Dual-frequency antenna system based on decoupling structure multiplexing

Abstract

The invention discloses a dual-frequency antenna system based on decoupling structure multiplexing, and belongs to the field of microwave communication, the dual-frequency antenna system is integrated with a 1 * 2DRA array and an MED antenna, two dielectric resonators are symmetrically arranged on a dielectric substrate, top metal patches are arranged on the upper surfaces of the dielectric resonators in a one-to-one correspondence mode, and the top metal patches are arranged on the dielectric substrate in a one-to-one correspondence mode. The metalized via hole penetrates through the dielectric resonator and the dielectric substrate and is connected with the top metal patch and the metal ground; the metal ground is provided with a first coupling slot and a second coupling slot which are used for feeding, and the feed microstrip line group is arranged corresponding to the slots and feeds the two antennas respectively. The top metal patch has a 1 * 2DRA array decoupling function and an MED antenna electric dipole function. Metallized via holes are matched with gaps of the top metal patch to be equivalent to MED antenna magnetic dipoles. On the premise of not deteriorating the radiation performance of the antenna and not increasing the integration complexity, the 1 * 2DRA array decoupling and integration dual-frequency antenna system is realized, and the antenna is adaptive to 5G application.

Description

Technical Field

[0001] This invention relates to the field of microwave communication, and more particularly to a dual-frequency antenna system based on decoupling structure multiplexing. Background Technology

[0002] Dielectric resonator antennas (DRAs) offer advantages such as high design freedom, zero ohmic loss, high radiation efficiency, and flexible feeding methods, meeting the miniaturization and broadband requirements of modern MIMO communication systems. Typically, MIMO antenna array designs strive for compactness, with element spacing generally within 0.5 wavelengths. The closer the antenna elements are, the more energy of the excited element couples to neighboring elements, leading to energy loss and reduced radiation efficiency. Simultaneously, the correlation between antenna elements increases, potentially significantly reducing channel capacity. Therefore, focusing on methods to reduce mutual coupling in DRAs within MIMO systems is of great importance.

[0003] Based on reported MIMO decoupling designs, decoupling schemes can be broadly categorized into three types: The first method achieves polarization diversity and pattern diversity by rationally designing antenna layouts or exciting antennas with specific modes, patterns, or polarizations, thereby effectively decoupling between antennas. However, this decoupling scheme has certain limitations, relying too heavily on specific radiation modes, patterns, and polarizations.

[0004] The second approach involves metamaterials. As artificial structures, these possess electromagnetic properties not found in natural materials through periodic, regular arrangement, thereby reducing coupling between antennas. Electromagnetic bandgap structures (EBGs), a special type of metamaterial, have high-impedance electromagnetic surfaces within a certain frequency band, thus forming surface wave bandgap to suppress surface wave propagation. However, this method introduces problems such as large physical spacing, complex design processes, and negative impacts on antenna radiation.

[0005] The third method involves loading decoupling structures, including metal strips, metal vias, defective grounding structures (DGS), and frequency selective surfaces (FSS). DGS structures primarily involve etching various shaped slots onto a metal ground plane. Because these slots possess resonant and band-stop filtering characteristics, they can effectively suppress coupling currents, thus achieving decoupling. However, these embedded structures require modifications to the antenna or ground plane, making the original DRA design less independent, which can further complicate the design process of MIMO DRAs. Summary of the Invention

[0006] Purpose of the invention: To address the aforementioned existing technologies, this invention proposes a dual-band antenna system based on decoupling structure reuse. Under the condition of ensuring that the antenna radiation performance and integration complexity are not degraded, broadband MIMO DRA decoupling is achieved, and a magnetic-electric dipole (MED) antenna is introduced on the basis of broadband DRA, thereby forming a dual-band antenna system suitable for 5G applications.

[0007] Technical solution: A dual-band antenna system based on decoupling structure multiplexing, integrating a 1×2 DRA array and a MED antenna, including a top metal patch, a dielectric resonator, a dielectric substrate, a metal ground, a feed substrate, and a feed microstrip line group stacked from top to bottom; Two dielectric resonators are arranged side by side and symmetrically on the upper surface of the dielectric substrate along the y-direction; Two top-layer metal patches are placed one-to-one on the upper surface of the two dielectric resonators; Two metallized vias pass vertically through the dielectric resonator and the dielectric substrate, respectively, connecting the top metal patch and the metal ground. Two first coupling slots and one second coupling slot are provided on the metal ground; the two first coupling slots are located at the center of the two dielectric resonators respectively, and are used to provide coupling power to the dielectric resonators; the second coupling slot is located in the slot between the two dielectric resonators, and is used to provide coupling power to the MED antenna. The power-fed microstrip line group includes two first power-fed microstrip lines and one second power-fed microstrip line; the two first power-fed microstrip lines are respectively aligned with two first coupling slots; the second power-fed microstrip line is aligned with the second coupling slot.

