of TCA tends to millimeter waves.

[0041] Therefore, to solve this problem, the embodiments of the present invention reduce the number of "active" elements in the TCA while maintaining the overall parameter performance of the array and keeping the characteristics of the radiation pattern within an acceptable range. Reducing the number of "active" elements in the TCA in turn reduces the total number of active and passive circuit components (including balanced transformers, matching networks, phase shifters, and amplifiers) required for the array as a whole. This can in turn reduce the cost and complexity of the phased array antenna.

[0042] According to an embodiment of the present invention, instead of actively feeding or exciting each antenna element in the array, only a subset of the antenna elements are actively fed, and the remaining antenna elements are terminated with a properly designed passive impedance. In the present invention, an antenna element driven by an excitation voltage of an excitation source may be referred to as an "active antenna element", and an antenna element terminated by a finite passive impedance may be referred to as a "passive antenna element". In various embodiments, such an excitation source may be a transmitter module (or simply a "transmitter"), a receiver module (or simply a "receiver"), or a transceiver module, etc.

[0043] Since the antenna elements are relatively closely spaced, there is strong mutual coupling between the multiple passive antenna elements and between the passive antenna elements and the active antenna elements. Therefore, current is generated on the passive antenna elements, causing the passive antenna elements to produce a radiation pattern. By properly designing the excitation voltage that drives the active antenna elements and properly designing the circuit components for the passive impedance of the passive antenna elements, an acceptable radiation pattern with a specified gain and sidelobe level can be obtained. Genetic algorithms can be used to design and optimize the excitation voltage that drives the active antenna elements and the passive impedance that terminates the passive antenna elements to meet the required characteristics of the radiation pattern. The resulting tightly coupled array can operate over a wide frequency range without significant grating lobes. Therefore, embodiments of the present invention can produce a phased antenna array that keeps the performance of the array within the design specifications while reducing the overall cost of the array.

[0044] Go to Figure 1, shows a schematic diagram of a "partially excited" TCA 100 including printed dipole antenna elements. In this context, "partially excited" means that only a subset of all antenna elements are driven by an excitation voltage from an excitation source, while the remaining antenna elements are terminated by passive impedances, thus being "passive antenna elements". As described above, such excitation sources may be transmitters, receivers, and / or transceivers, etc.

[0045] from Figure 1 As can be seen in the example of , two of every three columns include passive antenna elements 20, while every third column includes an alternative active antenna element 10 and a passive antenna element 20. Each active antenna element 10 is actively fed by an excitation circuit 15 (denoted by V~), while each passive antenna element 20 is terminated by a finite passive impedance 25 (denoted by R+jX). Figure 3A and Figure 3B Two examples of RLC circuits are shown, including a plurality of lumped circuit components that may be used to achieve the passive impedance of the passive antenna element 20.

[0046] And in Figure 1 In the embodiment, the antenna element is a printed dipole, and the antenna element can be any of various other types of elements (such as microstrip patch or bow-tie dipole antenna). Figure 1 In the invention, each antenna element is printed on a dielectric substrate. The active antenna element 10 is connected to a transmitter or a receiver. Figure 1 , the TCA 100 is shown in transmit mode. If the array is in receive mode, each active antenna element 10 will include a receiver front end instead of a voltage source 15. Whether in transmit or receive mode, each active antenna element 10 is connected to a plurality of circuit components including phase shifters, amplifiers, impedance matching circuits, and duplexers (not shown) to control / change the amplitude and phase of signals input to or received by the active antenna element.

[0047] In order for the passive antenna element 20 to benefit from the mutual coupling with the active antenna element 10, the inter-element distance or spacing separating the antenna of each active antenna element 10 from the antenna of each adjacent passive antenna element 20 is much smaller than that of a conventional antenna array, and in particular, in some embodiments, does not exceed half the wavelength of the highest operating frequency of the TCA 100. In other embodiments, the inter-element spacing may preferably be half the wavelength of the highest operating frequency of the TCA 100.

