Hybrid transparent dielectric resonator phased array antenna with high solar cell coverage

Abstract

This invention relates to a hybrid transparent dielectric resonator phased array antenna with high solar cell coverage. The phased array antenna consists of eight antenna elements arranged laterally to form a one-dimensional phased array. Each antenna element has a three-layer structure: a transparent sapphire material in the middle of the upper layer and transparent quartz material surrounding the sapphire material; a solar panel in the middle layer; and a lower layer consisting of a first metal ground layer, a first dielectric substrate, a metal feed line, a second dielectric substrate, and a feed line structure formed by a second metal ground layer. A rectangular slot is located between the solar panel and the first metal ground layer. The metal feed line intersects the rectangular slot perpendicularly, and the stepped metal feed line ends in a coaxial port. This antenna improves antenna gain, expands impedance bandwidth, maximizes energy harvesting area, and ensures structural integrity.

Description

Technical Field

[0001] This invention relates to the field of self-powered communication, specifically to a solar-powered phased array antenna with beam scanning capability, suitable for highly integrated wireless communication systems that combine energy harvesting and communication functions. Background Technology

[0002] Traditional wireless communication systems typically rely on batteries or external power sources. However, the limited battery life and the difficulty of wired charging in many scenarios increase operating costs and significantly reduce stability. Today, clean energy is rapidly developing, giving rise to various forms of green energy such as solar, wind, and nuclear power. Among these, solar energy, with its fewer limitations and multiple utilization methods, is widely known and utilized, making it a significant representative of clean energy. Against this backdrop, solar antennas that integrate energy harvesting and communication functions have become an ideal choice for large-scale base station deployments and communication equipment used in remote outdoor environments, drones, and offshore platforms.

[0003] For solar antennas, balancing antenna efficiency with the area allocated to the solar cells is one of the most critical design challenges. The integration of the antenna and solar cell can negatively impact the performance of both components; the solar cell may hinder antenna radiation, while the shading created by the antenna structure can affect the photoelectric conversion efficiency of the solar cells. Therefore, a major challenge in solar antenna design is achieving effective compatibility between the antenna and the solar cell. Past solar antenna designs have been limited to antenna arrays and often confined to lower communication frequency bands. With technological advancements, modern communication systems place increasingly higher demands on solar antenna design, requiring operation at higher frequencies and support for large-scale array integration. These trends bring new challenges. A long-standing practical problem is the limited mechanical durability and environmental stability of transparent conductive materials such as silver nanowires and metal meshes. Their electrical and optical properties tend to degrade over time when exposed to environmental factors such as sunlight and humidity. Furthermore, in designs where the metal layer of the solar cell is used as a discrete radiating element, the area occupied by the solar cell in the entire array aperture decreases significantly at high frequencies. In addition, achieving electrical connections for a large number of discrete, miniaturized solar cell units presents further challenges, including complex interconnect networks and potential antenna performance degradation due to connection components. Furthermore, exposed solar cell patches still require additional transparent encapsulation protection to reduce aging and wear caused by external environmental factors. Summary of the Invention

[0004] Technical Problem: The purpose of this invention is to propose a hybrid transparent dielectric resonator phased array antenna with high solar cell coverage. This design combination effectively extends the antenna's operating bandwidth and improves gain. Furthermore, this method avoids the inherent trade-off between conductivity and transparency that typically exists in transparent conductive materials at high frequencies, thereby improving radiation efficiency. It also maximizes energy harvesting area and structural integrity.

[0005] Technical Solution: To solve the above-mentioned technical problems, this invention proposes a hybrid transparent dielectric resonator phased array antenna with high solar cell coverage. This phased array antenna consists of eight antenna elements arranged horizontally to form a one-dimensional phased array antenna. Each antenna element has a three-layer structure, including a transparent sapphire material in the middle of the upper layer and transparent quartz material around the transparent sapphire material, a solar panel in the middle layer, and a feed structure consisting of a first metal ground layer, a first dielectric substrate, a metal feed line, a second dielectric substrate, and a second metal ground layer in the lower layer. A rectangular groove is located between the solar panel and the first metal ground layer. The metal feed line is perpendicularly intersected with the rectangular groove line, and the end of the stepped metal feed line is connected to a coaxial port.

