Low-profile broadband dual-polarized microstrip antenna

Abstract

The invention belongs to the technical field of radar antennas, and discloses a low-profile broadband dual-polarized microstrip antenna, which comprises a radiation layer, a support layer and a feed layer which are sequentially arranged from top to bottom, and is characterized in that the radiation layer comprises a top printed board and a radiation patch printed on the top printed board; the feed layer comprises a gap layer, a bottom layer printed board and a bottom layer metal ground which are sequentially arranged from top to bottom, the gap layer is a top layer metal ground, two 'H'-shaped gaps which are in T-shaped orthogonal distribution are etched on the gap layer, a plurality of metalized shielding via holes which are in annular distribution are formed in the bottom layer printed board, and the bottom layer metal ground is a metal ground. And the gap layer, the bottom layer printed board, the metalized shielding via hole in the bottom layer printed board and the bottom layer metal ground form a substrate integrated waveguide back cavity. According to the antenna, the depth of the back cavity structure is greatly reduced, the low-profile design is realized, and the working bandwidth of the microstrip antenna is widened; the microstrip antenna has the advantages of being simple in structure, low in processing cost, easy to integrate and the like, and has wide application prospects in the field of satellite communication.

Description

Technical Field

[0001] This invention belongs to the field of radar antenna technology, and mainly relates to a low-profile broadband dual-polarized microstrip antenna. Background Technology

[0002] With the rapid development and application of satellite communication technology, the need for optimization and modification of antenna functions and performance has become increasingly apparent, as antennas are key devices for transmitting and receiving wireless signals. As a result, antenna technology with low profile, wide bandwidth, and multi-polarization characteristics has a broader application prospect.

[0003] The invention patent with publication number CN115149243A proposes a dual-band dual-polarized stacked patch antenna and wireless communication device, which features a compact structure, multiple frequency bands, multiple polarizations, and high isolation. This antenna introduces multi-layer patch stacking technology, but its profile is relatively high. The invention patent with publication number CN115332784A proposes a broadband dual-polarized antenna operating in the X-band, which features broadband, multiple polarizations, and miniaturization. This antenna introduces a back cavity structure, but its profile is relatively high and its weight is relatively heavy. The invention patent with publication number CN113540756A proposes a broadband dual-polarized antenna, which features broadband and multiple polarizations. This antenna introduces patch stacking technology and a microstrip balun feed structure, but its profile is relatively high and its structure is relatively complex, which may limit its application in the field of satellite communication.

[0004] Therefore, there is an urgent need to design a low-profile, broadband, dual-polarized microstrip antenna that simultaneously possesses low profile, broadband, and dual-polarization characteristics to meet application requirements. Summary of the Invention

[0005] To address the problems in the prior art, this invention proposes a low-profile broadband dual-polarized microstrip antenna. This antenna combines the broadband characteristics of a cavity antenna with the low-profile characteristics of a microstrip antenna, and also has the advantages of simple structure, low processing cost, and easy integration.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: A low-profile broadband dual-polarized microstrip antenna includes a radiating layer, a supporting layer, and a feeding layer arranged sequentially from top to bottom. The radiating layer includes a top printed circuit board and a radiating patch printed on the top printed circuit board. The feeding layer includes a slot layer, a bottom printed circuit board, and a bottom metal ground layer arranged sequentially from top to bottom. The slot layer is the top metal ground layer, on which two T-shaped orthogonally distributed "H"-shaped slots are etched. The bottom printed circuit board has a plurality of ring-shaped metallized shielding vias inside. The slot layer, the bottom printed circuit board, the metallized shielding vias therein, and the bottom metal ground layer constitute a substrate integrated waveguide back cavity.

[0007] Furthermore, the substrate integrated waveguide back cavity has two feed metallized vias inside, which are distributed on the center vertical line of the "H"-shaped slot and close to the "H"-shaped slot.

[0008] Furthermore, taking the "H"-shaped gap as the center line, the metallized shielding vias that are in the same direction as the power-feeding metallized vias are far away from the "H"-shaped gap, while the metallized shielding vias that are in the opposite direction to the power-feeding metallized vias are close to the "H"-shaped gap.

[0009] Furthermore, the radiating patch is a square metal patch.

[0010] Furthermore, the dielectric constant of both the top and bottom printed circuit boards is 2.94.

