A high-density dual-polarized side-fire antenna unit based on glass substrate and liquid crystal material

Abstract

This invention discloses a broadband dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material, comprising a multilayer dielectric substrate. A metal ground plane and four feed ports are disposed on the lower surface of a first dielectric substrate. A first glass layer is disposed between the first and second dielectric substrates. A second glass layer is disposed between the second and third dielectric substrates. Holes are drilled along two diagonals of the first dielectric substrate, with solid third metal pillars penetrating each hole. Through-holes are drilled around the perimeter and center of the first dielectric substrate, the first glass layer, and the second dielectric substrate. Several first metal pillars are evenly distributed within the through-holes around the perimeter, and four second metal pillars are evenly distributed as feed probes within the through-hole at the center. The four second metal pillars connect the four feed ports and a radiating patch on the lower surface of the second glass layer. This invention effectively improves the antenna radiation gain and bandwidth.

Description

Technical Field

[0001] This invention belongs to the field of liquid crystal device technology, specifically relating to a high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material. Background Technology

[0002] Side-fire antennas have their maximum radiation direction perpendicular to the antenna array, making them easy to integrate and highly suitable for mobile terminal communications. Common side-fire antenna element types include patch antennas, dielectric resonant antennas, and slot antennas. Patch antennas, as a relatively common type of side-fire antenna, are now widely used in terminal devices. However, current research on dual-polarized side-fire antennas is mostly based on low frequencies, and in high-frequency bands, they are generally single-polarized. Furthermore, the antenna structure primarily uses conventional dielectric substrates, resulting in high production costs and a lack of configurability. After arraying, they often have limited functionality and fail to achieve ideal results.

[0003] Liquid crystal materials have long attracted researchers' attention due to their sensitivity to electromagnetic fields and low loss characteristics. Liquid crystals possess strong electrical tunability; their properties can be controlled by surface anchoring, external electric or magnetic fields, and they exhibit different dielectric constants under different voltages. Compared to traditional dielectric substrates, glass-encapsulated liquid crystal materials offer low cost and configurability. In recent years, advancements in photolithography and liquid crystal packaging technologies have made glass-substrate antennas a cutting-edge research area. Conventional liquid crystal antennas, limited by the properties of the glass itself, can only transmit electromagnetic energy through coupling, which results in significant energy loss. With the introduction of the latest TGV processing technology, metallized vias on the encapsulated liquid crystal glass substrate have proven feasible, undoubtedly providing new ideas for liquid crystal antenna design. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material, realizing a dual-polarization design for the side-fire antenna, enabling the antenna to have a wide operating bandwidth while possessing low loss and high gain characteristics.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material includes a multilayer dielectric substrate, comprising a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate stacked sequentially from bottom to top; wherein:

[0007] A metal ground plane and power supply ports are disposed on the lower surface of the first dielectric substrate, and the power supply ports include four ports.

[0008] A first glass layer is provided between the first dielectric substrate and the second dielectric substrate;

[0009] A second glass layer is provided between the second dielectric substrate and the third dielectric substrate;

[0010] Holes are drilled along the two diagonals of the first dielectric substrate, and solid third metal pillars are inserted through each hole.

[0011] Through holes are drilled around the perimeter and center of the first dielectric substrate, the first glass layer, and the second dielectric substrate. Several first metal pillars are evenly distributed in the through holes around the perimeter, and four second metal pillars are evenly distributed in the through hole in the center as power feed probes.

[0012] Radiation patches are respectively provided on the upper and lower surfaces of the second glass layer, and the four second metal pillars connect the four feed ports and the radiation patches on the lower surface of the second glass layer.

[0013] Furthermore, the second dielectric substrate is a liquid crystal material.

[0014] Furthermore, there are several third metal pillars, which are evenly distributed along the holes on the two diagonals of the first dielectric substrate.

[0015] Furthermore, the four power supply ports have the same structure, wherein the first port and the third port are evenly distributed on the longitudinal axis of symmetry of the first dielectric substrate, and the second port and the fourth port are evenly distributed on the transverse axis of symmetry of the first dielectric substrate.

[0016] Furthermore, the distances from the four power supply ports to the intersection of the horizontal and vertical axes of symmetry of the first dielectric substrate are equal.

[0017] Furthermore, in the horizontal polarization state, the first and third ports are excited with a phase difference of 180°; in the vertical polarization state, the second and fourth ports are excited with a phase difference of 180°.

[0018] Furthermore, when multiple side-fire antenna elements form an antenna array, adjacent side-fire antenna elements share the plurality of first metal pillars.

[0019] Furthermore, the upper surface of the first dielectric substrate also includes metal gaps.

[0020] Furthermore, the metal gap is flower-shaped, with its four protruding petals coinciding with the four power supply ports.

