Dual-band dual-polarized millimeter-wave array antenna and communication device

Abstract

Provided in the embodiments of the present application are a dual-band dual-polarized millimeter-wave array antenna and a communication device. The antenna comprises a first line-source exciter, a CTS array, and a second line-source exciter, wherein one end of the CTS array is connected to an output port of the first line-source exciter, and the other end thereof is connected to an output port of the second line-source exciter; the first line-source exciter is configured to excite the CTS array to operate in a first mode and at a first frequency; the second line-source exciter is configured to excite the CTS array to operate in a second mode and at a second frequency; electric field polarizations of the CTS array in the first mode and the second mode are orthogonal; a waveguide structure of the output port of the first line-source exciter satisfies a single-mode transmission condition for a third mode, and after propagating to the CTS array, an excitation signal in the third mode is converted into the first mode; and a waveguide structure of the output port of the second line-source exciter satisfies a single-mode transmission condition for a fourth mode, and after propagating to the CTS array, an excitation signal in the fourth mode is converted into the second mode.

Description

Dual-frequency dual-polarization millimeter-wave array antennas and communication equipment

[0001] Cross-referencing

[0002] This application claims priority to Chinese Patent Application No. 202410673878.5, filed on May 28, 2024, entitled "Dual-Frequency Dual-Polarized Millimeter-Wave Array Antenna and Communication Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This document relates to the field of wireless communication technology, and in particular to a dual-frequency dual-polarized millimeter-wave array antenna and communication equipment. Background Technology

[0004] With the rapid development of wireless communication technology, millimeter-wave technology has become a research hotspot in this field. As a key component for transmitting and receiving signals in wireless communication systems, the performance of antennas directly affects the performance of the communication system. Existing millimeter-wave antenna designs are mostly focused on single-frequency, single-polarization, resulting in low antenna aperture utilization. Therefore, the industry has proposed dual-frequency, dual-polarization, common-aperture millimeter-wave antennas.

[0005] Dual-frequency, dual-polarization, common-aperture millimeter-wave antennas combine different frequency and polarization characteristics within the same aperture, effectively improving aperture utilization, reducing the number of antennas, and thus lowering costs.

[0006] However, for dual-band, dual-polarization, common-aperture millimeter-wave antennas, ensuring high isolation between the two ports so that antennas operating in two different frequency bands and polarizations do not interfere with each other remains a design challenge. Summary of the Invention

[0007] This application provides a dual-frequency dual-polarized millimeter-wave array antenna and a communication device.

[0008] In a first aspect, a dual-frequency dual-polarization millimeter-wave array antenna is provided, comprising: a first line source exciter, a continuous transverse stub CTS array, and a second line source exciter; one end of the CTS array is connected to the output port of the first line source exciter, and the other end of the CTS array is connected to the output port of the second line source exciter; wherein, the first line source exciter is used to excite the CTS array to operate in a first mode and a first frequency, and the second line source exciter is used to excite the CTS array to operate in a second mode and a second frequency, wherein the electric field polarization of the CTS array in the first mode and the second mode is orthogonal; wherein, the waveguide structure of the output port of the first line source exciter satisfies the single-mode transmission condition of a third mode, and the excitation signal in the third mode is converted into the first mode after propagating from the output port of the first line source exciter to the CTS array; and, the waveguide structure of the output port of the second line source exciter satisfies the single-mode transmission condition of a fourth mode, and the excitation signal in the fourth mode is converted into the second mode after propagating from the output port of the second line source exciter to the CTS array.

[0009] In a second aspect, a communication device is provided, comprising the dual-frequency dual-polarized millimeter-wave array antenna described in the first aspect. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 is an isometric view of a dual-frequency dual-polarized millimeter-wave array antenna provided in an embodiment of this application.

[0012] Figure 2 is an isometric view of a dual-frequency dual-polarized millimeter-wave array antenna provided in another embodiment of this application.

[0013] Figure 3 is a schematic diagram of a three-dimensional model of a dual-frequency dual-polarized millimeter-wave array antenna provided in another embodiment of this application.

[0014] Figure 4 is a top view of a dual-frequency dual-polarized millimeter-wave array antenna provided in an embodiment of this application.

[0015] Figure 5 is a schematic diagram showing the positional relationship between the output port of the third line source exciter, the upper metal plate of the parallel plate waveguide, the metal ridge, and the metal wall of the parallel plate waveguide provided in an embodiment of this application.

[0016] Figure 6A is a three-dimensional structural schematic diagram of a first line source exciter provided in an embodiment of this application.

[0017] Figure 6B is a three-dimensional structural schematic diagram of a second line source exciter provided in an embodiment of this application.

[0018] Figure 7 is a waveguide electric field vector distribution diagram of the first line source exciter of a dual-frequency dual-polarized millimeter-wave array antenna when it is operating in TE1 mode according to an embodiment of this application.

