Antenna apparatus and antenna system

Abstract

An antenna apparatus and an antenna system. The antenna apparatus is an antenna array composed of a plurality of micro-strip antenna units. Each micro-strip antenna unit comprises a dielectric substrate, a radiation patch, a metal base plate, a feed probe and a shorting pin, wherein the radiation patch is located on an upper surface of the dielectric substrate; the metal base plate is located on a lower surface of the dielectric substrate; the feed probe runs through the dielectric substrate to connect one end of the radiation patch to the metal base plate; and the shorting pin runs through the dielectric substrate to connect the other end of the radiation patch to the metal base plate. By configuring a shorting pin on a radiation patch and simultaneously exciting a first-order mode and a second-order mode, the radiation power of micro-strip antenna units in a preset region can be suppressed to generate a radiation null, such that signals radiated by the micro-strip antenna units can realize asymmetry, thereby realizing the asymmetry of an antenna array. By using an antenna system composed of the antenna array, the coupling suppression of a transceiving array of the antenna system can be realized, thereby improving the isolation degree of the transceiving array.

Description

Antenna device and antenna system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on July 12, 2023, with application number 202310862249.2 and invention name “An antenna device and antenna system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communications, and in particular to an antenna device and an antenna system. Background Art

[0003] With the increasing demand for mobile communication capacity, not only are base station communication frequencies gradually shifting towards higher bandwidth bands, but also higher requirements are being placed on full-duplex communication in high-frequency macro base stations. For example, if a base station simultaneously handles the transmission of enhanced mobile broadband (eMBB) and uplink ultra-wideband (UL-centric broadband communication, UCBC), a certain degree of isolation is required when eMBB and UCBC operate simultaneously on the same frequency to minimize mutual interference between arrays within the base station. Therefore, improving the isolation between the transmit and receive arrays to ensure the proper operation of full-duplex systems in high-frequency macro base stations is a key research direction in current base station communications.

[0004] In this regard, traditional technology proposes to load an isolation wall in the transmitting and receiving antenna array, and to achieve decoupling between the transmitting and receiving array surfaces by loading a choke slot in the isolation wall, thereby improving the isolation of the transmitting and receiving array surfaces.

[0005] However, the decoupling structures used in traditional technologies (e.g., isolation walls, choke slots, etc.) are large in size and difficult to apply to application scenarios such as compact arrays and multiple-input multiple-output (MIMO).

[0006] Therefore, there is an urgent need for an antenna device that can solve the decoupling problem between the transmitting and receiving arrays and thus improve the isolation between the transmitting and receiving arrays.

[0007] Summary of the Invention

[0008] The present application provides an antenna device and an antenna system for suppressing the coupling of the antenna system's transceiver arrays by suppressing the radiation power at a specific angle, thereby improving the isolation of the transceiver arrays.

[0009] In a first aspect, the present application provides an antenna device, which is an antenna array composed of multiple microstrip antenna units. Each microstrip antenna unit includes at least one polarization unit, and each polarization unit includes a dielectric substrate, a radiating patch, a metal base plate, a feeding probe, and a short-circuit post. The radiating patch is located on the upper surface of the dielectric substrate, the metal base plate is located on the lower surface of the dielectric substrate, the feeding probe passes through the dielectric substrate to connect one end of the radiating patch to the metal base plate, and the short-circuit post passes through the dielectric substrate to connect the other end of the radiating patch to the metal base plate. When the antenna device is working, each microstrip antenna unit is used to simultaneously excite the first-order mode and the second-order mode through the radiating patch to generate an asymmetric radiation signal at the operating frequency. The asymmetric radiation signal has a radiation zero point in a preset area, and the operating frequency is between the frequency corresponding to the first-order mode and the frequency corresponding to the second-order mode.

[0010] In this application, by configuring short-circuit posts on the radiating patch and simultaneously exciting the first-order and second-order modes, the radiated power of the microstrip antenna unit in a predetermined area can be suppressed, resulting in a radiation null. This results in asymmetric signals radiated by the microstrip antenna unit, and consequently, asymmetric antenna signals radiated by the antenna array composed of the aforementioned multiple microstrip antenna units. Therefore, an antenna system constructed using this antenna array can suppress coupling between the antenna system's transmit and receive arrays, thereby improving the isolation between the transmit and receive arrays.

[0011] In a possible implementation, the short-circuit post is located near the electric wall generated by the second-order mode on the radiation patch, and the position of the short-circuit post does not overlap with the position of the electric wall generated by the first-order mode on the radiation patch.

[0012] In this embodiment, placing the shorting post near the electrical barrier of the second-order mode shifts the resonant frequency of the first-order mode toward a higher frequency without affecting the resonant frequency of the second-order mode. This helps bring the frequencies corresponding to the first-order mode and the second-order mode closer together, thereby improving the antenna matching effect.

