Millimeter wave broadband circularly polarized magnetoelectric dipole antenna loaded with parasitic patch and array

Abstract

The invention belongs to the technical field of electrical elements, and particularly relates to a millimeter wave broadband circularly polarized magnetoelectric dipole antenna and array loaded with parasitic patches. A pair of E-shaped electric dipole structures is arranged on the top surface of an upper-layer substrate; the E-shaped electric dipole structure comprises a transversely arranged E-shaped patch and a transverse branch knot connected with the side edge of the E-shaped patch; the two E-shaped patches are arranged in a staggered mode, and the transverse branch knot of one E-shaped patch corresponds to the notch of the other E-shaped patch. A C-shaped parasitic patch corresponding to the E-shaped patch is arranged on the bottom surface of the upper substrate layer; and the projection of the n-shaped parasitic patches half surrounds the projection of the middle vertical edge of the corresponding E-shaped patch, so that circularly polarized radiation is realized by reconstructing the E-shaped electric dipole structure, regulating and controlling the surface current distribution of the E-shaped electric dipole structure, and on the basis, a new axial ratio point is introduced by loading a pair of n-shaped parasitic patches and utilizing electromagnetic coupling between the n-shaped parasitic patches and the main radiating body, so that the radiation efficiency is improved. And the axial ratio bandwidth of the antenna is effectively expanded.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrical elements, and particularly relates to an antenna, in particular to a millimeter wave broadband circularly polarized magnetic electric dipole antenna loaded with a parasitic patch and an array. BACKGROUND

[0002] With the deep integration and development of 5G / 6G communication and satellite communication technology, the stability and reliability of the millimeter wave frequency band circularly polarized antenna are required to be higher in the communication system, and a circularly polarized antenna solution with a wider frequency band, lower cross polarization and more stable radiation pattern is urgently needed. However, the existing circularly polarized antenna still has some deficiencies: the working frequency band is mostly concentrated in a lower frequency band, which is difficult to meet the needs of 5G millimeter wave communication; the impedance bandwidth and axial ratio bandwidth are narrow, which limits its application in wideband communication; and the design structure of some broadband circularly polarized antennas and arrays is complex, resulting in high insertion loss.

[0003] Therefore, due to the technical problem that the low working frequency band and narrow axial ratio bandwidth of the antenna make it difficult to meet the needs of 5G millimeter wave communication, a new millimeter wave broadband circularly polarized magnetic electric dipole antenna loaded with a parasitic patch and an array need to be designed.

[0004] It should be noted that the above information disclosed in the background section of the present application is only used to understand the background of the present application, and therefore, the above description is not considered to constitute prior art information. SUMMARY

[0005] The embodiments of the present disclosure at least provide a millimeter wave broadband circularly polarized magnetic electric dipole antenna loaded with a parasitic patch and an array.

[0006] In a first aspect, the embodiments of the present disclosure provide a millimeter wave broadband circularly polarized magnetic electric dipole antenna, comprising: an upper substrate layer, a top surface of the upper substrate layer is provided with a pair of E-shaped electric dipole structures, and the two E-shaped electric dipole structures are rotationally symmetrical; The E-shaped electric dipole structure comprises an E-shaped patch arranged transversely, and a transverse branch connected to a side edge of the E-shaped patch; The two E-shaped patches are arranged in a staggered manner, and the transverse branch of one E-shaped patch corresponds to a notch of the other E-shaped patch; A bottom surface of the upper substrate layer is provided with a pair of H-shaped parasitic patches corresponding to the E-shaped patches, wherein one H-shaped parasitic patch has an opening facing downward, and the other H-shaped parasitic patch has an opening facing upward; The projection of the H-shaped parasitic patch half-encloses the projection of the middle vertical edge of the corresponding E-shaped patch.

[0007] In one alternative implementation, when the opening of the i-shaped parasitic patch is facing upward or downward, one of its vertical sides is longer than the other vertical side, and at this time the longer vertical sides of the two i-shaped parasitic patches are positioned close to each other.