[0048] It should be noted that Figure 1 The pattern of active antenna elements 10 and passive antenna elements 20 shown is only one example of a pattern that can be used to form a tightly coupled array according to embodiments described herein. For example, according to some embodiments, the H plane ( Figure 1 The spacing between antenna elements in the Y-axis of the E plane ( Figure 1 The spacing in the X-axis of the antenna array is much smaller. Therefore, according to some embodiments, one antenna element in every three antenna elements in each column may be active. Any other symmetrical or even asymmetrical design pattern may be used. For example, Figure 2 An example of a random distribution of active antenna elements 10 in an array 200 is shown. In general, there is a limit to the number of passive antenna elements that can be located between any two consecutive active antenna elements in a given row or column of the array. This is because if the distance between each two active antenna elements becomes too large, beyond a certain point it may become too impractical to prevent grating lobes from appearing in the radiation pattern.

[0049] and Figure 1 A printed dipole antenna element is shown, but other types of antenna elements may be used. For example, Figure 4A and Figure 4B As can be seen in FIG. 1 , each antenna element 30, 40 may include a circular patch antenna ( Figure 4A ) or square patch antenna ( Figure 4B ).exist Figure 4A and Figure 4B In , X represents the position of the excited polarized antenna element. Figure 4A and Figure 4B In the embodiment, the active antenna elements 30, 40 both include a first antenna element 35a, 45a for transmitting or receiving electromagnetic waves according to a first polarization, and a second antenna element 35b, 45b for transmitting or receiving electromagnetic waves according to a second polarization orthogonal to the first polarization.

[0050] Other types of antenna elements that may be used include slot antennas and other types of planar multilayer antennas, depending on the application. Figure 4A and Figure 4B As in the case of , each antenna element can provide single polarization or dual polarization.

[0051] Steering Figure 5A , Figure 5B and Figure 6 , shows another example design of an antenna element that can be used with a tightly coupled antenna array according to this embodiment. In order to cover the three millimeter wave frequency bands allocated to 5G wireless communications, Figure 5A and Figure 5BAn example antenna element includes a dual-polarized slotted bow-tie antenna element 200. The antenna element 200 includes a first conductive layer 210 in which a plurality of slots 212 are formed, the first conductive layer 210 is separated from a second conductive layer 220, and a plurality of slots 214 are formed in the second conductive layer 220. Specifically, the first conductive layer 210 is separated from the second conductive layer 220 by a dielectric 205 having a thickness of d2. The slots 212 and the slots 214 extend the path of the current flowing through the conductive layer 210 and the conductive layer 220, so that resonance can be generated at an appropriate frequency band. By optimizing the shape, size and position of the slots 212 and the slots 214, different resonances can be generated at different frequencies to manufacture a multi-band antenna. The conductive layer 220 is used to generate additional resonances at the lower end of the operating frequency band. The conductive layer 210 and the conductive layer 220 are placed on a dielectric substrate 215 having a thickness of d1 and are located on top of the ground layer 215.

[0052] Figure 5A , Figure 5B and Figure 6 One advantage of the bow-tie antenna element 200 is that the bow-tie antenna element 200 can occupy a relatively small area while operating over a relatively wide frequency range. Using a broadband antenna element can simplify the design of a tightly coupled antenna array (described in further detail below) because using a broadband antenna element can improve the frequency behavior of the terminated passive impedance of the passive antenna element.

[0053] According to an embodiment of the present invention, any of a variety of genetic algorithms can be used to optimize the terminating passive impedance of the passive antenna element and the excitation voltage driving the active antenna element to achieve acceptable directivity and sidelobe level (SLL). Typically, for each steering angle of the array, a mask specifying acceptable directivity and SLL is provided, and the optimization attempts to obtain appropriate impedance and excitation voltage so that the radiation pattern of the array does not violate the mask.