[0013] In a possible implementation manner, the distance between the short-circuit post and the feeding probe is greater than 3 / 4 times the length of the radiation patch, and the length of the radiation patch is related to the wavelength corresponding to the operating frequency.

[0014] In this embodiment, since the electric barrier of the second-order mode is generally located at 3 / 4 of the length of the radiating patch, after adjusting the amplitude and phase by adjusting the shorting post, the distance between the shorting post and the feed probe is greater than 3 / 4 times the length of the radiating patch. This facilitates adjusting the radiation null point to a predetermined area while ensuring that the microstrip antenna unit can radiate non-corresponding signals, thereby facilitating coupling suppression between the antenna system's transceiver arrays and improving the isolation of the transceiver arrays.

[0015] In a possible implementation, the radiation patch presents a branch-loaded slow-wave transmission structure along the length direction, and the length of the radiation patch is less than or equal to 1 / 2 times the wavelength corresponding to the operating frequency.

[0016] Exemplarily, the length of the radiation patch is approximately equal to 0.4 times the wavelength corresponding to the operating frequency.

[0017] In this embodiment, since the size of the microstrip antenna unit is large when the operating frequency point is between the first-order mode and the second-order mode, it may be difficult to be suitable for compact array applications. Therefore, the radiating patch is made into a branch-loaded slow-wave transmission structure, which is beneficial to shortening the size of the radiating patch and significantly reducing the waveguide wavelength, thereby achieving miniaturization of the microstrip antenna unit size.

[0018] In one possible embodiment, at least one polarization unit is a ±45° dual-polarization unit, wherein the radiation patch of the +45° polarization unit and the radiation patch of the -45° polarization unit are placed crosswise, and an insulating medium is arranged between the radiation patch of the +45° polarization unit and the radiation patch of the -45° polarization unit.

[0019] In this embodiment, each microstrip antenna unit is configured as a dual-polarization unit. Compared with using a single-polarization unit to implement a microstrip antenna unit, the use of a dual-polarization unit not only increases the degree of freedom of the antenna, but also increases the communication capacity and improves the anti-interference capability, which is beneficial to improving the communication performance of the antenna device.

[0020] In a possible implementation, the distance between the short-circuit post of the +45° polarization unit and the end of the radiation patch of the +45° polarization unit is not equal to the distance between the short-circuit post of the -45° polarization unit and the end of the radiation patch of the -45° polarization unit.

[0021] In this embodiment, the distances between the short-circuit post and the ends of the radiation patches of the two polarization units are different, which is beneficial to increasing the asymmetry of the radiation signal radiated by the microstrip antenna unit.

[0022] In a possible implementation, the microstrip antenna unit further includes a plurality of scattering columns, and the plurality of scattering columns are symmetrically distributed around the at least one polarization unit.

[0023] Exemplarily, multiple scattering columns are located on one side of the line connecting the positions of the two feeding probes of the ±45° dual-polarization unit, and the multiple scattering columns are symmetrically distributed based on the perpendicular bisector of the line connecting the positions of the two feeding probes, and the center distance between two adjacent scattering columns in the multiple scattering columns is consistent.

[0024] In this embodiment, since, after the scattering column is loaded, the surface current near the metal base plate where the microstrip antenna unit is located will be more concentrated in the area near the loaded scattering column, therefore, by configuring the scattering column around at least one polarization unit of the microstrip antenna unit, it is beneficial to enhance the radiation power suppression effect of the preset area and enhance the asymmetry of the signal radiated by the microstrip antenna unit.

[0025] In a possible implementation, the antenna device further includes a plurality of electromagnetic bandgap structures, and the plurality of electromagnetic bandgap structures are evenly distributed around a subarray including at least two microstrip antenna units.

[0026] In this embodiment, the electromagnetic bandgap structure has frequency and phase bandgap characteristics, which can influence the propagation of electromagnetic waves within a certain frequency band. When multiple microstrip antenna elements are arranged in an array, coupling may occur between the individual microstrip antenna elements, resulting in a decrease in asymmetric performance (or suppression performance). This embodiment suppresses this coupling by adding an electromagnetic bandgap structure, thereby enhancing the isolation between the microstrip antenna elements. This helps to strengthen the asymmetric performance (or suppression performance), specifically, ensuring that the asymmetric performance of the antenna array is consistent with the asymmetric performance of the microstrip antenna elements.

[0027] In a possible implementation, the electromagnetic bandgap structure includes a metal column and a conductive sheet. The conductive sheet is located on a surface of a dielectric substrate, and the metal column passes through the dielectric substrate and is connected to the geometric center of the conductive sheet.

[0028] In a possible implementation, the subarray includes two microstrip antenna units. For example, the subarray is a 1×2 subarray or a 2×1 subarray.

