Antenna unit structure and phased array antenna

Abstract

The invention discloses an antenna unit structure and a phased array antenna including several of the antenna unit structures, wherein the antenna unit structure includes a first radiation unit, a second radiation unit, a feeding unit and a frequency selection surface; the first radiation unit is arranged between the second radiation unit and the feeding unit respectively; the frequency selection surface is used to transmit the electromagnetic waves of the first radiation unit, and is also used to suppress the electromagnetic waves in the direction outside the antenna unit, and confine the electromagnetic waves of the corresponding antenna unit within the antenna unit; the first radiation unit includes a main body and a plurality of sawtooth extensions; the center of the main body has a through hole; each sawtooth extension is fixed to the main body and extends into the through hole; the frequency selection surface is fixed to the main body of the first radiation unit. The antenna unit structure and the phased array antenna of the antenna unit structure described in the present invention have the effects of achieving miniaturization, expanding impedance bandwidth, and increasing isolation between antenna units.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave antennas, and in particular relates to an antenna unit structure based on metamaterial decoupling and a phased array antenna composed of a plurality of the antenna unit structures. Background Art

[0002] With the rapid development of wireless communication technology, the role of antenna systems in modern electronic devices has become increasingly important. Antenna arrays, especially densely arranged antenna arrays, often face the problem of performance degradation due to the electromagnetic coupling effect between array elements. This coupling not only affects the radiation efficiency and directivity of the antenna, but may also cause system instability and interference. Therefore, how to effectively reduce or eliminate the coupling effect in antenna arrays has become a hot topic in the field of antenna design and wireless communication.

[0003] Traditional radiation patches are usually rectangular or circular (such as the first metal patch and the second metal patch involved in the prior art publication number CN118431753A). The decoupling methods of antenna units in the prior art include using physical isolation, changing the array element spacing, adjusting the feed network, etc., but these methods are often limited by space constraints, increased costs or performance sacrifices. Summary of the invention

[0004] In view of this, the present invention aims to overcome the shortcomings of the prior art and proposes a new structure for decoupling antennas using FSS, which can not only effectively reduce the coupling effect in the antenna array, but also has the advantages of flexible design, high cost-effectiveness, and easy integration. Through the implementation of the present invention, it is expected that the overall performance of the antenna system can be significantly improved to meet the needs of modern wireless communication systems for high-performance antennas.

[0005] In order to solve the above problems and achieve the above objectives, the present invention adopts the following technical solutions:

[0006] An antenna unit structure comprises a first radiation unit, a second radiation unit and a feeding unit; the first radiation unit is arranged between the second radiation unit and the feeding unit respectively; and further comprises a frequency selective surface, the frequency selective surface is used to transmit the electromagnetic wave of the first radiation unit, and is also used to suppress the electromagnetic wave in the direction outside the antenna unit, and confine the electromagnetic wave of the corresponding antenna unit within the antenna unit; the reflection coefficient and the transmission coefficient are calculated by spectrum analysis through the frequency selective surface;

[0007] The first radiation unit includes a main body and a plurality of sawtooth extensions; the main body has a through hole in the center; each sawtooth extension is fixed to the main body and extends into the through hole; the frequency selection surface is fixed to the main body of the first radiation unit; the plurality of sawtooth extensions are arranged at intervals.

[0008] Compared with the prior art, the first radiation unit of the antenna unit structure described in this embodiment includes a main body and a plurality of sawtooth extensions, so that the first radiation unit is set in a sawtooth shape, which can effectively increase the equivalent radiation length of the patch, thereby improving the radiation efficiency of the antenna without increasing the physical size. The frequency selective surface can improve the out-of-band isolation characteristics of the antenna. The technology of decoupling through the frequency selective surface antenna can not only effectively reduce the coupling effect in the antenna array, but also has the advantages of flexible design, high cost-effectiveness, and easy integration. Through the implementation of the present invention, it is expected that the overall performance of the antenna system can be significantly improved to meet the needs of modern wireless communication systems for high-performance antennas.

[0009] Preferably, in order to better reduce the coupling between the antenna unit structures in the phased array antenna, the first radiating unit includes a plurality of polygonal figures, and the plurality of polygonal figures are distributed in the body of the first radiating unit in a centrally symmetrical manner with the center of the through hole as the center of the circle; the polygonal figures include at least two sizes of quadrilaterals; and a gap is formed between two adjacent polygonal figures.

[0010] Preferably, in order to better improve the working efficiency of the frequency selective surface, the four sides of the two sizes are arranged in an array to form a matrix; the number of the matrix is ​​at least two.

