Ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and two-stage Wilkinson differential feed

Abstract

The invention discloses an ultra-wideband dual-polarization dielectric resonator antenna based on multimode resonance and two-stage Wilkinson differential feed. The ultra-wideband dual-polarization dielectric resonator antenna comprises a dielectric substrate, a cylindrical dielectric resonator, two pairs of coaxial probes, two groups of two-stage Wilkinson power dividers and two feed ports, the cylindrical dielectric resonator is arranged at the central position of the dielectric substrate; the two pairs of coaxial probes are symmetrically arranged in pairs along + / -x and + / -y directions by taking the center of the cylindrical dielectric resonator as an original point; and the two feed ports are respectively connected with the input ends of the corresponding two-stage Wilkinson power dividers and are used for carrying out differential feed on the corresponding coaxial probes and exciting a radiation mode polarized in the x-axis direction and a radiation mode polarized in the y-axis direction and orthogonal to the radiation mode. According to the invention, a dual-polarization radiation mode with a compact structure, a wide band and low coupling is realized, each polarization further increases the bandwidth by exciting a plurality of resonant modes with close frequency points, and low coupling is realized through differential feed and medium regulation field valley composite decoupling.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication and antenna engineering, and particularly relates to a kind of ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and two-stage wilkinson differential feed. BACKGROUND

[0002] As a key component for electromagnetic wave transceiving in communication systems, the performance of antenna directly affects the signal quality, transmission rate and capacity of the system. With the development of the fifth generation (5G) and sixth generation (6G) mobile communication technology, the comprehensive performance of the antenna is required to be higher in communication systems, especially in large-scale MIMO (Multiple-Input Multiple-Output) array, the antenna unit needs to have the characteristics of wideband, high isolation, multi-polarization, miniaturization and easy integration at the same time.

[0003] Among them, the wideband performance has become one of the key indicators in antenna design. With the continuous expansion of wireless communication spectrum and the trend of multi-standard coexistence, a single antenna unit needs to cover multiple frequency bands to support multi-service coordination and carrier aggregation functions. Wideband antenna not only can maintain good impedance matching and radiation performance in a larger frequency range, thereby improving system throughput and spectrum utilization efficiency, but also can effectively offset the detuning caused by processing errors, structural deviations and changes in use environment, thereby improving the reliability and environmental adaptability of the system. Therefore, how to realize efficient and stable wideband radiation while maintaining compact structure is one of the core goals of current communication system antenna design.

[0004] Dual-polarized antenna can realize two mutually orthogonal polarization forms in the same radiator, thereby effectively improving channel capacity, reducing polarization mismatch and enhancing anti-multipath fading capability, and has become an important type of antenna in modern communication systems. Dielectric resonator antenna (DRA) has attracted widespread attention in dual-polarized antenna design due to its high radiation efficiency, low loss, compact structure and easy realization of multi-mode resonance. However, the existing dual-polarized DRA generally has limited bandwidth, large coupling between ports and complex feed network, etc., which makes it difficult to balance between wideband characteristics and structure simplification. In traditional design, dual-polarized DRA generally realizes orthogonal polarization by exciting different modes, but the bandwidth of each mode is narrow, and the overall working bandwidth is limited. In order to improve the performance, researchers try to introduce parasitic structure, defected ground structure (DGS) or differential feed method to reduce the coupling between ports, but these methods are often complex in structure, high in manufacturing cost, and have deficiencies in wideband coverage capability.

[0005] The disadvantages of existing dual-polarized dielectric resonator antennas and the main challenges in design and application are as follows:

[0006] (1) Limited bandwidth. Most dual-polarized dielectric resonator antennas only rely on a single resonant mode or two adjacent modes, the frequency interval between modes is large and impedance matching is difficult, resulting in narrow overall bandwidth, which is difficult to meet the demand of ultra-wideband communication;

[0007] (2) Strong port coupling. Since the two feed ports excite different modes in the same dielectric body, if the field distribution is not completely orthogonal or symmetric, port coupling is easy to occur, which causes signal crosstalk and polarization isolation to decrease, thereby affecting the radiation efficiency and system stability;

[0008] (3) Limited bandwidth of the feed network. Traditional differential feed structure relies on external balun or single-stage Wilkinson power divider to realize anti-phase signals, which has narrow bandwidth and large insertion loss, and cannot support wideband differential excitation;

[0009] (4) Complex structure. Some improved schemes introduce multi-layer dielectric, parasitic structure or defect ground to improve bandwidth and isolation, but at the same time increase the processing complexity and volume, which is not conducive to integration and large-scale application.

