Transparent antenna applied to ocean communication buoy

Abstract

The invention provides a transparent antenna applied to an ocean communication buoy. The transparent antenna comprises a coplanar waveguide, an impedance matching structure, a mode matching structure, an asymmetric quasi-one-dimensional SSPPs transmission structure and a quasi-one-dimensional elliptical matching structure which are sequentially arranged in parallel, the coplanar waveguide sequentially excites the impedance matching structure, the mode matching structure, the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure; the central conductor width of the impedance matching structure is transited from the central conductor width of the coplanar waveguide to the unit width of the quasi-one-dimensional SSPPs transmission structure, so that impedance matching is realized; the mode matching structure is used for coplanar waveguide and SSPPs mode matching; the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are main radiation parts, end-fire radiation is formed by phase modulation of the quasi-one-dimensional SSPPs transmission structure, and then the end-fire radiation enters a free space through radiation of the quasi-one-dimensional elliptical matching structure. According to the invention, the antenna with high optical transparency is realized, and the radiation efficiency is good.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a transparent antenna applied to an ocean communication buoy. Background Art

[0002] Marine communication buoys are an important part of the marine information network. They have important functions such as communication, navigation positioning, and meteorological monitoring. The realization of these functions is inseparable from the radio transceiver device - the antenna. For a long time, the antenna, as an independent communication device, has been difficult to integrate with the buoy body. Its large mass and volume lead to a reduction in the available space of the buoy, a reduction in load capacity, and even the risk of capsizing under the waves. Most marine communication buoys are powered by solar energy. If an optically transparent communication antenna can be developed, it can be integrated with the solar power panel, greatly increasing the available space and load capacity of the communication buoy. At the same time, the high optical transmittance of the transparent antenna can avoid large-scale shading of sunlight by the communication device, and will not affect the power supply efficiency of the solar panel, thus realizing the multifunctionality of electromagnetic communication and energy replenishment in the same space.

[0003] Traditional transparent antenna technology mainly relies on the inherent properties of transparent conductor materials to achieve optical transparency of electromagnetic devices, such as the use of indium tin oxide (ITO). However, the material conductivity (carrier density) and optical transparency restrict each other. While achieving transparent performance, the antenna performance is largely sacrificed, resulting in deterioration of the working performance of electromagnetic devices, decreased signal coverage strength, shortened communication distance, greatly reduced coverage area, and low transmittance. Therefore, developing antenna design technology with high transmittance and high radiation efficiency is a practical issue to improve the service performance of marine communication buoys. Summary of the invention

[0004] The present invention provides a transparent antenna applied to an ocean communication buoy, so as to solve the defect in the prior art that the communication performance of the antenna is poor while achieving optical transparency, and realize a highly optically transparent antenna with good radiation efficiency.

[0005] The present invention provides a transparent antenna for use in an ocean communication buoy, comprising a coplanar waveguide, an impedance matching structure, a mode matching structure, an asymmetric quasi-one-dimensional SSPPs (Spoof Surface Plasmon Polaritons, artificial surface plasmon) transmission structure and a quasi-one-dimensional elliptical matching structure arranged in parallel in sequence;

[0006] The coplanar waveguide (CPW) is used to sequentially excite the impedance matching structure, the mode matching structure, the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure;

[0007] The central conductor width of the impedance matching structure transitions from the central conductor width of the coplanar waveguide to the unit width of the quasi-one-dimensional SSPPs transmission structure to achieve impedance matching;

[0008] The mode matching structure is used to obtain mode matching between the coplanar waveguide and the SSPPs;

[0009] The quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are the main radiation parts, which are phase modulated by the asymmetric quasi-one-dimensional SSPPs transmission structure to form end-fire radiation, and then radiate into free space through the quasi-one-dimensional elliptical matching structure.

[0010] According to a transparent antenna applied to an ocean communication buoy provided by the present invention, the quasi-one-dimensional SSPPs transmission structure includes a plurality of asymmetric quasi-one-dimensional SSPPs units arranged in parallel and a dielectric substrate.

[0011] According to a transparent antenna for use in ocean communication buoys provided by the present invention, the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are both composed of quasi-one-dimensional conductive metal wires, the percentage of opaque conductive material in the area of ​​the main radiation part is much less than 10%, and the optical transmittance reaches more than 90%.

[0012] According to a transparent antenna for marine communication buoys provided by the present invention, the upper and lower sides of each SSPPs are metal grooves of different depths, so that the upper and lower sides of each SSPPs respectively obtain propagation modes with different phase propagation constants.

[0013] According to a transparent antenna applied to an ocean communication buoy provided by the present invention, the conductor wires at the bottom of the metal grooves on the upper and lower sides of each SSPPs extend above the outer contour conductor structure, so that the electric field of the redundant mode flows into the outer contour in the form of current to eliminate the redundant mode, so that the transmission modes on the upper and lower sides of each SSPPs do not interfere with each other.

