An antenna array side edge reflector with isolation circuit and array antenna

Abstract

An antenna array side edge reflecting element with an isolation circuit and an array antenna, side edge reflecting elements are arranged on both sides of the array antenna and between adjacent radiation element columns, the side edge reflecting element comprises a first filter unit for filtering electric fields between co-polarization and / or different polarization of different antenna radiation elements in the same frequency band, a second filter unit for filtering different frequency band radiation elements, a radiator circuit receiving the filtered induced current and generating directional radiation waves towards the antenna radiation direction, and a grounding circuit connected with the antenna ground plate. Applied to a multi-frequency dual-polarized antenna, it can filter out radio wave interference, so that each antenna in the array can work well within the working frequency band, and the waves directed to both sides by each column of antenna array elements can be well directed to the array pointing angle direction without causing interference to the antenna itself. In the case of miniaturization of the array, good port isolation can be obtained between all working frequency band antenna elements.

Description

Technical Field

[0001] This invention relates to a communication antenna, specifically an antenna array side reflector with isolation circuitry and an array antenna. Background Technology

[0002] With the rapid development of 5G communication technology, the miniaturization of base stations is becoming increasingly important. However, as the size of base stations gradually decreases, the spacing between array elements gradually diminishes, leading to increased interference between array elements. For multiple-input multiple-output (MIMO) arrays composed of multiple array elements, the distance between each array element is also gradually decreasing, exacerbating the interference problem between array elements.

[0003] To address the issues of mutual interference between antenna elements in each column and low antenna gain due to the small size of the reflectors, many scholars both domestically and internationally have conducted research. The common approach is to install side reflectors on the sides of each column of antenna elements. Existing side reflectors are typically in the form of metal strips. When antenna elements are compactly packed together in the array, the added side reflectors may cause interference between antenna elements in the same column. Furthermore, when the array contains dual-polarized antennas operating in multiple frequency bands, the side reflectors can also interfere with antennas operating in other frequency bands. Therefore, when the array size is small, conventional side reflectors have gradually become ineffective, and the frequency band that the reflectors can operate in is insufficient to meet the array's requirements. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of conventional side reflectors in meeting the requirements of miniaturized array antennas, and to provide an antenna array side reflector with isolation circuit and an array antenna.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an antenna array side-reflecting element with isolation circuit, comprising:

[0006] The first filtering unit has phase selection characteristics and filters the electric field between the same polarization and / or different polarizations of different antenna radiating elements in the same frequency band within the operating frequency band.

[0007] The radiating circuit is connected to the first filter unit, receives the induced current filtered by the first filter unit, and generates radio waves that are radiated in a directional manner toward the antenna radiation direction.

[0008] A grounding circuit is connected to the first filter unit and / or the radiator circuit, and is connected to the antenna ground plane.

[0009] The first filtering unit intercepts and filters out the same-direction currents and / or different-phase currents with a phase difference of 90° formed by the electric field waves of different antenna radiating units.

[0010] Furthermore, it also includes a second filtering unit, which has frequency selectivity. When the first filtering unit operates in the low-frequency band, the second filtering unit operates in the high-frequency band and filters the electric field of the high-frequency antenna radiating unit.

[0011] The radiator circuit includes two symmetrically arranged directional radiators, and a filter circuit is connected between the two directional radiators. The filter circuit forms either the first filter unit or the first filter unit and the second filter unit.

[0012] The radiator circuit also includes a Vivaldi radiator, which is positioned between the two directional radiators and connected to the directional radiators on both sides via two sets of filter circuits.

[0013] The radiator circuit includes two symmetrically arranged directional radiators and two sets of strip circuits. The two sets of strip circuits are respectively connected to the two directional radiators. Each set of strip circuits includes two strips of different lengths. The two sets of strip circuits are symmetrically arranged to form a dipole radiator. The two strips of different lengths in each set of strip circuits are connected by a filter circuit. The filter circuit forms the first filter unit or the first filter unit and the second filter unit.

[0014] The radiator circuit and the filter circuit are respectively disposed on both sides of the dielectric substrate and connected through vias on the dielectric substrate. The two sets of line circuits are respectively connected to the two directional radiators through the connection circuit and vias on the other side of the dielectric substrate.

[0015] The present invention also provides an array antenna, wherein the above-mentioned antenna array side reflective elements with isolation circuits are provided on both sides of the array antenna and between adjacent rows of radiating elements.

