Dual-band port-and-pattern self-decoupled patch antenna

Abstract

The application discloses a dual-band port and pattern self-decoupling patch antenna, and the top metal layer is a left-right symmetrical structure, comprising two rectangular metal patches arranged side by side and serving as radiation units; a flat-bottomed inverted U-shaped groove is arranged on each metal patch; four ground columns are arranged on the adjacent edges of the two metal patches at intervals; the inner conductors of two coaxial feeding probes pass through the bottom metal layer and the dielectric substrate and are connected to the two rectangular metal patches respectively. The flat-bottomed inverted U-shaped groove is used for adjusting the current path and the resonant mode, so that dual-band radiation is realized; the two ground columns on the two metal patches are a pair of each other, and the four pairs of ground columns are used for suppressing high-low frequency coupling, so that the coupling path is blocked by forming a weak field area, and dual-band decoupling is realized. The application realizes decoupling based on the structure of the ground column, reduces the profile and does not increase the size of the additional patch, and the pattern is corrected.

Description

Technical Field

[0001] This invention relates to an antenna for a wireless communication system, and more particularly to a dual-band decoupling antenna. Background Technology

[0002] Compared to single-frequency antennas, dual-frequency antennas can significantly improve the channel capacity and spectral efficiency of communication systems. However, with the rapid development of wireless communication, the mutual coupling effect between antennas has become a key bottleneck restricting system performance. Mutual coupling can cause a series of problems, such as impedance mismatch, pattern distortion, and decreased radiation efficiency. Currently, most mainstream decoupling schemes are designed for single-frequency antennas. Although they can alleviate coupling interference in single-frequency scenarios to some extent, they cannot meet the complex requirements of dual-frequency antennas for simultaneous decoupling of two frequency bands. Therefore, it is urgent to explore new efficient decoupling methods suitable for dual-frequency antenna arrays.

[0003] In existing technologies, dual-frequency metasurfaces are used to elevate unit isolation to a new level, but this comes at the cost of increased profile and complex structure, and pattern decoupling is still not addressed, making it difficult to integrate into a simple array. To simultaneously achieve pattern correction while decoupling at the dual frequency, another existing dual-frequency metasurface scheme achieves low mutual coupling and pattern correction simultaneously. Figure 1 While the results are satisfactory, there is still room for optimization in terms of profile and complexity. Summary of the Invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a dual-band port and pattern self-decoupling patch antenna is proposed to achieve self-decoupling without increasing the extra size of the metal patch, and at the same time, achieve pattern decoupling.

[0005] Technical solution: A dual-band port and pattern self-decoupling patch antenna, comprising: a top metal layer, a dielectric substrate, a bottom metal layer, and a coaxial feed probe; The top metal layer has a symmetrical structure, including two rectangular metal patches arranged side by side as radiating units; Each metal patch has a flat-bottomed inverted U-shaped groove; four grounding posts are spaced apart on the adjacent edges of two metal patches; After the inner conductors of the two coaxial feed probes pass through the bottom metal layer and the dielectric substrate, they are respectively connected to the two rectangular metal patches; The flat-bottomed inverted U-shaped groove is used to regulate the current path and resonant mode to achieve dual-frequency radiation; the two symmetrical grounding posts on the two metal patches are paired with each other, and the four pairs of grounding posts are used to suppress high and low frequency coupling. By forming a weak field region to block the coupling path, dual-frequency decoupling is achieved.

[0006] Furthermore, the distances from the left and right sides of the flat-bottomed inverted U-shaped groove to the adjacent side of the metal patch are consistent.

[0007] Furthermore, the feed port of the coaxial feed probe is located on the vertical centerline of the metal patch.

[0008] Furthermore, the horizontal length of the rectangular metal patch is between 0.30λ0 and 0.35λ0, and the vertical width is between 0.25λ0 and 0.30λ0, where λ0 is the free space wavelength corresponding to the low-frequency center frequency; the distance between the edges of the two metal patches is between 0.015λ0 and 0.020λ0.