[0008] In one optional embodiment, a lower substrate is disposed below the upper substrate, and the upper substrate and the lower substrate are connected by an adhesive layer.

[0009] In one alternative embodiment, a metal floor layer is provided on the top surface of the lower substrate, and H-shaped narrow slits are etched on the metal floor layer.

[0010] In one alternative embodiment, a T-shaped microstrip power divider is disposed on the bottom surface of the lower substrate layer.

[0011] In one optional embodiment, a pair of through-hole metallized vias are provided on the upper substrate layer, the adhesive layer and the lower substrate layer, and a metal pillar is provided in the through-hole metallized via. The metallized via corresponds to the E-shaped patch, and the metallized via penetrates the corresponding E-shaped patch.

[0012] In one optional embodiment, the upper substrate layer and the lower substrate layer are made of Rogers 3003. The adhesive layer is a 0.1mm thick RO4450F semi-cured sheet.

[0013] Secondly, this disclosure also provides an antenna array employing the above-described millimeter-wave broadband circularly polarized magnetoelectric dipole antenna, comprising: Four arrays of E-shaped electric dipole structures are arranged on the same upper substrate, with a spacing of 6.5 mm between each E-shaped electric dipole structure.

[0014] In one alternative embodiment, a T-shaped microstrip power divider corresponding to an electric dipole structure is disposed on the bottom surface of the lower substrate, and the T-shaped microstrip power divider is connected through a main T-shaped power divider with a bend line.

[0015] In one alternative implementation, the H-shaped narrow slits corresponding to the E-shaped electric dipole structure are disposed on the same metal floor layer.

[0016] The beneficial effects of this invention are as follows: This millimeter-wave broadband circularly polarized magnetoelectric dipole antenna has a pair of E-shaped electric dipole structures on the top surface of the upper substrate, with the two E-shaped electric dipole structures being rotationally symmetrical. The E-shaped electric dipole structure includes: a laterally arranged E-shaped patch and a laterally connected branch to the side of the E-shaped patch; the two E-shaped patches are staggered, with the laterally connected branch of one E-shaped patch corresponding to the notch of the other E-shaped patch; the bottom surface of the upper substrate has an i-shaped parasitic patch corresponding to the E-shaped patch, with one i-shaped parasitic patch opening downwards and the other i-shaped parasitic patch opening upwards; the projection of the i-shaped parasitic patch semi-encloses the projection of the middle vertical side of the corresponding E-shaped patch, thereby realizing circularly polarized radiation by reconstructing the E-shaped electric dipole structure and controlling its surface current distribution. On this basis, by loading a pair of i-shaped parasitic patches, a new axial ratio point is introduced by utilizing the electromagnetic coupling between them and the main radiator, effectively expanding the axial ratio bandwidth of the antenna.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a millimeter-wave broadband circularly polarized magnetoelectric dipole antenna provided in an embodiment of the present disclosure; Figure 2 A three-dimensional schematic diagram of a millimeter-wave broadband circularly polarized magnetoelectric dipole antenna provided for embodiments of this disclosure; Figure 3 The surface current distribution of an E-shaped patch at different times provided in this embodiment of the present disclosure; Figure 4 A schematic diagram of the simulated current distribution of an inverted parasitic patch at a frequency of 21 GHz, provided for an embodiment of this disclosure; Figure 5 This is a schematic projection of an E-shaped electric dipole structure provided in an embodiment of the present disclosure; Figure 6 A schematic diagram of an antenna array provided in an embodiment of this disclosure; Figure 7 The S-parameter response and gain curve of a circularly polarized magnetoelectric dipole antenna element provided in this embodiment of the present disclosure; Figure 8 Axial ratio curve of a circularly polarized magnetoelectric dipole antenna element provided in an embodiment of this disclosure; Figure 9 The radiation pattern of a circularly polarized magnetoelectric dipole antenna element provided in an embodiment of this disclosure; Figure 10 This is a schematic diagram illustrating the evolution process of a circularly polarized magnetoelectric dipole antenna element provided in an embodiment of this disclosure. Figure 11 Axis ratio comparison diagram of evolved antennas provided in embodiments of this disclosure Figure 12 Comparison diagram of evolved antenna S11 provided in the embodiments of this disclosure Figure 13 Schematic diagrams of two fully common-feed network structures provided in the embodiments of this disclosure. Figure 14 This is a schematic diagram comparing the impedance matching of two types of fully common-feed networks provided in the embodiments of this disclosure.