[0011] Preferably, the body of the first radiation unit comprises a first surface and a second surface, the first surface faces the second radiation unit, and the second surface faces the feeding unit; and the frequency selection surface is fixed to at least one of the first surface and the second surface.

[0012] Preferably, the plurality of sawtooth extensions are arranged in a circular array; the maximum diameter of each of the sawtooth extensions is 1 / 5-1 / 3 of the maximum aperture of the through hole.

[0013] Preferably, when projected in a direction from the first radiation unit toward the second radiation unit, the projections of the feeding unit and the sawtooth extension body are both located in the through hole, and the projections of the feeding unit and the sawtooth extension body partially overlap.

[0014] Preferably, the antenna unit structure further includes a resistive unit, and the resistive unit surrounds the second radiation unit and the outer periphery of the frequency selective surface.

[0015] Preferably, the sheet resistance of the resistive unit is 60-70Ω / sq; or 70-80Ω / sq.

[0016] Preferably, according to the antenna unit structure as described above, the process of calculating the reflection coefficient and the transmission coefficient by spectrum analysis through the frequency selective surface is as follows: the frequency selective surface spectrum domain is obtained by Fourier transform and using the following formula:

[0017]

[0018] in, ; ;

[0019] In the formula is the magnetic permeability of vacuum, a and b are the unit period values ​​in two periodic directions, k0 is the wave vector size corresponding to the wavelength in vacuum, is the Green's function in the spectral domain; H x inc is the magnetic field intensity of the incident wave in the x direction, H y inc is the magnetic field intensity of the incident wave in the y direction; α mn , β mn The tangential wave number in the two-dimensional periodic direction respectively; k x , k y are the wave vector components of the incident plane wave in the x and y directions of the illumination plane respectively; Ω is the tilt angle of the two periodic directions of the frequency selective surface; where θ and φ are the incident angle and azimuth of the plane wave respectively; where ∆x and ∆y are the length and width of each discrete subunit respectively; and They represent the tangential equivalent magnetic currents in the X and Y directions respectively, and j is a natural number.

[0020] Preferably, the feed unit includes a first feed unit and a second feed unit, the first feed unit is connected to the first radiation unit; the second feed unit is connected to the second radiation unit.

[0021] Preferably, the miniaturization of the antenna, the expansion of the impedance bandwidth, and the increase of the isolation between the antenna units are achieved, thereby significantly improving the performance and application range of the antenna system. The present invention also provides a phased array antenna, comprising at least two antenna unit structures; the antenna unit structure is the antenna unit structure described in any of the above embodiments; the edges of adjacent antenna unit structures are in contact with each other; the frequency selective surface of each of the antenna unit structures is used to suppress the electromagnetic waves radiated from one antenna unit from directly coupling to another antenna unit.

[0022] Beneficial effects of the present invention:

[0023] Compared with the prior art, the antenna unit structure and the phased array antenna composed of the antenna unit structure disclosed in the present invention respectively have the frequency selective surface fixedly arranged on the first radiation unit and adopt the frequency selective surface decoupling technology to make it have high reflection or high transmission characteristics for electromagnetic waves outside the working frequency band, and exhibit low reflection or low transmission characteristics for electromagnetic waves of other frequencies, which can improve the out-of-band isolation characteristics of the antenna.

[0024] In addition, the frequency selective surface structure can be designed to suppress electromagnetic waves outside the array element, and confine the electromagnetic waves of each unit within the array element. This directivity control can reduce the direct coupling of electromagnetic waves radiated from one antenna to another antenna. The frequency selective surface structure can suppress surface waves propagating on the surface of the medium and reduce the occurrence of standing wave deterioration caused by increased coupling between antennas during large-angle scanning.

[0025] In summary, the antenna unit structure and the phased array antenna composed of the antenna unit structure described in the present invention are not only small in size, but also can effectively reduce the coupling effect in the antenna array, and also have the advantages of flexible design, high cost-effectiveness, and easy integration. Through the implementation of the present invention, it is expected that the overall performance of the antenna system can be significantly improved to meet the needs of modern wireless communication systems for high-performance antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the drawings of the present invention will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0027] Figure 1 An array layout diagram of an antenna array according to an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of an antenna unit according to an embodiment of the present invention.