[0009] Furthermore, the width of the flat-bottomed inverted U-shaped groove is between 0.0035λ0 and 0.004λ0, the horizontal length of the flat-bottomed inverted U-shaped groove is between 0.25λ0 and 0.30λ0, and the vertical length is between 0.10λ0 and 0.15λ0.

[0010] Furthermore, the center-to-center spacing of the two pairs of grounding posts on the outer side in the vertical direction is consistent, both between 0.05λ0 and 0.010λ0; the center-to-center spacing of the two pairs of grounding posts on the inner side in the vertical direction is consistent, both between 0.05λ0 and 0.010λ0; at the same time, in the horizontal direction, the two pairs of grounding posts on the outer side are located between the inverted U-shaped groove and the two pairs of grounding posts on the inner side.

[0011] Furthermore, on a metal patch, the center-to-center distance between the two outer grounding posts is between 0.25λ0 and 0.30λ0, and the center-to-center distance between the two inner grounding posts is between 0.10λ0 and 0.15λ0.

[0012] Beneficial effects: Existing mutual coupling suppression schemes for single-frequency antennas are mostly unsuitable for dual-frequency scenarios; existing dual-frequency decoupling antennas generally suffer from high profile and complex structure, with some designs still failing to solve the problem of pattern coupling. This invention achieves dual-frequency radiation by setting inverted U-shaped slots on two patch units to regulate the current path and resonant mode; it suppresses high- and low-frequency coupling through four pairs of grounding posts and achieves dual-frequency decoupling by forming a weak field region to block the coupling path; decoupling and symmetrical design together optimize current distribution, correct pattern distortion, and ensure stable radiation performance under dual-frequency conditions.

[0013] The dual-band decoupling antenna of this invention can simultaneously achieve frequency band isolation and pattern decoupling without increasing the radiation area or adding extra layers, providing a lighter and more compact feasible path for dual-band arrays in high-performance wireless communication systems. Attached Figure Description

[0014] Figure 1 This is a schematic cross-sectional view of the dual-band port and pattern self-decoupling patch antenna of the present invention. Figure 2 This is a schematic diagram of the top metal layer structure of the antenna of the present invention; Figure 3 This is a schematic diagram of the underlying metal feeding structure of the antenna of the present invention; Figure 4 The electric field vector diagram of the antenna at 3.5 GHz is shown in the example, where (a) is a top view, (b) is a Y-axis cross-sectional view, and (c) is an x-axis cross-sectional view. Figure 5 The electric field vector diagram for the antenna at 4.9 GHz in this embodiment is shown, where (a) is a top view, (b) is a Y-axis cross-sectional view, and (c) is an x-axis cross-sectional view. Figure 6 The S-parameter curve of the antenna in the example is shown below; Figure 7 The gain curve of the antenna in the example is shown. Figure 8 The simulated radiation pattern of the antenna at 3.5 GHz is shown in the example. Figure 9 The simulated radiation pattern of the antenna at 4.9 GHz is shown in the example. Detailed Implementation

[0015] The invention will now be further explained with reference to the accompanying drawings.

[0016] A dual-band port and pattern self-decoupling patch antenna, such as Figure 1 As shown, it consists of a top metal layer 1, a dielectric substrate 2, a bottom metal layer 3, and a coaxial feed probe 4.

[0017] like Figure 2 As shown, the top metal layer 1 has a symmetrical structure with rectangular metal patches 11 and 12 arranged side by side, serving as radiating elements. The lengths of the rectangular metal patches 11 and 12 are between 0.30λ0 and 0.35λ0, and the widths are between 0.25λ0 and 0.30λ0, where λ0 is the free-space wavelength corresponding to the center frequency of 3.5GHz. The side-to-side spacing between the two metal patches 11 and 12 is between 0.015λ0 and 0.020λ0, and the center-to-center spacing is between 0.30λ0 and 0.35λ0.