[0019] Figure 8 is a partial three-dimensional structural schematic diagram of a dual-frequency dual-polarized millimeter-wave array antenna provided in an embodiment of this application.

[0020] Figure 9 is a schematic diagram showing the variation of the reflectance coefficient of different CTS arrays operating in TEM mode.

[0021] Figure 10 shows the S-parameters and isolation frequency response curves obtained by simulation of a dual-frequency dual-polarized millimeter-wave array antenna provided in the embodiments of this application.

[0022] Figure 11 shows the E-plane and H-plane radiation patterns of a dual-frequency dual-polarized millimeter-wave array antenna obtained from simulation when the antenna operates at the center frequency, according to an embodiment of this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings of one or more embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the protection scope of this document.

[0024] The terms "first," "second," etc., used in this application and claims are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, in this application and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0025] With the rapid development of wireless communication technology, millimeter wave technology has become a research hotspot in this field. Commercial application of millimeter wave technology is imminent. Currently, many terminal manufacturers are researching millimeter wave technology; for example, some mobile phone manufacturers have launched commercial millimeter wave smartphones, and others are supporting and researching millimeter wave customer premises equipment (CPE). Therefore, related radio frequency technologies, especially antenna technology, will inevitably become a focus.

[0026] Millimeter wave applications are multifaceted. On one hand, handheld terminals, due to space constraints, widely utilize Application Intrusion Prevention (AIP) technology, integrating antennas onto chips. On the other hand, CPEs or external repeater devices offer more space, allowing for the development of higher-performance antennas. 5G CPEs, as 5G terminal devices, perform secondary relaying of received 5G mobile communication signals, converting them into Wi-Fi or wired signals to enable more local devices to access the internet. Similar in function to routers, 5G CPEs are larger, have higher antenna gain, higher power, and stronger signal transmission and reception capabilities than mobile phones. They are used in various outdoor 5G scenario tests and may be used in vehicle-to-everything (V2X) applications in the future. Connected vehicles equipped with modified 5G CPEs will use the CPE to exchange large amounts of data collected by the vehicle with the cloud.

[0027] In addition, satellite terminal communication technology is developing rapidly. China has already completed the commercialization of short message and voice calls and is gradually transitioning to the stage of geostationary Earth Orbit (GEO) and low Earth orbit satellites. These technologies provide a faster communication experience, but also place higher demands on antennas.

[0028] Existing millimeter-wave antenna designs are mostly focused on single frequency and single polarization, resulting in low antenna aperture utilization. To address this, the industry has proposed dual-frequency, dual-polarization, common-aperture millimeter-wave antennas. Dual-frequency, dual-polarization, common-aperture millimeter-wave antennas combine different frequency and polarization performance designs within the same aperture, effectively improving aperture utilization, reducing the number of antennas, and thus lowering costs.

[0029] However, for dual-band, dual-polarization, common-aperture millimeter-wave antennas, ensuring high isolation between the two ports so that antennas operating in two different frequency bands and polarizations do not interfere with each other remains a design challenge.

[0030] In addition, for millimeter waves, atmospheric attenuation weakens the signal strength and affects communication quality. This requires the antenna to have high gain to compensate for atmospheric attenuation and improve communication quality.

[0031] Furthermore, there is an impedance mismatch problem when the Continuous Transverse Stub (CTS) array operates in two orthogonal modes simultaneously.

[0032] To address at least one of the aforementioned problems, this application proposes a dual-frequency, dual-polarized millimeter-wave array antenna. The design features of the proposed dual-frequency, dual-polarized millimeter-wave array antenna include, but are not limited to, at least one of the following.

[0033] 1) Based on two orthogonal modes, the transverse electromagnetic (TEM) mode and the transverse electro (TE1) mode, dual-frequency dual-polarization performance is achieved.

[0034] 2) Based on the single-mode transmission conditions of the rectangular waveguide, the source exciter for TEM mode and TE1 mode is designed using a waveguide power divider feed structure, so that the two line source exciters have cutoff characteristics for one of the TEM mode and TE1 mode, thereby achieving high isolation between the two ports of the dual-frequency dual-polarized millimeter-wave array antenna.

[0035] 3) Based on CTS technology, high gain is achieved by using a CTS standing wave array.

[0036] 4) The impedance mismatch problem when the CTS array operates in two orthogonal modes is solved by using CTS cells with sawtooth slots and parallel plate waveguides with metal ridges.

[0037] The following is a detailed description of a dual-frequency, dual-polarized millimeter-wave array antenna proposed in this application.

[0038] As shown in Figures 1, 2, 3 and 4, an embodiment of this application provides a dual-frequency dual-polarized millimeter-wave array antenna that may include: a first line source exciter 1, a CTS array 2 and a second line source exciter 3, wherein one end of the CTS array 2 is connected to the output port of the first line source exciter 1 and the other end of the CTS array 2 is connected to the output port of the second line source exciter 3.