[0029] In a second aspect, the present application provides an antenna system comprising a transmitting array and a receiving array. The transmitting array is configured to transmit asymmetric radiated signals, and the receiving array is configured to receive asymmetric radiated signals. The transmitting array can be implemented using the antenna device described in any embodiment of the first aspect, and the receiving array can be implemented using the antenna device described in any embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of an embodiment of a microstrip antenna unit provided by the present application;

[0031] FIG2A is an exemplary diagram of the design principle of the microstrip antenna unit provided in this application;

[0032] FIG2B is an example diagram showing a comparison of the directional patterns of the microstrip antenna units corresponding to the various steps in FIG2A ;

[0033] FIG3A is a top view of a miniaturized microstrip antenna unit provided by the present application;

[0034] FIG3B is a perspective view of a miniaturized microstrip antenna unit provided by the present application;

[0035] FIG4A is a perspective view of a miniaturized dual-polarized microstrip antenna unit provided by the present application;

[0036] FIG4B is a top view and a cross-sectional view of a miniaturized dual-polarized microstrip antenna unit provided by the present application;

[0037] FIG5A is a perspective view of a microstrip antenna unit provided by the present application and equipped with a scattering post;

[0038] FIG5B is a top view of a microstrip antenna unit provided by the present application and equipped with a scattering post;

[0039] FIG6 is a schematic diagram of the surface current distribution on the metal base plate of the dual-polarized antenna unit of the present application when no scattering columns are loaded and when scattering columns are loaded;

[0040] FIG7 is an example diagram comparing the directional patterns of the dual-polarized antenna unit provided by the present application and the traditional dual-polarized antenna unit;

[0041] FIG8A is a perspective view of an electromagnetic bandgap structure provided by the present application;

[0042] FIG8B is a top view of the electromagnetic bandgap structure provided by the present application;

[0043] FIG9 is an example diagram of a dispersion curve obtained by simulating the electromagnetic bandgap structure provided by the present application under periodic boundary conditions;

[0044] FIG10 is an example diagram of an antenna array provided by the present application, which is composed of multiple microstrip antenna units and multiple electromagnetic band gap structures;

[0045] FIG11 is an example diagram of the impedance bandwidth of the antenna array provided in this application;

[0046] FIG12 is an example diagram comparing the radiation patterns of the antenna array provided by the present application and a traditional antenna array at 25.5 GHz;

[0047] FIG13 is an example diagram showing a comparison of port isolation between the antenna array provided by the present application and a conventional antenna array;

[0048] FIG14 is an example diagram of an antenna system composed of an antenna array provided in this application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0050] The terms "first," "second," "third," "fourth," and the like (if any) in the specification and claims of this application and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0051] It should be understood that the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0052] The following is a brief introduction to the professional terms involved in this application:

[0053] Asymmetry refers to the asymmetry of the antenna's radiation pattern. Compared to the symmetrical radiation patterns of conventional antennas, the antenna unit proposed in this application effectively suppresses the radiated power in a specific lateral area, but does not suppress the radiated power in the same area on the opposite side. As a result, the radiation patterns on both sides are not completely consistent, hence the term asymmetry.

[0054] First-order mode: refers to a field strength mode in which the electric field distribution along the length direction of the radiating patch of the microstrip antenna unit (i.e., the direction in which the longer side is located) has only one half-wave. For example, as shown in Figure 1, if the direction in which the longer side of the radiating patch is defined as the y direction, and the direction in which the shorter side of the radiating patch is defined as the x direction, then the first-order mode is the TM01 mode. For another example, if the direction in which the longer side of the radiating patch is defined as the x direction, and the direction in which the shorter side of the radiating patch is defined as the y direction, then the first-order mode is the TM10 mode. This application is introduced using the example shown in Figure 1.

[0055] Second-order mode: refers to a field intensity pattern with two half-waves in the electric field distribution along the length direction of the radiating patch of the microstrip antenna unit (i.e., the direction in which the longer side is located). For example, as shown in Figure 1, if the direction in which the longer side of the radiating patch is defined as the y direction, and the direction in which the shorter side of the radiating patch is defined as the x direction, then the second-order mode is the TM02 mode. For another example, if the direction in which the longer side of the radiating patch is defined as the x direction, and the direction in which the shorter side of the radiating patch is defined as the y direction, then the second-order mode is the TM20 mode. This application is introduced with the example shown in Figure 1.

[0056] Electric wall: A surface that satisfies the boundary conditions of an ideal conductor, meaning that both E and H are zero inside the conductor. Electric field lines are perpendicular to the conductor's surface, while magnetic field lines are parallel to it. Surfaces perpendicular to electric field lines are generally called electric walls.

[0057] Space angle filtering antenna: Compared with the symmetrical radiation pattern of traditional antennas, the proposed antenna unit can effectively suppress the radiation power in a specific lateral angle area, thereby creating a radiation null point in that direction. This antenna unit is a space angle filtering antenna.