[0018] Two metal patches each have flat-bottomed inverted U-shaped grooves 13 and 14. The length of the inverted U-shaped groove along the x-axis is between 0.25λ0 and 0.30λ0, the length along the y-axis is between 0.10λ0 and 0.15λ0, and the width of the groove is between 0.0035λ0 and 0.004λ0. The distance between the bottom edge of the inverted U-shaped groove and the top edge of the patch is between 0.10λ0 and 0.15λ0; the distance from the inverted U-shaped groove to the left and right edges of the patch is consistent, both between 0.045λ0 and 0.05λ0.

[0019] Four grounding posts are spaced apart along the x-axis on the adjacent edges of metal patches 11 and 12, namely grounding posts 15, 19, 21, 17 and 16, 20, 22, 18 from top to bottom. Along the x-axis, each grounding post is located between the inverted U-shaped groove and its adjacent side. The center-to-center spacing of grounding posts 15 and 16 is the same as that of grounding posts 17 and 18, both between 0.05λ0 and 0.010λ0; the center-to-center spacing of grounding posts 19 and 20 is the same as that of grounding posts 21 and 22, both between 0.05λ0 and 0.010λ0. Furthermore, grounding posts 15 and 17 are located on the right side of the inverted U-shaped groove 13 between grounding posts 19 and 21, and grounding posts 16 and 18 are located on the left side of the inverted U-shaped groove 14 between grounding posts 20 and 22. Along the y-axis, each grounding post is located between the upper and lower edges of the U-shaped groove and the patch. The center-to-center distance between grounding posts 15 and 17 is between 0.25λ0 and 0.30λ0, and the center-to-center distance between grounding posts 19 and 21 is between 0.10λ0 and 0.15λ0.

[0020] After the inner conductors of the two coaxial feed probes 4 pass through the bottom metal layer 3 and the dielectric substrate 2, they are connected to the metal patches 11 and 12 respectively. The feed ports 41 and 42 are located on the y-axis midline of their respective patches.

[0021] The inverted U-shaped grooves 13 and 14 form a dual-frequency structure, and the four pairs of symmetrically arranged grounding posts form a decoupling structure.

[0022] The port excitation generates a signal, which is fed into the top metal patch 11 through the power supply port 41, thereby generating quasi-TM signals at 3.5 GHz and 4.9 GHz on the metal patch. 10 Model and Quasi-TM 21 Furthermore, thanks to the four pairs of grounding post structures, weak field regions are simultaneously generated at the two center frequencies of 3.5GHz and 4.9GHz at the feed positions on the mutually coupled metal patches 12. At this time, the energy of the weak field region cannot be transferred downward to the feed port 42, so that the port cannot be excited, thereby achieving better isolation characteristics.

[0023] The core resonant mode of a typical rectangular microstrip antenna is TM. 10 The resonant frequency of a mode is directly related to the physical dimensions of the patch. The inverted U-shaped slot of this invention introduces additional resonant modes by altering the current path on the patch surface. By precisely controlling the current path and resonant mode through the dimensional parameters of the inverted U-shaped slot and the distance between the slot and the patch edge, dual-frequency operation at 3.5GHz and 4.9GHz is achieved. Simultaneously, the narrow slot width avoids excessively weakening the patch's radiation capability while precisely separating the frequency intervals of the two resonant modes, preventing frequency band overlap or mutual interference, ultimately achieving dual-frequency operation at 3.5GHz and 4.9GHz.