[0021] In the picture: Upper substrate layer 1, E-shaped electric dipole structure 11, E-shaped patch 12, lateral branch 13, and C-shaped parasitic patch 14; Lower substrate 2, metal ground plane 21, H-shaped narrow slit 22, T-shaped microstrip power divider 23; Adhesive layer 3; Metallized through holes 4, metal pillars 41; Main T-type power divider 5. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0024] With the deep integration and development of 5G / 6G communication and satellite communication technologies, communication systems are placing higher demands on the stability and reliability of circularly polarized antennas in the millimeter-wave band. There is an urgent need for circularly polarized antenna solutions with wider bandwidth, lower cross-polarization, and more stable radiation patterns. However, existing circularly polarized antennas still have several shortcomings: their operating frequency bands are mostly concentrated in lower frequency bands, making it difficult to meet the needs of 5G millimeter-wave communication; their impedance bandwidth and axial ratio bandwidth are relatively narrow, limiting their application in broadband communication; and some broadband circularly polarized antennas and their array designs are complex, resulting in high insertion loss.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] like Figure 1As shown, at least one disclosed embodiment provides a millimeter-wave broadband circularly polarized magnetoelectric dipole antenna, comprising: an upper substrate layer 1, wherein a pair of E-shaped electric dipole structures 11 are disposed on the top surface of the upper substrate layer 1, the two E-shaped electric dipole structures 11 being rotationally symmetrical; each E-shaped electric dipole structure 11 includes: a laterally disposed E-shaped patch 12, and a laterally disposed branch 13 connected to the side of the E-shaped patch 12; the two E-shaped patches 12 are staggered, wherein the laterally disposed branch 13 of one E-shaped patch 12 corresponds to the notch of the other E-shaped patch 12; the bottom of the upper substrate layer 1... The surface is provided with an incline parasitic patch 14 corresponding to the E-shaped patch 12, one of the incline parasitic patches 14 having an opening facing downwards and the other having an opening facing upwards; the projection of the incline parasitic patch 14 will semi-enclose the projection of the middle vertical side of the corresponding E-shaped patch 12, thereby realizing circular polarization radiation by reconstructing the E-shaped electric dipole structure 11 and controlling its surface current distribution. On this basis, by loading a pair of incline parasitic patches 14, a new axial ratio point is introduced by utilizing the electromagnetic coupling between them and the main radiator, effectively expanding the axial ratio bandwidth of the antenna.

[0028] In this embodiment, the E-shaped patch 12 is arranged horizontally, such that the opening of the upper E-shaped patch 12 faces downward and the opening of the lower E-shaped patch 12 faces upward. The horizontal branch 13 connected to the upper E-shaped patch 12 is located above one opening of the lower E-shaped patch 12, and the horizontal branch 13 connected to the lower E-shaped patch 12 is located below one opening of the upper E-shaped patch 12.

[0029] In this embodiment, when the E-shaped patch 12 is in the horizontal direction, the opening formed by the vertical side and the middle vertical side connecting the E-shaped patch 12 and the horizontal branch 13 corresponds to the horizontal branch 13 of another E-shaped patch 12.

[0030] In one alternative implementation, when the opening of the i-shaped parasitic patch 14 is facing upward or downward, one of its vertical sides is longer than the other vertical side, and at this time the longer vertical sides of the two i-shaped parasitic patches 14 are positioned close to each other.