[0010] In summary, the existing technology cannot simultaneously realize a dual-polarized dielectric resonator antenna with wide bandwidth, low coupling and easy integration under the premise of compact structure.

[0011] Therefore, how to realize a dual-polarized dielectric resonator antenna with ultra-wideband, low coupling and good polarization performance at the same time while maintaining compact structure and easy processing has become a key problem to be solved in the current antenna design field. SUMMARY

[0012] The purpose of the application is to solve the problems of narrow bandwidth, large port coupling, insufficient bandwidth of the feed network and complex structure of the existing dual-polarized dielectric resonator antenna. The application provides an ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and double-stage Wilkinson differential feed. The multi-mode resonance bandwidth is combined in the dielectric resonator, and the port coupling is suppressed by combining the common-mode suppression characteristics of the wideband differential feed and the dielectric regulated field valley, which significantly expands the operating bandwidth, improves the isolation and simplifies the structure, thereby realizing compact structure, wide bandwidth, high isolation and easy integration at the same time. Each polarization further excites multiple resonant modes close to the frequency point to increase the bandwidth, and differential feed and dielectric regulated field valley are combined to realize low coupling.

[0013] Technical solution: The application provides an ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and double-stage Wilkinson differential feed, which comprises a dielectric substrate, a cylindrical dielectric resonator, a first coaxial probe, a second coaxial probe, a third coaxial probe, a fourth coaxial probe, a first double-stage Wilkinson power divider, a second double-stage Wilkinson power divider, a first feed port and a second feed port.

[0014] The cylindrical dielectric resonator is arranged at the upper center position of the dielectric substrate.

[0015] The first coaxial probe, the second coaxial probe, the third coaxial probe and the fourth coaxial probe are arranged in pairs of symmetry along the ±x and ±y directions with the center of the cylindrical dielectric resonator as the origin.

[0016] The first double-stage Wilkinson power divider and the second double-stage Wilkinson power divider are arranged on the lower surface of the dielectric substrate and are arranged orthogonally to each other, and the output ends of the first double-stage Wilkinson power divider and the second double-stage Wilkinson power divider are connected to the first coaxial probe, the second coaxial probe, the third coaxial probe and the fourth coaxial probe respectively.

[0017] The common mode suppression characteristics of differential feed and the dielectric regulation field valley method are combined to form an electric field valley in the coaxial probe and resonator coupling area, and the in-phase stray mode is suppressed.

[0018] The first feed port is connected to the input end of the first double-stage Wilkinson power divider, and is used for differential feed to the corresponding coaxial probe, so as to excite HEM y 111 , HEM y 112 , HEM y 113 , HEM y 31δ , HEM y 32δ modes in the cylindrical dielectric resonator, and the polarization direction is the x-axis.

[0019] The second feed port is connected to the input end of the second double-stage Wilkinson power divider, and is used for differential feed to the corresponding coaxial probe, so as to excite HEM x 111 , HEM x 112 , HEM x 113 , HEM x 31δ , HEM x 32δ modes in the cylindrical dielectric resonator, and the polarization direction is the y-axis.

[0020] Further, each coaxial probe is connected with the corresponding dual-stage Wilkinson power divider through a through hole on the dielectric substrate and can be reliably grounded.

[0021] Further, an opening is arranged at the contact position of each coaxial probe and the ground metal layer to form a coaxial via hole shield.

[0022] Further, the first dual-stage Wilkinson power divider and the second dual-stage Wilkinson power divider are orthogonally arranged on the lower surface of the dielectric substrate through a bridge structure.

[0023] Further, each dual-stage Wilkinson power divider comprises an input microstrip transmission line, a first-stage λ / 4 microstrip transmission line, a second-stage λ / 4 microstrip transmission line and an output microstrip transmission line.

[0024] The first-stage λ / 4 microstrip transmission line and the second-stage λ / 4 microstrip transmission line are connected in parallel to form a two-stage structure, the input microstrip transmission line is connected with the input of the two-stage structure, a Wilkinson isolation resistor is arranged between the two-stage structure, and the output microstrip transmission line is connected with the output of the two-stage structure, the electrical lengths of the two output microstrip transmission lines are different by half of the guided wave wavelength λg, and differential feeding of the coaxial probe is realized.

[0025] Further, by adjusting the radius and height of the cylindrical dielectric resonator, the insertion position and length of the coaxial probe, the resonant points of each mode are effectively overlapped in the frequency band, and the impedance bandwidth of the antenna is improved.