[0024] The mutual coupling of dual-frequency patch antennas mainly originates from surface wave coupling and spatial coupling, and existing solutions struggle to simultaneously suppress high- and low-frequency coupling. This invention addresses this by using four pairs of grounding posts to reshape the patch's electric field distribution by suppressing electromagnetic coupling paths between antennas, thus achieving decoupling between high and low frequency bands. Specifically, the center-to-center spacing of the grounding posts on the upper and lower sides along the y-axis corresponds to λ0 at 3.5 GHz. When a low-frequency surface wave propagates to the grounding post, it is short-circuited to ground, preventing further propagation to adjacent patches, thereby suppressing the low-frequency surface wave. Simultaneously, the symmetrical arrangement of the grounding posts alters the electric field distribution of the coupling patch 12, making the location of its feed port 42 a weak field region with extremely low electric field strength. According to the principle of electromagnetic induction, this weak field region cannot generate sufficient induced current to excite port 42, thereby blocking the low-frequency coupling path and achieving isolation at 3.5 GHz. For the high-frequency portion, due to the shorter wavelength, spatial coupling is mainly concentrated on the inner side of the patch, meaning the strongest radiation field is concentrated near the U-shaped groove. The inner grounding posts weaken the radiation field intensity in this region through a short-circuit effect, reducing direct illumination to adjacent patches. Meanwhile, the center-to-center spacing of the two pairs of grounding posts on the inner side along the y-axis matches λ0 at 4.9GHz, ensuring that the feed port 42 of the coupling patch is also in a weak field region at high frequencies and cannot be excited, thus achieving isolation at 4.9GHz. The four pairs of grounding posts are symmetrically distributed along the x and y axes, ensuring the symmetrical electric field distribution of the patch under dual-frequency conditions, avoiding the introduction of new coupling or impedance distortion due to the grounding posts, and ensuring the consistency and stability of dual-band decoupling.

[0025] Furthermore, this invention optimizes the current distribution and corrects pattern distortion through decoupling and symmetrical design, ensuring stable radiation performance under dual frequencies.

[0026] In this embodiment, the substrate material is Rogers RO4003C, with a dielectric constant of 2.2 and a loss angle of 0.0009. The rectangular metal patches 11 and 12 have a length of 0.33λ0 and a width of 0.29λ0; the side-to-side spacing between the two metal patches 11 and 12 is 0.018λ0, and the center-to-center spacing is 0.31λ0. The inverted U-shaped grooves 13 and 14 have a length of 0.28λ0 along the x-axis, a length of 0.11λ0 along the y-axis, and a groove width of 0.0038λ0; the distance between the bottom edge of the inverted U-shaped grooves 13 and 14 and the top edge of the patch is 0.13λ0, and the distance from the U-shaped groove to the left and right edges of the patch is 0.047λ0. Along the x-axis, the center-to-center spacing of grounding posts 15, 16, 17, and 18 is 0.09λ0, and the center-to-center spacing of grounding posts 19, 20, 21, and 22 is 0.05λ0. Along the y-axis, the center-to-center spacing of grounding posts 15, 16, 17, and 18 is 0.29λ0, and the center-to-center spacing of grounding posts 19, 20, 21, and 22 is 0.14λ0. The low-frequency and high-frequency electric field vector diagrams of the antenna are shown in the figure. Figure 4 , Figure 5 As shown.

[0027] The simulation results of antenna matching, isolation, and gain response in this embodiment are as follows: Figure 6 , Figure 7 As shown, the impedance matching bandwidth of this embodiment antenna is 0.7% at 3.5 GHz and 1.8% at 4.9 GHz. The maximum gain is 6.57 dB at 3.5 GHz and 7.34 dB at 4.9 GHz. The isolation is greater than 19.27 dB at 3.5 GHz and greater than 24.43 dB at 4.9 GHz. Figure 8 This is the simulated H-plane radiation pattern of the antenna in this embodiment at 3.5 GHz. The 3-dB beamwidth in the H-plane is 85.1°, and the cross-polarization level within the 3-dB beamwidth in the H-plane is -15.13dB. Figure 9 This is the simulated H-plane radiation pattern of the antenna in this embodiment at 4.9 GHz. The 3-dB beamwidth in the H-plane is 87.5°, and the cross-polarization level within the 3-dB beamwidth in the H-plane is -11.24 dB. Compared with existing dual-band patch antenna decoupling techniques, this invention, based on a grounding post structure, achieves decoupling while reducing the profile and without increasing the size of the additional patch, thus also correcting the radiation pattern.