[0031] like Figure 5 As shown, in this embodiment, when the E-shaped patch 12 is positioned horizontally, the projection of the longer vertical side of the C-shaped parasitic patch 14 is located within the gap formed by the vertical side connected by the horizontal branch 13 of the E-shaped patch 12 and the middle vertical side. The shorter vertical side of the C-shaped parasitic patch 14 is located in another gap. The projection of the horizontal side of the C-shaped parasitic patch 14 coincides with the projection of the horizontal side of the E-shaped patch 12, so as to semi-enclose the projection of the middle vertical side of the E-shaped patch 12.

[0032] In this embodiment, the projection of the horizontal side of the H-shaped narrow slit 22 is located between the projections of the two E-shaped patches 12.

[0033] In one optional embodiment, a lower substrate 2 is disposed below the upper substrate, and the upper substrate and the lower substrate 2 are connected by an adhesive layer 3.

[0034] In one alternative embodiment, a metal floor layer 21 is provided on the top surface of the lower substrate 2, and an H-shaped narrow slit 22 is etched on the metal floor layer 21.

[0035] In one alternative embodiment, a T-shaped microstrip power divider 23 is disposed on the bottom surface of the lower substrate layer.

[0036] like Figure 2 As shown, in an optional embodiment, a pair of through-hole metallized vias 4 are provided on the upper substrate layer 1, the adhesive layer 3 and the lower substrate layer, and a metal pillar 41 is provided in the through-hole metallized via 4; the through-hole metallized via 4 corresponds to the E-shaped patch 12, and the through-hole metallized via 4 penetrates the corresponding E-shaped patch 12.

[0037] In this embodiment, when the E-shaped patch 12 is arranged horizontally, the metallized through hole 4 is located on the vertical side where the E-shaped patch 12 connects to the horizontal branch 13.

[0038] In this embodiment, the line connecting the centers of the metallized vias 4 of the two E-shaped patches 12 is parallel to the vertical side of the E-shaped patch 12.

[0039] In one optional embodiment, the upper substrate layer 1 and the lower substrate layer are made of Rogers 3003 with a relative permittivity of 3 and a loss tangent of 0.0013; the adhesive layer 3 is a 0.1 mm thick RO4450F prepreg with a relative permittivity of 3.55 and a loss tangent of 0.004.

[0040] In this embodiment, the antenna adopts an integrated unit structure design, which significantly improves the ease of manufacturing. Meanwhile, low-loss Rogers 3003 substrate is selected as the base layer, minimizing dielectric loss and ensuring the antenna's radiation efficiency in the millimeter-wave band.

[0041] In this embodiment, the magnetoelectric dipole antenna itself possesses excellent characteristics such as wide bandwidth, low cross-polarization, and stable radiation pattern. This allows the designed circularly polarized antenna to achieve wider impedance and axial ratio bandwidth, lower cross-polarization level, and more stable radiation pattern while maintaining a simple structure. Furthermore, Rogers 3003 is selected as the substrate material in the design, and its excellent low-loss characteristics help to further reduce antenna loss and improve overall performance.

[0042] like Figure 6As shown, in this embodiment, the main radiator, namely the E-shaped electric dipole structure 11, is printed on the top surface of the upper substrate layer 1 and functions as an electric dipole. The bottom surface of the lower substrate layer uses a T-shaped microstrip power divider 23 with an input impedance of 50Ω as a feeding structure to feed the upper main radiator. The metal ground plane layer 21 on its top surface is etched with an H-shaped narrow slot 22, and a metallized via 4 penetrates the entire structure. Both of these together serve as a magnetic dipole. The feeding structure provides excitation for the antenna element. The magnetic dipole interacts with the electric dipole on the upper substrate through electromagnetic coupling, thereby generating circularly polarized radiation. To further extend the axial ratio bandwidth of the circularly polarized magnetoelectric dipole antenna, a pair of inverted parasitic patches 14 are etched on the bottom surface of the upper substrate layer 1. Based on the inherent characteristics of magnetoelectric dipoles, such as low cross-polarization and stable radiation pattern, the millimeter-wave broadband circularly polarized magnetoelectric dipole antenna in this embodiment can maintain excellent radiation directivity stability and good cross-polarization suppression capability even when operating in the millimeter-wave high-frequency band (such as 16 GHz-34 GHz). By designing based on magnetoelectric dipoles and raising the operating frequency band of the circularly polarized antenna to the millimeter-wave range, high-frequency operation of 16 GHz-34 GHz can be achieved.