[0016] Furthermore, the array antenna includes a first radiating element operating in a first frequency band and a second radiating element operating in a second frequency band, wherein the frequency of the first frequency band is higher than that of the second frequency band; the side reflective element of the antenna array is divided into a first reflective element disposed on both sides of the array antenna and between adjacent columns of the first radiating elements, and a second reflective element disposed on both sides of the array antenna and between adjacent columns of the second radiating elements; the first filter unit and radiator circuit of the first reflective element operate in the first frequency band, and the first filter unit and radiator circuit of the second reflective element operate in the second frequency band.

[0017] Furthermore, in the first and second reflective elements disposed on both sides of the array antenna, the radiator circuit includes two symmetrically arranged directional radiators, and a filter circuit in the form of the first filter unit is connected between the two directional radiators.

[0018] The radiator circuit also includes a Vivaldi radiator, which is positioned between the two directional radiators and connected to the directional radiators on both sides via two sets of filter circuits.

[0019] The second reflective element further includes a second filtering unit, which has frequency selectivity. The second filtering unit operates in the first frequency band and filters the electric field of the first radiating unit.

[0020] The radiator circuit, which is disposed between adjacent first radiating unit columns and between adjacent second radiating unit columns, includes two symmetrically arranged directional radiators and two sets of strip circuits. The two sets of strip circuits are respectively connected to the two directional radiators. Each set of strip circuits includes two strips of different lengths. The two sets of strip circuits are symmetrically arranged to form a dipole radiator. The two strips of different lengths in each set of strip circuits are connected by a filter circuit. The filter circuit forms either the first filter unit or the first filter unit and the second filter unit.

[0021] The first and second radiation units are dual-polarized radiation units. The first reflective element is disposed on the oblique side of the first radiation unit, and the second reflective element is disposed on the oblique side of the second radiation unit, with its center offset from the center of the first radiation unit in a direction perpendicular to the array.

[0022] The first and second reflective elements are cascaded between adjacent first radiating element columns and between adjacent second radiating element columns, and are coupled to the antenna ground plane through corresponding grounding circuits.

[0023] The array antenna provided by the present invention further includes one or more columns of third radiating elements, the columns of third radiating elements operating in one or more frequency bands, and the operating frequency band of the third radiating elements being different from the first frequency band and the second frequency band; the side reflective element is further divided into third reflective elements that match the operating frequency band of the third radiating element.

[0024] The beneficial effects of this invention are as follows: The first filtering unit of the side-reflecting element can filter out electromagnetic interference between different antenna radiating elements in the same or different columns of the same frequency band, ensuring that all antennas in the array can operate well within their operating frequency band, maintaining normal radiated power, half-power beamwidth, front-to-back ratio, and cross-polarization ratio. The remaining filtered current is radiated back to the main radiation direction of the array through the radiating circuit, thus providing gain. Applied to multi-frequency dual-polarized antennas, it can filter out electromagnetic interference, ensuring that all antennas in the array can operate well within their operating frequency band. The radiating circuit of the side-reflecting element serves as a radiating unit on the side reflection band and can form an array on the side reflection band, ensuring that waves from each column of antenna elements directed to both sides are well radiated back to the array's pointing angle by the side reflection band without interfering with the antennas themselves. Even with a miniaturized array, good port isolation can be achieved between the ports of all antenna elements in all operating frequency bands. The reflection strip composed of side-reflecting elements can control the half-power beamwidth of the main radiation beam to 65+ / -10° when it is close to the array elements, achieving the industry's top level. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the topology of the side reflector element of the high-frequency radiating unit in the base station antenna array.

[0026] Figure 2 This is a schematic diagram of the topology of the side reflector element of the low-frequency radiating unit in the base station antenna array.

[0027] Figure 3 This is a schematic diagram of the topology of the side reflector element of a dual-band antenna in a base station antenna array.

[0028] Figure 4 This is a schematic diagram of the first embodiment of the side-reflecting element.

[0029] Figure 5 This is a schematic diagram of the first surface of the second embodiment of the side-reflecting element.

[0030] Figure 6 This is a schematic diagram of the second surface of a second embodiment of a side-reflecting element.

[0031] Figure 7 This is a schematic diagram of embodiment 1 of a dual-frequency antenna array according to the present invention.