[0026] Beneficial effects: The present application combines multi-mode resonance and differential feeding technology, realizes the dielectric resonator antenna with ultra-wideband low-coupling dual-polarized radiation characteristics through a dual-stage Wilkinson broadband power division network, and can be widely applied to wideband wireless communication systems, large-scale MIMO antenna arrays, radar sensing and high-speed data transmission fields. Compared with the prior art, the present application has the following advantages:

[0027] (1) The present application realizes a dual-polarized radiation mode with compact structure, significantly widened bandwidth and low-coupling port through a single cylindrical dielectric resonator body;

[0028] (2) The present application obtains two mutually orthogonal polarization forms by exciting HEM x and HEM y modes in the cylindrical dielectric resonator; under each polarization, further select HEM 111 and HEM 113 modes with adjacent resonant frequencies and similar patterns as the main working modes, combine multi-mode bandwidth through differential feeding to form a first-stage wideband radiation;

[0029] (3) By adjusting the radius and height of the cylindrical dielectric resonator, the insertion position and length of the probe, the present invention can make the above-mentioned mode resonant points effectively overlap in a wider frequency band, thereby significantly improving the antenna impedance bandwidth;

[0030] (4) This invention utilizes a two-stage Wilkinson broadband differential feed network to maintain good amplitude and phase consistency of differential equal-amplitude inverted signals over a wider frequency range. Thanks to the feed network's ability to provide stable differential excitation in the mid-to-high frequency range, the cylindrical dielectric resonator not only excites HEM signals but also... 111 HEM 113 Low-order dominant modes, while also effectively stimulating HEM at higher frequency bands. 31δ and HEM 32δ Higher-order modes are used to participate in radiation and form a continuous coverage with the aforementioned main mode on the frequency axis, thereby achieving the second stage of bandwidth expansion.

[0031] (5) Compared with traditional designs that rely on only a few modes, this invention uses differential feeding and dielectric geometry parameters in the same dielectric resonator to co-excite multiple low-order and high-order modes under controllable conditions, which significantly improves the overall impedance bandwidth while maintaining the stability of the radiation pattern and polarization characteristics. This design, which achieves a balance between multi-mode coordination and radiation characteristics, places high demands on the frequency spacing between modes, the orthogonality of the field distribution, and the broadband phase response of the feeding network, which constitutes the important innovation and technical difficulty of this invention.

[0032] (6) This invention uses a two-stage Wilkinson power divider as the feed network. The power divider consists of two quarter-wavelength impedance transformation lines and isolation resistors. By changing the impedance and length of each transmission line, broadband impedance matching between the feed network and the dielectric resonator is achieved. Compared with the traditional single-stage Wilkinson structure, the two-stage design divides a single impedance change into two gradual transitions, significantly expanding the antenna's operating bandwidth. By introducing a path difference of half the guided wavelength λg (ΔL = λg / 2) in the output branch, the phase difference between the two output signals can be maintained at close to 180° throughout the entire operating band, thereby achieving stable differential feeding over a wide frequency range.

[0033] (7) To solve the problem of trace crossing in the planar wiring of the two sets of power dividers, this invention introduces a bridge bridging structure at the intersection of the two sets of power dividers. This structure achieves non-coplanar electrical bridging through the lower bridge board and vias, thereby ensuring the continuity of transmission line impedance and avoiding signal crosstalk. Through this design, a compact layout can be achieved on a single-layer circuit board, greatly improving the structural integration and fabrication feasibility.

[0034] (8) This invention achieves low coupling characteristics between the two ports through a differential feeding mechanism. The differential feeding forms a virtual ground plane at the center of the two probes, which enhances the orthogonality of the electric field distributions under the two polarizations and makes them less prone to mutual interference, thereby effectively reducing the coupling between the ports. Furthermore, by combining the dielectric-controlled field valley technology, a stable electric field valley is formed in the coupling region between the probe and the resonator, which further improves the isolation performance between the ports;

[0035] (9) Compared with the various dual-polarized dielectric resonator antennas currently available, existing designs are often complex in structure and require additional baluns or phase-shifting networks, making it difficult to achieve efficient integration. The dual-polarized dielectric resonator antenna proposed in this invention can simultaneously meet the engineering requirements of miniaturization and broadband. While maintaining a simple structure and convenient processing, it also takes into account ultra-wideband characteristics and excellent isolation performance. It is suitable for multiple-input multiple-output (MIMO) communication systems, V2X vehicle communication, Wi-Fi, and 6G and other next-generation broadband wireless communication fields, and has significant application and promotion value. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of an ultrawideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding proposed in this invention; wherein, Figure 1 (a) in the diagram is the overall structure of the proposed antenna. Figure 1 (b) in the figure is a side view of the proposed antenna;

[0037] Figure 2 The S-parameter diagrams of each port of an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding proposed in this invention are shown.