[0043] In this embodiment, the millimeter-wave broadband circularly polarized magnetoelectric dipole antenna is designed based on the fundamental principle of magnetoelectric dipoles. Fed via microstrip lines, it simultaneously excites electric dipole modes and magnetic dipole modes with equal amplitude and orthogonal phase (90° out of phase). These two modes are orthogonally superimposed in space and radiate together, thereby achieving efficient radiation of circularly polarized waves.

[0044] like Figure 8 and Figure 9 As shown, in this embodiment, the E-shaped electric dipole structure 11 is simulated and analyzed. The surface current distribution of the antenna at four consecutive different times (0°, 90°, 180°, 270°) is as follows. Figure 3 As shown, it can be clearly observed that the current rotates counterclockwise within the period, exciting right-hand circularly polarized radiation. To further extend the impedance bandwidth and axial ratio bandwidth, a pair of inverted parasitic patches 14 are loaded onto the E-shaped electric dipole structure 11. Analysis shows that the surface current distribution of the loaded inverted parasitic patches 14 is as follows: Figure 4 As shown in the figure, the surface current exhibits a stable counterclockwise rotation characteristic within the period. This rotating current distribution forms circularly polarized radiation, generating an axial ratio point, thereby expanding the axial ratio bandwidth. By reconstructing the E-shaped electric dipole structure 11 and controlling its surface current distribution, circularly polarized radiation is achieved. Furthermore, by loading a pair of i-shaped parasitic patches 14 and utilizing their electromagnetic coupling with the main radiator, a new axial ratio point is introduced, effectively expanding the antenna's axial ratio bandwidth.

[0045] In this embodiment, one possible design flow for a millimeter-wave broadband circularly polarized magnetoelectric dipole antenna is as follows: Step 1: Determine the substrate material to be used based on factors such as relative permittivity, loss tangent, and cost.

[0046] Step 2: Calculate the approximate dimensions of the model based on the expected operating frequency of the millimeter-wave broadband circularly polarized magnetoelectric dipole antenna.

[0047] Step 3: Determine the feeding method and design a linearly polarized magnetoelectric dipole antenna for the millimeter-wave band. Perform preliminary model simulation. The linearly polarized magnetoelectric dipole antenna model is as follows: Figure 10 As shown in (a).

[0048] Step 4: A pair of transverse stubs 13 were introduced into the basic structure of the online polarized magnetoelectric dipole antenna, forming a preliminary circularly polarized magnetoelectric dipole antenna (labeled as antenna 2), as shown below. Figure 10 As shown in (b), the antenna 2 model is simulated and analyzed. Figure 11 It can be seen that within the frequency band, the axial ratio is less than 3 dB near 25 GHz, which initially forms a circularly polarized antenna, but the bandwidth is very narrow.

[0049] Step 5: Add a pair of inverted L-shaped bent line structures to the top patch of antenna 2 to construct the structure as shown. Figure 10 The improved antenna 3 structure is shown in (c). Modeling and simulation analysis of antenna 3 are performed, and the simulation results are as follows: Figure 11 As shown, the axial ratio performance of antenna 3 is significantly improved, with its 3 dB axial ratio bandwidth being much wider than that of antenna 2, demonstrating the effective enhancement of circular polarization characteristics by this structure. However, analysis of its impedance matching characteristics reveals that the improved structure has poor return loss performance within the bandwidth, and the matching level at some frequency points does not reach the ideal state, such as... Figure 12 As shown in the figure. This phenomenon indicates that although the introduction of the inverted L-shaped bend successfully modulates the current distribution and optimizes the axial ratio, it also has a certain impact on the input impedance characteristics of the antenna.