[0054] Specifically, at each frequency at which the array is set to operate, the termination impedance is fixed to the optimized value obtained for the broadside steering angle, and only the excitation voltage is optimized for other non-broadside steering angles. Therefore, the optimized impedance is only a function of frequency and does not change when steering the beam. For each frequency and each steering angle, a different set of optimized excitation voltages may be required.

[0055] To design the termination impedance of each passive antenna element, different topologies of lumped or distributed circuit elements can be used (e.g. Figure 3A and Figure 3B). The value of each lumped or distributed circuit element may be obtained in either of two ways. According to the first approach, an optimization technique may be used to obtain the value of each lumped or distributed circuit element so that the impedance of the circuit at the antenna frequency band is close to the impedance obtained from the above antenna optimization. According to the second approach, a rational function may be fit to the impedance data, and then a conventional circuit synthesis method may be used to extract the value of each lumped or distributed circuit element.

[0056] Go to Figure 7 , a flowchart of a method of manufacturing a tightly coupled antenna array according to an embodiment of the present invention will now be described.

[0057] At block 302, an initial frequency is selected, and a scan angle of 0° is selected.

[0058] At block 304, an initial terminating passive impedance for each passive antenna element is selected.

[0059] At block 306, an initial excitation voltage for each active antenna element is selected.

[0060] At block 308, the current on each antenna element (passive and active) is calculated, for example using an impedance matrix for the array.

[0061] At block 310, the radiation pattern of the array is calculated, for example, by multiplying the array factor by the radiation pattern of each antenna element. The radiation pattern of each element is calculated by assuming that the element is embedded in the array environment (rather than a single, separate element).

[0062] At block 312, the radiation pattern calculated at block 310 is compared to a predefined mask, and a cost function is calculated based on the comparison.

[0063] At block 314 , the cost function is compared to a preset tolerance.

[0064] If the cost function is greater than the preset tolerance, and if the scan angle is currently set to zero, the excitation voltage and passive impedance are modified using a genetic algorithm, and the process returns to block 308 .

[0065] If the cost function is greater than the preset tolerance, and if the scan angle is not currently set to zero, the excitation voltage is modified using a genetic algorithm and the process returns to block 308 .

[0066] If the cost function is less than the preset tolerance, then at block 320 a determination is made as to whether the optimization has been performed for all scanning angles.

[0067] If optimization has not been performed for all scan angles, then the next scan angle is selected at block 326 , the passive impedance is held fixed at block 328 , and the process returns to block 306 .

[0068] If optimization has been performed for all scan angles, then at block 322 a determination is made as to whether optimization has been performed for all frequencies.

[0069] If optimization has not been performed for all frequencies, then at block 330 the next frequency is selected and the scan angle is set to 0, and the process returns to block 304 .

[0070] If optimization has been performed for all frequencies, then at block 324, the optimization ends.

[0071] Figure 8 and Fig. 9 The radiation pattern of a tightly coupled antenna array according to an embodiment of the present invention (dashed line) and the expected radiation pattern of an idealized tightly coupled antenna array (solid line) are shown, where when the main beam is scanned to θ=30°, φ=0°, all antenna elements will be excited at 50 GHz. Figure 8 shows the directivity in the E-plane (the plane parallel to the dipole), while Fig. 9 Directivity in the H-plane (the plane perpendicular to the dipole) is shown.

[0072] exist Figure 8 and Fig. 9 In the embodiment of the present invention, the tightly coupled antenna array is an array of 32x13 elements, with 77 active elements and 339 passive elements.

[0073] As can be seen above, the advantage of the tightly coupled array described in this article is that the array can significantly reduce the number of active antenna elements compared to more traditional phased arrays. By taking advantage of the strong coupling between the antenna elements and generating appropriate currents on the passive antenna elements by properly tuning the terminating passive impedance at the passive elements, the complexity and cost of the tightly coupled phased array are greatly reduced compared to traditional fully excited arrays. In addition, as described above, the current distribution on the passive and active elements can be tuned so that the radiation pattern of the array maintains a specified gain and sidelobe level.