[0032] Figure 8 yes Figure 7 The simulation results of half-power beamwidth when a column of high-frequency radiating elements is excited, as shown in the embodiment.

[0033] Figure 9 yes Figure 7The figure shows the simulation results of half-power beamwidth when a column of low-frequency radiating elements is excited, according to the embodiment shown.

[0034] Figure 10 yes Figure 7 Simulation results of the same-port isolation between high-frequency radiation unit columns in the illustrated embodiment.

[0035] Figure 11 yes Figure 7 Simulation results of the inter-port isolation of the low-frequency radiation unit in the embodiment shown.

[0036] Figure 12 This is a schematic diagram of another embodiment of a dual-frequency antenna array according to the present invention.

[0037] The markings in the diagram are: 1. High-frequency radiating element, 2. Low-frequency radiating element, 3. Antenna ground plane, 4. First reflector element, 5. Second reflector element, 6. Directional radiator, 7. Vivaldi radiator, 8. Filter circuit, 9. Strip circuit, 10. Connection circuit, 11. Dielectric substrate. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. The specific contents listed in the following embodiments are not limited to the technical features necessary to solve the technical problem described in the claims. Furthermore, the enumerations are merely a part of the present invention, and not all of the embodiments.

[0039] The side-reflecting element of the antenna array with isolation circuit of the present invention includes a first filtering unit, a radiating element circuit, and a grounding circuit. Depending on the radiating element targeted by the side-reflecting element, the first filtering unit and the radiating element circuit operate in the corresponding frequency band. The first filtering unit for high-frequency radiating elements operates in a higher frequency band, and the first filtering unit for low-frequency radiating elements operates in a lower frequency band. The first filtering unit is used to filter out electric field interference between different radiating elements within the operating frequency band. The radiating element circuit is connected to the first filtering unit, receives the induced current filtered by the first filtering unit, and generates an electromagnetic wave with the same polarization as the incoming wave, radiating it directionally in the antenna radiation direction.

[0040] The first filtering unit has phase selection characteristics, filtering the electric field between different antenna radiating elements with the same polarization and / or different polarizations within the operating frequency band. For example, it filters the electric field between two antennas with the same polarization or between different polarizations, or it filters the electric field between adjacent radiating elements in the same column with different polarizations to improve the isolation between ports with different polarizations. When the electric field propagates from two mutually opposite points and induces a current in the circuit structure of the side reflector element, a portion of the in-phase current is intercepted and filtered out by the first filtering unit, while the current with a 90° phase difference is intercepted and filtered out by another portion of the first filtering unit. The remaining current flows to the radiating circuit and generates an electromagnetic wave with the same polarization as the incoming wave, radiating directionally towards the base station radiation direction.

[0041] For side reflectors used in dual-band or multi-band antennas, since the side reflector for the low-frequency antenna radiating element is generally positioned higher, when the base station operates in a higher frequency band, a portion of the circuitry in this low-frequency side reflector will inevitably be higher than the high-frequency antenna radiating element. Therefore, some of the electric field from that frequency band will inevitably strike this circuitry. A second filtering unit targeting different frequency bands can also be incorporated into this side reflector. This second unit has frequency selectivity and will intercept and filter out the induced current generated by the radiated electric field from the high-frequency antenna radiating element.

[0042] The grounding circuit is used to connect the side reflector to the antenna ground plane. The first part of the grounding circuit connects the relevant circuit structures in the side reflector. This part can connect only the necessary grounded circuit structures, and the circuit structures should be connected separately as much as possible to avoid changing the current path. The other part of the grounding circuit is coupled to the antenna ground plane. Coupled grounding ensures that its current has minimal impact on other modules of the base station and minimal impact on the base station's third-order intermodulation.

[0043] Figure 4 In the illustrated embodiment, the radiator circuit includes two symmetrically arranged directional radiators 6 and one Vivaldi radiator 7. The Vivaldi radiator is positioned between the two directional radiators 6 and connected to the directional radiators on both sides via two sets of filter circuits 8. The two sets of filter circuits 8, in the form of bent-line band-stop filters, form the first filter unit, which is responsible for intercepting and filtering out electric field waves of different polarizations from different antenna radiating elements in the same antenna array. This ensures that the 45° polarized electric field signal and the -45° polarized electric field signal do not interfere with each other after reaching the reflection boundary, thereby preventing the isolation between different polarization ports of the same antenna array from deteriorating due to the use of side reflective elements.