[0008] Furthermore, the two dielectric resonators serve as radiating elements of the 1×2 DRA array; the top metal patch is a decoupling structure for the 1×2 DRA array, used to weaken the coupled electric field along the x-direction inside the dielectric resonator to reduce the mutual coupling of the 1×2 DRA array; simultaneously, the top metal patch constitutes an electric dipole of the MED antenna; the metallized via, combined with the gap between the two top metal patches, is equivalent to a magnetic dipole of the MED antenna; the electric dipole and the magnetic dipole together constitute the MED antenna.

[0009] Furthermore, the center-to-center distance between the two dielectric resonators is 0.5λ0, where λ0 is the free-space wavelength corresponding to the center frequency.

[0010] Furthermore, the relative inner edges of the two top metal patches are flush with the relative inner surfaces of the corresponding dielectric resonators.

[0011] Furthermore, the two metallized vias are respectively located close to the inner surface of the dielectric resonator.

[0012] Furthermore, the first coupling gap is an H-shaped gap, and the second coupling gap is a rectangular gap.

[0013] Furthermore, the first feed microstrip line has a long strip structure, and the two first feed microstrip lines are port 1# and port 2#, respectively. When one port is used as the RF excitation signal feed port, the other port is used as the matching load port.

[0014] Furthermore, the second feed microstrip line is L-shaped, with its short side perpendicular to the second coupling slot and its long side parallel to the first feed microstrip line.

[0015] Furthermore, the DRA operates in the 5G N79 band, and the MED antenna operates in the 5G N78 band.

[0016] Beneficial effects: Compared with existing decoupled microstrip antennas, this invention improves the in-band mutual coupling level of the 1×2 DRA array while avoiding problems such as increased antenna size, deteriorated antenna radiation performance, poor environmental compatibility, and high integration difficulty. Furthermore, by reusing the decoupling structure, a MED antenna is further introduced on top of the broadband DRA, effectively realizing a dual-band antenna system suitable for 5G applications. Different frequency ratios can be achieved by independently adjusting the dimensions of both antennas.

[0017] Specifically, this invention constructs a pair of metal patches on the upper surface of a 1×2 DRA array antenna, thereby reducing the coupled electric field along the x-direction inside the induced DRA unit to achieve a decoupling effect. This structure can greatly reduce the mutual coupling between DRAs, while the decoupling structure is simple, avoiding problems such as increased antenna size, deteriorated antenna radiation performance, poor environmental compatibility, and high integration difficulty.

[0018] The decoupling structure, i.e., the top metal patch, is reused as an electric dipole, and a metallized via is further introduced to function as a magnetic dipole, working together with the metal patch as a magnetoelectric dipole antenna. By loading microstrip lines and rectangular slots to excite the MED antenna, good radiation performance of the MED antenna is achieved without affecting the decoupling effect of the 1×2 DRA array.

[0019] Since the polarization directions of the 1×2 DRA array and the MED antenna are orthogonal, they can be independently controlled to a certain extent, meaning that different frequency ratios can be achieved by adjusting their dimensions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the dual-band antenna system according to an embodiment of the present invention; Figure 2The simulation S-parameters of the conventional 1×2 DRA and the 1×2 low-coupling DRA of the present invention are compared, where (a) corresponds to the conventional 1×2 DRA and (b) corresponds to the 1×2 low-coupling DRA of the present invention. Figure 3 The simulation S-parameters and gains of the traditional 1×2 DRA and the 1×2 low-coupling DRA of the present invention are compared, where (a) corresponds to the S-parameters and gains, and (b) corresponds to the S-parameters and gains. Figure 4 The simulation radiation pattern is shown when port 1 is excited, where (a) corresponds to 4.34 GHz and (b) corresponds to 4.82 GHz. Figure 5 The simulation radiation pattern is shown when port 3 is excited, where (a) corresponds to 3.44 GHz and (b) corresponds to 3.90 GHz. Detailed Implementation

[0021] The invention will now be further explained with reference to the accompanying drawings.

[0022] like Figure 1 As shown, a dual-band antenna system based on decoupling structure multiplexing integrates a 1×2 DRA array and a MED antenna. Specifically, it includes a top metal patch 1, a dielectric resonator 3, a dielectric substrate 4, a metal ground 5, a feed substrate 8, and a feed microstrip line group, which are stacked sequentially from top to bottom.

[0023] Two dielectric resonators 3 are arranged side-by-side along the y-direction on the upper surface of the dielectric substrate 4, and are symmetrically positioned about the x-axis centerline of the dielectric substrate 4. The dielectric resonators 3 serve as the radiating units of the DRA. The center-to-center distance between the two dielectric resonators 3 is 0.5λ0, where λ0 is the free-space wavelength corresponding to the center frequency.