[0029] Figure 3 A schematic diagram of an aperture coupling feeding layer according to an embodiment of the present invention;

[0030] Figure 4 A first radiation unit and an FSS layer according to an embodiment of the present invention;

[0031] Figure 5 A resistive unit layer according to an embodiment of the present invention;

[0032] Figure 6 A second radiation unit according to an embodiment of the present invention;

[0033] Figure 7The isolation between the central antenna unit and all surrounding antenna units when no FSS layer is added;

[0034] Figure 8 It is the superposition of the coupling degree between all surrounding antenna units and the central antenna unit when the FSS layer is not added;

[0035] Fig. 9 The isolation between the central antenna unit and all surrounding antenna units when the FSS layer is added;

[0036] Fig.10 It is the superposition of the coupling degrees of all surrounding antenna units and the central antenna unit when the FSS layer is added. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the present invention rather than for limiting the protection scope of the present invention.

[0038] Reference Figure 1 This embodiment relates to an antenna unit structure, including a first radiation unit 112, a second radiation unit 115, a feeding unit and a frequency selective surface (FSS). The first radiation unit 112 is arranged between the second radiation unit 115 and the feeding unit. The first radiation unit 112 can emit electromagnetic waves, and the second radiation unit 115 can receive electromagnetic waves emitted by the first radiation unit 112. The feeding unit can be used to feed the first radiation unit 112 and the second radiation unit 115. The frequency selective surface is used to transmit the electromagnetic waves of the first radiation unit 112, and is also used to suppress the electromagnetic waves in the direction outside the antenna unit, and confine the electromagnetic waves of the corresponding antenna unit within the antenna unit. The first radiation unit 112 includes a body and a plurality of sawtooth extensions. The center of the body has a through hole. In order to increase the equivalent radiation length of the antenna unit without increasing the size of the antenna unit structure, each sawtooth extension is fixed to the body and extends into the through hole. The frequency selective surface is fixed to the body of the first radiation unit 112. Preferably, the plurality of sawtooth extensions are spaced apart from each other and are arranged symmetrically. The symmetry may be arranged in a central symmetric manner with the center of the through hole, or may be arranged in a symmetric manner with a certain diameter of the through hole as an axis. Arranging in a symmetric manner can reduce unnecessary interference and enable the antenna to maintain good radiation characteristics in multiple frequency bands.

[0039] In this embodiment, the sawtooth extension of the first radiating unit 112 can realize the miniaturization of the antenna. It can effectively increase the equivalent radiation length of the patch, thereby improving the radiation efficiency of the antenna without increasing the physical size. This design not only helps to reduce the overall size of the antenna, but also improves the working performance of the antenna in different frequency bands. The sawtooth design can also provide better frequency selectivity, so that the antenna can maintain good radiation characteristics in multiple frequency bands.

[0040] In recent years, frequency selective surface (FSS), as a new type of electromagnetic material, has shown great application potential in the field of electromagnetic compatibility and antenna decoupling due to its unique frequency selectivity and spatial filtering characteristics. FSS is a two-dimensional periodic structure that can produce reflection, transmission or absorption effects on electromagnetic waves of specific frequencies. The present invention can achieve effective management of electromagnetic waves emitted by the corresponding antenna unit structure by carefully designing the structure and arrangement of FSS on the antenna unit structure, thereby reducing the coupling between multiple antenna unit structures without affecting the normal operation of the antenna. The frequency selective surface described in this embodiment can be made of ceramic-based multi-layer composite wave-transparent material and highly conductive metal material.

[0041] The working principle of the frequency selective surface is based on the electron vibration caused by the interaction between the incident wave and the wire in the frequency selective surface. In the frequency selective surface, the wires in different directions will cause the electrons to oscillate to different degrees, which can be regarded as dipole units. When most of the energy of the incident wave is converted into electron vibration, the transmission coefficient of the frequency selective surface is low; conversely, the transmission capacity is strong. Therefore, different shapes of frequency selective surfaces will produce different operating frequencies under the same incident wave, and slight adjustments to the frequency selective surface of the same shape will also have a significant impact on its transmission characteristics, which reveals the key elements of the working mechanism of the frequency selective surface. Frequency selective surfaces are widely used in spatial filtering of electromagnetic waves due to their selective filtering function for incident electromagnetic waves at specific frequencies, polarization states and incident angles. According to the response characteristics of electromagnetic waves to specific frequencies, frequency selective surfaces can be divided into two categories: patch type and aperture type. The patch type frequency selective surface is composed of periodic metal patch units on a dielectric substrate. The resonant characteristics at a specific frequency lead to a band-stop filtering effect, that is, it exhibits a high reflection ability near the resonant frequency. In contrast, the aperture-type frequency selective surface is realized by a metal sheet composed of periodically arranged openings of the same size, and exhibits a bandpass filtering characteristic, that is, it allows electromagnetic waves to pass through at the resonant frequency. In this embodiment, the frequency selective surface is preferably of the aperture type.