[0058] The antenna device provided herein includes an antenna array composed of multiple microstrip antenna units. Because the directional pattern of the signal radiated by each microstrip antenna unit is asymmetric, the signal radiated by the antenna device as a whole also has a high degree of asymmetry, which is beneficial for achieving coupling suppression between the antenna system's transceiver arrays and thereby improving the isolation between the transceiver arrays.

[0059] The structure of each microstrip antenna unit 10 is described below with reference to FIG1 :

[0060] FIG1 is a schematic diagram of an embodiment of a microstrip antenna unit 10 provided in this application. Each microstrip antenna unit 10 includes a dielectric substrate 101, a radiating patch 102, a metal base plate 103, a feed probe 104, and a shorting post 105. It should be noted that when multiple microstrip antenna units 10 form an antenna array, the multiple microstrip antenna units 10 share the same dielectric substrate 101 and the same metal base plate 103.

[0061] The dielectric substrate 101 is made of an insulating dielectric, while the radiating patch 102, metal base plate 103, feeding probe 104, and shorting post 105 are each made of conductive materials such as metal. The dielectric substrate 101 supports the radiating patch 102 and the metal base plate 103. The radiating patch 102, serving as a radiator, is located on the upper surface of the dielectric substrate 101, while the metal base plate 103, serving as a ground plane, is located on the lower surface of the dielectric substrate 101. The feeding probe 104, serving as a feeding device, connects the radiating patch 102 and the metal base plate 103. The shorting post 105, serving as a shorting device, shorts the radiating patch 102 and the metal base plate 103. The feeding probe 104 and shorting post 105 are located at opposite ends of the radiating patch 102. For example, the feeding probe 104 penetrates the dielectric substrate 101 to connect one end of the radiating patch 102 to the metal bottom plate 103 , and the shorting post 105 penetrates the dielectric substrate 101 to connect the other end of the radiating patch 102 to the metal bottom plate 103 .

[0062] When the microstrip antenna unit 10 is working, the microstrip antenna unit 10 simultaneously excites the first-order mode and the second-order mode through the radiation patch 102 to generate an asymmetric radiation signal at the working frequency. The asymmetric radiation signal has a radiation zero point in a preset area, and the working frequency is between the frequency corresponding to the first-order mode and the frequency corresponding to the second-order mode.

[0063] The first-order mode is a field intensity pattern with only one half-wave along the length of the radiating patch 102 of the microstrip antenna unit 10 (i.e., the direction of the longer side); the second-order mode is a field intensity pattern with two half-waves along the length of the radiating patch 102 of the microstrip antenna unit 10 (i.e., the direction of the longer side). When the microstrip antenna unit 10 passes through the radiating patch 102 equipped with the shorting post 105 and simultaneously excites the first-order and second-order modes, an unevenly distributed current is generated on the radiating patch 102, radiating an asymmetric radiation signal. This asymmetric radiation signal has a radiation null in a predetermined region, meaning that the antenna's radiation power in the predetermined region is low, resulting in an asymmetric distribution of the radiation power across the entire radiation pattern. Optionally, the shorting post 105 is located near the electric wall generated by the second-order mode on the radiating patch, and the location of the shorting post 105 does not overlap with the electric wall generated by the first-order mode on the radiating patch.

[0064] For ease of understanding, the principle of the microstrip antenna unit radiating an asymmetric signal is described below with reference to FIG2A :

[0065] Step 1 in Figure 2A illustrates an example of a microstrip antenna unit without a short-circuit device and using a feed probe. When a microstrip antenna unit simultaneously excites a first-order mode (e.g., the TM01 mode) and a second-order mode (e.g., the TM02 mode), while this can result in uneven current distribution across the patch, the frequency corresponding to the first-order mode differs by a factor of two from the frequency corresponding to the second-order mode. This means that the two modes are difficult to match within the same frequency band. To successfully excite both modes simultaneously, short-circuit posts are added to the edges of the microstrip antenna unit to bring the two modes closer together, thereby improving the antenna's matching. As shown in step 2 in Figure 2A, short-circuit posts are placed near the electrical barrier of the second-order mode to bring the frequencies of the two modes closer together. For example, after the short-circuit posts are placed on the radiating patch, the center frequency of the first-order mode can be shifted toward the second-order mode while the frequency of the second-order mode remains unchanged, thereby reducing the frequency difference between the first-order and second-order modes. For example, in step 2 of FIG2A , the difference between f2 and f1 is less than the difference between f2 and f1 in FIG2A . Then, as shown in step 3 of FIG2A , the short-circuit post is moved in a direction away from the feeding probe, which can adjust the current amplitude ratio and phase difference of the two modes while bringing the frequency points corresponding to the two modes closer, so that the signal radiated by the microstrip antenna unit suppresses the radiation energy in the preset area and a radiation zero point appears. In the example shown in FIG2B , by adjusting the position of the short-circuit post, the microstrip antenna unit has a radiation zero point near 60°. In this example, the short-circuit post is arranged near the electric wall of the second-order mode, which can move the resonant frequency of the first-order mode to a high frequency without affecting the resonant frequency of the second-order mode. Therefore, it is beneficial to bring the frequency corresponding to the first-order mode and the frequency corresponding to the second-order mode closer, thereby improving the matching effect of the antenna.