[0039] In this design, the first line source exciter 1 excites the CTS array 2 to operate in the first mode and at the first frequency, while the second line source exciter 3 excites the CTS array 2 to operate in the second mode and at the second frequency. Alternatively, the first line source exciter 1 excites the CTS array 2 to operate in the first mode, and the second line source exciter 3 excites the CTS array 2 to operate in the second mode. The operating frequency band of the CTS array 2 in the first mode is the first frequency band, and the operating frequency band of the CTS array 2 in the second mode is the second frequency band. The electric field polarization of the CTS array in the first and second modes is orthogonal. This design yields a dual-frequency, dual-polarization millimeter-wave antenna.

[0040] Furthermore, the waveguide structure of the output port of the first line source exciter 1 satisfies the single-mode transmission condition of the third mode. The excitation signal in the third mode propagates from the output port of the first line source exciter 1 to the CTS array 2 and is then converted into the first mode. Similarly, the waveguide structure of the output port of the second line source exciter 3 satisfies the single-mode transmission condition of the fourth mode. The excitation signal in the fourth mode propagates from the output port of the second line source exciter 3 to the CTS array 2 and is then converted into the second mode. This design allows the first line source exciter to have cutoff characteristics for the second mode and the second line source exciter to have cutoff characteristics for the first mode, thereby maintaining high isolation between the two ports of the antenna.

[0041] Isolation represents the proportion of a signal fed to one port (one polarization) of a dual-polarized antenna that appears in the other port (another polarization). For multi-port antennas, such as dual-polarized antennas or dual-band dual-polarized antennas, the isolation between ports should be greater than a certain value when both transmit and receive are used.

[0042] The mode of an antenna refers to the microwave mode propagating in the waveguide of the antenna, including the following three types.

[0043] 1) TE mode indicates that all electric field components are perpendicular to the transmission direction, that is, there are no electric field components in the transmission direction.

[0044] 2) TM mode indicates that all magnetic field components are perpendicular to the transmission direction, that is, there are no magnetic field components in the transmission direction.

[0045] 3) TEM mode, which indicates that both the electric and magnetic field components are perpendicular to the direction of propagation.

[0046] In the three modes mentioned above, "T" is an abbreviation for Transverse, which originally means "horizontal" and in microwave mode refers to "the direction perpendicular to the transmission direction"; "E" is an abbreviation for Electro (electric field); and "M" is an abbreviation for magnetic (magnetic field).

[0047] Since waveguides can contain an infinite number of electromagnetic wave structures or distributions, each electromagnetic field distribution is called a wave mode (or mode), and each wave mode has a corresponding dielectric wavelength and a different phase velocity. A hollow waveguide with a uniform cross-section is called a homogeneous waveguide. Electromagnetic wave modes in a homogeneous waveguide can be divided into two main categories: electromagnetic (TM) modes and magnetic (TE) modes. Among these, due to differences in the internal field structure of the waveguide, TE modes can be further divided into multiple modes such as TE1, TE01, TE02, TE10, TE11, TE20, and TE21. Wave mode conversion can be achieved by changing the field structure. This part is existing technology and will not be elaborated upon further in this paper.

[0048] In this application, the first mode and the second mode are different modes, the third mode and the fourth mode are different modes, the third mode can be converted into the first mode, and the fourth mode can be converted into the second mode. Any mode that meets this setting can adopt the structural design of a dual-frequency dual-polarized millimeter-wave antenna provided in the embodiment of this application to obtain a millimeter-wave antenna with high isolation between the two ports.

[0049] In some embodiments, the first mode is the transverse electromagnetic wave TE1 mode, the third mode is the TE01 mode, the second mode is the transverse electromagnetic wave TEM mode, and the fourth mode is the TE10 mode.

[0050] Furthermore, in some embodiments, the waveguide structure of the output port of the first line source exciter 1 is rectangular, and the waveguide structure satisfies the single-mode transmission condition of TE01 mode. The excitation signal in TE01 mode propagates from the output port of the first line source exciter 1 to the CTS array 2 and is converted into TE1 mode, which has a cutoff characteristic for TEM mode. The waveguide structure of the output port of the second line source exciter 3 is rectangular, and the waveguide structure satisfies the single-mode transmission condition of TE10 mode. The excitation signal in TE10 mode propagates from the output port of the second line source exciter 3 to the CTS array 2 and is converted into TEM mode, which has a cutoff characteristic for TE1 mode.

[0051] As shown in Figures 1, 2, 3 and 4, in a dual-frequency dual-polarized millimeter-wave antenna proposed in this application embodiment, the first line source exciter 1 is placed at the left end of the CTS array 2, and the second line source exciter 3 is placed at the right end of the CTS array 2. The first line source exciter 1 and the second line source exciter 3 both have two identical functions: on the one hand, they excite the line source, and on the other hand, they serve as terminal reflectors. The distance between the output port and the nearest CTS element is λg / 2.