[0042] In order to identify and reduce unwanted interference, the present invention converts the signal or electromagnetic wave in the time domain of the selected frequency surface into the frequency domain for analysis, converts the waveform in time or space into a spectrum representing its frequency components, that is, using the spectrum domain method to analyze in the frequency domain, which can more easily identify and process the specific frequency components in the signal, thereby identifying and reducing unwanted interference. Using the spectrum domain method to analyze in the frequency domain can decompose complex fluctuations or signals into a simple sine wave combination, each sine wave corresponds to a specific frequency, so that the corresponding reflection coefficient can be obtained. and transmission coefficient , the reflection coefficient is obtained by adjusting and transmission coefficient The frequency selective surface can reflect, transmit or absorb electromagnetic waves of specific frequencies.

[0043] Using the duality principle in the electromagnetic field, the aperture-type frequency selective surface is stimulated by the incident field to produce an induced magnetic current, and the scattering field of a single unit can be expressed as:

[0044] (Announcement 1)

[0045] Among them, is the angular frequency, is the dielectric constant of vacuum, is the scattered wave magnetic field intensity, is the vector potential of the magnetic field, and the tangential magnetic field boundary condition on the FSS unit aperture surface is:

[0046] ,in , are the magnetic field intensities of the incident wave and the scattered wave, respectively, is the equivalent magnetic current, and all three are vector quantities. is the surface impedance. Generally, the conductive layer on the surface of the FSS screen has a small impedance and can be regarded as an ideal conductor (PEC) surface, that is, Zs=0.

[0047] The process of calculating the reflection coefficient and transmission coefficient by spectrum analysis of the frequency selective surface is as follows: Applying Fourier transform and using Floquet's theorem, the spectral domain expression can be obtained as follows:

[0048]

[0049] (Formula 2) is the magnetic permeability of vacuum, a and b are the periods of FSS units in two directions in two-dimensional space, k0 is the wave vector size corresponding to the wavelength in vacuum, is the Green’s function in the spectral domain, which is related to the matching medium on both sides of the frequency selective surface unit. x incis the magnetic field intensity of the incident wave in the x direction, H y inc is the magnetic field intensity of the incident wave in the y direction; α mn , β mn The tangential wave number in the two-dimensional periodic direction. Since the FSS array is a two-dimensional periodic structure, it can be seen from the properties of Fourier transform that α and β are no longer continuous values, but some discrete values, which correspond to the corresponding Floquet harmonics, and their expressions are:

[0050] ; (Formula 3).

[0051] Where k x , k y are the wave vector components of the incident plane wave in the x and y directions of the illumination plane respectively; Ω is the tilt angle of the frequency selective surface in the two periodic directions.

[0052] ; (Formula 4)

[0053] Where θ and φ are the plane wave incident angle and azimuth, respectively.

[0054] Formula 2 is solved by the moment method. For general regular graphic units, the induced magnetic flow to be solved can be expanded using the global basis function. The basis function of other graphic units such as the Y ring is expanded using the Rooftop expansion in the subdomain basis function. The expression of this basis function is:

[0055] (Formula 5)

[0056] (Formula 6)

[0057] in (Formula 7)

[0058] (Formula 8)

[0059] Where ∆x and ∆y are the length and width of each discrete subunit, respectively. Substituting the equivalent magnetic flux expanded by the basis functions of Formulas 5 to 8 into Formula 2, the equivalent magnetic flux in the X and Y directions can be obtained. and , by taking j as a natural number, we can expand formula 2 into a matrix equation by taking different values, and then we can calculate the reflection coefficient H x inc and transmission coefficient Hy inc The reflection, transmission or absorption effect of the frequency selective surface on electromagnetic waves of a specific frequency can be achieved by adjusting the change of the reflection coefficient and the transmission coefficient.

[0060] The first radiation unit 112 of the present invention adopts a sawtooth-shaped radiation patch to achieve miniaturization of the antenna. In this solution, by changing the traditional rectangular or circular radiation patch to a sawtooth shape, the equivalent radiation length of the patch can be effectively increased, thereby improving the radiation efficiency of the antenna without increasing the physical size. This design not only helps to reduce the overall size of the antenna, but also improves the working performance of the antenna in different frequency bands. The sawtooth design can also provide better frequency selectivity, so that the antenna can maintain good radiation characteristics in multiple frequency bands.