[0066] In this embodiment, by configuring shorting posts 105 on radiating patch 102 and simultaneously exciting the first-order and second-order modes, the radiated power of the microstrip antenna unit 10 in a predetermined area is suppressed, generating a radiation null. This results in asymmetric signals radiated by the microstrip antenna unit 10, and consequently, asymmetric antenna signals radiated by the antenna array composed of the aforementioned multiple microstrip antenna units 10. Consequently, an antenna system constructed using this antenna array can suppress coupling between the antenna system's transmit and receive arrays, thereby improving the isolation between the transmit and receive arrays.

[0067] Optionally, the distance between the short-circuit post 105 and the feeding probe 104 (i.e., L0 in FIG1 ) is greater than 3 / 4 times the length of the radiating patch 102 (i.e., L1 in FIG1 ), and the length of the radiating patch 102 is related to the wavelength corresponding to the operating frequency. Exemplarily, the length of the radiating patch 102 is 0.5 times the wavelength corresponding to the operating frequency. Since the electric wall of the second-order mode is generally at 3 / 4 of the length of the radiating patch 102, after adjusting the amplitude and phase by adjusting the short-circuit post 105, the distance between the short-circuit post 105 and the feeding probe 104 is greater than 3 / 4 times the length of the radiating patch 102. This is beneficial for adjusting the radiation zero point to a preset area while ensuring that the microstrip antenna unit can radiate non-corresponding signals, thereby facilitating the coupling suppression of the transmit and receive arrays of the antenna system, thereby improving the isolation of the transmit and receive arrays.

[0068] Furthermore, in a possible embodiment, as shown in FIG3A and FIG3B , the radiation patch 102 presents a branch-loaded slow-wave transmission structure along the length direction. The branch-loaded slow-wave transmission structure presents a symmetrical zigzag shape along the length direction of the radiation patch 102. Configuring the radiation patch 102 as a branch-loaded slow-wave transmission structure can reduce the size of the radiation patch 102 along the length direction, that is, when obtaining the same radiation signal, the length of the radiation patch configured as a branch-loaded slow-wave transmission structure (for example, L1' in FIG3A) is smaller than the length of an ordinary rectangular radiation patch (for example, L1 in FIG1). Optionally, the length of the radiation patch 102 is less than or equal to 1 / 2 times the wavelength corresponding to the operating frequency. Exemplarily, the length of the radiation patch 102 is approximately equal to 0.4 times the wavelength corresponding to the operating frequency. Exemplarily, the width of the radiation patch 102 is approximately equal to 0.08 times the wavelength corresponding to the operating frequency.

[0069] In this embodiment, since, when the operating frequency of the microstrip antenna unit 10 is between the first-order mode and the second-order mode, the size of the microstrip antenna unit is relatively large (that is, the size of the radiation patch along the length direction is relatively large, for example, the size of the radiation patch along the length direction is greater than or close to 1 / 2 times the wavelength corresponding to the operating frequency), it may be difficult to be suitable for compact array applications. Therefore, making the radiation patch into a branch-loaded slow-wave transmission structure is beneficial to shortening the size of the radiation patch and significantly reducing the waveguide wavelength, thereby realizing the miniaturization of the size of the microstrip antenna unit.

[0070] Furthermore, each microstrip antenna unit 10 includes at least one polarization unit.

[0071] In one possible implementation, as shown in example (a) on the left side of FIG4A , each microstrip antenna unit 10 includes a polarization unit, and each polarization unit includes a radiating patch 102, a feeding probe 104, and a shorting post 105. When multiple single-polarization microstrip antenna units 10 form an antenna array, the multiple microstrip antenna units 10 share the same dielectric substrate 101 and the multiple microstrip antenna units 10 share the same metal base plate 103.

[0072] In another possible embodiment, as shown in example (b) on the left side of Figure 4A , each microstrip antenna unit 10 includes two polarization units with different polarization directions, that is, each microstrip antenna unit 10 is a dual-polarization unit. Since each polarization unit includes a radiating patch 102, a feeding probe 104, and a shorting post 105, each microstrip antenna unit 10 includes two radiating patches 102, two feeding probes 104, and two shorting posts 105. Furthermore, the two polarization units share the same dielectric substrate 101 and the same metal base plate 103.

[0073] In example (b) shown in FIG4A , the microstrip antenna unit 10 is a ±45° dual-polarization unit, wherein the radiating patch of the +45° polarization unit and the radiating patch of the -45° polarization unit are placed crosswise, and an insulating medium is provided between the radiating patch of the +45° polarization unit and the radiating patch of the -45° polarization unit.

