Dual-polarized wideband matching planar phased array antenna

Abstract

The application discloses a dual-polarized wideband matching planar phased array antenna, which periodically surrounds two-layer metal square patches by a combination of I-shaped metal strips and L-shaped metal strips grounded. E The surface wave restriction effect of the combination on dual-polarized operation and the weakening effect of induced current of H adjacent square patches are utilized to form a low-profile planar phased array with dual-polarized wideband active impedance matching and a large scanning range.

Description

Technical Field

[0001] This invention relates to a microwave communication device, and more particularly to a dual-polarized broadband matched planar phased array antenna. Background Technology

[0002] Phased array antennas, characterized by high gain and wide scanning coverage, are widely used in radar, long-range communication, satellite communication, and millimeter-wave communication. Dual-polarized phased arrays are advantageous for improving polarization adaptability and avoiding multipath interference distortion, while patch-type planar phased arrays offer advantages in increasing integration and reducing profile. Therefore, dual-polarized planar phased arrays are commonly used in millimeter-wave applications. However, the matching bandwidth of a dual-polarized planar phased array is typically influenced by a combination of factors, including element bandwidth, inter-element coupling, scanning angle, and element arrangement. Therefore, achieving broadband matching during large-angle scanning with a dual-polarized broadband planar phased array presents a significant challenge.

[0003] There are three main types of existing patch-type planar phased arrays. The first type is a phased array constructed from a single patch antenna. Its structure is relatively simple and can be applied to single-polarization or dual-polarization scenarios. However, this design has a low base bandwidth and is not suitable for broadband matching phased array applications. The second type is a patch antenna with improved non-centrosymmetric structures, such as etched U-shaped slots on the patch antenna. It utilizes the added resonant current to extend the base bandwidth. However, due to its non-centrosymmetric structure, this design is difficult to apply in dual-polarization scenarios. Furthermore, even after adding an electromagnetic bandgap as an active impedance matching optimization measure, the recovery of active impedance matching at large scan angles is limited, resulting in a narrow matching bandwidth. The third type is a centrosymmetric stacked patch antenna, which achieves both base bandwidth extension and dual-polarization characteristics. A near-field shrinkage dielectric layer is added to maintain broadband active impedance matching at large scan angles. However, the overall profile is high, the structure is complex, and the cost is high. Therefore, it is necessary to propose a planar phased array antenna that can achieve both dual-polarization and broadband matching at large scan angles under low profile conditions. Summary of the Invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a dual-polarized broadband matched planar phased array antenna is proposed, which realizes a two-dimensional dual-polarized phased array while maintaining a low profile, and achieves broadband matching at a large scanning angle.

[0005] Technical solution: A dual-polarized broadband matched planar phased array antenna, comprising a top metal layer, a first substrate layer, a middle metal layer, a second substrate layer, a metal ground layer, a third substrate layer, and a bottom metal layer stacked sequentially, and further comprising several grounding vias and several feeding vias;

[0006] The top metal layer includes periodically spaced square metal patches, each surrounded by four L-shaped metal strips and four I-shaped metal strips. The four L-shaped metal strips form a square structure with a break in the center of each side, i.e., there is a gap between the adjacent ends of two L-shaped metal strips, and each I-shaped metal strip is located in the gap. Adjacent square metal patches share one side of two L-shaped metal strips and one I-shaped metal strip.

[0007] The intermediate metal layer includes periodically spaced square metal patches, each with a square groove in the center, and the square metal patches are directly opposite the top metal patches.

[0008] The metal ground layer consists of periodically spaced pairs of circular slots; each pair of circular slots corresponds to the vertical and horizontal symmetry lines of the top and middle metal square patches, respectively.

[0009] The bottom metal layer includes pairs of metal strips arranged periodically at equal intervals; each pair of metal strips consists of a horizontal metal strip and a vertical metal strip, and each strip has a small metal disk connected to its end.

[0010] Grounding vias are used to connect the L-shaped metal strip to the metal ground, and the grounding vias are evenly spaced on the L-shaped metal strip; power supply vias pass through the circular slot and are used to connect the small metal disk to the middle layer metal square patch.

[0011] The top layer of metal square patch, L-shaped metal strip, I-shaped metal strip, middle layer of metal square patch and grounding via constitute the phased array radiator; the horizontal metal strip and vertical metal strip, together with the metal ground layer and the third substrate layer, constitute the horizontal and vertical polarized microstrip feed lines of the phased array radiator.