[0044] In this embodiment, the directional radiator 6 is a circular radiator. The radiation direction of the directional radiator can be changed by altering the position of the current feed into the radiator and the length and width of the radiator. The directional radiator 6 can also be square, square ring, circular ring, or double ring with unequal length and width, etc.

[0045] Depending on actual needs, the structure and implementation of the filter circuit 8 can be changed so that it can also filter the electric field between the same polarization of different antenna radiating elements, or simultaneously implement the second filter unit.

[0046] Directional radiator 6 and Vivaldi radiator 7 are responsible for beam reflection. Simulations show that within a certain frequency band, by making the radius of directional radiator 6 appropriately sized and exciting it at a certain position, the direction of its radiated beam can be significantly deflected within the lateral and axial range of the directional radiator, and its gain in the main radiation direction can reach approximately 5 dBi. By using the directional radiator, side-incoming radio waves can be directionally radiated back to the main radiation direction of the array, maximizing the gain. By using the Vivaldi antenna radiator, radio waves can be further radiated along the main radiation direction of the array, making the half-power beamwidth and gain of the base station antenna controllable. By combining the filter circuit, directional radiator, and Vivaldi radiator, without compromising the isolation between the array antenna elements at a lower cost, and while miniaturizing the array, beams directed towards both sides of the antenna can be directionally radiated back to the main radiation direction of the base station antenna, making it suitable for various base station antennas currently on the market.

[0047] Figure 5 and Figure 6 In the illustrated embodiment, the radiator circuit includes two symmetrically arranged directional radiators 6 and two sets of line circuits 9, disposed on one side of the dielectric substrate 11. The operation mode of the two directional radiators 6, which are symmetrical about the structural center, is similar to... Figure 4 The illustrated embodiment is similar; when it receives current transmitted through the striplines, it can radiate it directionally towards the main radiation direction of the array. Each stripline circuit includes two striplines of different lengths. These two striplines transmit current on one side, with the longer stripline responsible for transmitting current in the lower frequency band of the operating frequency band, and the shorter stripline responsible for transmitting current in the higher frequency band. In both sets of stripline circuits, the two longer striplines and the two shorter striplines are symmetrical about the structural center, and they themselves can form a dipole radiator, reflecting incoming waves.

[0048] The other side of the dielectric substrate 11 is as follows Figure 6As shown, two sets of filter circuits 8 and two symmetrically arranged vertical connection circuits 10 are provided. The two sets of filter circuits 8 are respectively connected to two striplines of different lengths in two sets of stripline circuits on the other side of the dielectric substrate via vias. One end of the connection circuit 10 is connected to the longer stripline in the stripline circuit via a via, and the other end is connected to the directional radiator 6 via a via. Adjusting the position of the via connecting to the directional radiator 6 controls the current feed position into the directional radiator, thereby controlling the current distribution on the radiator. The impedance matching and radiation direction of the directional radiator are determined by the via position and the radius of the radiator. Adjusting the length and width of the connection circuit 10 controls the phase and impedance of the radio wave when it reaches the directional radiator.

[0049] Figure 6 The two sets of filter circuits 8 shown employ multiple bent lines with varying lengths and widths to form a high-order filter circuit structure, equivalent to a high-order band-stop filter. By controlling its dimensions, it can be used in different frequency bands. It can filter out unwanted radio waves in its own operating frequency band, as well as cross-band interference waves from other frequency bands. Depending on the needs, this filter circuit can be used to form the first filter unit or the first filter unit and the second filter unit.

[0050] The specific forms of the first and second filtering units are set according to actual needs and are not limited to the above embodiments. For example, high-order band-stop filter circuits can be manufactured by using bent strips of various sizes or by cascading bent strips with straight broadband lines. Alternatively, components capable of achieving inductive and capacitive characteristics can be combined in series or parallel, and broadband filtering can be achieved through different parameter combinations. The bent strips are not limited to those on the same plane. Any combination of bent strips of varying sizes, whether uniformly or non-uniformly distributed in different spaces or on different layers of a dielectric substrate, or using spiral, sine, or cosine distributed lines or metal tubes in a plane or space to manufacture combinations of bent strips or bent metal tubes with varying dimensional parameters, should be covered within the scope of this application.