[0006] In the upper structure of the antenna unit, the transparent quartz material is a rectangular dielectric with a rectangular through-hole at its center; the transparent sapphire material is a rectangular dielectric located in the rectangular through-hole at the center of the transparent quartz material.

[0007] The transparent sapphire material is an anisotropic material with a high dielectric constant of ε. rx = 9.3、ε ry = 9.3、ε rz = 11, dielectric loss is 0.0006; transparent quartz material has a dielectric constant of 3.9 and dielectric loss of 0.001.

[0008] The solar panel has a metal grid on its surface, which is composed of branch-shaped and trunk-shaped line segments. The branch-shaped line segments are 0.05 mm wide and 1.5 mm apart; the trunk-shaped line segments are 0.7 mm wide and 31 mm apart.

[0009] The solar panel has a rectangular groove cut at its center to couple the excited electromagnetic waves from the metal feed line to the upper transparent sapphire material, and the coverage ratio of the solar cell is as high as 92.6%.

[0010] The metal feed line is formed by connecting two rectangular metal wires of different lengths and widths, namely a first rectangular metal wire and a second rectangular metal wire, in a stepped shape.

[0011] The first and second dielectric substrates are made of Rogers 4350 material with a thickness of 0.5 mm, a dielectric constant of 3.48, and a dielectric loss tangent of 0.0037.

[0012] The antenna element operates in the 8.6-12GHz frequency band, operates in far-field mode, and has directional radiation characteristics.

[0013] The phased array antenna, consisting of eight antenna elements arranged horizontally to form a one-dimensional phased array, is fed through a coaxial port. The feed layer is designed with stepped metal feed lines to improve impedance matching between the antenna and the input port.

[0014] The hybrid transparent dielectric resonator phased array antenna achieves beam scanning within a range of ±45°, possesses low cross-polarization level and stable scanning characteristics, and the isolation of each port within the frequency band is less than -15dB in the scanning state.

[0015] Beneficial Effects: This invention proposes a hybrid transparent dielectric resonator phased array antenna with high solar cell coverage, suitable for Ku-band applications. In the proposed design, the antenna employs a hybrid transparent dielectric structure composed of two high-transparency and low-loss materials. The central dielectric material is made of transparent sapphire with anisotropic dielectric constant, while the surrounding dielectric material is made of transparent quartz with a lower dielectric constant. This design combination effectively extends the antenna's operating bandwidth and improves gain. Furthermore, this method avoids the inherent trade-off between conductivity and transparency that typically exists in transparent conductive materials at high frequencies, thereby improving radiation efficiency. Simultaneously, the dielectric material exhibits excellent environmental stability and serves as a robust protective layer for the solar cell, protecting it from mechanical damage. On the other hand, the solar cell is integrated as the antenna's ground plane, maximizing energy harvesting area and structural integrity. This configuration also eliminates the need to interconnect numerous discrete solar cell units, significantly reducing the system complexity introduced by additional isolation or interconnect components. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the antenna unit structure of the present invention.

[0017] Figure 2 This is a top view of the antenna unit of the present invention.

[0018] Figure 3 This is a front view of the antenna unit of the present invention.

[0019] Figure 4 This is a top view of the feed layer of the antenna array of the present invention; Figure 4 (a) in the image is a top view of the solar panel. Figure 4 (b) is a top view of the stepped metal feeder. Figure 4(c) is a top view of the bottom metal surface.

[0020] Figure 5 These are the simulation parameters for the antenna element of this invention; Figure 5 In the figure, (a) is the curve of the input impedance of the antenna element as a function of frequency. Figure 5 (b) in the figure is the curve of the reflection coefficient of the antenna element as a function of frequency.

