A differential decoupling antenna based on misaligned double strips

Abstract

The application discloses a differential decoupling antenna based on misaligned double strips, in the top metal layer, two rectangular metal patches are arranged side by side, two metal strips are arranged horizontally above and below the rectangular metal patches respectively, and are misaligned in parallel to form a decoupling structure. The inner cores of four coaxial feeding probes are respectively inserted vertically upward from below the bottom metal layer and are connected with one rectangular metal patch in pairs correspondingly, and the two feeding probes connected with the same rectangular metal patch form a pair of differential ports. The application misaligns the strips parallel to the two patch units above and below the two patch units, and the arrangement direction of the strips is consistent with the arrangement direction of the differential ports, so that a weak field is generated on the coupled patch, and the decoupling of the differential antenna is realized. The misaligned arrangement obtains relatively high isolation in a relatively compact case. Meanwhile, the size of the antenna is relatively small, and the horizontal ECC is also reduced.

Description

Technical Field

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

[0002] Differential antennas offer better performance stability, reducing performance fluctuations caused by structural asymmetry. They also possess strong anti-interference capabilities, enhancing the transmission efficiency of differential-mode signals and thus improving signal anti-interference ability. Currently, with the rapid development of wireless communication, device miniaturization has become an inevitable trend, highlighting the increasing necessity of tightly packed multi-element patch antenna arrays. However, when differential antennas are tightly packed to save space, mutual interference between antennas can cause many adverse effects, such as mismatch, pattern distortion, and degraded radiation performance. Therefore, while existing decoupling techniques are mostly applied to single-fed antennas, which can reduce coupling between single-fed antennas to a certain extent, they cannot be directly applied to differential-fed antennas due to the numerous feed ports and complex coupling paths of differential-fed antennas. Therefore, it is necessary to explore methods to reduce mutual coupling between elements in multi-element differential antenna arrays.

[0003] Existing technologies propose using decoupling networks to achieve high levels of decoupling, but their structural complexity, radiator size, and center-to-center spacing remain insufficient for large-scale MIMO systems, making it difficult to meet the requirements of compact antenna arrays. To reduce antenna structural complexity, existing technologies employ characteristic modes and H-shaped structures to achieve low mutual coupling and consistent radiation patterns; however, their structural complexity still needs optimization, and the center-to-center spacing and radiator size remain relatively large, still failing to meet the requirements of compact antenna arrays.

[0004] In summary, while achieving low mutual coupling, these existing methods struggle to reduce radiator size, radiator center-to-center spacing, and structural complexity. Summary of the Invention

[0005] Purpose of the invention: In view of the above-mentioned prior art, a differential decoupling antenna based on staggered arrangement of dual stripes is proposed, which simplifies the structure, reduces the center spacing between radiators and the size of radiators, and achieves radiation pattern decoupling.

[0006] Technical solution: A differential decoupling antenna based on staggered dual stripes, including a top metal layer, an intermediate dielectric substrate, a bottom metal ground layer, and a feeding structure;

[0007] The top metal layer includes two rectangular metal patches and two metal strips; the two rectangular metal patches are arranged side by side; the two metal strips are arranged horizontally above and below the rectangular metal patches, respectively, and the two metal strips are parallel to each other and staggered by a certain length, forming a decoupled structure.

[0008] The power supply structure includes four coaxial power supply probes; the inner core of each coaxial power supply probe is inserted vertically upward from below the bottom metal ground and connected to a rectangular metal patch in pairs, and the power supply points are all located on the horizontal axis of symmetry of the patch; the two power supply probes connected to the same rectangular metal patch form a pair of differential ports.

[0009] Furthermore, the left end of the upper metal strip is located between the left edge of the left metal patch and the outer feed point of the patch, and the right end of the upper metal strip is located between the two feed points of the right metal patch; the left end of the lower metal strip is located between the two feed points of the left metal patch, and the right end of the lower metal strip is located between the right edge of the right metal patch and the outer feed point of the patch.

[0010] Furthermore, the two rectangular metal patches have the same dimensions, with a length between 0.22λ0 and 0.28λ0 and a width between 0.22λ0 and 0.28λ0; the distance between the two rectangular metal patches is between 0.022λ0 and 0.028λ0; where λ0 is the free space wavelength corresponding to the center frequency.

[0011] Furthermore, the center-to-center distance between the feed points of two coaxial feed probes on the same rectangular metal patch is between 0.052λ0 and 0.057λ0.