[0074] For example, as shown in FIG4B , the microstrip antenna unit includes two dielectric substrates (i.e., dielectric substrate 101-1 and dielectric substrate 101-2). The upper dielectric substrate 101-1 is primarily used for printing the radiating patch 102-1 of the -45° polarization unit, while the lower dielectric substrate 101-2 is primarily used for printing the radiating patch 102-2 of the +45° polarization unit and the metal base plate 103. For example, the radiating patch 102-1 of the -45° polarization unit is located on the upper surface of the upper dielectric substrate 101-1, the radiating patch 102-2 of the +45° polarization unit is located on the upper surface of the lower dielectric substrate 101-2, and the metal base plate 103 is located on the lower surface of the lower dielectric substrate 101-2.

[0075] Optionally, the distance between the short-circuit post 105 of the +45° polarization unit and the end of the radiation patch 102-2 of the +45° polarization unit is not equal to the distance between the short-circuit post 105 of the -45° polarization unit and the end of the radiation patch 102-1 of the -45° polarization unit.

[0076] In this embodiment, each microstrip antenna element 10 is configured as a dual-polarized element. Compared to using a single-polarized element to implement a microstrip antenna element 10, the use of a dual-polarized element not only increases the antenna's degrees of freedom, but also increases communication capacity and enhances anti-interference capabilities, thereby improving the communication performance of the antenna system. Furthermore, the different distances between the shorting post 105 and the ends of the radiating patches of the two polarized elements help increase the asymmetry of the radiated signals emitted by the microstrip antenna element 10.

[0077] Furthermore, in a possible implementation, the microstrip antenna unit 10 further includes a plurality of scattering columns, and the plurality of scattering columns are symmetrically distributed around at least one polarization unit.

[0078] As shown in Figures 5A and 5B , a microstrip antenna unit 10 including a ±45° dual-polarization unit is used as an example. Multiple scattering posts 106 are symmetrically distributed around the ±45° dual-polarization unit. Optionally, the multiple scattering posts 106 are located on one side of a line connecting the positions of the two feeding probes 104 of the ±45° dual-polarization unit, and the multiple scattering posts 106 are symmetrically distributed about the perpendicular midline of the line connecting the positions of the two feeding probes 104.

[0079] Optionally, the center-to-center spacing between two adjacent scattering pillars 106 in the plurality of scattering pillars 106 is uniform, that is, the plurality of scattering pillars 106 are evenly distributed around the ±45° dual-polarization unit. In the example shown in FIG5B , 24 scattering pillars 106 are configured around the ±45° dual-polarization unit. It should be understood that in actual applications, the number of scattering pillars 106 configured around the ±45° dual-polarization unit can be adjusted, and accordingly, the center-to-center spacing between two adjacent scattering pillars 106 can also be adjusted, which is not limited here.

[0080] In one example, as shown in Figures 5A and 5B , the radius R1 of the scattering pillar 106 is 0.1mm to 0.2mm, and the center-to-center spacing d4 of adjacent scattering pillars 106 is 0.4mm to 0.8mm. The radius R2 of the shorting pillar 105 is 0.05mm to 0.2mm. The length L3 of the radiating patch 102-1 for the -45° polarization unit is 3.3mm to 3.9mm, and the width W3 is 0.84mm to 1.24mm. The length L4 of the radiating patch 102-2 for the +45° polarization unit is 3mm to 3.6mm, and the width W4 is 0.84mm to 1.24mm.

[0081] Figure 6 shows the surface current distribution on the metal substrate of the dual-polarized antenna unit of the present application, both without and with scattering posts. As shown in Figure 6, when scattering posts 106 are loaded, the surface current near the metal substrate 103 where the microstrip antenna unit 10 is located is more concentrated in the area near the loaded scattering posts 106. Therefore, by configuring scattering posts 106 around at least one polarization unit of the microstrip antenna unit 10, it is beneficial to enhance the radiation power suppression effect in a predetermined area and increase the asymmetry of the signal radiated by the microstrip antenna unit 10.

[0082] In addition, Figure 7 shows a comparison of the 25GHz antenna pattern of the dual-polarized antenna unit with spatial angle filtering capability proposed in this application and a conventional dual-polarized antenna unit. Compared to conventional antenna units, the sidelobe level of the dual-polarized antenna unit proposed in this application is reduced by 3.8dB, effectively suppressing the sidelobe level at specific angles and achieving good asymmetry.

[0083] Furthermore, in one possible embodiment, the antenna device provided in the present application further includes a plurality of electromagnetic band gap (EBG) structures 20. The EBG structure 20 is an artificial periodic structure having frequency band gap and phase band gap characteristics, and can affect the propagation of electromagnetic waves within a certain frequency band.