[0021] Furthermore, the radius of the power supply port is larger than the radius of the petals.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention provides a high-density dual-polarized side-fire antenna element based on a glass substrate and liquid crystal material. Differential feeding improves polarization isolation and achieves symmetrical antenna pattern. Each element has four ports: in horizontal polarization, the first and third ports are excited with a 180° phase difference; in vertical polarization, the second and fourth ports are excited with a 180° phase difference, achieving common-aperture dual polarization. A cavity-type dielectric substrate increases the bandwidth of the entire element through a central metal gap. Dividing the entire cavity into four triangular cavities significantly improves isolation between different ports. A double-layer radiating patch extends the bandwidth; the metal gap and the double-layer radiating patch form a Yagi-like structure, providing different resonant points and improving antenna radiation gain. Adjusting the height of the surrounding metal walls changes the element's beamwidth, and adjusting the beamwidth also improves antenna gain. Adjusting the height of the second metallized apertures around the perimeter further changes the element's beamwidth, thus improving antenna gain. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural schematic diagram of the side-fire antenna unit in an embodiment of the present invention;

[0025] Figure 2 This is a front view of the side-fire antenna unit in an embodiment of the present invention;

[0026] Figure 3 This is a top view of the side-fire antenna unit in an embodiment of the present invention;

[0027] Figure 4 This is a top view of the side-fire antenna array in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the return loss of the side-fire antenna unit under different liquid crystal dielectrics in an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the insertion loss of the side-fire antenna unit under different liquid crystal dielectrics in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram showing the gain of the side-fire antenna unit under different liquid crystal dielectrics in an embodiment of the present invention.

[0031] Figure label:

[0032] 1. First dielectric substrate, 2. First glass layer, 3. Second dielectric substrate, 4. Second glass layer, 5. Third dielectric substrate, 6. Via, 7. Third metal pillar, 8. Power supply port, 9. Radiation patch, 10. Metal gap, 6-1. First metal pillar, 6-2. Second metal pillar, 8-1. First port, 8-2. Second port, 8-3. Third port, 8-4. Fourth port. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] like Figures 1-3 As shown, this invention proposes a high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material, comprising:

[0035] Multilayer dielectric substrates are manufactured using multilayer printed circuit board technology, such as... Figure 2 As shown, the multilayer dielectric substrates are: a first dielectric substrate 1, a second dielectric substrate 3, and a third dielectric substrate 5; wherein:

[0036] The first dielectric substrate 1 is rectangular, and a metal layer is disposed on its lower surface as a ground plane and a power supply port 8 is disposed thereon. The power supply port 8 includes four identical ports, namely the first port 8-1, the second port 8-2, the third port 8-3, and the fourth port 8-4. The first port 8-1 and the third port 8-3 are evenly distributed on the longitudinal axis of symmetry of the first dielectric substrate 1, and the second port 8-2 and the fourth port 8-4 are evenly distributed on the transverse axis of symmetry of the first dielectric substrate 1. The distances from the four ports to the intersection of the transverse and longitudinal axes of symmetry are equal.

[0037] The upper layer of the first dielectric substrate 1 has a metal gap 10 at its center. The metal gap 10 can be flower-shaped, with its four protruding petals coinciding with the four power supply ports. The radius of the power supply ports is larger than the radius of the petals. (Reference) Figure 3 As shown, one embodiment is given, wherein the metal gap 10 is four small circles with radius r uniformly hollowed out on a large circle with radius R, where R > r, and the radius of the power supply port is also greater than r.

[0038] The second dielectric substrate 3 is made of liquid crystal material;

[0039] Furthermore, a first glass layer 2 is provided between the first dielectric substrate 1 and the second dielectric substrate 3;

[0040] A second glass layer 4 is provided between the second dielectric substrate 3 and the third dielectric substrate 5;

[0041] Holes are drilled at equal intervals along the diagonal of the first dielectric substrate 1, and solid third metal pillars 7 are inserted through each equally spaced hole. Additionally, vias 6 are drilled along the first dielectric substrate 1, the first glass layer 2, and the second dielectric substrate 3. First metal pillars 6-1 and second metal pillars 6-2 are arranged within the vias 6 according to their functions. Several first metal pillars 6-1 are evenly distributed within the vias 6 around the antenna element to improve isolation. Radiation patches 9 are located on the upper and lower surfaces of the second glass layer 4. Four second metal pillars 6-2 serve as feed probes, connecting the feed port 8 and the radiation patches 9 on the lower surface of the second glass layer 4.

[0042] As one of the alternative implementation schemes, the multilayer dielectric substrate is made of Rogers 4360 material, and the thickness of each dielectric substrate is 0.2mm. According to the processing technology, the third metal pillar 7, the first metal pillar 6-1, and the second metal pillar 6-2 are selected with a radius of 0.1mm.

[0043] like Figure 3 As shown, the via 7 where the third metal pillar 7 is placed is 2mm high, and the via 6 is 5mm high. The third metal pillars 7 are evenly distributed along the diagonal of the first dielectric substrate 1, making the antenna element structure completely symmetrical and divided into four parts, effectively improving the port isolation.