[0012] Furthermore, the side length of the top metal square patch is 0.2~0.25λ0, where λ0 is the air wavelength corresponding to the center frequency; the side length of the square frame structure is 0.5λ0; the center strip length of the type I metal strip is 0.08~0.12λ0, and the edge strip lengths at both ends of the type I metal strip are 0.03~0.07λ0.

[0013] Furthermore, the side length of the middle layer metal square patch is 0.01λ0 longer than the side length of the top layer metal square patch.

[0014] Beneficial effects: Existing patch-type planar phased arrays cannot simultaneously achieve broadband matching for cross-section, dual polarization, and large scan angles. This invention periodically surrounds two layers of square metal patches with an I-shaped metal strip and a grounded L-shaped metal strip. The combination utilizes the surface wave confinement effect during dual polarization operation, as well as the... E Face to face HThe weakening effect of the induced current of adjacent square patches on the surface forms a low-profile planar phased array with a large scanning range and dual-polarized broadband active impedance matching.

[0015] Specifically, the I-type metal strip is located on the top metal layer and periodically surrounds the top metal square patch. Each top metal square patch surrounds the I-type metal strip and is located on the horizontal and vertical lines of symmetry of the patch. Adjacent top metal square patches share one I-type metal strip. Combined with the grounded L-type metal strip, since the I-type metal strip introduces additional coupling signals between adjacent patches when operating in a resonant state, these signals cancel out the original coupling signals between patches, effectively reducing surface waves during dual-polarization operation. E Face to face H Induced current on adjacent patches.

[0016] Each square metal patch is surrounded by four L-shaped grounding metal strips located at its four corners. Adjacent square metal patches share one side of two L-shaped metal strips. The L-shaped metal strips are connected to the metal ground via grounding vias and periodically wrap around the two layers of square metal patches. Combined with the I-shaped metal strips, the equivalent electric wall characteristics of the grounding vias and L-shaped metal strips between adjacent patches effectively reduce surface wave interference during dual-polarization operation. E Face to face H Induced current on adjacent patches.

[0017] The combination of I-type and L-type metal strips is located at the same height as the top and middle layer square metal patches, thus enabling broadband matching with a large scanning range of dual polarization while maintaining a low profile. Attached Figure Description

[0018] Figure 1 A schematic diagram of the layer structure of a dual-polarization broadband matched planar phased array antenna;

[0019] Figure 2 A schematic diagram of the top metal layer structure of a dual-polarized broadband matched planar phased array antenna;

[0020] Figure 3 A schematic diagram of the intermediate metal layer structure for a dual-polarized broadband matched planar phased array antenna;

[0021] Figure 4 A schematic diagram of the metallic ground structure for a dual-polarized broadband matched planar phased array antenna;

[0022] Figure 5 A schematic diagram of the bottom metal layer structure of a dual-polarized broadband matched planar phased array antenna;

[0023] Figure 6 The active phased array port scanning method proposed in this invention is used during different element ports. SParameter curves, where (a) corresponds to the active edge unit. S Parameter (b) corresponds to the active central unit. S parameter;

[0024] Figure 7 The images show the horizontal and vertical polarization scanning patterns of the phased array proposed in this invention at 33 GHz and 37 GHz, where (a) corresponds to horizontal polarization at 33 GHz, (b) corresponds to vertical polarization at 33 GHz, (c) corresponds to horizontal polarization at 37 GHz, and (d) corresponds to vertical polarization at 37 GHz. Detailed Implementation

[0025] The invention will now be further explained with reference to the accompanying drawings.

[0026] like Figure 1 As shown, a dual-polarized broadband matched planar phased array antenna includes a top metal layer 1, a first substrate layer 2, a middle metal layer 3, a second substrate layer 4, a metal ground layer 5, a third substrate layer 6, and a bottom metal layer 7 stacked sequentially. It also includes several grounding vias 8 and several feeding vias 9.

[0027] like Figure 2 As shown, the top metal layer 1 consists of periodically spaced top metal square patches 101, four L-shaped metal strips 102 surrounding each top metal square patch 101, and four I-shaped metal strips 103. The four L-shaped metal strips 102 are arranged centrally symmetrically, forming a square frame structure with a break in the center of each side. That is, there is a gap between adjacent ends of two L-shaped metal strips 102, and each I-shaped metal strip 103 is located within this gap, meaning that the I-shaped metal strips 103 are located in pairs on the horizontal and vertical symmetry lines of the patches. Adjacent top metal square patches 101 share one side of two L-shaped metal strips 102 and one I-shaped metal strip 103. The side length of the top metal square patch 101 is 0.2~0.25λ0, where λ0 is the air wavelength corresponding to the center frequency; the side length of the square frame structure is 0.5λ0; the center strip length of the type I metal strip 103 is 0.08~0.12λ0, and the edge strip lengths at both ends of the type I metal strip 103 are 0.03~0.07λ0.