[0038] Figure 3 The electric field distribution of the XOZ plane of the dielectric resonator is shown in the figure below, which illustrates the ultrawideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding proposed in this invention, when the first feed port is individually excited and operates at different frequencies. Figure 3 (a) shows the electric field distribution on the XOZ surface of the dielectric resonator operating at 3.2 GHz. Figure 3 (b) shows the electric field distribution on the XOZ surface of the dielectric resonator operating at 4.2 GHz. Figure 3 (c) in the figure shows the electric field distribution of the XOZ surface of the dielectric resonator when it is operating at 4.8 GHz;

[0039] Figure 4 The electric field distribution of the YOZ plane of the dielectric resonator is shown in the figure below, which illustrates the ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding proposed in this invention, when the second feed port is individually excited and operates at different frequencies. Figure 4(a) shows the electric field distribution of the YOZ plane of the dielectric resonator operating at 3.2 GHz. Figure 4 (b) shows the electric field distribution on the YOZ plane of the dielectric resonator operating at 4.2 GHz. Figure 4 (c) in the figure shows the electric field distribution of the YOZ plane of the dielectric resonator when it is operating at 4.8 GHz;

[0040] Figure 5 This invention presents a magnetic field distribution diagram of the lower surface of a 6.2 GHz dielectric resonator when individually excited at different feed ports, based on multimode resonance and dual-stage Wilkinson differential feeding, according to the present invention. Figure 5 (a) in the diagram is the magnetic field distribution on the lower surface of the dielectric resonator when the first feed port is excited alone. Figure 5 (b) in the figure is the magnetic field distribution on the lower surface of the dielectric resonator when the second feed port is excited alone;

[0041] Figure 6 This invention presents a magnetic field distribution diagram of the lower surface of a 6.8 GHz dielectric resonator when individually excited at different feed ports, based on multimode resonance and dual-stage Wilkinson differential feeding, according to the present invention. Figure 6 (a) in the diagram is the magnetic field distribution on the lower surface of the dielectric resonator when the first feed port is excited alone. Figure 6 (b) in the figure is the magnetic field distribution on the lower surface of the dielectric resonator when the second feed port is excited alone;

[0042] Figure 7 This invention presents the electric field pattern of an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding, where the first feed port is excited alone. Figure 7 (a) in the text is 2.8 GHz. Figure 7 (b) in the text is 4.4 GHz. Figure 7 (c) in the text refers to 6GHz;

[0043] Figure 8 This invention presents the electric field pattern of an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding, where the first feed port is excited alone; wherein, Figure 8 (a) in the text is 2.8 GHz. Figure 8 (b) in the text is 4.4 GHz. Figure 8 (c) in the text refers to 6GHz;

[0044] Figure 9This invention presents the electric field pattern of an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding, when the second feed port is excited alone; wherein, Figure 9 (a) in the text is 2.8 GHz. Figure 9 (b) in the text is 4.4 GHz. Figure 9 (c) in the text refers to 6GHz;

[0045] Figure 10 This invention presents the electric field pattern of an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding, where the second feed port is excited alone; wherein, Figure 10 (a) in the text is 2.8 GHz. Figure 10 (b) in the text is 4.4 GHz. Figure 10 (c) in the figure represents 6 GHz. Detailed Implementation

[0046] The technical solution of the present invention will now be further described in conjunction with the accompanying drawings and embodiments.

[0047] like Figure 1 As shown, this embodiment of the invention discloses an ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding. It achieves a compact structure, significantly widened bandwidth, and low port coupling dual-polarized radiation mode through a single cylindrical dielectric resonator. It mainly includes a dielectric substrate 1, a cylindrical dielectric resonator 2, a first coaxial probe 3, a second coaxial probe 4, a third coaxial probe 5, a fourth coaxial probe 6, a first dual-stage Wilkinson power divider 7, a second dual-stage Wilkinson power divider 8, a first feed port 9, a second feed port 10, a ground plane 11, and a bridge structure 12 for trace crossing.

[0048] In this embodiment of the invention, the cylindrical dielectric resonator 2 is located at the center above the dielectric substrate 1, and the bottom of the cylindrical dielectric resonator 2 is tightly attached to the ground plane 11. Two pairs of coaxial probes (the first coaxial probe 3 and the third coaxial probe 5 form one pair, and the second coaxial probe 4 and the fourth coaxial probe 6 form another pair) are symmetrically arranged along the ±x and ±y directions with the center of the cylindrical dielectric resonator 2 as the origin. All coaxial probes penetrate into the interior of the cylindrical dielectric resonator 2 from below the ground plane 11. All contact points between the coaxial probes and the ground plane 11 are provided with through holes and solder ring structures to achieve a stable electrical connection. All coaxial probes are connected to the lower microstrip line through the through holes of the dielectric substrate 1 and reliably grounded. The through holes at the contact points between the coaxial probes and the ground plane 11 form a coaxial via shield.