[0028] 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 port and pattern self-decoupling patch antenna, characterized in that, include: Top metal layer (1), dielectric substrate (2), bottom metal layer (3) and coaxial feed probe (4); The top metal layer (1) has a left-right symmetrical structure, including two rectangular metal patches arranged side by side as radiating units; Each metal patch has a flat-bottomed inverted U-shaped groove; the flat-bottomed inverted U-shaped groove is used to adjust the current path and resonant mode, and to excite the quasi-TM. 10 Model and Quasi-TM 21 To achieve dual-frequency radiation; Two metal patches are provided with four grounding posts spaced apart on their adjacent edges. The two grounding posts on the two metal patches are symmetrically arranged and form a pair. The center spacing of the two pairs of grounding posts on the outer side in the vertical direction is the same, and the center spacing of the two pairs of grounding posts on the inner side in the vertical direction is the same. In the horizontal direction, the two pairs of grounding posts on the outer side are located between the inverted U-shaped groove and the two pairs of grounding posts on the inner side. Four pairs of grounding posts are used to suppress high-frequency and low-frequency coupling. The two outer pairs of grounding posts block the low-frequency surface wave coupling path, and the two inner pairs of grounding posts weaken the high-frequency space wave coupling. By forming a weak field region at adjacent patch feed positions to block the coupling path, dual-frequency port decoupling and pattern correction are achieved at the same time. After the inner conductors of the two coaxial feed probes (4) pass through the bottom metal layer (3) and the dielectric substrate (2), they are connected to the two rectangular metal patches respectively.

2. The dual-band port and pattern self-decoupling patch antenna according to claim 1, characterized in that, The distance from the left and right sides of the flat-bottomed inverted U-shaped groove to the adjacent side of the metal patch is the same.

3. The dual-band port and pattern self-decoupling patch antenna according to claim 1, characterized in that, The feed port of the coaxial feed probe (4) is located on the vertical center line of the metal patch.

4. The dual-band port and pattern self-decoupling patch antenna according to any one of claims 1-3, characterized in that, The horizontal length of the rectangular metal patch is between 0.30λ0 and 0.35λ0, and the vertical width is between 0.25λ0 and 0.30λ0, where λ0 is the free space wavelength corresponding to the low-frequency center frequency; the side-to-side spacing between two adjacent metal patches is between 0.015λ0 and 0.020λ0.

5. The dual-band port and pattern self-decoupling patch antenna according to claim 4, characterized in that, The width of the flat-bottomed inverted U-shaped groove is between 0.0035λ0 and 0.004λ0, the horizontal length of the flat-bottomed inverted U-shaped groove is between 0.25λ0 and 0.30λ0, and the vertical length is between 0.10λ0 and 0.15λ0.

6. The dual-band port and pattern self-decoupling patch antenna according to claim 5, characterized in that, The center-to-center spacing of the two pairs of grounding posts on the outer side in the vertical direction is consistent, both between 0.05λ0 and 0.010λ0; the center-to-center spacing of the two pairs of grounding posts on the inner side in the vertical direction is consistent, both between 0.05λ0 and 0.010λ0; at the same time, in the horizontal direction, the two pairs of grounding posts on the outer side are located between the inverted U-shaped groove and the two pairs of grounding posts on the inner side.

7. The dual-band port and pattern self-decoupling patch antenna according to claim 6, characterized in that, On a metal patch, the center-to-center distance between the two outer grounding posts is between 0.25λ0 and 0.30λ0, and the center-to-center distance between the two inner grounding posts is between 0.10λ0 and 0.15λ0.

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