[0061] In addition, the present invention adopts frequency selective surface decoupling technology to add an FSS layer to the first radiation unit 112, so that it has high reflection or high transmission characteristics for electromagnetic waves outside the working frequency band, and exhibits low reflection or low transmission characteristics for electromagnetic waves of other frequencies, which can improve the out-of-band isolation characteristics of the antenna.

[0062] In addition, the FSS structure can be designed to suppress electromagnetic waves outside the array element and confine the electromagnetic waves of each unit within the array element. This directivity control can reduce the direct coupling of electromagnetic waves radiated from one antenna to another. The FSS structure can suppress surface waves propagating on the surface of the medium and reduce the standing wave degradation caused by increased coupling between antennas during large-angle scanning.

[0063] As a preferred solution, in order to expand the bandwidth of the antenna unit structure, the feeding unit in an embodiment of the present invention adopts aperture coupling feeding plus double-layer radiation patch feeding technology to expand the antenna bandwidth.

[0064] As a preferred embodiment, in order to better reduce the coupling between antenna unit structures, the first radiation unit 112 of this embodiment includes a plurality of polygonal figures, which are distributed in the body of the first radiation unit 112 in a centrally symmetrical manner with the center of the through hole as the center of the circle. In order to satisfy the transmission of electromagnetic waves generated by the first radiation unit 112, or to reflect or absorb electromagnetic waves generated in other places, the polygonal figures include at least two sizes of quadrilaterals; a gap is formed between two adjacent polygonal figures.

[0065] As a preferred embodiment, in order to better achieve the transmission or absorption effect on the electromagnetic waves generated by the first radiation unit 112; the four sides of the two sizes are arranged in an array to form a matrix; the number of the matrix is ​​at least two. Other graphics are arranged between two adjacent matrices. Other polygonal graphics can be graphics of symmetrical structures, and gaps are also formed between other adjacent polygonal graphics. The frequency selective surface can be composed of only a few of the above-mentioned quadrilaterals; it can also be composed of the above-mentioned four-sided deformation combined with other polygonal graphics. By setting different graphics or sizes, the requirements of transmitting the electromagnetic waves generated by the first radiation unit 112 itself and reflecting or absorbing the electromagnetic waves generated by other antenna unit structures can be met.

[0066] As a preferred embodiment, the body of the first radiation unit 112 includes a first surface and a second surface, the first surface faces the second radiation unit 115, and the second surface faces the feeding unit; the frequency selective surface is fixed to at least one of the first surface and the second surface. Preferably, in order to improve the working efficiency of the frequency selective surface, the frequency selective surface can be fixed on both the first surface and the second surface. Preferably, in order to accurately confine the electromagnetic waves of the antenna unit structure within the antenna unit and reflect or absorb electromagnetic waves outside the antenna unit, the area of ​​the single quadrilateral is 1 / 100-1 / 50 of the area of ​​the first surface or the second surface. The area size of the quadrilateral can be set according to the application scenario of the antenna unit structure. The gap between two adjacent quadrilaterals is greater than zero and less than or equal to the shortest side of one of the quadrilaterals. The area of ​​other figures is greater than or equal to the area of ​​the smallest quadrilateral and less than or equal to 1 / 40 of the area of ​​the first surface or the second surface.

[0067] As a preferred embodiment, in order to achieve better frequency selectivity of the antenna unit structure, so that the antenna unit structure can maintain good radiation characteristics in multiple frequency bands, a plurality of the sawtooth extensions can be arranged in a circular array; and the maximum diameter of each of the sawtooth extensions is 1 / 5-1 / 3 of the maximum aperture of the through hole.

[0068] As another preferred embodiment, in order to achieve miniaturization or micro-miniaturization of the antenna unit structure, under the condition of projection in the direction from the first radiation unit 112 to the second radiation unit 115, the projections of the feed unit and the sawtooth extension are both located in the through hole, and the projections of the feed unit and the sawtooth extension partially overlap. The projection of the sawtooth extension is rectangular. A plurality of sawtooth extensions are combined to form a sawtooth shape, and this sawtooth design can also provide better frequency selectivity, so that the antenna can maintain good radiation characteristics in multiple frequency bands. The length of the rectangle formed by the projection of the sawtooth extension is less than the minimum diameter of the through hole, and is greater than or equal to 1 / 5 of the minimum diameter of the through hole.