[0049] In this embodiment of the invention, a power supply network is located beneath the dielectric substrate 1, and a two-stage Wilkinson power divider is used as the power supply network. A first two-stage Wilkinson power divider 7 and a second two-stage Wilkinson power divider 8 are distributed orthogonally on the lower surface of the substrate. The input terminal of the first two-stage Wilkinson power divider 7 is connected to the first power supply port 9, and its output is connected to the bottom pad of a pair of coaxial probes formed by the first coaxial probe 3 and the third coaxial probe 5. The input terminal of the second two-stage Wilkinson power divider 8 is connected to the second power supply port 10, and its output is connected to the bottom pad of another pair of coaxial probes formed by the second coaxial probe 4 and the fourth coaxial probe 6. The two power supply ports supply power to the corresponding probes through the input terminals of their respective two-stage Wilkinson power dividers to provide differential excitation to the dielectric resonator 2. Since the two sets of power supply networks have traces crossing on the lower surface of the dielectric substrate 1, in order to prevent signal interference, the embodiment of the present invention provides a bridge structure 12 in the crossing area. The bridge structure 12 is composed of a bridge plate and a via pair, so that the signals can be non-coplanarly connected. At the same time, copper removal is performed in the area under the bridge to reduce parasitic capacitance, thereby ensuring the continuity of transmission line impedance and isolation.

[0050] In this embodiment of the invention, each two-stage Wilkinson power divider consists of multiple microstrip transmission lines and isolation resistors. The input terminal of the two-stage Wilkinson power divider is connected to an input microstrip transmission line with a characteristic impedance of 50 ohms, and then sequentially connected to λ / 4 microstrip transmission lines with characteristic impedances Z1 and Z2 connected in parallel with the first and second stages. 100-ohm Wilkinson isolation resistors are placed between the two stages and at the output terminal to absorb unbalanced power, achieving port power equalization and reflection suppression, and widening the matching bandwidth. Finally, two signals with equal amplitude are output from the 50-ohm output microstrip transmission line. By changing the impedance and length of each microstrip transmission line, broadband impedance matching between the feed network and the dielectric resonator is achieved. Furthermore, this two-stage structure forms a two-stage impedance gradient, enabling good impedance matching over a wide frequency band.

[0051] To achieve differential feeding, the electrical lengths of the two output microstrip transmission lines are designed to differ by half the guided wave wavelength λg (ΔL = λg / 2), thus creating a phase difference of approximately 180° within the operating frequency band. This ensures that the two signals are output with equal amplitude and opposite phase, and are then fed into symmetrically arranged coaxial probes to achieve stable differential excitation. When the output microstrip transmission lines of the two-stage Wilkinson power divider intersect in the plane, the bridge structure 12 uses a lower bridge plate and vias to bridge the intersection, thereby avoiding trace conflicts and maintaining the nominal impedance of the transmission lines.

[0052] This invention combines the common-mode suppression characteristics of differential feeding with the dielectric-controlled valley method to effectively suppress HEM. 21δ HEM 22δEquivalent stray modes. In this embodiment of the invention, two pairs of orthogonal coaxial probes are controlled by two feed ports to excite the HEM in the cylindrical dielectric resonator 2. x and HEM y The mode is used to obtain two mutually orthogonal polarization radiation modes, including: HEM y 111 HEM y 112 HEM y 113 HEM y 31δ HEM y 32δ Pattern, HEM x 111 HEM x 112 HEM x 113 HEM x 31δ With HEM x 32δ The two modes are: the former is linearly polarized radiation predominantly in the x-direction, and the latter is linearly polarized radiation in the y-direction orthogonal to the former. Within each polarization radiation mode, HEM is further selected. 111 With HEM 113 These two modes, with adjacent resonant frequencies and similar radiation patterns, serve as the primary operating modes. Multimode bandwidth merging is achieved through differential feeding to form the first stage of broadband radiation. Specifically, the first feed port 9 differentially feeds the first coaxial probe 3 and the third coaxial probe 5, arranged along the x-axis, via the first dual-stage Wilkinson power divider 7. This is equivalent to introducing two equal-amplitude, opposite-phase current sources along the x-axis, thereby preferentially exciting the HEM in the dielectric resonator. y 111 With HEM y 113 The mode generates broadband Ex-polarized radiation; similarly, the second feed port 10 differentially feeds a pair of second coaxial probes 4 and fourth coaxial probes 6 arranged along the y-axis via a second two-stage Wilkinson power divider 8, forming an equal-amplitude, anti-phase current source in the y-axis direction, preferentially exciting the HEM. x 111 With HEM x 113 The pattern produces broadband Ey-polarized radiation. Due to the HEM... 111 With HEM 113 The resonant frequencies of the same modes are adjacent and their radiation patterns are similar. Their combined effect creates a bandwidth superposition effect, significantly extending the antenna's operating bandwidth. The modal fields excited by the two sets of differential probes are spatially orthogonal, effectively suppressing cross-coupling and achieving dual-polarized low-coupling radiation.