[0021] Figure 6 This is a performance comparison between the antenna element of the present invention and a conventional single-dielectric antenna element; Figure 6 Figure (a) shows a performance comparison of the reflection coefficients of the two antenna elements. Figure 6 (b) in the figure is a performance comparison diagram of the gain of the two antenna elements.

[0022] Figure 7 The S-parameters of the antenna array of this invention; Figure 7 In the diagram, (a) represents the reflection coefficients at each port of the 8-element antenna array. Figure 7 In the diagram, (b) represents the port isolation of the 8-element antenna array.

[0023] Figure 8 This is the radiation pattern of the far-field antenna of the present invention; Figure 8 (a) in the image is the far-field scanning pattern at 9 GHz. Figure 8 (b) in the image is the far-field scanning pattern at 10 GHz. Figure 8 (c) in the image represents the far-field scanning pattern at 11 GHz. Figure 8 In the figure, (d) represents the curves of antenna array aperture efficiency and gain as a function of frequency.

[0024] The diagram shows: 1. Transparent sapphire material; 2. Transparent quartz material; 3. Solar panel; 4.1. Rectangular groove; 4.2. Coaxial port; 4.3. First metal ground layer; 4.4. Second metal ground layer; 5. Metal feed line; 5.1. First rectangular metal line; 5.2. Second rectangular metal line; 6.1. First dielectric substrate; 6.2. Detailed Implementation

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

[0026] like Figure 1 , 2As shown in Figures 3 and 4, the high solar cell coverage hybrid transparent dielectric resonator phased array antenna of the present invention consists of eight antenna elements arranged laterally to form a one-dimensional phased array antenna. Each antenna element has a three-layer structure, including a transparent sapphire material 1 in the middle of the upper layer and transparent quartz material 2 around the transparent sapphire material 1, a solar panel 3 in the middle layer, and a feed structure consisting of a first layer of metal ground 4.3, a first layer of dielectric substrate 6.1, a metal feed line 5, a second layer of dielectric substrate 6.2, and a second layer of metal ground 4.4 in the lower layer. A rectangular slot line 4.1 is located between the solar panel 3 and the first layer of metal ground 4.3. The metal feed line 5 is perpendicularly intersected by the rectangular slot line 4.1, and the end of the metal feed line 5 is connected to a coaxial port 4.2. The transparent sapphire material 1 is an anisotropic material with a high dielectric constant of ε. rx = 9.3、ε ry = 9.3、ε rz = 11, dielectric loss is 0.0006. The square dielectric surrounding the transparent sapphire material 1 is made of transparent quartz material 2, with a dielectric constant of 3.9 and a dielectric loss of 0.001; the metal grid on the surface of the solar panel 3 is composed of branched and trunk segments, with the branch segments being 0.05 mm wide and spaced at 1.5 mm, while the trunk segments are 0.7 mm wide and spaced at 31 mm. The first dielectric layer 6.1 and the second dielectric layer 6.2 are composed of Rogers 4350 material with a dielectric constant of 3.48 and a dielectric loss tangent of 0.0037, with a thickness of 0.5 mm. At the center of the antenna element, a rectangular slot 4.1 is cut into the first layer of metal ground 4.3; the eight antenna elements are arranged horizontally to form a one-dimensional phased array antenna, which is fed through the coaxial port 4.2. The feeding layer is designed with a stepped metal feed line 5 to improve the impedance matching between the antenna and the input port. The metal feed line 5 is composed of two rectangular metal lines 5.1 and 5.2 with different lengths and widths, and is connected to the grounded coaxial port 4.2 at the end.