[0074] Embodiments of the tightly coupled arrays disclosed herein can be used for mobile stations and fixed stations in 5G millimeter wave wireless communication systems. However, the embodiments are by no means limited to such applications. For example, embodiments of the tightly coupled arrays disclosed herein can be used in any application requiring broadband or multi-band phased array antennas. For example, millimeter wave automotive radars can benefit from the embodiments described herein. Other local millimeter wave wireless networks in the automotive industry (e.g., permanent networks within vehicles or temporary networks formed by multiple vehicles in motion) can also benefit from the embodiments described herein.

[0075] When used in conjunction with the terms "comprising" or "including" in the claims and / or the specification, the word "a" or "an" may mean "one", but it is also consistent with the meaning of "one or more", "at least one" and "one or more", unless the content clearly indicates otherwise. Similarly, the word "another" may mean at least a second or more, unless the content clearly indicates otherwise.

[0076] As used herein, the terms "coupled," "coupled," or "connected" may have several different meanings depending on the context in which the terms are used. For example, as used herein, the terms "coupled," "coupled," or "connected" may indicate that two elements or devices are directly connected to each other, or, depending on the particular context, are connected to each other by mechanical elements through one or more intermediate elements or devices. The term "and / or" herein, when used in connection with a list of items, is meant to include any one or more of the items in the list.

[0077] As used herein, reference to "about" or "approximately" a number or "substantially" equal to a number means within + / - 10% of that number.

[0078] Although the present invention has been described in conjunction with specific embodiments, it will be appreciated that the present invention is not limited to these embodiments and that changes, modifications and variations may be made to these embodiments by those skilled in the art without departing from the scope of the present invention.

[0079] It is also contemplated that any portion of any aspect or embodiment discussed in this specification may be implemented or combined with any portion of any other aspect or embodiment discussed in this specification.

Claims

1. A tightly coupled antenna array, characterized in that: include: A plurality of tightly coupled antenna elements, used for sending or receiving electromagnetic waves, the plurality of antenna elements comprising: A plurality of active antenna elements, each active antenna element being excited by an excitation source; A plurality of passive antenna elements, each passive antenna element being terminated by a finite passive impedance; Wherein, each antenna element of the array is adjacent to a plurality of other antenna elements of the array, and a distance between each antenna element of the plurality of other antenna elements and the antenna element does not exceed half of the wavelength of the electromagnetic wave.

2. The array according to claim 1, characterized in that The excitation source includes a transmitter, a receiver or a transceiver.

3. The array according to claim 1 or 2, characterized in that: The antenna elements of the array are used to send or receive electromagnetic waves of different wavelengths; Among the different wavelengths, the spacing does not exceed half of the minimum wavelength of the electromagnetic wave.

4. The array according to any one of claims 1 to 3, characterized in that The antenna elements of the array include patch antennas.

5. The array according to any one of claims 1 to 4, characterized in that The antenna elements of the array include linear dipole antennas.

6. The array according to any one of claims 1 to 4, characterized in that The antenna elements of the array include bow-tie antennas.

7. The array according to claim 6, characterized in that The bow-tie antenna comprises: a first conductive layer having one or more grooves formed in the first conductive layer; The second parasitic conductive layer has one or more grooves formed therein and is separated from the first conductive layer by a medium.

8. An array according to any one of claims 1 to 7, characterized in that The antenna elements of the array are used to send or receive electromagnetic waves with a frequency of 20 GHz to 80 GHz.

9. The array according to any one of claims 1 to 8, characterized in that Each active antenna element of the array is used to transmit or receive the electromagnetic wave according to a first polarization and a second polarization orthogonal to the first polarization.

10. The array according to any one of claims 1 to 9, characterized in that Each active antenna element is used to be excited by the corresponding excitation source through a corresponding impedance matching circuit.