[0053] By adjusting the radius and height of the cylindrical dielectric resonator 2, as well as the insertion position and length of the coaxial probe, the resonant points of the above modes can be effectively overlapped in a wider frequency band, thereby significantly improving the antenna impedance bandwidth.

[0054] Building upon this, this embodiment of the invention further utilizes a two-stage Wilkinson broadband differential feed network to maintain good amplitude and phase consistency of the differential equal-amplitude inverted signal over a wider frequency range. Thanks to the feed network's ability to provide stable differential excitation in the mid-to-high frequency range, the cylindrical dielectric resonator not only excites HEM signals... 111 HEM 113 Low-order dominant modes, while also effectively stimulating HEM at higher frequency bands. 31δ and HEM 32δ Higher-order modes are incorporated into the radiation and form a continuous coverage with the aforementioned dominant mode on the frequency axis, achieving the second stage of bandwidth expansion. Compared with traditional designs that rely on only a few modes, this embodiment of the invention, through differential feeding and geometric parameter design within the same dielectric resonator, collaboratively excites multiple low-order and high-order modes under controllable conditions. This significantly improves the overall impedance bandwidth while maintaining the stability of the radiation pattern and polarization characteristics. This design, which achieves a balance between multi-mode collaboration and radiation characteristics, places high demands on the frequency spacing between modes, the orthogonality of the field distribution, and the broadband phase response of the feeding network, constituting the important innovation and technical challenge of this invention.

[0055] Compared to the traditional single-stage Wilkinson structure, the dual-stage Wilkinson power divider design proposed in this invention divides a single impedance jump into two gradual transitions, significantly expanding the antenna's operating bandwidth. By introducing a path difference of half the guided wavelength λg (ΔL = λg / 2) in the output branch, the phase difference between the two output signals can be maintained at approximately 180° throughout the entire operating band, thereby achieving stable differential feeding over a wide frequency range. To address the routing crossover problem between the two sets of feed networks in planar wiring, this invention introduces a bridge structure 12 at the intersection of the two power dividers. This bridge structure 12 achieves non-coplanar electrical bridging through a bridge plate and vias, thereby ensuring transmission line impedance continuity and avoiding signal crosstalk. This design allows for a compact layout on a single-layer circuit board, significantly improving structural integration and fabrication feasibility.

[0056] This invention achieves low coupling characteristics between the two ports through a differential feeding mechanism. The differential feeding forms a virtual ground plane at the centers of the two probes, enhancing the orthogonality of the electric field distributions under the two polarizations and reducing mutual interference, thereby effectively reducing coupling between the ports. Furthermore, by combining dielectric-controlled field valley technology, a stable electric field valley is formed in the coupling region between the probe and the resonator, further improving the isolation performance between the ports.

[0057] Figure 2 The diagram shows the S-parameter curves of each port of the ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and dual-stage Wilkinson differential feeding proposed in this embodiment of the invention. Figure 2 It can be seen that the -10 dB common impedance bandwidth of this dual-polarized antenna is 6.14 GHz (2.35–8.49 GHz), with a relative bandwidth of 113.28%, and the operating frequency band covers most areas of the S-band and C-band. The isolation between the two ports within the operating frequency band is greater than 20 dB in most frequency ranges, indicating that the structure of this embodiment still has excellent port decoupling performance under broadband conditions.

[0058] Figure 3 This diagram shows the electric field distribution of the XOZ plane of the dielectric resonator at different operating frequencies when the antenna proposed in this embodiment of the invention is excited only at the first feed port. Figure 3 (a) shows the electric field distribution at 3.2 GHz, mainly corresponding to HEM. y 111 model; Figure 3 (b) shows the electric field distribution at 4.2 GHz, corresponding to HEM y 112 model; Figure 3 (c) in the figure represents the electric field distribution at 4.8 GHz, corresponding to HEM y 113 model.