[0084] As shown in FIG8A , the electromagnetic bandgap structure 20 includes a metal post 201 and a conductive sheet 202. The conductive sheet 202 is located on the surface of the dielectric substrate 101. The metal post 201 extends through the dielectric substrate 101 and connects the conductive sheet 202 at its geometric center. For example, as shown in FIG8A , the conductive sheet 202 in the electromagnetic bandgap structure 20 can be a square metal patch, with the metal post 201 coinciding with the geometric center of the square patch. Because coupling may occur between the individual microstrip antenna units 10 when multiple microstrip antenna units 10 are arrayed, resulting in a decrease in asymmetric performance (or suppression performance), the electromagnetic bandgap structure 20 is added to suppress such coupling, thereby enhancing isolation between the microstrip antenna units 10 and strengthening the asymmetric performance (or suppression performance). This helps maintain consistency between the asymmetric performance of the antenna array and the asymmetric performance of the microstrip antenna units.

[0085] In one example, as shown in Figure 8B , the radius R of metal pillar 201 is 0.05mm to 0.15mm, the length L2 of the square patch is 0.3mm to 0.7mm, and the width W2 is 0.3mm to 0.7mm. The length L2 of the square patch is related to the operating frequency of the antenna unit. For example, if the antenna unit operates at 25.8GHz, the length L2 of the square patch is approximately equal to 0.04 wavelengths of the operating frequency.

[0086] Figure 9 shows the dispersion curve obtained by simulating the electromagnetic bandgap structure 20 provided by this application under periodic boundary conditions. The simulation results shown in Figure 9 demonstrate that, at specific dimensions (e.g., those shown in Figure 8B ), surface waves at frequencies of 19.5 GHz and even higher can be effectively suppressed, thereby suppressing the radiated power in a predetermined region and achieving a radiation null.

[0087] Furthermore, multiple electromagnetic bandgap structures 20 are evenly distributed around a subarray comprising at least two microstrip antenna units 10. Optionally, a subarray includes 2 microstrip antenna units 10. For example, a subarray comprising at least two microstrip antenna units 10 is a 1×2 subarray or a 2×1 subarray. Optionally, a subarray includes 4 microstrip antenna units 10. For example, a subarray comprising at least two microstrip antenna units 10 is a 2×2 subarray. This is not limited here. Compared to the solution in which multiple electromagnetic bandgap structures are distributed only in one microstrip antenna unit in the conventional technology, the present application evenly distributes multiple electric field bandgap structures around at least two microstrip antenna units, which is beneficial to maintaining the consistency of the radiation direction of at least two microstrip antenna units, thereby ensuring the asymmetry of the directional pattern of the entire antenna device.

[0088] For example, a subarray including at least two microstrip antenna units 10 is taken as a 1×2 subarray. As shown in FIG10 , every two microstrip antenna units 10 form a subarray (i.e., a 1×2 subarray), and a plurality of electromagnetic bandgap structures 20 are evenly distributed around the 1×2 subarray. In addition, a plurality of subarray groups are regularly arranged into an antenna array, and a plurality of electromagnetic bandgap structures 20 are evenly distributed around each 1×2 subarray in the antenna array. For example, the row spacing between adjacent microstrip antenna units 10 in the antenna array is 0.6 times the wavelength corresponding to the operating frequency, and the column spacing between adjacent microstrip antenna units 10 is 0.5 times the wavelength corresponding to the operating frequency.

[0089] In one example, as shown in FIG10 , the antenna array includes 64 dual-polarized antenna units, the antenna array scale is 8×8, the row spacing d1 between adjacent microstrip antenna units 10 is 7 mm to 8 mm, the column spacing d2 between adjacent microstrip antenna units 10 is 5.75 mm to 6.75 mm; the adjacent spacing d3 between the electromagnetic band gap structures 20 is 0.87 mm to 1.27 mm.

[0090] As shown in Figure 11, the impedance bandwidth of the antenna array with spatial angle filtering capability proposed in this application is shown. From the simulation results shown in Figure 11, it can be seen that the impedance bandwidth of the antenna array ranges from 24.7 to 27.1 GHz.

[0091] Figure 12 shows a comparison of the radiation patterns of the proposed antenna array with spatial angle filtering capability and a conventional antenna array at 25.5 GHz. The simulation results in Figure 12 demonstrate that, at 25 GHz, the proposed antenna array with spatial angle filtering capability reduces the sidelobe level by 3.89 dB compared to the conventional antenna array.

[0092] Figure 13 shows a comparison of port isolation between the proposed antenna array with spatial angle filtering and a conventional antenna array. The simulation results in Figure 13 show that, compared to conventional antenna arrays, the proposed antenna array with spatial angle filtering significantly improves isolation across the entire frequency band, with port isolation increasing by 16.1 dB when scanning within a ±15° spatial domain.