[0011] Furthermore, the support layer is made of PMI foam material with a dielectric constant of 1.07.

[0012] Furthermore, the thickness of the bottom printed circuit board is equal to the depth of the substrate integrated waveguide back cavity.

[0013] Furthermore, the radiating layer, support layer, and power feeding layer are integrated using an adhesive bonding process.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a low-profile broadband dual-polarized microstrip antenna. Unlike conventional dual-polarized microstrip antennas with wire-fed or probe-coupled feeding structures, this low-profile broadband dual-polarized microstrip antenna employs a substrate-integrated waveguide cavity structure. This cavity structure consists of a slot layer, a bottom printed circuit board with annularly distributed metallized shielding vias, and a bottom metal ground plane. This not only significantly reduces the depth of the cavity structure, achieving a low-profile design, but also broadens the operating bandwidth of the microstrip antenna. This microstrip antenna features simple structure, low manufacturing cost, and easy integration, and has broad application prospects in the field of satellite communication. Attached Figure Description

[0015] Figure 1 A perspective view of an embodiment of the present invention.

[0016] Figure 2 Top view of an embodiment of the present invention.

[0017] Figure 3 Side view of an embodiment of the present invention.

[0018] Figure 4 A top view of the layer containing the square patch in an embodiment of the present invention.

[0019] Figure 5 A top view of the slit layer in an embodiment of the present invention.

[0020] Figure 6 A top view of the substrate-integrated waveguide back cavity according to an embodiment of the present invention.

[0021] Figure 7 A schematic diagram of dual-port standing wave ratio and isolation in an embodiment of the present invention.

[0022] Figure 8 The periodic boundary horizontal polarization E-plane and H-plane lobe patterns of this invention embodiment, wherein, Figure 8 (a) is surface E. Figure 8 (b) is the H-plane.

[0023] Figure 9 The periodic boundary vertical polarization E-plane and H-plane lobe patterns of this invention embodiment, wherein, Figure 9 (a) is surface E. Figure 9 (b) is the H-plane.

[0024] The components are: 1. Radiation patch; 2. Top printed circuit board; 3. Support layer; 4. Slot layer; 5. Bottom printed circuit board; 6. Bottom metal ground; 7. Feed metallized via; 8. Substrate integrated waveguide back cavity; 9. "H" shaped slot; 10. Metallized shielding via. Detailed Implementation

[0025] The specific embodiments of the present invention will be further explained below with reference to the accompanying drawings.

[0026] like Figures 1-6 As shown, a low-profile broadband dual-polarized microstrip antenna is used to achieve dual-line polarization characteristics through dual-port excitation. It includes a radiating layer, a support layer 3, and a feed layer arranged sequentially from top to bottom. The radiating layer, support layer 3, and feed layer are integrated by adhesive bonding.

[0027] The radiating layer includes a radiating patch 1 and a top printed circuit board 2. The radiating patch 1 is printed on the top printed circuit board 2 by a printing process. The radiating patch 1 is a square metal patch. The dielectric constant of the top printed circuit board 2 is 2.94, and its length is denoted as L. The radiating patch 1 is denoted as L1.

[0028] The support layer 3 is made of PMI foam material with a dielectric constant of 1.07, and its thickness is denoted as h.

[0029] The feed layer includes, from top to bottom, a slot layer 4, a bottom printed circuit board 5, and a bottom metal ground layer 6. The dielectric constant of the bottom printed circuit board 5 is 2.94, and its thickness is denoted as h1. The slot layer 4 is the top metal ground layer, on which two T-shaped orthogonally distributed "H"-shaped slots 9 are etched, namely a vertically polarized "H"-shaped slot and a horizontally polarized "H"-shaped slot. The slot length of the vertically polarized "H"-shaped slot is denoted as L2, the width as K1, and the end length as L21. The slot length of the horizontally polarized "H"-shaped slot is denoted as L3, the width as K2, and the end length as L31. The T-shaped orthogonal distribution ensures a high level of isolation between the two polarization ports. The bottom printed circuit board 5 has several annularly distributed metallized shielding vias 10. The two substrate integrated waveguide back cavities 8, consisting of the gap layer 4, the bottom printed circuit board 5 and the annularly distributed metallized shielding vias 10, and the bottom metal ground 6, serve as the back cavity structures for the horizontally polarized microstrip antenna and the vertically polarized microstrip antenna, respectively. The thickness of the bottom printed circuit board 5 is the depth of the substrate integrated waveguide back cavity 8, which is h1.