[0024] Two top metal patches 1 are respectively disposed on the upper surfaces of the two dielectric resonators 3, and the inner sides of the two top metal patches 1 are flush with the inner sides of the two dielectric resonators 3.

[0025] Two metallized vias 2 pass vertically through the two dielectric resonators 3 and the dielectric substrate 4, respectively, to connect the two top metal patches 1 and the metal ground 5. The two metallized vias 2 are located close to the inner surfaces of the two dielectric resonators 3.

[0026] Two H-shaped slots 6 and a rectangular slot 7 are provided on the metal ground 5. The two H-shaped slots 6 are respectively facing the two dielectric resonators 3, and the rectangular slot 7 is located between the slots of the two dielectric resonators 3.

[0027] The feeding microstrip line group consists of two first feeding microstrip lines 9 and one second feeding microstrip line 10. The two elongated first feeding microstrip lines 9 are respectively positioned opposite the two H-shaped slots 6 and perpendicular to the middle horizontal bar of each H-shaped slot 6. The second feeding microstrip line 10 is L-shaped, with its short side perpendicular to the rectangular slot 7 and its long side parallel to the first feeding microstrip lines 9. The two first feeding microstrip lines 9 serve as port #1 and port #2, respectively, and the second feeding microstrip line 10 serves as port #3.

[0028] In the above structure, the top metal patch 1 is a decoupling structure used to reduce the mutual coupling between the two DRAs. At the same time, the top metal patch 1 constitutes an electric dipole for low-frequency radiation. The metallized vias 2 located on the dielectric resonator 3 and the dielectric substrate 4, as well as the gap between the two top metal patches 1, are equivalent to the operation of a magnetic dipole.

[0029] A first feed microstrip line 9 for feeding a 1×2 DRA and a second feed microstrip line 10 for feeding a MED antenna are provided on the lower surface of the feed substrate 8. An H-shaped slot and a rectangular slot are provided on the metal ground 5, wherein the H-shaped slot 6 is used for coupling feed of the dielectric resonator 3, and the rectangular slot 7 is used for feeding the MED antenna.

[0030] In this embodiment, the DRA operates in the 5G N79 band H-plane coupling. When a signal is fed into one of the DRA's feed ports, its other port acts as a matching load. The RF excitation signal is fed in through the first feed microstrip line structure 9 and fed to the dielectric resonator 3 through the H-type slot coupling on the metal ground 5. The excited DRA unit operates in the fundamental mode TE. 111 In another DRA unit, a coupled electric field distributed along the x-direction is generated.

[0031] To improve the mutual coupling between the 1×2 DRA arrays, a top metal patch 1 is added to the upper surface of each dielectric resonator 3, thereby reducing the coupling electric field distributed along the x-direction inside the DRA. This improves the isolation between the two DRAs, ultimately increasing the isolation to over 25dB within the operating bandwidth.

[0032] Building upon the excellent isolation performance of the 1×2 DRA array antenna, a metallized via 2 is further introduced below the top metal patch 1 to function as the magnetic dipole of the MED antenna. Simultaneously, the top metal patch 1 of the decoupled structure is reused as the electric dipole of the MED antenna. Finally, a rectangular slot 7 is added to the metal ground 5, and a second feed microstrip line 10 is introduced to feed the MED antenna. In this embodiment, through parameter tuning, the final MED antenna operates in the N78 frequency band with excellent radiation performance.

[0033] In this embodiment, the dielectric resonator 3 uses ER9.9 dielectric ceramic material with a dielectric constant of 9.9±0.2 and a loss angle of 1.5×10⁻⁶. -4The thickness is 6mm; the center-to-center distance between the two DRA units is 0.5λ0. The dielectric substrate 4 is RO4003C with a dielectric constant of 3.55, a loss angle of 0.0027, and a thickness of 1.524mm. The power supply substrate 8 is RO4003C with a dielectric constant of 3.55, a loss angle of 0.0027, and a thickness of 0.508mm.

[0034] Figure 2 The S-parameter simulation results of a traditional 1×2 DRA and a 1×2 DRA array with a decoupled loading structure as described in this embodiment are presented at the same frequency and spacing. It can be seen that the DRA in this embodiment operates in the N79 frequency band, with a -10dB impedance matching bandwidth of 17.7%, and an overall in-band mutual coupling level below -25 dB. In contrast, the in-band mutual coupling level of a traditional 1×2 DRA is only -12 dB. Therefore, the 1×2 DRA proposed in this invention significantly improves the mutual coupling level compared to the traditional 1×2 DRA.