[0093] As shown in Figure 14, an example diagram of an antenna system composed of antenna arrays provided in this application is provided. The antenna system includes a transmitting array and a receiving array. The specific implementation of the transmitting array and the receiving array is as shown in the antenna device shown in Figure 10 above. The signal radiated by the transmitting array has a radiation null point in a preset area, and the signal radiated by the receiving array has a radiation null point in a preset area. Arranging the sides of the transmitting array and the receiving array with radiation null points relative to each other, that is, arranging the sides of the transmitting array and the receiving array with sidelobe suppression relative to each other, can achieve good isolation between the transmitting and receiving arrays, thereby improving the communication performance of the antenna.

[0094] In this embodiment, not only is the radiation power suppressed in a preset area by the microstrip antenna unit 10 to generate a radiation zero point, but the electromagnetic bandgap structure 20 is also used to construct a 1×2 subarray form so that the directional patterns of each microstrip antenna unit 10 in the array have good consistency. Therefore, the antenna array composed of the aforementioned microstrip antenna unit 10 and the electromagnetic bandgap structure 20 can not only achieve coupling suppression of the transmit and receive arrays of the antenna system, thereby improving the isolation of the transmit and receive arrays, but also ensure that the transmit and receive antenna arrays still have good isolation under quasi-far-field spacing and when independently scanning.

[0095] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna device, characterized in that: include: An antenna array composed of multiple microstrip antenna units, each of which includes at least one polarization unit, each of which includes a dielectric substrate, a radiation patch, a metal bottom plate, a feeding probe and a short-circuit column, the radiation patch is located on the upper surface of the dielectric substrate, the metal bottom plate is located on the lower surface of the dielectric substrate, the feeding probe penetrates the dielectric substrate to connect one end of the radiation patch with the metal bottom plate, and the short-circuit column penetrates the dielectric substrate to connect the other end of the radiation patch with the metal bottom plate; Each of the microstrip antenna units is used to simultaneously excite the first-order mode and the second-order mode through the radiation patch to generate an asymmetric radiation signal at an operating frequency, wherein the asymmetric radiation signal has a radiation zero point in a preset area, and the operating frequency is between a frequency corresponding to the first-order mode and a frequency corresponding to the second-order mode.

2. The antenna device according to claim 1, characterized in that The short-circuit post is located near the electric wall generated by the second-order mode on the radiation patch, and the position of the short-circuit post does not overlap with the position of the electric wall generated by the first-order mode on the radiation patch.

3. The antenna device according to claim 1 or 2, characterized in that: The distance between the short-circuit post and the feeding probe is greater than 3 / 4 times the length of the radiation patch, and the length of the radiation patch is related to the wavelength corresponding to the operating frequency point.

4. The antenna device according to any one of claims 1 to 3, characterized in that: The radiation patch presents a branch-loaded slow-wave transmission structure along the length direction, and the length of the radiation patch is less than or equal to 1 / 2 times the wavelength corresponding to the working frequency.

5. The antenna device according to any one of claims 1 to 4, characterized in that: The at least one polarization unit is a ±45° dual polarization unit, wherein the radiation patch of the +45° polarization unit and the radiation patch of the -45° polarization unit are placed crosswise, and an insulating medium is arranged between the radiation patch of the +45° polarization unit and the radiation patch of the -45° polarization unit.

6. The antenna device according to claim 5, characterized in that The distance between the short-circuit post of the +45° polarization unit and the end of the radiation patch of the +45° polarization unit is not equal to the distance between the short-circuit post of the −45° polarization unit and the end of the radiation patch of the −45° polarization unit.

7. The antenna device according to any one of claims 1 to 6, characterized in that: The microstrip antenna unit further includes a plurality of scattering columns, and the plurality of scattering columns are symmetrically distributed around the at least one polarization unit.

8. The antenna device according to claim 7, characterized in that: The multiple scattering columns are located on one side of the line connecting the positions of the two feeding probes of the ±45° dual-polarization unit, the multiple scattering columns are symmetrically distributed based on the perpendicular bisector of the line connecting the positions of the two feeding probes, and the center distance between two adjacent scattering columns among the multiple scattering columns is consistent.

9. The antenna device according to any one of claims 1 to 8, characterized in that: The antenna device further comprises a plurality of electromagnetic bandgap structures, and the plurality of electromagnetic bandgap structures are evenly distributed around a subarray comprising at least two of the microstrip antenna units.

10. The antenna device according to claim 9, characterized in that: The electromagnetic bandgap structure comprises a metal column and a conductor sheet, wherein the conductor sheet is located on the surface of the dielectric substrate, and the metal column penetrates the dielectric substrate and is connected to the geometric center of the conductor sheet.

11. The antenna device according to claim 9 or 10, characterized in that: The subarray includes two microstrip antenna units, and the subarray is a 1×2 subarray or a 2×1 subarray.

12. An antenna system, characterized in that: include: A transmitting array and a receiving array, wherein the transmitting array is the antenna device according to any one of claims 1 to 11, and the receiving array is the antenna device according to any one of claims 1 to 11; The transmitting array is used to transmit an asymmetric radiation signal; The receiving array is used to receive the asymmetric radiation signal.

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