[0069] In order to achieve miniaturization or micro-miniaturization of the antenna unit structure, the first radiation unit 112 and the second radiation unit 115 are respectively patch structures, and the first surface and the second surface of the first radiation unit 112 may be the two largest surfaces of the first radiation unit 112. The second radiation unit 115 may be circular.

[0070] The first radiating unit 112 in the phased array antenna described in this embodiment is on the same layer as the frequency selective surface 111. The frequency selective surface 111 can reduce the coupling between antenna units and improve isolation. The first radiating unit 112 adopts a serrated design, which effectively reduces the size of the radiating patch, thereby realizing the miniaturization of the antenna. This design not only reduces the physical volume of the antenna, but also helps to improve the radiation efficiency and frequency response of the antenna, so that the antenna can be arranged more compactly in a limited space. The second radiating unit 115 in the phased array antenna described in this embodiment is used to expand the bandwidth of the antenna unit. The aperture coupling feeding layer (113 / 114) in the phased array antenna described in this embodiment is located at the bottom layer of the antenna, and its function is to feed the antenna, which can realize H / V dual-polarization feeding. The square resistivity of the resistive unit layer 110 in the phased array antenna described in this embodiment can be 70Ω / sq., which can reduce the strong inductive effect between the antenna radiating patch and the metal stratum, thereby expanding the antenna bandwidth and reducing the antenna profile.

[0071] As a preferred embodiment, in order to reduce the coupling between the second radiation units 115 of the antenna unit structure after the combination of multiple antenna unit structures, a resistive unit 110 may also be included, and the resistive unit 110 surrounds the second radiation unit 115 and the periphery of the frequency selection surface. The resistive unit 110 can also reduce the strong inductive effect between the first radiation unit 112, the second radiation unit 115 and the metal ground. In this embodiment, a double-layer resistive unit 110 is used to reduce the coupling of the second radiation unit 115. In addition, the resistive unit 110 can reduce the strong inductive effect between the vertical radiation patch and the metal ground. The shape of each resistive unit 110 can be a hollow regular hexagon; the first radiation unit 112 and the second radiation unit 115 are both located in the regular hexagonal space enclosed by the resistive unit 110.

[0072] As a preferred embodiment, in order to further reduce the strong inductive effect between the first radiation unit 112, the second radiation unit 115 and the metal ground in the vertical direction, the square resistivity of the resistive unit 110 is 60-70Ω / sq; or 70-80Ω / sq.

[0073] As a preferred embodiment, the feed unit includes a first feed unit 113 and a second feed unit 114, the first feed unit is connected to the first radiation unit 112, and the second feed unit is connected to the second radiation unit 115. The feed unit includes a horizontally polarized aperture coupling feed layer and a vertically polarized aperture coupling feed layer. Figure 3 Schematic diagram of aperture coupling feeding layer, the feeding layer is located at the bottom layer of the antenna unit structure, and its function is to feed the antenna, and can realize H / V dual polarization feeding. The first feeding unit 113 is a horizontally polarized aperture coupling feeding layer, and the second feeding unit 114 is a vertically polarized aperture coupling feeding layer.

[0074] When projected in the direction from the first radiation unit 112 to the second radiation unit 115, the overall projection of the antenna unit structure is a regular polygon, so that the multiple antenna unit structures can better meet the design requirements during application. Preferably, the overall projection of the antenna unit structure is a positive even-numbered deformation, such as a square, a regular hexagon, etc.

[0075] As a preferred embodiment, in order to effectively reduce the coupling effect in the antenna array, it also has the advantages of flexible design, high cost-effectiveness, and easy integration. The present invention also provides a phased array antenna, which includes at least two antenna unit structures; the antenna unit structure is the antenna unit structure described in any of the above embodiments; the edges of adjacent antenna unit structures are in contact with each other; the frequency selective surface of each antenna unit structure is used to suppress the electromagnetic waves radiated from one antenna unit from directly coupling to another antenna unit. Multiple antenna unit structures can be in contact with each other, for example, the edges of the resistive unit 110 of a single antenna unit structure are in contact with each other.