[0052] Based on the theory of parallel plate waveguides, it can be deduced that the electric field polarization of the TEM mode and TE1 mode in a parallel plate waveguide is orthogonal. When the TE1 mode operates at a high frequency and the TEM mode operates at a low frequency, they can have the same waveguide wavelength λg. Based on this theory, this application proposes a dual-frequency, dual-polarization millimeter-wave array antenna as shown in Figure 1. Two line source exciters are integrated at both ends of the CTS array, exciting either the TE1 mode or the TEM mode from the left or right sides respectively. The operating frequency band in TE1 mode—the first band—can be 38.4-39 GHz, and the operating frequency band in TEM mode—the second band—can be 28-28.7 GHz. By designing the structure and dimensions of the output ports of the two line source exciters, mode cutoff characteristics are achieved, thereby realizing high port isolation.

[0053] The design of a dual - frequency and dual - polarization millimeter - wave array antenna proposed in the embodiments of this application includes three parts: the first line - source exciter 1, the second line - source exciter 3, and the CTS array 2.

[0054] 1) The first line - source exciter 1 is used to excite the CTS array 2 to operate in the TE1 mode

[0055] In order to make the first - mode line - source exciter have mode - cutoff characteristics and improve the antenna port isolation, the rectangular waveguide size of its output port meets the single - mode transmission condition of the rectangular waveguide. By selecting the values of the waveguide width and waveguide height, the cutoff of the TE10 - mode excitation signal is achieved in the output - port region, while ensuring the normal propagation of the TE01 - mode excitation signal. That is, the output port of the first line - source exciter suppresses and reflects the excitation signal of the TEM mode and does not affect the propagation of the TE1 - mode excitation signal.

[0056] The cutoff wavelength and propagation condition of the TEmn mode in the rectangular waveguide are:

[0057] where a is the width of the rectangular waveguide and b is the height of the rectangular waveguide.

[0058] On this basis, the single - mode transmission condition of the TE01 mode is: max(2a, b)<λ<2b (2)

[0059] where λ represents the wavelength of the excitation signal that the rectangular waveguide can propagate. λ is related to the first frequency and the dielectric constant of the medium in the rectangular waveguide. a represents the width of the rectangular waveguide in the x - direction, b represents the height of the rectangular waveguide in the z - direction. The x - direction is parallel to the plane where the CTS array 2 is located and perpendicular to the series direction of the CTS array 2, and the z - direction is perpendicular to the plane where the CTS array 2 is located.

[0060] As an example, if the first frequency band is 38 GHz to 39 GHz, then the range of λ is 5.18 - 5.32 mm. Assuming that the dielectric constant of the medium in the waveguide of the output port of the first line - source exciter 1 is 2.2, according to formula (2), it can be calculated that when the height b of the rectangular waveguide satisfies 2.66 mm < b < 5.18 mm and 2a < b, that is, the waveguide structure of the output port of the first line - source exciter 1 meets the following conditions:

[0061] a < 3.48 mm and 2.66 mm < b < 5.18 mm.

[0062] At this point, the TE01 mode excitation signal propagates independently within the rectangular waveguide, while the TE10 mode excitation signal cannot propagate within it. Therefore, the output port of the first line source exciter 1 can be designed as a rectangular waveguide with a gradually increasing width. For example, the output port of the first line source exciter 1 can be designed as a rectangular waveguide with a height b of 3.65 mm and a width a transitioning from 2.5 mm to 3.3 mm. This size of rectangular waveguide satisfies the single-mode transmission conditions of the TE01 mode. The TE01 mode excitation signal propagates from the output port of the first line source exciter 1 to the CTS array 2 and is then converted into the TE1 mode. The first line source exciter 1 has cutoff characteristics for the TEM mode operating at 28 GHz to 29 GHz, thereby improving antenna port isolation.

[0063] Optionally, Figure 7 shows the electric field vector distribution diagram inside the waveguide of the first line source exciter 1 when the dual-frequency dual-polarized millimeter-wave antenna proposed in this application operates in TE1 mode. It can be seen that the direction of the electric field vector is parallel to the upper and lower metal plates of the first line source exciter 1.

[0064] As a concrete example, as shown in Figure 6A, the first line source exciter 1 can adopt an 8-waveguide power divider feed structure, including one power divider input port, eight power divider output ports, and several matching stubs. The waveguide structure of the power divider output port is a rectangular waveguide with a width a gradually decreasing along the y-direction (marked by the dashed line in Figure 6A), and the height b of the waveguide along the z-direction is 3.65 mm. Specifically, the width a of the rectangular waveguide increases linearly from 2.5 mm to 3.3 mm. The metal wall 11 at the power divider output port is tapered from wide to narrow as the width of the rectangular waveguide changes. In a dual-frequency dual-polarized millimeter-wave antenna shown in Figures 2 and 3, this metal wall 11 is connected to the metal ridge 5 on the lower metal plate 42 of the parallel plate waveguide 4 in the CTS array 2.

[0065] 2) The second line source exciter 3 is used to excite the CTS array 2 to operate in TEM mode.