[0028] like Figure 3 As shown, the intermediate metal layer 3 is composed of intermediate metal square patches 301 with square grooves 302 arranged periodically at equal intervals, and the intermediate metal square patches 301 are directly opposite the top metal square patches 101. When the side length of the intermediate metal square patch 301 is 0.01λ0 longer than the side length of the top metal square patch 101, it has the maximum bandwidth.

[0029] like Figure 4As shown, the metal ground layer 5 is a metal ground 502 with periodically etched circular groove pairs. Each pair of circular grooves 501 corresponds to the vertical and horizontal symmetry lines of the top and middle layer metal square patches, respectively.

[0030] like Figure 5 As shown, the bottom metal layer 7 is composed of pairs of metal strips arranged periodically at equal intervals. Each pair of metal strips consists of a horizontal metal strip 701 and a vertical metal strip 702, and each strip has a small metal disk 703 connected to its end.

[0031] In the above structure, the periods involved in each part of the top metal layer 1, the middle metal layer 3, the metal ground layer 5, and the bottom metal layer 7 are all consistent. Grounding vias 8 are used to connect the L-shaped metal strip 102 to the metal ground 502. The grounding vias 8 are evenly spaced on the L-shaped metal strip 102, with the grounding vias 8 forming a square frame around a patch. Adjacent patches share a row of grounding vias 8. Feed vias 9 pass through the circular slot 501 and are used to connect the small metal disk 703 to the middle layer metal square patch 301. The horizontal metal strip 701 and the vertical metal strip 702, together with the metal ground layer 5 and the third substrate layer 6, constitute the horizontal and vertical polarized microstrip feed lines of the phased array radiator.

[0032] In this invention, each input signal is pre-configured with an equal phase distribution and fed from each horizontal or vertical polarized microstrip feeder. Under the action of the phased array radiator composed of the top metal square patch 101, L-shaped metal strip 102, I-shaped metal strip 103, the middle layer metal square patch 301 with square slot 302, and the grounding via 8, a horizontal or vertical polarized beam radiating along a specified direction is realized, and broadband active matching can be achieved.

[0033] In this process, the combination of I-shaped and L-shaped metal strips periodically surrounding the top and middle layer square metal patches, along with grounding vias, effectively restricts surface wave flow during vertical and horizontal polarization operation. This significantly improves the efficiency of the phased array during large scan angle radiation, and helps reduce gain fluctuations and extend the scan range. Simultaneously, this combination reduces gain fluctuations during dual-polarization operation. E Face to face H The induced current on the adjacent intermediate layer metal square patches reduces the reflected signals from the horizontal and vertical polarized microstrip feed lines, ensuring broadband active matching during dual-polarization operation with a large scan angle. Since the combination of the I-type and L-type metal strips is located at the same height as the top and intermediate layer metal square patches, broadband matching over a large dual-polarization scan range can be achieved while maintaining a low profile.

[0034] Compared with existing state-of-the-art technologies, the patch-type planar phased array proposed in this invention can achieve broadband matching at large scanning angles and two-dimensional dual-polarization phased arrays while maintaining a low profile. In this embodiment, the side length of the top-layer metal square patch 101 is 0.23λ0, the parallel strip spacing of the two L-shaped metal strips 102 is 0.5λ0, the center strip length of the I-shaped metal strip 103 is 0.1λ0, the edge strip length is 0.05λ0, and the side length of the middle-layer metal square patch 301 is 0.24λ0. The active elements simulated at the edge and center unit ports are... S Parameters such as Figure 6 As shown, when the phased array operates under direct illumination, the -10 dB active impedance matching bandwidth of the edge elements can cover 32-37.4 GHz, and the -10 dB active impedance matching bandwidth of the center element can cover 32-37.5 GHz; under 15° scanning conditions, the -10 dB active impedance matching bandwidth of the edge elements can cover 32-37.4 GHz, and the -10 dB active impedance matching bandwidth of the center element can cover 32-37.5 GHz; under 30° scanning conditions, the -10 dB active impedance matching bandwidth of the edge elements can cover 32-37.3 GHz, and the -10 dB active impedance matching bandwidth of the center element can cover 32-37.4 GHz; under 45° scanning conditions, the -10 dB active impedance matching bandwidth of the edge elements can cover 32.1-37.1 GHz, and the -10 dB active impedance matching bandwidth of the center element can cover 32.3-37.2 GHz. Therefore, within the ±45° scan range, the -10 dB active impedance matching bandwidth reaches 13.7%, effectively covering 33-37 GHz.