[0027] This solar antenna features an impedance bandwidth of 8.6 to 12 GHz, corresponding to a relative bandwidth of 33%. The maximum radiation efficiency of the one-dimensional phased array antenna exceeds 95%. Furthermore, the array supports beam scanning within a ±45° range. The maximum aperture efficiency and effective area ratio of the integrated solar cell reach 96.1% and 92.6%, respectively. The solar cell can provide a maximum output power of 9.6 mW. The proposed design retains the traditional architecture of the solar cell, providing not only complete mechanical protection but also endowing the solar cell antenna with high electromagnetic performance and large aperture utilization efficiency. Through this design, the solar cell and antenna are well-integrated and compatible. It offers a feasible solution for energy-autonomous applications, particularly in outdoor environments and satellite communication platforms.

[0028] To facilitate the explanation of the design process of each structural parameter, given the structural parameters, the overall size of the antenna is 120mm × 15mm × 4.1mm. The antenna is designed on a double-layer dielectric substrate with a dielectric constant of 3.48 and a loss tangent of 0.0037, with each dielectric layer having a thickness of 0.5mm. The upper and lower surfaces of the dielectric substrate are covered with metal ground planes. The port on the second metal ground plane 4.4 of the bottom layer is connected to the central metal feed line 5 through a coaxial port 4.2. The first metal ground plane 4.3 has a rectangular groove 4.1 with a length of 8.5mm cut at the center of the antenna element. The solar panel 3 covers the first metal ground plane 4.3, with a thickness of 0.2mm, and also has a rectangular groove 9mm cut at the center. The metal grid on the surface of the solar panel consists of branched and trunk segments. The branch segments are 0.05mm wide and spaced 1.5mm apart, while the trunk segments are 0.7mm wide and spaced 31mm apart. Because the branch lines are densely distributed, during manufacturing and assembly, the branches should be kept perpendicular to the electric field direction, i.e., parallel to the feed rectangular slot lines. This suppresses induced currents and prevents them from affecting the antenna's radiation performance. For vertically distributed trunk lines, their distribution is sparser, and their impact on antenna performance is relatively small. However, to further minimize potential interference, the design and manufacturing process should ensure that these metal lines are kept away from areas of strong electric field concentration, thereby effectively reducing their impact on the antenna's electromagnetic characteristics.

[0029] Above the solar panel 3, a hybrid transparent dielectric resonator structure is covered. This layer is a cube with a height of 2.8 mm, mainly composed of a transparent sapphire dielectric material at the center of the antenna unit and transparent quartz crystal dielectric materials around it. The transparent sapphire material 1 measures 9 mm × 10 mm × 2.8 mm and is a high dielectric constant anisotropic material with a dielectric constant of ε. rx = 9.3、ε ry = 9.3、ε rz= 11, dielectric loss is 0.0006. The surrounding square frame is made of transparent quartz material 2, with a dielectric constant of 3.9 and a dielectric loss of 0.001. The hybrid dielectric layer completely covers the solar panel, providing it with mechanical protection. The antenna can excite two adjacent resonant modes in the 8.6-12 GHz frequency band, effectively extending the antenna's operating bandwidth. From Figure 5 As can be seen, two distinct resistance peaks / reactance zeros are clearly observed, indicating the existence of two different modes. Mode 1 primarily originates from the slot structure, and its resonant frequency is affected by the slot length. Mode 2 primarily originates from the hybrid dielectric structure. Through precise calculation and design, low-dielectric-constant quartz material is placed around the anisotropic sapphire material at the center, allowing the quartz material to act as a matching layer, significantly reducing electric field reflection within the dielectric and thus improving antenna matching. Figure 6 As shown, before and after adding quartz material, the resonant frequency of mode 2 shifts to a lower frequency, the operating bandwidth is significantly improved, and the antenna gain is also increased.