[0066] According to the above formula (1), the single-mode transmission condition of TE10 mode can be determined as: max(a,2b)<λ<2a (3)

[0067] Where λ represents the wavelength of the excitation signal that the rectangular waveguide can propagate, and λ is related to the second frequency and the dielectric constant of the medium inside the rectangular waveguide. a represents the width of the rectangular waveguide in the x-direction, and b represents the height of the rectangular waveguide in the z-direction. The x-direction is parallel to the plane where CTS array 2 is located and perpendicular to the series connection direction of CTS array 2. The z-direction is perpendicular to the plane where CTS array 2 is located.

[0068] As an example, if the second frequency band is 28 GHz - 29 GHz, the range of λ is 6.97 - 7.22 mm. Assuming that the relative permittivity of the medium in the waveguide at the output port of the second line source exciter 3 is 2.2, the waveguide structure at the output port of the second line source exciter 3 satisfies the following conditions:

[0069] 5.32 mm < a < 6.97 mm, and b < 2.66 mm.

[0070] At this time, the excitation signal of the TE10 mode propagates alone in the rectangular waveguide, while the excitation signal of the TE01 mode cannot propagate in this rectangular waveguide. Accordingly, the output port of the second line source exciter 3 can be designed as a rectangular waveguide. For example, the output port of the first line source exciter 1 is designed as a rectangular waveguide with a height b of 2.1 mm and a width of 6.2 mm. The rectangular waveguide of this size satisfies the single-mode transmission condition of the TE10 mode. The excitation signal in the TE10 mode propagates from the output port of the second line source exciter 3 to the CTS array 2 and then is converted into the TEM mode. The second line source exciter 3 has a cutoff characteristic for the TE1 mode operating at 38 GHz - 39 GHz, which can improve the antenna port isolation.

[0071] As a specific example, as shown in FIG. 6B, the second line source exciter 3 can adopt a one-to-four waveguide power divider feeding structure, including 1 power division input port, 4 power division output ports, and several matching branches. The waveguide structure of the power division output port is rectangular. The height b of this rectangular waveguide along the z direction is 2.1 mm, and the width a of this rectangular waveguide in the x direction is 6.2 mm. In a dual-band dual-polarized millimeter-wave antenna shown in FIGS. 2 and 3, there is a height difference between the output port of the second line source exciter 3 and the CTS array 2. The upper metal plates of the two are connected as a plane, and the lower metal plates are connected in a stepped manner. For details, please refer to FIG. 5.

[0072] 3) Design of the CTS array 2

[0073] As can be seen from FIGS. 1, 2, 3, and 4, a dual-band dual-polarized millimeter-wave antenna provided by an embodiment of the present application is a metal structure filled with a medium. This antenna integrates a first line source exciter and a second line source exciter, and these two line source exciters respectively excite two orthogonal modes and operate in two frequency bands.

[0074] Specifically, as shown in FIGS. 1, 2, 3, and 4, the structure of a dual-band dual-polarized millimeter-wave antenna provided by an embodiment of the present application can be divided into three parts: left, middle, and right. The middle is the CTS array 2, the left end is the first line source exciter 1, and the right end is the second line source exciter 3.

[0075] As an example, as shown in Figures 2, 3 and 4, the CTS array 2 includes multiple CTS units 21 connected in series, that is, the CTS array 2 used in the embodiments of this application is a series-fed type.

[0076] In some embodiments, the waveguide structure of the CTS array 2 is a parallel plate waveguide. Specifically, as shown in Figures 2 and 3, the CTS array 2 includes a plurality of CTS units 21 evenly spaced along the y-direction on the upper metal plate 41 of the parallel plate waveguide 4. In a specific implementation, the plurality of CTS units 21 can be formed on the upper metal plate 41 of the parallel plate waveguide 4 by etching.

[0077] The CTS unit 21 includes a sawtooth slot 211 disposed on the upper metal plate 41 along the x-direction. The x-direction is perpendicular to the y-direction, and the plane formed by the x-direction and the y-direction is parallel to the parallel plate waveguide 4.

[0078] As an example, as shown in Figures 2, 3 and 4, the CTS unit 21 includes two rows of sawtooth slots 211 disposed opposite each other on the upper metal plate 41 along the x direction, and the two rows of sawtooth slots penetrate the upper metal plate 41.

[0079] Optionally, the serrations can be rectangular, but of course, they can also be other shapes.

[0080] Optionally, as shown in Figures 2 and 3, multiple metal ridges 5 are provided on the side of the lower metal plate 42 of the parallel plate waveguide 4 opposite to the upper metal plate 41. One end of the metal ridge 5 is connected to an output port of the first line source exciter 1, and the other end of the metal ridge 5 is connected to a metal wall 6. The metal wall 6 is connected to an output port of the second line source exciter 3. As shown in Figures 2 and 5, since there is a height difference between the output port of the second line source exciter 3 and the CTS array 2, the output port 31 of the second line source exciter 3 is stepped in the yz section. The upper metal plate 311 corresponding to the upper step is directly connected to the upper metal plate 41 of the parallel plate waveguide 4, the lower metal plate 312 corresponding to the lower step is connected to the metal wall 6, and the metal ridges 5 are connected to the metal wall 6.