[0012] Furthermore, the two metal strips are identical in size, with a length between 0.35λ0 and 0.40λ0 and a width between 0.010λ0 and 0.020λ0.

[0013] Furthermore, the distance between the two metal strips and the top and bottom sides of the rectangular metal patch is the same, both between 0.01λ0 and 0.02λ0.

[0014] Beneficial Effects: Existing differential decoupling antennas have large radiator sizes and complex structures, resulting in large center-to-center spacing between radiator elements and large radiator sizes. This invention achieves decoupling of the differential antenna by arranging parallel strips vertically and vertically offset between two patch elements, with the strips aligned with the differential port orientation and forming an asymmetrical structure. This generates a weak field on the mutual coupling patches, achieving decoupling of the differential antenna. This offset arrangement achieves high isolation within a relatively compact framework. Simultaneously, the antenna size is smaller, and the ECC (envelope correlation coefficient) level is reduced. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the differential decoupling patch antenna of the present invention.

[0016] Figure 2 This is a top view of the differential decoupling patch antenna of the present invention.

[0017] Figure 3 This is a bottom-view structural diagram of the differential decoupling patch antenna of the present invention;

[0018] Figure 4 The following are simulation results of the differential decoupling patch antenna in the embodiment, where (a) represents the S-parameters and (b) represents the gain curve;

[0019] Figure 5 The simulated radiation pattern of the differential decoupling patch antenna at 3.47 GHz in the embodiment is shown. Detailed Implementation

[0020] The invention will now be further explained with reference to the accompanying drawings.

[0021] like Figure 1 As shown, a differential decoupling antenna based on staggered dual stripes consists of a top metal layer 1, an intermediate dielectric substrate 2, a bottom metal ground layer 3, and a feeding structure 4.

[0022] like Figure 2 As shown, the top metal layer 1 is located on the upper surface of the intermediate dielectric substrate 2 and is composed of rectangular metal patches 11 and 12, and metal strips 13 and 14. The rectangular metal patches 11 and 12 are arranged side by side, and the parallel metal strips 13 and 14 are arranged above and below the rectangular metal patches 11 and 12 respectively, so that the top metal layer forms a left-right asymmetrical structure.

[0023] like Figure 1 , Figure 3 As shown, the power supply structure 4 consists of coaxial power supply probes 41-44. The inner cores of coaxial power supply probes 41 and 42 are inserted vertically upward from below the bottom metal ground 3 and connected to the rectangular metal patch 11, with the power supply point located on the horizontal axis of symmetry of the patch. The inner cores of coaxial power supply probes 43 and 44 are inserted vertically upward from below the bottom metal ground 3 and connected to the rectangular metal patch 12, with the power supply point also located on the horizontal axis of symmetry of the patch. Coaxial power supply probes 41 and 42 form a pair of differential ports, and coaxial power supply probes 43 and 44 also form a pair of differential ports, with the power supply points of coaxial power supply probes 41 and 44 located on the outer side relative to each other.

[0024] The left end of metal strip 13 is located between the left edge of metal patch 11 and the feed point of coaxial feed probe 41, and the right end of metal strip 13 is located between the feed points of coaxial feed probes 43 and 44; the left end of metal strip 14 is located between the feed points of coaxial feed probes 41 and 42, and the right end of metal strip 14 is located between the right edge of metal patch 12 and the feed point of coaxial feed probe 44.

[0025] In the above structure, rectangular metal patches 11 and 12 form a radial structure; metal strips 13 and 14 form a decoupling structure.

[0026] Rectangular metal patches 11 and 12 have identical dimensions, with a length (y-axis direction) between 0.22λ0 and 0.28λ0 and a width (x-axis direction) between 0.22λ0 and 0.28λ0. The spacing between rectangular metal patches 11 and 12 is between 0.022λ0 and 0.028λ0. The center-to-center distance between the feed points of two coaxial feed probes on the same rectangular metal patch is between 0.052λ0 and 0.057λ0. Metal strips 13 and 14 have identical dimensions, with a length between 0.35λ0 and 0.40λ0 and a width between 0.010λ0 and 0.020λ0. The distances from metal strips 13 and 14 to the top and bottom edges of rectangular metal patches 11 and 12 are identical, both between 0.01λ0 and 0.02λ0. Here, λ0 is the free-space wavelength corresponding to the center frequency.