[0050] Step Six: To improve the antenna impedance matching performance, the slot structure of antenna 3 was changed from the original straight slot to an H-shaped slot. The H-shaped slot, by introducing a symmetrical branch structure, effectively adjusted the equivalent capacitance and inductance distribution in the slot region, thereby optimizing the antenna's input impedance characteristics. Figure 12As shown, the optimized antenna reflection coefficient |S11| is below -10 dB across the entire operating frequency band, significantly improving impedance matching performance and achieving a wider impedance bandwidth, demonstrating a clear performance improvement over antenna 3. To further extend the antenna's axial ratio bandwidth, a pair of vertically symmetrical stub structures were introduced into the top radiating patch. These stub structures create effective structural perturbations on the patch surface, altering the amplitude and phase distribution of the surface current, thereby exciting degenerate modes with equal amplitude and orthogonal phase, effectively widening the circularly polarized axial ratio bandwidth. The final optimized antenna structure is shown below. Figure 10 As shown in (d), this structure achieves good impedance and radiation characteristics while maintaining a compact size. Figure 11 Furthermore, the axial ratio performance curves of the antenna in the main operating frequency band are given. The results show that the antenna axial ratio is always below 3 dB in the target frequency band, and the axial ratio bandwidth is significantly better than that of antenna 3.

[0051] Step 7: Based on antenna 4, a pair of C-shaped parasitic patches 14 are introduced at the bottom of the upper substrate to form a structure as shown in the figure. Figure 10 Antenna 5 structure is shown in (e). The performance of antenna 5 was compared and analyzed using HFSS electromagnetic simulation software. The comparison results of its reflection coefficient |S11| and axial ratio are as follows: Figure 11 and Figure 12 As shown. By Figure 12 Comparison curves of the |S11| parameter and Figure 7 It can be seen that antenna 5 exhibits excellent impedance matching characteristics, and its impedance bandwidth has been significantly improved compared to antenna 4. Figure 11 The comparison of the axial ratio performance of antenna 4 and antenna 5 is shown. It can be clearly seen that antenna 5 achieves a wider axial ratio bandwidth than antenna 4.

[0052] Step 8: Verify the performance of the linearly polarized magnetoelectric dipole antenna and simulate the structure of the circularly polarized antenna by optimizing the electric dipole structure.

[0053] Step 9: By observing the simulation results, find the key parameters for changing the impedance bandwidth and axial ratio bandwidth in order to achieve the performance of the broadband circularly polarized antenna.

[0054] Step 10: Establish a full simulation model, perform small-scale optimizations to obtain the antenna's optimal performance, and complete the design.

[0055] like Figure 6 As shown, at least one other disclosed embodiment also provides an antenna array employing the above-described millimeter-wave broadband circularly polarized magnetoelectric dipole antenna, comprising: four sets of E-shaped electric dipole structures 11 arrayed on the same upper substrate, wherein the spacing between each E-shaped electric dipole structure 11 is 6.5 mm.

[0056] In one optional embodiment, a T-shaped microstrip power divider 23 corresponding to an electric dipole structure is disposed on the bottom surface of the lower substrate 2, and the T-shaped microstrip power divider 23 is connected through a main T-shaped power divider 5 with a bend line.

[0057] In one alternative embodiment, the H-shaped narrow slit 22 corresponding to the E-shaped electric dipole structure 11 is disposed on the same metal floor layer 21.