[0059] Figure 4 This diagram shows the electric field distribution of the YOZ plane of the dielectric resonator at different operating frequencies when the antenna is individually excited at the second feed port. Figure 4 (a) in the figure represents the HEM at 3.2 GHz. x 111 Model electric field distribution; Figure 4 (b) in the figure represents the HEM at 4.2 GHz. x 112 Model electric field distribution; Figure 4 (c) in the figure represents the HEM at 4.8 GHz. x 113 Model electric field distribution. (Comprehensive) Figure 3 and Figure 4 It is evident that the electric field distributions obtained by exciting the first and second ports are orthogonal to each other, confirming the independence and orthogonality of the modes excited by the two sets of feed ports in the polarization direction, thus realizing dual-polarized radiation.

[0060] Figure 5 The diagram shows the magnetic field distribution on the lower surface of the dielectric resonator when the antenna proposed in this embodiment of the invention operates at a frequency of 6.2 GHz. Figure 5(a) shows the magnetic field distribution when the first feed port is excited alone, mainly manifested as HEM y 31δ model; Figure 5 (b) shows the magnetic field distribution when the second feed port is excited alone, corresponding to HEM x 31δ The magnetic field exhibits a circumferential periodic distribution, and the two modes are orthogonal to each other, indicating that the multimode higher-order resonance has been successfully excited at this frequency.

[0061] Figure 6 This is a magnetic field distribution diagram on the lower surface of the dielectric resonator when the antenna proposed in this embodiment of the invention operates at a frequency of 6.8 GHz. Wherein, Figure 6 In the diagram, (a) represents the magnetic field distribution under the first port excitation, corresponding to the HEM. y 32δ model; Figure 6 (b) in the figure represents the magnetic field distribution under second-port excitation, corresponding to HEM x 32δ The electromagnetic field distribution is basically symmetrical after rotating 90° in space, which further illustrates that the field distribution of the bipolarized radiation mode has good orthogonality and small coupling between ports.

[0062] Figure 7 The radiation pattern of the antenna proposed in this embodiment of the invention in the XOZ plane is shown when the first feed port is excited alone. Figure 7 (a) in the text is 2.8 GHz. Figure 7 (b) in the text is 4.4 GHz. Figure 7 (c) in the figure represents 6 GHz. It can be seen that the antenna maintains good main lobe direction consistency and cross-polarization suppression capability in both low and mid-high frequency bands, with the main radiation direction remaining basically stable at each frequency point, resulting in high radiation efficiency.

[0063] Figure 8 This is the radiation pattern in the YOZ plane of the antenna proposed in this embodiment of the invention when the first feed port is excited alone. Figure 8 (a) in the text is 2.8 GHz. Figure 8 (b) in the text is 4.4 GHz. Figure 8 (c) represents 6 GHz. As shown in the figure, the main polarization direction of the YOZ plane is orthogonal to that of the XOZ plane, indicating that the mode excited by the first port maintains stable linear polarization characteristics over a wide frequency range.

[0064] Figure 9 This is the radiation pattern of the XOZ plane of the antenna proposed in an embodiment of the present invention when the second feed port is excited alone. Figure 9 (a) in the text is 2.8 GHz. Figure 9 (b) in the text is 4.4 GHz.Figure 9 (c) represents 6GHz, and its radiation pattern is similar to... Figure 7 The polarization characteristics of the directional patterns are mutually orthogonal and have good stability throughout the entire bandwidth.

[0065] Figure 10 This is the radiation pattern of the YOZ plane of the antenna proposed in this embodiment of the invention when the second feed port is excited alone. Figure 10 (a) in the text is 2.8 GHz. Figure 10 (b) in the text is 4.4 GHz. Figure 10 (c) in the diagram represents 6 GHz. Its radiation pattern is visible and... Figure 8 The polarization characteristics of the radiation patterns shown are mutually orthogonal and have good stability throughout the entire bandwidth.

[0066] comprehensive Figures 3 to 10 The results show that the ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and dual-stage Wilkinson differential feeding proposed in this embodiment of the invention has the following characteristics:

[0067] (1) It achieves an ultra-wide impedance bandwidth of 6.14 GHz (2.35–8.49 GHz) with a relative bandwidth of 113.28%.

[0068] (2) The isolation within the operating frequency band is greater than 20 dB in most frequency ranges.

[0069] (3) The dual-polarization mode has a stable radiation pattern across the entire frequency band and good cross-polarization suppression.

[0070] (4) Compact structure (electrical dimensions approximately π×0.3×0.3×0.6λ0) 3 It is simple to manufacture and suitable for broadband MIMO and high-density array system applications.