[0076] The phased array antenna described in this embodiment has equal numbers of resistive units 110, frequency selective surfaces 111, first radiating units 112, horizontally polarized aperture coupled feed layers 113, vertically polarized aperture coupled feed layers 114, and second radiating units 115. The first radiating units 112, horizontally polarized aperture coupled feed layers 113, vertically polarized aperture coupled feed layers 114, and second radiating units 115 between adjacent antenna units are separated by resistive units 110, respectively, which can reduce the strong inductance effect between each radiating unit and the metal formation in the phased array antenna, thereby expanding the antenna bandwidth and reducing the antenna profile, further realizing the miniaturization of the antenna, the expansion of the impedance bandwidth, and the increase of the isolation between the antenna units, thereby significantly improving the performance and application range of the antenna system. The first radiation unit 112 and the second radiation unit 115 respectively have metallized vias, which can be electrically connected to the horizontal polarization aperture coupling feeding layer 113 and the vertical polarization aperture coupling feeding layer 114, and enable the feeding unit to stably feed the first radiation unit 112 and the second radiation unit 115.

[0077] In this embodiment, each first radiating unit 112 in the phased array antenna adopts a zigzag radiating patch to achieve antenna miniaturization. The equivalent radiation length of the patch can be effectively increased. This design not only helps to reduce the overall size of the antenna, but also improves the working performance of the antenna in different frequency bands. The zigzag design can also provide better frequency selectivity, so that the antenna can maintain good radiation characteristics in multiple frequency bands.

[0078] The resistive unit 110 of the phased array antenna in this embodiment surrounds the second radiating unit 115 and the periphery of the frequency selective surface. The resistive unit 110 can also reduce the strong inductive effect between the first radiating unit 112, the second radiating unit 115 and the metal ground. In this embodiment, a double-layer resistive unit 110 is used to reduce the coupling of the second radiating unit 115. In addition, the resistive unit 110 can reduce the strong inductive effect between the vertical radiating patch and the metal ground.

[0079] The feeding unit of the phased array antenna of the embodiment includes a first feeding unit 113 and a second feeding unit 114, wherein the first feeding unit is connected to the first radiating unit 112; and the second feeding unit is connected to the second radiating unit 115. The feeding unit includes a horizontally polarized aperture coupling feeding layer and a vertically polarized aperture coupling feeding layer. The first feeding unit 113 is a horizontally polarized aperture coupling feeding layer, and the second feeding unit 114 is a vertically polarized aperture coupling feeding layer.

[0080] The feed unit includes a first feed unit 113 and a second feed unit 114, wherein the first feed unit is connected to the first radiation unit 112, and the second feed unit is connected to the second radiation unit 115. The feed unit includes a horizontally polarized aperture coupling feed layer and a vertically polarized aperture coupling feed layer. Figure 3 Schematic diagram of aperture coupling feeding layer, the feeding layer is located at the bottom layer of the antenna unit structure, and its function is to feed the antenna, and can realize H / V dual polarization feeding. The first feeding unit 113 is a horizontally polarized aperture coupling feeding layer, and the second feeding unit 114 is a vertically polarized aperture coupling feeding layer.

[0081] Combined with reference Figure 7-Figure 10 In the figure, the horizontal axis is frequency and the vertical axis is isolation. Figure 7 is the isolation between the central antenna unit and all surrounding antenna units when no FSS layer is added, Figure 8 is the superposition of the coupling degree between all surrounding antenna units and the central antenna unit when the FSS layer is not added. Fig. 9 When adding the FSS layer, the isolation between the central antenna unit and all surrounding antenna units is: Fig.10 This is the superposition of the coupling degrees of all surrounding antenna units and the central antenna unit when the FSS layer is added. It can be seen that after adding the FSS layer, the antenna isolation increases by more than 6dB.

[0082] Therefore, the phased array antenna described in the present invention can significantly improve the overall performance of the antenna system and meet the requirements of modern wireless communication systems for high-performance antennas.

[0083] In summary, the antenna unit structure and the phased array antenna composed of the antenna unit structure disclosed in the present invention respectively have high reflection or high transmission characteristics for electromagnetic waves outside the working frequency band, and low reflection or low transmission characteristics for electromagnetic waves of other frequencies by fixing the frequency selective surface on the first radiation unit and using the frequency selective surface decoupling technology, thereby improving the out-of-band isolation characteristics of the antenna.

[0084] In addition, by fixing the frequency selective surface on the first radiation unit and using the frequency selective surface decoupling technology, the first radiation unit has high reflection or high transmission characteristics for electromagnetic waves outside the working frequency band, and low reflection or low transmission characteristics for electromagnetic waves of other frequencies, which can improve the out-of-band isolation characteristics of the antenna.