[0058] In this embodiment, the antenna array's feeding system adopts an integrated design. A complete common-feed network is etched on the bottom surface of the lower substrate 2. This network is centered on a main T-shaped power divider 5 with a bend in the line, and is combined with multiple secondary small T-shaped power dividers, namely the T-shaped microstrip power dividers 23 of the millimeter-wave broadband circularly polarized magnetoelectric dipole antenna, to form an equal-amplitude and in-phase distribution structure. This provides consistent and low-loss feeding excitation for the four antenna elements, thereby ensuring the balance and stability of the overall radiation performance of the array. To construct the antenna array, a fully coplanar feeding network with a bend in the line is used. This design is not only simple in structure and easy to process and test, but also effectively improves the impedance matching performance of the array and suppresses frequency shift caused by mutual coupling and other reasons. The array design is simple and has good impedance performance. The antenna array is designed using a common-feed network, which is simple in structure and easy to process. At the same time, the bend in the line structure (equivalent to a 1 / 4 impedance transformation segment) is added to improve impedance matching and frequency shift.

[0059] In this embodiment, by loading a pair of i-shaped parasitic patches 14, the impedance bandwidth and axial ratio bandwidth of the antenna and antenna array are extended. The impedance bandwidth of the antenna array covers a range of 18.34 GHz to 33.86 GHz, reaching 67.48%; the axial ratio bandwidth is 19.45 GHz to 30.35 GHz, achieving 47.39% axial ratio bandwidth, meeting the requirements of broadband communication. These characteristics make it perfectly suited for high-requirement application scenarios such as 5G / 6G millimeter-wave communication, satellite communication, and vehicle radar, providing a high-performance antenna solution for next-generation broadband and high-reliability wireless systems.

[0060] In this embodiment, the cross-polarization of the radiation pattern of the antenna and its array at the center frequency and axial ratio point is less than -20 dB, and it has stable radiation directivity.

[0061] In this embodiment, one possible design step for the array is: Step 1: Study the feeding network structure of the antenna array, and select a fully common-feed network for array configuration. Figure 13 Figure (a) illustrates a power supply network structure that uses a single-stage T-type power divider as the main distribution node, in conjunction with four second-stage T-type power dividers, namely T-type microstrip power dividers 23, to achieve 2×2 equal-amplitude in-phase power supply. However, due to... Figure 14Simulation results show that the array has poor impedance matching performance, with the reflection coefficient failing to reach below -10 dB within the target frequency band. Analysis indicates that this problem mainly stems from a severe mismatch between the output port of the feed network and the input impedance of the antenna elements. To improve the matching performance, in Figure 13 An improved feeder network is proposed in (b). This design... Figure 13 Based on (a), a section of the transmission line of the first-stage T-type power divider is replaced with a bent structure, forming the main T-type power divider 5 with a bent line. This bent structure is equivalent to a 1 / 4 impedance transformation section, which can improve impedance matching and frequency shift. The simulation results after using this improved feeder network array are as follows: Figure 14 As shown, the impedance matching of the array is significantly improved, and the reflection coefficient is below -10 dB throughout the entire target frequency band, verifying the effectiveness of the structural optimization scheme.

[0062] Step 2: Select the feed network and perform preliminary modeling and simulation of the antenna array model.

[0063] Step 3: By observing the simulation results, find the key parameters for changing the impedance bandwidth and axial ratio bandwidth in order to achieve the performance of the broadband circularly polarized antenna.

[0064] Step 4: Establish a full simulation model, perform small-scale optimizations to obtain the antenna's optimal performance, and complete the design.

[0065] In summary, this millimeter-wave broadband circularly polarized magnetoelectric dipole antenna features a pair of E-shaped electric dipole structures 11 arranged on the top surface of the upper substrate. These two E-shaped electric dipole structures 11 are rotationally symmetrical. Each E-shaped electric dipole structure 11 includes a laterally arranged E-shaped patch 12 and a laterally arranged branch 13 connected to the side of the E-shaped patch 12. The two E-shaped patches 12 are staggered, with the laterally arranged branch 13 of one E-shaped patch 12 corresponding to a notch in the other E-shaped patch 12. The bottom surface of the upper substrate layer 1 is provided with a section connecting the E-shaped patch 1... The corresponding i-shaped parasitic patch 14 has one i-shaped parasitic patch 14 with its opening facing downwards and the other i-shaped parasitic patch 14 with its opening facing upwards. The projection of the i-shaped parasitic patch 14 will semi-enclose the projection of the middle vertical side of the corresponding E-shaped patch 12, thereby realizing circular polarization radiation by reconstructing the E-shaped electric dipole structure 11 and regulating its surface current distribution. On this basis, by loading a pair of i-shaped parasitic patches 14, a new axial ratio point is introduced by utilizing the electromagnetic coupling between them and the main radiator, effectively expanding the axial ratio bandwidth of the antenna.