[0081] Optionally, the spacing between two adjacent metal ridges in the plurality of metal ridges 5 is equal to the spacing between two adjacent sawtooth slots in the CTS unit 21.

[0082] As a specific example, as shown in Figure 4, the CTS array 2 may include six (or other numbers) CTS units 21 connected in series, with a spacing of λg between two adjacent CTS units 21. Each CTS unit 21 is constructed by etching two rows of serrated slits through an upper metal plate 41 with a thickness of 2 mm. These two rows of serrated slits are symmetrical about the x-axis, and the serrations are rectangular metal blocks of 1.4 mm × 1 mm × 2 mm, arranged periodically along the x-axis. Optionally, several metal ridges 5 are evenly spaced along the x-axis on the lower metal plate 41 of the parallel plate waveguide 4.

[0083] As described above, the metal ridge 5 placed on the lower metal plate 42 of the parallel plate waveguide 4 forming the CTS array 2 is open at one end and connected to the metal wall 11 between the power divider output port of the first line source exciter 1; the other end of the metal ridge 5 is closed and connected to the lower metal plate of the second line source exciter 3, as shown in Figure 5. The sum of the heights of the metal ridge 5 and the lower metal plate 42 of the parallel plate waveguide 4 is the height of the lower metal plate 312 of the second line source exciter 3.

[0084] In order to radiate enough energy through fewer radiating branches, the CTS array 2 is in the form of a standing wave array. The first line source exciter 1 and the second line source exciter 3, which have mode cutoff characteristics, are placed at both ends of the CTS array 2 as terminal reflectors.

[0085] Optionally, the spacing between two adjacent CTS units 21 is λg, the spacing between the output port of the first line source exciter 1 and the nearest CTS unit 21 is λg / 2, and the spacing between the output port of the second line source exciter 3 and the nearest CTS unit 21 is λg / 2.

[0086] As an example, in order to reduce the waveguide wavelength λg, thereby shortening the spacing between array elements—CTS units 21 and suppressing grating lobes, the waveguides of CTS array 2, first line source exciter 2 and second line source exciter 3 are all filled with a dielectric material with a relative permittivity of 2.2.

[0087] As a more specific example, according to the above formulas (2) and (3), when the first line source exciter 1 operates at a frequency of 38.6 GHz in TE1 mode and the second line source exciter 3 operates at a frequency of 28.3 GHz in TEM mode, the two have approximately the same waveguide wavelength λg and can share a CTS array as the radiation aperture.

[0088] It should be noted that the height of the parallel plate waveguide 4 forming the CTS array 2 needs to meet the propagation conditions of the TE1 mode within the parallel plate waveguide, which results in a relatively large height for the parallel plate waveguide. Therefore, when the antenna excites the TEM mode, the CTS array 2 cannot achieve good impedance matching (as shown by the black curve in Figure 9 – case 1). To improve impedance matching, as shown in Figures 1 to 4, this embodiment also loads several rectangular metal blocks as serrations between the CTS elements 21, forming a CTS element 21 containing multiple serrations. In addition, this embodiment also uniformly places several metal ridges 5 along the x-axis direction on the lower metal plate 42 of the parallel plate waveguide 4, thereby affecting the height and slot width of the parallel plate waveguide 4 to further improve the impedance matching of the CTS array. Figure 9 compares the reflection coefficient frequency response curves of a general CTS array in the related art and the series-fed CTS array 2 proposed in this embodiment (whose partial structure is shown in Figure 8). In Figure 9, case 1 corresponds to the reflection coefficient frequency response curve of the CTS array in the related art, and case 2 corresponds to the reflection coefficient frequency response curve of the CTS array in the related art. As can be seen from Figure 9, when the CTS array of this application is operating in TEM mode, the reflection coefficient of the CTS array 2 can be improved by using sawtooth CTS units and loading metal ridges 5 on the lower metal plate 41 of the parallel plate waveguide 4.

[0089] This application proposes a dual-frequency dual-polarization millimeter-wave array antenna. Besides employing a high-gain CTS array and achieving dual-frequency dual-polarization performance in two orthogonal electric field polarization modes (first and second modes) by exciting the CTS array with a first and a second line source exciter respectively, it further designs the waveguide structure of the output port of the first line source exciter according to the single-mode transmission conditions of the third mode, ensuring the first line source exciter has cutoff characteristics for the fourth mode. Additionally, it designs the waveguide structure of the output port of the second line source exciter according to the single-mode transmission conditions of the fourth mode, ensuring the second line source exciter has cutoff characteristics for the third mode (wherein, the excitation signal in the third mode propagates from the output port of the first line source exciter to the CTS array and is converted to the first mode, and the excitation signal in the fourth mode propagates from the output port of the second line source exciter to the CTS array and is converted to the second mode), thereby ensuring high isolation between the two ports of the antenna.