[0014] According to a transparent antenna applied to an ocean communication buoy provided by the present invention, the mode matching structure includes a coplanar waveguide floor and a central conductor, and the coplanar waveguide floor is located on both sides of the central conductor and is exponentially away from the central conductor.

[0015] According to a transparent antenna for marine communication buoy provided by the present invention, the depth of the metal grooves on the upper and lower sides of the central conductor increases linearly to the depth of the metal grooves on the upper and lower sides corresponding to the SSPPs;

[0016] The transverse metal line width and the longitudinal metal line width on the central conductor both decrease linearly to the metal line width of the SSPPs.

[0017] According to a transparent antenna for marine communication buoy provided by the present invention, the metal line widths on the left and right sides of each SSPPs are lw / 2, and the other metal line widths are lw;

[0018] The transverse metal line width and the longitudinal metal line width on the central conductor both decrease linearly to the other metal line widths lw of the SSPPs.

[0019] According to a transparent antenna applied to a marine communication buoy provided by the present invention, the optical transmittance OR and reflectance OT of each SSPPs are calculated by the following formula:

[0020]

[0021]

[0022] Among them, A metal is the area occupied by the metal wire in SSPPs, A unit is the area of ​​the entire quasi-one-dimensional SSPPs unit, d is the lateral width of the entire quasi-one-dimensional SSPPs unit, p is the longitudinal width of the entire quasi-one-dimensional SSPPs unit, a is the width of the metal grooves on the upper and lower sides of the SSPPs, h1 is the depth of the metal grooves on the upper side of the SSPPs, h2 is the depth of the metal grooves on the lower side of the SSPPs, w is the lateral width of the dielectric substrate, r1 is the major semi-axis of the quasi-one-dimensional elliptical matching structure, and r2 is the minor semi-axis of the quasi-one-dimensional elliptical matching structure.

[0023] According to a transparent antenna for marine communication buoys provided by the present invention, the thinner the metal wire of the SSPPs, the higher the optical transmittance and the lower the optical reflectance. Specifically, when the metal wire width is less than 80 μm, without considering the dielectric substrate, the main radiation part obtains a visible light transmittance of more than 90%, and correspondingly, the visible light reflectance at this time is less than 10%.

[0024] The transparent antenna provided by the present invention is applied to marine communication buoys. It uses an asymmetric quasi-one-dimensional SSPPs transmission structure for phase modulation to form end-fire radiation, and then radiates into free space through a quasi-one-dimensional elliptical matching structure. The mode matching of the coplanar waveguide and the SSPPs is obtained through the mode matching structure, thereby realizing a highly optically transparent antenna with good radiation efficiency, being independent of expensive transparent conductive materials such as ITO, and having a small size and a low profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of a transparent antenna applied to a marine communication buoy provided by the present invention;

[0027] Figure 2 It is a schematic diagram of an asymmetric quasi-one-dimensional SSPPs structure in a transparent antenna applied to an ocean communication buoy provided by the present invention;

[0028] Figure 3 It is a schematic diagram of impedance and radiation characteristics of a transparent antenna applied to a marine communication buoy provided by the present invention;

[0029] Figure 4 It is a normalized direction diagram of the transparent antenna applied to the marine communication buoy provided by the present invention at the center frequency of 15 GHz;

[0030] Figure 5 It is a schematic diagram showing the variation of the optical transmittance and reflectivity of the radiation part of the transparent SSPPs end-fire antenna in the transparent antenna applied to the ocean communication buoy provided by the present invention with the metal line width. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Combine the following Figure 1 The invention describes a transparent antenna applied to an ocean communication buoy, comprising a coplanar waveguide, an impedance matching structure, a mode matching structure, an asymmetric quasi-one-dimensional SSPPs transmission structure and a quasi-one-dimensional elliptical matching structure arranged in parallel in sequence;

[0033] The coplanar waveguide is used to sequentially excite the impedance matching structure, the mode matching structure, the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure;

[0034] The central conductor width of the impedance matching structure transitions from the central conductor width of the coplanar waveguide to the unit width of the quasi-one-dimensional SSPPs transmission structure to achieve impedance matching;

[0035] The mode matching structure is used to obtain mode matching between the coplanar waveguide and the SSPPs;

[0036] The quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are the main radiation parts. The quasi-one-dimensional SSPPs transmission structure performs phase modulation to form end-fire radiation, which is then radiated into free space through the quasi-one-dimensional elliptical matching structure.

[0037] Figure 1 The waveguide structure of the medium-transparent SSPPs end-fire antenna includes a coplanar waveguide CPW with a length of L1, an impedance matching structure with a length of L2, a mode matching structure with a length of L3, an asymmetric quasi-one-dimensional SSPPs transmission structure with a length of L4, and a quasi-one-dimensional elliptical matching structure with a length of L5.