[0030] The two metallized feed vias 7 disposed inside the substrate integrated waveguide cavity 8 serve as the feed structure or excitation structure for the two cavity antennas, respectively, and are distributed on the vertical line of the center of the "H"-shaped slot 9 and close to the "H"-shaped slot 9. Among the metallized shielding vias 10, with the "H"-shaped slot (9) as the center line, the metallized shielding vias 10 that are in the same direction as the metallized feed vias 7 are far away from the "H"-shaped slot 9, while the metallized shielding vias 10 that are opposite to the metallized feed vias 7 are closer to the center line.

[0031] The preferred dimensions of the low-profile broadband dual-polarized microstrip antenna described in this embodiment are as follows: Microstrip antenna length / width L: 153mm Radiation patch 1, length L1: 90mm; PMI foam thickness h: 10.6mm; The thickness of the bottom printed circuit board, h1, is 2.032 mm. Vertically polarized "H" shaped gap length L2: 84mm; Vertically polarized "H" shaped slit length L21: 10mm; Vertical polarization "H" shaped slit width K1: 1mm; Horizontal polarization "H" shaped gap length L3: 70mm; Horizontal polarization "H" shaped gap length L31: 20mm; Horizontal polarization "H" shaped gap width K2: 1mm; The overall cross-section of the microstrip antenna in this embodiment is 13.1 mm, which is less than 1 / 16λ (λ is the intermediate frequency operating wavelength).

[0032] Figure 7 The curves showing the port VSWR and port isolation of the low-profile broadband dual-polarized microstrip antenna as a function of frequency are displayed. Figure 8 The images show the horizontal polarization E-plane and H-plane beamline patterns of a low-profile broadband dual-polarized microstrip antenna. Figure 9 The vertical polarization E-plane and H-plane beam patterns of the low-profile broadband dual-polarized microstrip antenna are shown respectively. Accordingly, the cavity-backed microstrip antenna described in this embodiment has a profile smaller than 1 / 16λ (λ is the low-frequency operating wavelength), an operating bandwidth better than 18%, and possesses low-profile and broadband characteristics.

[0033] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-profile broadband dual-polarized microstrip antenna, characterized in that, The structure includes a radiation layer, a support layer (3), and a feed layer arranged sequentially from top to bottom. The radiation layer includes a top printed circuit board (2) and a radiation patch (1) printed on the top printed circuit board (2). The feed layer includes a slot layer (4), a bottom printed circuit board (5), and a bottom metal ground (6) arranged sequentially from top to bottom. The slot layer (4) is the top metal ground, on which two "H"-shaped slots (9) are etched in a T-shape orthogonal distribution. The bottom printed circuit board (5) has several metallized shielding vias (10) arranged in a ring shape inside. The slot layer (4), the bottom printed circuit board (5), the metallized shielding vias (10) inside, and the bottom metal ground (6) constitute the substrate integrated waveguide back cavity (8).

2. The low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The substrate integrated waveguide back cavity (8) has two feed metallized vias (7) inside, which are distributed on the center vertical line of the "H"-shaped slot (9) and close to the "H"-shaped slot (9).

3. The low-profile broadband dual-polarized microstrip antenna according to claim 2, characterized in that, Using the "H"-shaped gap (9) as the center line, the metallized shielding via (10) that is in the same direction as the power supply metallized via (7) is far away from the "H"-shaped gap (9), while the metallized shielding via (10) that is opposite to the power supply metallized via (7) is close to the "H"-shaped gap (9).

4. The low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The radiation patch (1) is a square metal patch.

5. A low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The dielectric constants of the top printed circuit board (2) and the bottom printed circuit board (5) are both 2.

94.

6. A low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The support layer (3) is made of PMI foam material with a dielectric constant of 1.

07.

7. A low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The thickness of the bottom printed circuit board (5) is the depth of the substrate integrated waveguide back cavity (8).

8. A low-profile broadband dual-polarized microstrip antenna according to claim 1, characterized in that, The radiation layer, support layer (3), and power feeding layer are integrated by adhesive bonding.

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