[0035] Figure 7 The simulated scan patterns of horizontal and vertical polarization at 33 GHz and 37 GHz for this case are shown. Figure 7 As can be seen in (a), at 33 GHz, the beam gain within the horizontal polarization ±45° scanning range is between 22.9 and 24.7 dBi, with a gain fluctuation of 1.8 dB. Figure 7 As can be seen in (b), the beam gain within the vertical polarization ±45° scanning range is between 23.2 and 24.7 dBi, with a gain fluctuation of 1.5 dB. From... Figure 7 As can be seen from (c), at 37 GHz, the beam gain within the horizontal polarization ±45° scanning range is between 22.2 and 25.2 dBi, with a gain fluctuation of 3.0 dB. Figure 7As can be seen from (d), at 37 GHz, the beam gain within the ±45° vertical polarization scanning range is between 23.5 and 25.2 dBi, with a gain fluctuation of 1.7 dB. Therefore, this embodiment can achieve a ±45° horizontal and vertical polarization scanning range within the matched frequency band, and the scanning gain fluctuation is less than 3.0 dB, at which point the phased array profile is only 0.08 λ0.

[0036] 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-polarization broadband matched planar phased array antenna, characterized in that, It includes a top metal layer (1), a first substrate layer (2), a middle metal layer (3), a second substrate layer (4), a metal ground layer (5), a third substrate layer (6), and a bottom metal layer (7) stacked in sequence, and also includes several grounding vias (8) and several power supply vias (9). The top metal layer (1) includes periodically spaced top metal square patches (101), each top metal square patch (101) surrounded by four L-shaped metal strips (102) and four I-shaped metal strips (103); wherein, the four L-shaped metal strips (102) form a square frame structure with a break in the center of each side, that is, there is a gap between the adjacent ends of two L-shaped metal strips (102), and each I-shaped metal strip (103) is located in the gap; adjacent top metal square patches (101) share one side of two L-shaped metal strips (102) and one I-shaped metal strip (103). The intermediate metal layer (3) includes periodically spaced intermediate metal square patches (301), each intermediate metal square patch (301) has a square groove (302) in the center, and the intermediate metal square patches (301) and the top metal square patches (101) are directly opposite each other. The metal substrate (5) is a metal substrate (502) with periodically and equally spaced circular slot pairs; each pair of circular slots (501) corresponds to the vertical and horizontal symmetry lines of the top and middle metal square patches, respectively; The bottom metal layer (7) includes pairs of metal strips arranged periodically at equal intervals; each pair of metal strips consists of a horizontal metal strip (701) and a vertical metal strip (702), and each strip end is connected to a small metal disk (703). The grounding via (8) is used to connect the L-shaped metal strip (102) and the metal ground (502). The grounding via (8) is evenly distributed on the L-shaped metal strip (102). The power supply via (9) passes through the circular groove (501) and is used to connect the small metal disc (703) and the middle layer metal square patch (301). The top metal square patch (101), L-shaped metal strip (102), I-shaped metal strip (103), middle metal square patch (301) and grounding via (8) constitute the phased array radiator; the horizontal metal strip (701) and vertical metal strip (702) together with the metal ground layer (5) and the third substrate layer (6) constitute the horizontal and vertical polarized microstrip feed lines of the phased array radiator.

2. The dual-polarized broadband matched planar phased array antenna according to claim 1, characterized in that, The side length of the top metal square patch (101) is 0.2~0.25λ0, where λ0 is the air wavelength corresponding to the center frequency; the side length of the square frame structure is 0.5λ0; the center strip length of the type I metal strip (103) is 0.08~0.12λ0, and the edge strip lengths at both ends of the type I metal strip (103) are 0.03~0.07λ0.

3. The dual-polarized broadband matched planar phased array antenna according to claim 2, characterized in that, The side length of the middle layer metal square patch (301) is 0.01λ0 longer than the side length of the top layer metal square patch (101).

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