[0085] In addition, the frequency selective surface structure can be designed to suppress electromagnetic waves outside the array element, and confine the electromagnetic waves of each unit within the array element. This directivity control can reduce the direct coupling of electromagnetic waves radiated from one antenna to another antenna. The frequency selective surface structure can suppress surface waves propagating on the surface of the medium and reduce the occurrence of standing wave deterioration caused by increased coupling between antennas during large-angle scanning.

[0086] The implementation method of the present invention is described herein using specific examples, and the above description of the implementation method is only used to help understand the core idea of ​​the present invention.

[0087] In general, terms should be understood at least in part by their use in the context. For example, at least in part depending on the context, the term "one or more" used herein may be used to describe any feature, structure, or characteristic in the singular sense, or may be used to describe a combination of features, structures, or characteristics in the plural sense. Similarly, at least in part depending on the context, terms such as "the" may also be understood to convey singular usage or plural usage. The terms "first" and "second" used herein are merely used to name a certain feature, structure, or characteristic, to facilitate the description of the other feature, structure, or characteristic, and are not intended to limit their order, position, etc.

[0088] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0089] Finally, it should be noted that: for those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all of these changes and deformations should fall within the scope of protection of the claims of the present invention.

Claims

1. An antenna unit structure, comprising a first radiating unit, a second radiating unit and a feeding unit; the first radiating unit is arranged between the upper second radiating unit and the lower feeding unit; characterized in that: It also includes a frequency selective surface, which is used to transmit the electromagnetic waves of the first radiation unit, and is also used to suppress the electromagnetic waves in the direction outside the antenna unit, and confine the electromagnetic waves of the corresponding antenna unit within the antenna unit; the reflection coefficient and the transmission coefficient are calculated by performing spectrum analysis on the frequency selective surface; The first radiation unit includes a main body and a plurality of sawtooth extensions; the center of the main body has a through hole; each sawtooth extension is fixed to the main body and extends into the through hole; the plurality of sawtooth extensions are arranged at intervals; the first radiation unit includes a plurality of polygonal figures, which are distributed on the main body of the first radiation unit in a centrally symmetrical manner with the center of the through hole as the center of the circle; the polygonal figures include at least two sizes of quadrilaterals; a gap is formed between two adjacent polygonal figures; the frequency selection surface is composed of the polygonal figures; the frequency selection surface is an aperture type.

2. The antenna unit structure according to claim 1, characterized in that: The four sides of the two sizes are arranged in an array to form a matrix; the number of the matrix is ​​at least two.

3. The antenna unit structure according to claim 1 or 2, characterized in that: The plurality of sawtooth extensions are arranged in a circular array; the maximum diameter of each sawtooth extension is 1 / 5-1 / 3 of the maximum aperture of the through hole.

4. The antenna unit structure according to claim 1 or 2, characterized in that: The process of calculating the reflection coefficient and transmission coefficient by spectrum analysis of the frequency selective surface is as follows: Through Fourier transform, the frequency selective surface spectrum domain is obtained using the following formula: in, ; ; , where is the magnetic permeability of vacuum, a and b are the unit period values ​​in two periodic directions, k0 is the wave vector size corresponding to the wavelength in vacuum, is the Green's function in the spectral domain; H x inc is the magnetic field intensity of the incident wave in the x direction, H y inc is the magnetic field intensity of the incident wave in the y direction; α mn , β mn The tangential wave number in the two-dimensional periodic direction respectively; k x , k y are the wave vector components of the incident plane wave in the x and y directions of the illumination plane respectively; Ω is the tilt angle of the two periodic directions of the frequency selective surface; where θ and φ are the incident angle and azimuth of the plane wave respectively; and They represent the tangential equivalent magnetic currents in the X and Y directions respectively, and j is a natural number.

5. The antenna unit structure according to claim 1 or 2, characterized in that: A resistive unit is also included, and the resistive unit surrounds the second radiation unit and the outer periphery of the frequency selective surface.

6. The antenna unit structure according to claim 5, characterized in that: The square resistance of the resistive unit is 60-70Ω / sq; or 70-80Ω / sq.

7. The antenna unit structure according to claim 1 or 2, characterized in that: The feed unit includes a first feed unit and a second feed unit, the first feed unit is connected to the first radiation unit; the second feed unit is connected to the second radiation unit.

8. A phased array antenna, characterized in that: It comprises at least two antenna unit structures; the antenna unit structure is the antenna unit structure according to any one of claims 1 to 7; the edges of adjacent antenna unit structures are in contact with each other; and the frequency selective surface of each antenna unit structure is used to suppress the electromagnetic waves radiated from one antenna unit from being directly coupled to another antenna unit.

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