11. A method, characterized in that include: determining a radiation pattern to be generated by a tightly coupled antenna array; Determining, based on the radiation pattern, an excitation voltage of an excitation source of each of a plurality of active antenna elements of the antenna array and a finite passive impedance of each of a plurality of passive antenna elements of the antenna array; The antenna array is manufactured so that: each passive antenna element being terminated by said finite passive impedance determined for said passive antenna element; Each antenna element of the antenna array is adjacent to a plurality of other antenna elements of the antenna array, and a spacing between each antenna element of the plurality of other antenna elements is no more than half a wavelength of the electromagnetic wave.

12. The method according to claim 11, characterized in that The excitation source includes a transmitter, a receiver or a transceiver.

13. The method according to claim 11 or 12, characterized in that: The determining of the excitation voltage of the excitation source of each of the plurality of active antenna elements of the antenna array and the finite passive impedance of each of the plurality of passive antenna elements of the antenna array comprises: One or more genetic algorithms are used to determine the excitation voltage of the excitation source for each of the plurality of active antenna elements of the antenna array and the finite passive impedance of each of the plurality of passive antenna elements of the antenna array.

14. The method according to any one of claims 11 to 13, characterized in that Also includes: The antenna array is operated by driving each active antenna element according to the excitation voltage of the corresponding excitation source determined for the active antenna element.

15. The method according to any one of claims 11 to 14, characterized in that The determining of the excitation voltage of the excitation source of each of the plurality of active antenna elements of the antenna array and the finite passive impedance of each of the plurality of passive antenna elements of the antenna array comprises: For each of the plurality of frequencies at which the active antenna element is to be excited: For a broadside angle, the excitation voltage of the excitation source for each of the plurality of active antenna elements of the antenna array and the finite passive impedance of each of the plurality of passive antenna elements of the antenna array are determined.

16. The method according to any one of claims 11 to 15, characterized in that The determining the excitation voltage of the excitation source of each active antenna element of the plurality of active antenna elements of the antenna array comprises: For each of the plurality of frequencies at which the active antenna element is to be excited: For non-broadcast angles, the excitation voltage of the excitation source of each active antenna element of the plurality of active antenna elements of the antenna array is determined by fixing the determined finite passive impedance.

17. The method according to any one of claims 11 to 16, characterized in that Each finite passive impedance of each passive antenna element includes one or more lumped or distributed circuit components; For each passive antenna element, the method further comprises: determining a value of each lumped or distributed circuit component based on the finite passive impedance determined for the passive antenna element; The manufacturing of the antenna array comprises: For each finite passive impedance, the finite passive impedance is manufactured based on each lumped or distributed circuit component and the value determined for each lumped or distributed circuit component.

18. The method according to any one of claims 11 to 17, characterized in that The manufacturing of the antenna array includes manufacturing each antenna element so that each antenna element is used to send or receive electromagnetic waves of different wavelengths; Among the different wavelengths, the spacing does not exceed half of the minimum wavelength of the electromagnetic wave.

19. The method according to any one of claims 11 to 18, characterized in that The manufacturing of the antenna array includes manufacturing each antenna element, so that each antenna element of the antenna array includes a patch antenna, a linear dipole antenna or a bow-tie antenna.

20. The method according to claim 19, characterized in that The bow-tie antenna comprises: a first conductive layer having one or more grooves formed in the first conductive layer; The second parasitic conductive layer has one or more grooves formed therein and is separated from the first conductive layer by a medium.

21. The method according to any one of claims 11 to 20, characterized in that The manufacturing of the antenna array includes manufacturing each antenna element so that each active antenna element of the antenna array is used to transmit or receive the electromagnetic wave according to a first polarization and a second polarization orthogonal to the first polarization.

22. The method according to any one of claims 11 to 21, characterized in that The manufacturing of the antenna array includes manufacturing each antenna element so that: Each active antenna element is used to be excited by a corresponding one of the plurality of excitation sources through a corresponding impedance matching circuit.

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