[0066] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0067] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as a second element, component, region, layer, or segment.

[0068] Spatially relative terms, such as “inside,” “outside,” “below,” “below,” “down,” “above,” “up,” etc., may be used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. In addition to the orientations depicted in the figures, spatially relative terms may be intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “below” other elements or features would be oriented as “above” other elements or features. Thus, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0069] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A millimeter-wave broadband circularly polarized magnetoelectric dipole antenna, characterized in that, Comprising: An upper substrate layer (1), on the top surface of the upper substrate, there are provided a pair of E-shaped electric dipole structures (11), and the two E-shaped electric dipole structures (11) are rotationally symmetric; The E-shaped electric dipole structure (11) includes: a horizontally arranged E-shaped patch (12), and a horizontal stub (13) connected to the side of the E-shaped patch (12); The two E-shaped patches (12) are arranged with a dislocation, and the horizontal stub (13) of one E-shaped patch (12) corresponds to the notch of the other E-shaped patch (12); On the bottom surface of the upper substrate layer (1), there are provided U-shaped parasitic patches (14) corresponding to the E-shaped patches (12), one of the U-shaped parasitic patches (14) has an opening facing downwards, and the other U-shaped parasitic patch (14) has an opening facing upwards; The projection of the U-shaped parasitic patch (14) semi-surrounds the projection of the middle vertical side of the corresponding E-shaped patch (12).

2. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 1, wherein: When the opening of the U-shaped parasitic patch (14) faces upwards or downwards, one of its vertical sides is longer than the other vertical side, and at this time, the longer vertical sides of the two U-shaped parasitic patches (14) are arranged close to each other.

3. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 1, wherein: Below the upper substrate, there is provided a lower substrate (2), and the upper substrate and the lower substrate (2) are connected through an adhesive layer (3).

4. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 3, wherein: On the top surface of the lower substrate (2), there is provided a metal floor layer (21), and an H-shaped narrow slit (22) is etched on the metal floor layer (21).

5. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 4, wherein: On the bottom surface of the lower substrate layer, there is provided a T-shaped microstrip power divider (23).

6. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 5, wherein: On the upper substrate layer (1), the adhesive layer (3) and the lower substrate layer, there are provided a pair of through metalized vias (4), and metal columns (41) are arranged inside the metalized vias (4); The metalized vias (4) correspond to the E-shaped patches (12), and the metalized vias (4) penetrate through the corresponding E-shaped patches (12).

7. The millimeter-wave broadband circularly polarized magnetoelectric dipole antenna according to claim 3, wherein: The materials of the upper substrate layer (1) and the lower substrate layer are Rogers 3003; The adhesive layer (3) is a 0.1 mm thick RO4450F prepreg.

8. An antenna array employing a millimeter-wave broadband circularly polarized magnetoelectric dipole antenna as described in any one of claims 1-7, characterized in that, Comprising: Four groups of E-shaped electric dipole structures (11) arranged in an array on the same upper substrate, and the distance between each E-shaped electric dipole structure (11) is 6.5 mm.

9. The antenna array according to claim 8, wherein: On the bottom surface of the lower substrate (2), there is provided a T-shaped microstrip power divider (23) corresponding to the electric dipole structure, and the T-shaped microstrip power divider (23) is connected through a main T-shaped power divider (5) with a bent line.

10. The antenna array according to claim 8, wherein: The H-shaped narrow slit (22) corresponding to the E-shaped electric dipole structure (11) is disposed on the same metal floor layer (21).

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