[0090] The following simulation results illustrate the beneficial effects of the dual-frequency dual-polarized millimeter-wave array antenna proposed in this application.

[0091] A simulation of a dual-frequency dual-polarized millimeter-wave array antenna proposed in this application embodiment was performed, and the resulting S-parameters and isolation frequency response curves are shown in Figure 10. Simulation results show that when the dual-frequency dual-polarized millimeter-wave array antenna proposed in this application embodiment is fed using the TEM mode, the impedance bandwidth with |S11| < 10dB is 28GHz to 28.7GHz, |S22| > 5dB, and the port isolation is higher than 70dB. When the dual-frequency dual-polarized millimeter-wave array antenna proposed in this application embodiment is fed using the TE1 mode, the impedance bandwidth with |S22| < 10dB is 38.4GHz to 39GHz, |S11| > 7dB, and the port isolation is higher than 70dB.

[0092] Figure 11 shows the E-plane and H-plane radiation patterns of a dual-frequency dual-polarized millimeter-wave array antenna provided in this application embodiment when the antenna operates at the center frequency, obtained from simulation. As can be seen from Figure 11, when the dual-frequency dual-polarized millimeter-wave array antenna proposed in this application embodiment is fed with TEM mode, the center frequency is 28.3 GHz and the maximum gain is 21.1 dBi; when the dual-frequency dual-polarized millimeter-wave array antenna proposed in this application embodiment is fed with TE1 mode, the center frequency is 38.6 GHz and the maximum gain is 20.6 dBi.

[0093] Compared with related technologies, firstly, the two line source exciters in the dual-frequency dual-polarized millimeter-wave array antenna provided in this application embodiment have additional mode cutoff characteristics, realizing the integration of two line source exciters that excite two orthogonal modes respectively on one antenna, while ensuring high port isolation of the antenna. Secondly, the dual-frequency dual-polarized millimeter-wave array antenna provided in this application embodiment achieves dual polarization using only one set of lateral radiation slots, resulting in a simple structure. Thirdly, the dual-frequency dual-polarized millimeter-wave array antenna provided in this application embodiment solves the impedance mismatch problem when the series-fed CTS array operates simultaneously in TEM mode and TE1 mode by using a novel sawtooth slot-formed CTS unit and loading a metal ridge on the lower metal plate of the parallel plate waveguide. Fourthly, compared with the parallel-fed CTS array in related technologies that can operate simultaneously in TEM and TE1 modes, the dual-frequency dual-polarized millimeter-wave array antenna provided in this application embodiment, by combining the aforementioned first line source exciter, second line source exciter, and series-fed CTS array, has the advantage of low profile.

[0094] In summary, the dual-frequency dual-polarization millimeter-wave array antenna provided in this application embodiment has the advantages of high isolation and high gain, can realize integrated transmission and reception, improve antenna aperture utilization, and improve communication quality.

[0095] The above describes a dual-band dual-polarized millimeter-wave array antenna provided in the embodiments of this application. The dual-band dual-polarized millimeter-wave array antenna provided in the embodiments of this application has a maximum length, width, and height of approximately 85mm × 35mm × 6mm, and can be applied to fields such as 5G millimeter-wave, 5G point-to-point communication, and satellite communication. Specifically, it can be applied to terminal devices, including but not limited to 5G CPEs, vehicle-mounted terminals, and micro base stations.

[0096] This application also proposes a communication device, which includes a dual-band dual-polarization millimeter-wave array antenna provided in this application embodiment. This antenna achieves dual-band dual-polarization performance while ensuring high isolation between the two ports, realizing high gain, integrating transmission and reception, and improving antenna aperture utilization, thereby enhancing communication quality. The communication device may include, but is not limited to, a CPE, a vehicle-mounted terminal, and a satellite terminal.

[0097] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0098] In summary, the above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

[0099] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0100] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

Claims

1. A dual-frequency, dual-polarization millimeter-wave array antenna, comprising: First line source exciter (1), continuous transverse branch CTS array (2), and second line source exciter (3); One end of the CTS array (2) is connected to the output port of the first line source exciter (1), and the other end of the CTS array (2) is connected to the output port of the second line source exciter (3); Wherein, the first line source exciter (1) is used to excite the CTS array (2) to operate in a first mode and a first frequency, and the second line source exciter (3) is used to excite the CTS array (2) to operate in a second mode and a second frequency, wherein the electric field polarization of the CTS array in the first mode and the second mode is orthogonal; Wherein, the waveguide structure of the output port of the first line source exciter (1) satisfies the single-mode transmission condition of the third mode, and the excitation signal in the third mode is transformed into the first mode after propagating from the output port of the first line source exciter (1) to the CTS array (2); and the waveguide structure of the output port of the second line source exciter (3) satisfies the single-mode transmission condition of the fourth mode, and the excitation signal in the fourth mode is transformed into the second mode after propagating from the output port of the second line source exciter (3) to the CTS array (2).