[0027] Differential excitation generates equal-amplitude, reversed signals, which are fed into a rectangular metal patch 11 through a differential port formed by coaxial feed probes 41 and 42, thereby generating a TM signal on the rectangular metal patch. 10 The mode radiates outwards. In addition, thanks to the asymmetrical arrangement of metal strips 13 and 14, a weak field region is generated at the feed point position on the rectangular metal patch 12 that is coupled to the rectangular metal patch 11. At this time, the energy of the weak field region cannot be transferred downwards to the differential port formed by the coaxial feed probes 43 and 44, so the differential port cannot be excited, thereby achieving a better isolation characteristic.

[0028] In this embodiment, the dielectric substrate is made of Rogers RO4003C, with a dielectric constant of 3.55 and a loss angle of 0.0027. The rectangular metal patches 11 and 12 have a length and width of 0.25λ0; the spacing between the rectangular metal patches 11 and 12 is 0.025λ0. The center-to-center distance between the feed points of the two coaxial feed probes on the same rectangular metal patch is 0.054λ0. Metal strips 13 and 14 have the same dimensions, with a length of 0.37λ0 and a width of 0.015λ0. The distances from metal strips 13 and 14 to the top and bottom edges of the rectangular metal patches 11 and 12 are both 0.014λ0. The simulation results for antenna matching, isolation, and gain response are as follows: Figure 4 As shown, the impedance matching bandwidth of this embodiment is 2.4% with a 10-dB limit, the maximum gain in the operating frequency band is 4.83dB, and the isolation at 3.47GHz is greater than 29.06dB. Figure 5This is the simulated E-plane radiation pattern of the antenna in this embodiment at 3.47 GHz. The 3-dB beamwidth in the E-plane is 121.8°, and the cross-polarization level within the 3-dB beamwidth in the E-plane at this frequency is -12 dB. Compared with existing differential patch antenna decoupling techniques, this invention reduces the radiator size, the radiator center-to-center spacing, and the structural complexity by using a staggered arrangement of dual stripes, thus also reducing ECC.

[0029] 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 differential decoupling antenna based on staggered dual-strip arrangement, characterized in that, It includes a top metal layer, an intermediate dielectric substrate, a bottom metal ground layer, and a power supply structure; The top metal layer includes two rectangular metal patches and two metal strips; the two rectangular metal patches are arranged side by side; the two metal strips are arranged horizontally above and below the rectangular metal patches, respectively, and the two metal strips are parallel to each other and staggered by a certain length, forming a decoupled structure. The power supply structure includes four coaxial power supply probes; the inner core of each coaxial power supply probe is inserted vertically upward from below the bottom metal ground and connected to a rectangular metal patch in pairs, and the power supply points are all located on the horizontal axis of symmetry of the patch; the two power supply probes connected to the same rectangular metal patch form a pair of differential ports. The left end of the upper metal strip is positioned between the left edge of the left metal patch and the outer feed point of the patch, and the right end of the upper metal strip is positioned between the two feed points of the right metal patch; the left end of the lower metal strip is positioned between the two feed points of the left metal patch, and the right end of the lower metal strip is positioned between the right edge of the right metal patch and the outer feed point of the patch; the two metal strips are arranged in the same direction as the differential ports. Differential excitation generates a constant-amplitude, inverse signal, which is fed into a rectangular metal patch through a differential port, thereby generating a TM signal on the rectangular metal patch. 10 The model radiates outwards.

2. The differential decoupling antenna according to claim 1, characterized in that, The two rectangular metal patches have the same dimensions, with a length between 0.22λ0 and 0.28λ0 and a width between 0.22λ0 and 0.28λ0; the distance between the two rectangular metal patches is between 0.022λ0 and 0.028λ0; where λ0 is the free space wavelength corresponding to the center frequency.

3. The differential decoupling antenna according to claim 2, characterized in that, The center-to-center distance between the feed points of two coaxial feed probes on the same rectangular metal patch is between 0.052λ0 and 0.057λ0.

4. The differential decoupling antenna according to claim 3, characterized in that, The two metal strips are identical in size, with a length between 0.35λ0 and 0.40λ0 and a width between 0.010λ0 and 0.020λ0.

5. The differential decoupling antenna according to claim 4, characterized in that, The distance between the two metal strips and the top and bottom sides of the rectangular metal patch is the same, both between 0.01λ0 and 0.02λ0.

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