[0035] Because this invention reuses the decoupling structure, a MED antenna is introduced on the basis of the 1×2 DRA. Figure 3 The simulated S-parameters and gains of the 1×2 DRA and MED antenna in this embodiment are presented. It can be seen that the MED antenna operates in the N78 band, with a -10dB impedance matching bandwidth of 26.5% and an in-band peak gain of 5.60 dBi. Since the polarization directions of the MED antenna and DRA are orthogonal, they have a good level of isolation.

[0036] Figure 4 Simulated radiation patterns at 4.34 GHz and 4.82 GHz are given when the 1# port is excited (DRA). Since the 1×2 DRA array proposed in this invention is arrayed along the H plane, the H plane radiation pattern is slightly offset.

[0037] Figure 5 Simulated radiation patterns at 3.44 GHz and 3.90 GHz are presented when the antenna is excited at port 3 (MED antenna). The antenna radiation pattern is symmetrical, with a good front-to-back ratio and cross-polarization better than 25 dB.

[0038] This embodiment achieves broadband MIMO DRA decoupling while ensuring that antenna radiation performance, integration complexity, and other related performance are not degraded. Furthermore, by reusing the decoupling structure, a dual-band multi-antenna system covering both the N78 and N79 frequency bands is realized, making it better suited for 5G application scenarios.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-band antenna system based on decoupling structure multiplexing, characterized in that, It integrates a 1×2 DRA array and a MED antenna, including a top metal patch (1), a dielectric resonator (3), a dielectric substrate (4), a metal ground (5), a feed substrate (8), and a feed microstrip line group stacked from top to bottom; Two dielectric resonators (3) are arranged side by side and symmetrically on the upper surface of the dielectric substrate (4) along the y direction; Two top metal patches (1) are set on the upper surfaces of the two dielectric resonators (3) in a one-to-one correspondence; Two metallized vias (2) pass vertically through the dielectric resonator (3) and the dielectric substrate (4) respectively, connecting the top metal patch (1) and the metal ground (5). Two first coupling slots (6) and one second coupling slot (7) are opened on the metal ground (5); the two first coupling slots (6) are located at the center of the two dielectric resonators (3) respectively, and are used to provide coupling power to the dielectric resonators (3); The second coupling slot (7) is located in the slot between the two dielectric resonators (3) and is used to provide coupling feed for the MED antenna; The fed microstrip line group includes two first fed microstrip lines (9) and one second fed microstrip line (10). The two first-feed microstrip lines (9) are directly opposite the two first coupling slots (6); The second feed microstrip line (10) is positioned opposite the second coupling slot (7).

2. The dual-band antenna system based on decoupling structure multiplexing according to claim 1, characterized in that, The two dielectric resonators (3) serve as the radiating units of the 1×2 DRA array; the top metal patch (1) is a decoupling structure for the 1×2 DRA array, used to reduce the coupling electric field along the x-direction inside the dielectric resonator (3) to reduce the mutual coupling of the 1×2 DRA array; at the same time, the top metal patch (1) constitutes the electric dipole of the MED antenna; the metallized via (2) cooperates with the gap between the two top metal patches (1) and is equivalent to the magnetic dipole of the MED antenna; the electric dipole and the magnetic dipole together constitute the MED antenna.

3. The dual-band antenna system based on decoupling structure multiplexing according to claim 1 or 2, characterized in that, The center-to-center distance between the two dielectric resonators (3) is 0.5λ0, where λ0 is the free-space wavelength corresponding to the center frequency.

4. The dual-band antenna system based on decoupling structure multiplexing according to claim 1 or 2, characterized in that, The inner sides of the two top metal patches (1) are flush with the inner sides of the corresponding dielectric resonators (3).

5. The dual-band antenna system based on decoupling structure multiplexing according to claim 4, characterized in that, The two metallized vias (2) are respectively located close to the inner surface of the dielectric resonator (3).

6. The dual-band antenna system based on decoupling structure multiplexing according to claim 1 or 2, characterized in that, The first coupling gap (6) is an H-shaped gap, and the second coupling gap (7) is a rectangular gap.

7. The dual-band antenna system based on decoupling structure multiplexing according to claim 6, characterized in that, The first feed microstrip line (9) is a long strip structure. The two first feed microstrip lines (9) are port 1# and port 2# respectively. When one port is used as the RF excitation signal feed port, the other port is used as the matching load port.

8. The dual-band antenna system based on decoupling structure multiplexing according to claim 7, characterized in that, The second feed microstrip line (10) is L-shaped, with its short side perpendicular to the second coupling gap (7) and its long side parallel to the first feed microstrip line (9).

9. The dual-band antenna system based on decoupling structure multiplexing according to claim 1 or 2, characterized in that, The DRA operates in the 5G N79 band, and the MED antenna operates in the 5G N78 band.

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