[0051] Figure 1The above describes an embodiment of a high-frequency radiating unit and its two side-reflecting elements. In this embodiment, the high-frequency radiating unit is a ±45° dual-polarized radiating unit. The electric field polarization direction of each radiating unit is towards the array + / -45° direction. Therefore, the electric field wave that can be received in the + / -45° direction of the radiating unit is the largest. Thus, it is preferable to place the side-reflecting elements in the + / -45° direction of the radiating unit for better reflection or filtering effect. If the side-reflecting elements are placed on both sides of the radiating unit, and the line connecting their structural centers and the structural centers of the radiating unit is parallel to the array radially (i.e., the side-reflecting elements are located in the 90° direction of the radiating unit), when the radiating unit is excited, the current reaching the end of the radiator responsible for one polarization will radiate to the side-reflecting element, and then be transmitted from one end of the side-reflecting element to the other end, finally radiating to the end of the radiator responsible for the other polarization. This causes a change in the current path of the radiating unit, resulting in a deterioration in isolation in the operating frequency band. Therefore, even if spatial constraints prevent the side reflective elements from being fully positioned in the + / -45° direction of the radiating element, they should be avoided in the 90° direction. Instead, the side reflective elements should be positioned obliquely to the side of the high-frequency radiating element. Each of the two side reflective elements is responsible for one of the polarization electric fields on the high-frequency radiating element, and a certain distance is maintained between them to prevent the isolation between the two ports of the LPA array element from deteriorating.

[0052] When the side reflector is placed on both sides of the radiating element, it excites a certain polarization port of the radiating element. The resulting current is transmitted through the end of the radiator to the side reflector near the oscillator. Without a filter, this current will flow to the other end of the side reflector and radiate to the radiator of another radiating element near that end, thus affecting the standing wave of that radiating element. Therefore, placing the side reflector on both sides of the radiating element may affect the isolation between the different polarization ports of two adjacent radiating elements. Since this effect is not very serious, it can be effectively removed by using the first filter unit set in the side reflector, thereby improving the port isolation between adjacent array elements.

[0053] Figure 2 The diagram shows an embodiment of the arrangement of a row of low-frequency radiating elements and the side reflectors on both sides. (Compared to...) Figure 1 The same applies to the embodiment, where the side-reflecting element should also be located on the oblique side of the low-frequency radiation unit.

[0054] Figure 3The diagram illustrates an embodiment of the side-reflecting element arrangement for a dual-band antenna. It includes two columns of high-frequency radiating elements 1 and one column of low-frequency radiating elements 2. Each side of the array antenna has a column of first reflective elements 4, corresponding to the two columns of high-frequency radiating elements 1. The middle column of first reflective elements 4 is arranged in conjunction with the positions of the low-frequency radiating elements 2, following the aforementioned rules. Second reflective elements 5 for the low-frequency radiating elements 2 are arranged on both sides of the array antenna according to the aforementioned rules, and the centers of the second reflective elements 5 are not on the same vertical plane as the centers of any of the high-frequency radiating elements 1, but are offset in a direction perpendicular to the array.

[0055] Figure 7 The diagram shows a first embodiment of a dual-band antenna array using the side-reflecting element of this invention. It includes four columns of high-frequency radiating elements 1 and two columns of low-frequency radiating elements 2. The high-frequency radiating elements 1 are the first radiating elements, operating in the first frequency band of 1.4~2.7GHz, and the low-frequency radiating elements 2 are the second radiating elements, operating in the second frequency band of 0.69~0.96GHz. The center-to-center spacing of the low-frequency radiating elements 2 is only 120mm, and the center-to-center spacing of the high-frequency radiating elements 1 is only 110mm. When the array operates at 0.69~0.96GHz and 1.4~2.7GHz, without the side-reflecting element, the interference between the two columns of elements is very large, making it impossible for any single column of elements to independently complete its work effectively. Especially when operating at 0.69~0.75GHz and 1.4~1.9GHz, the half-power beamwidth (HPBW) of the radiation pattern is greater than 90°, and the isolation is around -15dB, far below the specifications for base station antennas.

[0056] like Figure 7 As shown, corresponding side-reflecting elements are arranged on both sides and between columns of the array antenna according to the above rules. These are divided into a first reflective element 4 for the high-frequency radiation unit 1 and a second reflective element 5 for the low-frequency radiation unit 2. The first filter unit and radiator circuit of the first reflective element 4 operate in the first frequency band, and the first filter unit and radiator circuit of the second reflective element 5 operate in the second frequency band.