2. The antenna according to claim 1, wherein, The first mode is the transverse radio wave TE1 mode, and the third mode is the TE01 mode; The second mode is the transverse electromagnetic wave (TEM) mode, and the fourth mode is the TE10 mode.

3. The antenna according to claim 2, wherein, The waveguide structure of the output port of the first line source exciter (1) is rectangular, and the waveguide structure satisfies the single-mode transmission condition of the TE01 mode. The excitation signal in the TE01 mode is converted into the TE1 mode after propagating from the output port of the first line source exciter (1) to the CTS array (2). The waveguide structure of the output port of the second line source exciter (3) is rectangular, and the waveguide structure satisfies the single-mode transmission condition of the TE10 mode. The excitation signal in the TE10 mode is converted into TEM mode after propagating from the output port of the second line source exciter (3) to the CTS array (2).

4. The antenna according to claim 3, wherein, The single-mode transmission conditions for the TE01 mode are as follows: max(2a,b)<λ<2b Wherein, λ represents the wavelength of the excitation signal that the rectangular waveguide can propagate, λ is related to the first frequency and the dielectric constant of the medium inside the rectangular waveguide, a represents the width of the rectangular waveguide in the x direction, b represents the height of the rectangular waveguide in the z direction, the x direction is parallel to the plane where the CTS array (2) is located and perpendicular to the series direction of the CTS array (2), and the z direction is perpendicular to the plane where the CTS array (2) is located.

5. The antenna according to claim 4, wherein, If the first frequency band is 38GHz to 39GHz, and the dielectric constant of the dielectric material inside the waveguide at the output port of the first line source exciter (1) is 2.2, then the waveguide structure at the output port of the first line source exciter (1) satisfies the following conditions: a < 3.48 mm, and 2.66 mm < b < 5.18 mm.

6. The antenna according to claim 3, wherein, The single-mode transmission condition of the TE10 mode is: max(a, 2b) < λ < 2a Where, λ represents the wavelength of the excitation signal that can propagate in the rectangular waveguide. λ is related to the second frequency and the dielectric constant of the medium in the rectangular waveguide. a represents the width of the rectangular waveguide in the x direction, and b represents the height of the rectangular waveguide in the z direction. The x direction is parallel to the plane where the CTS array (2) is located and perpendicular to the series direction of the CTS array (2). The z direction is perpendicular to the plane where the CTS array (2) is located.

7. The antenna according to claim 6, wherein, If the second frequency band is 28 GHz - 29 GHz and the dielectric constant of the medium in the waveguide at the output port of the second line source exciter (3) is 2.2, then the waveguide structure at the output port of the second line source exciter (3) satisfies the following conditions: 5.32 mm < a < 6.97 mm, and b < 2.66 mm.

8. The antenna according to any one of claims 1-7, wherein, The CTS array (2) includes a plurality of CTS units (21) connected in series.

9. The antenna according to claim 8, wherein, The CTS array (2) includes a plurality of CTS units (21) arranged at equal intervals along the y direction on the upper metal plate (41) of the parallel plate waveguide (4); Where, the CTS unit (21) includes a zigzag slot (211) arranged along the x direction on the upper metal plate (41). The x direction is perpendicular to the y direction, and the plane formed by the x direction and the y direction is parallel to the parallel plate waveguide (4).

10. The antenna according to claim 9, wherein, The CTS unit (21) includes two rows of zigzag slots (211) arranged oppositely along the x direction on the upper metal plate (41), and the two rows of zigzag slots penetrate through the upper metal plate (41).

11. The antenna according to claim 9, wherein, On the lower metal plate (42) of the parallel plate waveguide (4), on the side opposite to the upper metal plate (41), a plurality of metal ridges (5) are provided. One end of the metal ridge (5) is connected to an output port of the first line source exciter (1), and the other end of the metal ridge (5) is connected to a metal wall (6). The metal wall (6) is connected to an output port of the second line source exciter (3).

12. The antenna according to claim 11, wherein, The distance between two adjacent metal ridges among the plurality of metal ridges (5) is equal to the distance between two adjacent zigzag slots in the CTS unit (21).

13. The antenna according to claim 8, wherein, The distance between two adjacent CTS units (21) is λg. The distance between the output port of the first line source exciter (one) and the nearest CTS unit (21) is λg / 2, and the distance between the output port of the second line source exciter (3) and the nearest CTS unit (21) is λg / 2.

14. The antenna according to any one of claims 9-10, wherein, The dielectric constant of the medium in the parallel plate waveguide (4) is the same as the dielectric constant of the medium in the waveguides at the output ports of the first line source exciter (1) and the second line source exciter (3).

15. A communication device, comprising: The antenna according to any one of claims 1 - 14.

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