[0044] like Figure 4 As shown, the first metal pillar 6-1 can be shared when arraying with adjacent units to achieve high-density arrangement. For the third dielectric substrate 5, the vias 6 uniformly arranged below it and the upper radiating patch 9 are equivalent to forming an effective substrate-integrated waveguide metal back cavity, replacing the metal resonant cavity for radiation. The antenna is fed in a back-feed manner. The second metal pillar 6-2 can be regarded as a feed probe extending from the lower surface of the second glass layer 4 to the upper surface of the second dielectric substrate 3. This feed design can isolate the antenna feed structure from the outside world and reduce external interference. The radiating patch 9 is located on the upper and lower surfaces of the second glass layer 4 and transmits radiated energy through coupling.

[0045] Refer again Figure 3This broadband common-aperture dual-polarized side-fire antenna element, based on a glass substrate and liquid crystal material, employs probe feeding. To achieve symmetrical radiation patterns, differential feeding is used, improving polarization isolation. A single antenna element includes a feed port 8. In horizontal polarization, the first port 8-1 and the third port 8-3 are excited with a 180° phase difference; in vertical polarization, the second port 8-2 and the fourth port 8-4 are excited with a 180° phase difference, thus achieving common-aperture dual polarization. A multilayer dielectric substrate forms a cavity. Metal slots 10 on the upper surface of the first dielectric substrate 1 enhance the bandwidth of the entire element. Combined with a third metal pillar 7, the cavity is divided into four perfectly symmetrical triangular cavities S1, S2, S3, and S4, significantly improving isolation between different ports. A double-layer radiating patch is used to extend the bandwidth. The radiating slots and the double-layer patch form a Yagi-like structure, providing different resonant points and improving antenna radiation gain. Finally, by adjusting the height of the surrounding vias 6, the element beamwidth can be changed, and by adjusting the beamwidth, the antenna gain can be improved.

[0046] Figure 5 Figure 6 , Figure 7 The overall parameters of the present invention are shown for typical liquid crystal dielectric constants of 2.46 to 3.57, respectively, including the dual-polarization return loss, insertion loss, and gain pattern of the representative device. All of these indicate that the design effect of the present invention is good. It should be noted that since the antenna element structure is completely symmetrical, the electromagnetic parameters of its horizontal and vertical polarizations are completely identical, with only the mathematical coordinates being different. Therefore, the figures in this paper only show the data for vertical polarization.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. 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 high-density dual-polarized side-fire antenna element based on a glass substrate and liquid crystal material, characterized in that, It includes a multilayer dielectric substrate, consisting of a first dielectric substrate, a second dielectric substrate, and a third dielectric substrate stacked sequentially from bottom to top; wherein: A metal ground plane and power supply ports are disposed on the lower surface of the first dielectric substrate. The power supply ports include four ports, and the four power supply ports have the same structure. The first port and the third port are evenly distributed on the longitudinal axis of symmetry of the first dielectric substrate, and the second port and the fourth port are evenly distributed on the transverse axis of symmetry of the first dielectric substrate. The first port and the third port are excited in the horizontal polarization state with a phase difference of 180°; the second port and the fourth port are excited in the vertical polarization state with a phase difference of 180°. A first glass layer is provided between the first dielectric substrate and the second dielectric substrate; A second glass layer is provided between the second dielectric substrate and the third dielectric substrate; Holes are drilled along the two diagonals of the first dielectric substrate, and solid third metal pillars are inserted through each hole. Through holes are drilled around the perimeter and center of the first dielectric substrate, the first glass layer, and the second dielectric substrate. Several first metal pillars are evenly distributed in the through holes around the perimeter, and four second metal pillars are evenly distributed in the through hole in the center as power feed probes. Radiation patches are respectively provided on the upper and lower surfaces of the second glass layer, and the four second metal pillars connect the four feed ports and the radiation patches on the lower surface of the second glass layer. The second dielectric substrate is a liquid crystal material, and the upper surface of the first dielectric substrate also includes a metal gap. The metal gap is flower-shaped, with its four protruding petals coinciding with the four power supply ports. The radius of the power supply ports is greater than the radius of the petals.

2. A high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material according to claim 1, characterized in that, The third metal pillars are a plurality of ones, which are distributed at equal intervals along the holes on the two diagonals of the first dielectric substrate.

3. A high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material according to claim 1, characterized in that, The distances from the four power supply ports to the intersection of the horizontal and vertical axes of symmetry of the first dielectric substrate are equal.

4. A high-density dual-polarized side-fire antenna unit based on a glass substrate and liquid crystal material according to claim 1, characterized in that, When multiple side-fire antenna elements form an antenna array, adjacent side-fire antenna elements share the plurality of first metal pillars.

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