[0057] In this embodiment, the first reflective element 4 and the second reflective element 5 disposed on both sides of the array antenna can be adopted Figure 4 The illustrated embodiment is shown in the figure. By changing the size and structure of the relevant circuits, they can be made to operate in the corresponding frequency band. For example, the filter circuit 8 in the form of a bent-line band-stop filter in the figure can be reduced to the size required for the high-frequency radiation unit 1, and can then be used as the first filter unit for the first reflective element 4; conversely, it can be increased to the size required for the low-frequency radiation unit 2, and can then be used as the first filter unit for the second reflective element 5. The filter circuit 8 in the form of a bent-line band-stop filter in the figure is mainly used to improve the isolation between ports with different polarizations between adjacent array elements in the same column.

[0058] For a Vivaldi radiator, its operating and radiation bandwidths are both relatively wide, making it suitable for a broad frequency range. Due to the small array size and low element height, the antenna exhibits a wide beamwidth and lower gain in the pointing direction when operating at 0.69–0.75 GHz and 1.4–1.7 GHz. A directional radiator is positioned to radiate in the array's radiation direction within these frequency bands, thus reducing the bandwidth in the 0.69–0.75 GHz and 1.4–1.7 GHz bands without affecting the bandwidth in the 0.76–0.96 GHz and 1.71–2.7 GHz bands. By altering the structural dimensions and feed point location of the directional radiator, it can be adapted to either the first reflecting element 4 or the second reflecting element 5.

[0059] The first reflective element 4 and the second reflective element 5 set between adjacent columns can be adopted Figure 5 and 6 The embodiment shown is as follows. By changing the current structure in the figure, it can be made to operate in the corresponding frequency band. For the two sets of strip circuits 9 with different lengths that are symmetrical about the center of the structure, their function is not only as transmission circuits, but they can also act as dipole radiators to reflect the electric field back. Therefore, by modifying the length of the upper and lower strips, their radiation frequency band can be controlled, making them operate in the two frequency bands of 0.69~0.96GHz and 1.4~2.7GHz, which are the operating frequency bands of the array. By modifying the strip length of the equivalent dipole radiator, creating a length difference between the two arms, its radiation direction can be changed, achieving the effect of directional radiation. Similarly, by modifying the size of the directional radiator and the position of the vias in the figure, its radiation direction and operating frequency band can also be changed. By changing Figure 6 The size and circuit order of the mid-to-high-order band-stop filter circuit 8 can meet the requirements of the first filter unit in the first reflective element 4 and the second reflective element 5, respectively. As needed, it can realize electric field filtering between the same polarization of the two antennas and electric field filtering between different polarizations of the two antennas.

[0060] exist Figure 7 In the illustrated embodiment, every two first reflective elements 4 and one second reflective element 5 for the low-frequency radiating element 2 between the two columns of high-frequency radiating elements 1 are placed on a dielectric substrate. The second reflective element 5 for the lower frequency band is positioned above or diagonally above the first reflective element 4 for the higher frequency band. Through cascading with striplines, the current of the three modules is guided from both sides or the middle to the grounding circuit below the structure, and finally coupled to the antenna ground plane 3. A second filtering unit is also provided in the second reflective element 5 for the low-frequency radiating element 2 between columns, which can also be implemented using a filtering circuit 8.

[0061] exist Figure 7In the illustrated embodiment, the side-reflecting elements can filter out interference between any two array elements and, without interfering with other array elements or elements operating in other frequency bands within the same array, direct the electromagnetic waves directed to both sides back to the main radiation direction of the array. When the middle row of high-frequency radiating elements is excited, the half-power beamwidth of its array radial pattern as a function of frequency is shown in the curve. Figure 8 As shown, when a column of low-frequency radiating elements on the left is excited, the half-power beamwidth of its array radial pattern varies with frequency as follows: Figure 9 As shown. The isolation between high-frequency and low-frequency columns is as follows. Figure 10 and 11 As shown. In the case of array miniaturization, the side-reflecting element of this invention forms a side-reflecting band, maintaining the half-power beamwidth of the antenna operating in the higher frequency band at 65°+ / -5° and the half-power beamwidth of the antenna operating in the lower frequency band at 70°+ / -5°. The filter circuit structure mounted on the side-reflecting band ensures that the isolation between different columns of antennas in all operating frequency bands of the array reaches below -25dB at each port, allowing each antenna in the array to operate well within its operating frequency band, maintaining normal radiated power, half-power beamwidth, front-to-back ratio, and cross-polarization ratio. The materials used in the above experiments are relatively inexpensive FR4 series dielectric substrates with a dielectric constant of 4.4~5.2. If a dielectric substrate with higher precision and lower loss, such as the Rogues 5880, is used, the effect of this technology will be even better.