[0071] The dual-polarized dielectric resonator antenna proposed in this invention can simultaneously meet the engineering requirements of miniaturization and broadband operation. The designed cylindrical dielectric resonator has dimensions of approximately π × 16.85 × 16.85 × 33.7 mm. 3 (π×0.3×0.3×0.6λ0³, where λ0 is the free-space wavelength at the center frequency), the overall structure is compact and easy to integrate into the array. Simulation results show that the antenna has a -10dB impedance bandwidth of 6.14 GHz (2.35–8.49 GHz), with a relative bandwidth of 113.28%. It maintains a stable radiation pattern and excellent polarization purity in the 2.32–6.30 GHz range, with cross-polarization suppression better than 10 dB. The isolation between the two ports in the operating frequency band is greater than 20 dB in most frequency ranges, verifying the significant advantages of this invention in broadband, low-coupling dual polarization.

[0072] Compared to currently available dual-polarized dielectric resonator antennas, existing designs are often complex in structure, require additional baluns or phase-shifting networks, and are difficult to integrate efficiently. This invention, while maintaining a simple structure and ease of fabrication, also achieves ultra-wideband characteristics and excellent isolation performance. It is suitable for next-generation broadband wireless communication fields such as multiple-input multiple-output (MIMO) communication systems, V2X vehicle-to-everything (V2X) communication, Wi-Fi, and 6G, and has significant application and promotion value.

Claims

1. An ultra-wideband dual-polarized dielectric resonator antenna based on multi-mode resonance and dual-stage Wilkinson differential feeding, characterized in that: include: Dielectric substrate, cylindrical dielectric resonator, first coaxial probe, second coaxial probe, third coaxial probe, fourth coaxial probe, first two-stage Wilkinson power divider, second two-stage Wilkinson power divider, first feed port and second feed port. The cylindrical dielectric resonator is disposed at the center above the dielectric substrate; The first coaxial probe, the second coaxial probe, the third coaxial probe, and the fourth coaxial probe are arranged symmetrically in pairs along the ±x and ±y directions, respectively, with the center of the cylindrical dielectric resonator as the origin. The first and second dual-stage Wilkinson power dividers are placed on the lower surface of the dielectric substrate and arranged orthogonally to each other. Their output terminals are respectively connected to the first, second, third, and fourth coaxial probes. Each dual-stage Wilkinson power divider includes an input microstrip transmission line, a first-stage λ / 4 microstrip transmission line, a second-stage λ / 4 microstrip transmission line, and an output microstrip transmission line. The first-stage λ / 4 microstrip transmission line and the second-stage λ / 4 microstrip transmission line are connected in parallel to form a two-stage structure. The input microstrip transmission line is connected to the input of the two-stage structure. A Wilkinson isolation resistor is set between the two-stage structure, and the output microstrip transmission line is connected to the output of the two-stage structure. The electrical lengths of the two output microstrip transmission lines differ by half of the waveguide wavelength λg, thereby realizing differential feeding of the coaxial probes. By combining the common-mode suppression characteristics of differential feeding with the dielectric-controlled field valley method, an electric field valley is formed in the coupling region between the coaxial probe and the resonator to suppress in-phase stray modes. The first feed port is connected to the input of the first two-stage Wilkinson power divider and is used to differentially feed the corresponding coaxial probe, thereby exciting the HEM in the cylindrical dielectric resonator. y 111 HEM y 112 HEM y 113 HEM y 31δ HEM y 32δ The mode has its polarization direction along the x-axis. The second feed port is connected to the input of the second two-stage Wilkinson power divider, and is used to differentially feed the corresponding coaxial probe to excite the HEM in the cylindrical dielectric resonator. x 111 HEM x 112 HEM x 113 HEM x 31δ HEM x 32δ The mode has a polarization direction along the y-axis.

2. The ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding according to claim 1, characterized in that: Each coaxial probe is connected to the corresponding two-stage Wilkinson power divider via a through-hole on the dielectric substrate and is reliably grounded.

3. The ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding according to claim 2, characterized in that: An opening is provided at the contact point between each coaxial probe and the ground metal layer to form a coaxial via shield.

4. The ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding according to claim 1, characterized in that: The first and second dual-stage Wilkinson power dividers are arranged orthogonally to each other on the lower surface of the dielectric substrate via a bridge structure.

5. The ultra-wideband dual-polarized dielectric resonator antenna based on multimode resonance and dual-stage Wilkinson differential feeding according to claim 1, characterized in that: By adjusting the radius and height of the cylindrical dielectric resonator, as well as the insertion position and length of the coaxial probe, the resonant points of each mode can be effectively overlapped within the frequency band, thereby improving the antenna impedance bandwidth.

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