[0030] The simulation S-parameters of the final one-dimensional phased array antenna are as follows: Figure 7 As shown, from Figure 7 As can be seen, the solar-powered antenna achieved a bandwidth of 3.4 GHz in the 8.6-12 GHz range. The antenna elements maintained an isolation of approximately -15 dB across the entire operating frequency band. The far-field radiation pattern of the one-dimensional phased array antenna is shown below. Figure 8 As shown in the figure, the array exhibits low cross-polarization and stable beam scanning characteristics within a ±45° range. As shown in Figure 8(d), the array maintains good gain stability and a high aperture efficiency (above 90%) within a ±30° scanning range. When the scanning angle increases to 45°, the aperture efficiency drops to between 70% and 80%. The simulation results verify the feasibility of the antenna within the operating frequency band.

[0031] High-frequency simulation software such as Ansoft's HFSS and CST's Microwave Studio CST were selected. The curves obtained above were obtained under given conditions; similar curves can be obtained by changing the structural parameters.

[0032] 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 hybrid transparent dielectric resonator phased array antenna with high solar cell coverage, characterized in that: The phased array antenna consists of eight antenna elements arranged horizontally to form a one-dimensional phased array antenna. Each antenna element has a three-layer structure, including a transparent sapphire material (1) in the middle of the upper layer and a transparent quartz material (2) around the transparent sapphire material (1). The solar panel (3) is located in the middle layer. The feed structure consists of a first layer of metal ground (4.3), a first layer of dielectric substrate (6.1), a metal feed line (5), a second layer of dielectric substrate (6.2), and a second layer of metal ground (4.4) in the lower layer. The solar panel (3) and the first layer of metal ground (4.3) have a rectangular groove (4.1). The metal feed line (5) is perpendicularly intersected with the rectangular groove (4.1), and the end of the metal feed line (5) is connected to a coaxial port (4.2).

2. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 1, characterized in that: In the upper structure of the antenna unit, the transparent quartz material (2) is a rectangular medium, and a rectangular through hole is opened in the center of the transparent quartz material (2); the transparent sapphire material (1) is a rectangular medium, located in the rectangular through hole in the center of the transparent quartz material (2).

3. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 2, characterized in that: The transparent sapphire material (1) is an anisotropic material with a high dielectric constant of ε. rx =9.3、ε ry = 9.3、ε rz = 11, dielectric loss is 0.0006; transparent quartz material (2) has a dielectric constant of 3.9 and dielectric loss of 0.

001.

4. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 1, characterized in that: The solar panel (3) has a metal grid on its surface, which is composed of branch-shaped and trunk-shaped line segments. The width of the branch line segments is 0.05 mm and the spacing is 1.5 mm. The main line segment is 0.7 mm wide and the spacing is 31 mm.

5. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 4, characterized in that: The solar panel (3) has a rectangular groove (4.1) cut at its center to couple the excited electromagnetic waves from the metal feed line (5) to the upper transparent sapphire material (1), and the coverage ratio of the solar cell is as high as 92.6%.

6. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 5, characterized in that: The metal feed line (5) is formed by connecting two rectangular metal lines (5.1) and (5.2) of different lengths and widths into a stepped shape.

7. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 4, characterized in that: The first dielectric substrate (6.1) and the second dielectric substrate (6.2) are made of Rogers 4350 material with a thickness of 0.5 mm, a dielectric constant of 3.48, and a dielectric loss tangent of 0.0037.

8. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 1, characterized in that: The antenna element operates in the 8.6-12GHz frequency band, operates in far-field mode, and has directional radiation characteristics.

9. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 1, characterized in that: The phased array antenna, consisting of eight antenna elements arranged horizontally to form a one-dimensional phased array, is fed through a coaxial port (4.2). The feeding layer is designed with stepped metal feed lines (5) to improve impedance matching between the antenna and the input port.

10. The hybrid transparent dielectric resonator phased array antenna with high solar cell coverage according to claim 1, characterized in that: The hybrid transparent dielectric resonator phased array antenna achieves beam scanning within a range of ±45°, possesses low cross-polarization level and stable scanning characteristics, and the isolation of each port within the frequency band is less than -15dB in the scanning state.

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