[0062] Figure 12 This is another embodiment of a dual-band antenna. It consists of an array of 16 high-frequency radiating elements operating at 1.4–2.7 GHz and 8 low-frequency radiating elements operating at 0.69–0.96 GHz, arranged in a manner similar to… Figure 7 The implementations differ, but each array element operates well at 0.69~0.96GHz and 1.4~2.7GHz, and its radiation pattern remains normal.

[0063] The above are embodiments for dual-band array antennas. When the antenna array contains three or more frequency bands, that is, in addition to the first and second radiating elements operating in the first and second frequency bands, it also includes one or more columns of third radiating elements. These columns of third radiating elements operate in the third frequency band, or they operate in the third, fourth, or even more frequency bands respectively. The side-reflecting element should also be divided into third reflective elements that match the operating frequency band of the third radiating element. The specific form and placement of the third reflective element follow the above principles. Modifying its structural dimensions can make it suitable for the required frequency band. When used as a radiating element in each frequency band and operating in its respective frequency band, it will not cause any interference to the antenna operating in other frequency bands due to the side-reflecting element.

[0064] In addition to copper plating on a dielectric substrate, the side-reflecting element of this invention can also be implemented by directly using metal components. Laboratory tests have shown that using various shapes of metal structures such as aluminum strips, sheets, and plates to implement the circuit structure, with material thicknesses ranging from 1 to 3 mm, achieves good results. Specifically, when the spacing between each column of the array is slightly less than 1 / 4λ wavelength of the working array element (i.e., the array is miniaturized), the operation of any element in the array will not affect any element in other columns, and the port isolation between each column of elements is less than -25 dB.

[0065] The side-reflecting element is implemented without any solder joints. Its bottom can be fixed to the base station power divider board by placing a plastic or metal base and screwing it in, allowing the side-reflecting strip to be plugged in and unplugged. If a more flexible sliding rod is used to load the plastic base and fix the side-reflecting strip, axial movement of the reflective strip can also be achieved, making the topology position of the reflective strip intelligently adjustable. The side-reflecting strip has a maximum size of only 117mm*60mm*1mm, uses inexpensive materials, and has a simple manufacturing process, making it suitable for mass production.

[0066] The above description of specific embodiments is only for the purpose of helping to understand the technical concept and core idea of ​​the present invention. Although specific preferred embodiments have been used to describe and illustrate the technical solutions, they should not be construed as limiting the present invention itself. Those skilled in the art can make various changes in form and detail without departing from the technical concept of the present invention. These easily conceived changes or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A side-reflecting element for an antenna array with isolation circuitry, characterized in that: include: The first filtering unit has phase selection characteristics and filters the electric field between the same polarization and / or different polarizations of different antenna radiating elements in the same frequency band within the operating frequency band. The radiating circuit is connected to the first filter unit, receives the induced current filtered by the first filter unit, and generates radio waves that are radiated in a directional manner toward the antenna radiation direction. A grounding circuit, which is connected to the first filter unit and / or radiator circuit, and connected to the antenna ground plane; The radiator circuit includes two symmetrically arranged directional radiators (6), and a filter circuit (8) is connected between the two directional radiators. The filter circuit forms the first filter unit. The radiator circuit also includes a Vivaldi radiator (7), which is arranged between the two directional radiators (6) and connected to the directional radiators on both sides via two sets of filter circuits (8). Alternatively, the radiator circuit includes two symmetrically arranged directional radiators (6) and two sets of strip circuits (9). The two sets of strip circuits are respectively connected to the two directional radiators. Each set of strip circuits includes two strips of different lengths. The two sets of strip circuits are symmetrically arranged to form a dipole radiator. The two strips of different lengths in each set of strip circuits are connected through the filter circuit (8). The filter circuit forms the first filter unit.

2. The side-reflecting element of an antenna array with isolation circuit as described in claim 1, characterized in that: The first filtering unit intercepts and filters out the same-direction currents and / or different-phase currents with a phase difference of 90° formed by the electric field waves of different antenna radiating units.

3. The side-reflecting element of an antenna array with isolation circuit as described in claim 1, characterized in that: It also includes a second filtering unit, which has frequency selectivity. When the first filtering unit operates in the low-frequency band, the second filtering unit operates in the high-frequency band and filters the electric field of the high-frequency antenna radiating unit.

4. The side-reflecting element of an antenna array with isolation circuit as described in claim 3, characterized in that: The filtering circuit forms the first filtering unit and the second filtering unit.

5. The side-reflecting element of an antenna array with isolation circuit as described in claim 1, characterized in that: The radiator circuit and the filter circuit are respectively disposed on both sides of the dielectric substrate (11) and connected through vias on the dielectric substrate. The two sets of line circuits (9) are respectively connected to the two directional radiators (6) through the connection circuit (10) and vias on the other side of the dielectric substrate.

6. An array antenna, characterized in that: Antenna array side reflectors with isolation circuits as described in claim 1 or 2 are provided on both sides of the array antenna and between adjacent rows of radiating elements.

7. An array antenna as described in claim 6, characterized in that: It includes a first radiating element operating in a first frequency band and a second radiating element operating in a second frequency band, wherein the frequency of the first frequency band is higher than that of the second frequency band; the antenna array side reflective element is divided into a first reflective element (4) disposed on both sides of the array antenna and between adjacent columns of the first radiating elements and a second reflective element (5) disposed on both sides of the array antenna and between adjacent columns of the second radiating elements; the first filter unit and radiator circuit of the first reflective element operate in the first frequency band, and the first filter unit and radiator circuit of the second reflective element operate in the second frequency band.

8. An array antenna as described in claim 7, characterized in that: The radiator circuit includes two symmetrically arranged directional radiators (6) in the first reflective element (4) and the second reflective element (5) on both sides of the array antenna, and the filter circuit (8) of the first filter unit is connected between the two directional radiators.

9. An array antenna as described in claim 8, characterized in that: The radiator circuit also includes a Vivaldi radiator (7), which is positioned between the two directional radiators (6) and connected to the directional radiators (6) on both sides via two sets of filter circuits.

10. An array antenna as described in claim 7, characterized in that: The second reflective element (5) further includes a second filtering unit, which has frequency selectivity. The second filtering unit operates in the first frequency band and filters the electric field of the first radiating element.

11. An array antenna as described in claim 10, characterized in that: The radiator circuit includes two symmetrically arranged directional radiators (6) and two sets of strip circuits (9) in the first and second reflective elements (4) and the second reflective elements (5) between adjacent first radiating unit columns and adjacent second radiating unit columns. The two sets of strip circuits are respectively connected to the two directional radiators. Each set of strip circuits includes two strips of different lengths. The two sets of strip circuits are symmetrically arranged to form a dipole radiator. The two strips of different lengths in each set of strip circuits are connected by a filter circuit (8). The filter circuit forms the first filter unit or the first filter unit and the second filter unit.

12. An array antenna as described in claim 11, characterized in that: The radiator circuit and the filter circuit are respectively disposed on both sides of the dielectric substrate (11) and connected through vias on the dielectric substrate. The two sets of line circuits (9) are respectively connected to the two directional radiators (6) through the connection circuit (10) and vias on the other side of the dielectric substrate.

13. An array antenna as described in claim 7, characterized in that: The first and second radiation units are dual-polarized radiation units. The first reflective element (4) is disposed on the oblique side of the first radiation unit, and the second reflective element (5) is disposed on the oblique side of the second radiation unit, with its center offset from the center of the first radiation unit in a direction perpendicular to the array.

14. An array antenna as described in claim 13, characterized in that: The first and second reflective elements are cascaded between adjacent first radiating element columns and between adjacent second radiating element columns, and are coupled to the antenna ground plane through corresponding grounding circuits.

15. An array antenna as described in any one of claims 7-14, characterized in that: It also includes one or more columns of third radiating elements, the columns of third radiating elements operating in one or more frequency bands, and the operating frequency band of the third radiating elements being different from the first frequency band and the second frequency band; the side reflective element is further divided into third reflective elements that match the operating frequency band of the third radiating element.

Images