[0038] The characteristic impedance of the coplanar waveguide part can be 50Ω to excite the back-end part. The width of the central conductor of the impedance matching part can be transitioned from 3 mm of the CPW structure to 6.4 mm of the SSPPs structure. The mode matching part is used to achieve mode matching from CPW to asymmetric quasi-one-dimensional SSPPs. The main radiation part of the antenna is an asymmetric quasi-one-dimensional SSPPs structure and a quasi-one-dimensional elliptical matching structure. The quasi-one-dimensional SSPPs transmission structure performs phase modulation to form end-fire radiation, and then radiates into free space through the quasi-one-dimensional elliptical matching structure.

[0039] The detailed geometric parameters of the transparent antenna can be: L1 = 4 mm, L2 = 10 mm, L3 = 15 mm, L4 = 30 mm, L5 = 7 mm, w = 30 mm, r1 = 7 mm, r2 = 3.2 mm, L wh = 2 mm, L ws = 0.4 mm. In addition, the antenna is a single-layer structure with a cross-section of only 0.101 mm, has significant flexibility, and a cross-section of ≤0.0067λ0, making it easy to conform to offshore communication buoy equipment.

[0040] This embodiment uses an asymmetric quasi-one-dimensional SSPPs transmission structure for phase modulation to form end-fire radiation, which is then radiated into free space through a quasi-one-dimensional elliptical matching structure. The mode matching of the coplanar waveguide and the SSPPs is achieved through the mode matching structure, thereby realizing a highly optically transparent antenna with good radiation efficiency, being independent of expensive transparent conductive materials such as ITO, and having a small size and a low profile.

[0041] Based on the above embodiments, Figure 1As shown, the quasi-one-dimensional SSPPs transmission structure in this embodiment includes a plurality of asymmetric quasi-one-dimensional SSPPs units arranged in parallel and a dielectric substrate.

[0042] Figure 1 The SSPPs transmission structure includes 10 asymmetric quasi-one-dimensional SSPPs arranged in parallel, and the number of SSPPs is not limited in this embodiment. SSPPs can be made of copper, and the dielectric substrate can be made of PET (Polyethylene Terephthalate).

[0043] On the basis of the above embodiments, in this embodiment, the upper and lower sides of each SSPPs are metal grooves of different depths, so that the upper and lower sides of each SSPPs respectively obtain propagation modes with different phase propagation constants.

[0044] The unit structure of asymmetric quasi-one-dimensional SSPPs is as follows Figure 2 As shown in (a), its specific parameters are: a = 1.2 mm, h1 = 1 mm, h2 = 2.2 mm, d = 6.4 mm, p = 3 mm, lw = 10 μm. The thickness of the metal wire (such as copper) is 1 μm, and the dielectric substrate can be 100 μm thick PET. The upper and lower sides of the structure are metal grooves of different depths. The upper and lower sides of the structure can obtain modes with different phase propagation constants respectively, and these two modes do not interfere with each other.

[0045] This highly optically transparent antenna has a small size and a low profile, with the size of the radiating part being only 0.42λ0×2.46λ0×0.0067λ0.

[0046] On the basis of the above-mentioned embodiments, in this embodiment, the conductor lines at the bottom of the metal slots on the upper and lower sides of each SSPPs extend above the outer contour conductor structure, so that the electric field of the redundant mode flows into the outer contour in the form of current to eliminate the redundant mode, so that the transmission modes on the upper and lower sides of each SSPPs do not interfere with each other.

[0047] The energy distribution of the transmission modes on the upper and lower sides of each SSPPs is as follows: Figure 2 (b) shown. Figure 2 (c) shows the dispersion curve of the asymmetric quasi-one-dimensional SSPPs structure. The two transmission modes provided by the structure have different phase propagation constants at the same frequency. That is, there is a phase difference between the two at the same frequency, and the phase difference accumulates with the increase of the transmission distance. By selecting a suitable distance, the upper and lower sides can obtain the same phase propagation constant, realizing co-phase modulation.

[0048] Based on the above embodiments, Figure 1As shown, the mode matching structure in this embodiment includes a coplanar waveguide floor and a central conductor. The coplanar waveguide floor is located on both sides of the central conductor and is exponentially away from the central conductor.

[0049] Based on the above embodiments, Figure 1 As shown, the depth of the metal grooves on the upper and lower sides of the central conductor in this embodiment increases linearly to the metal groove depths h1 and h2 on the upper and lower sides corresponding to the SSPPs;

[0050] The lateral metal line width l on the central conductor wh and the longitudinal metal line width l ws They all decrease linearly to the metal line width lw of the SSPPs.

[0051] Based on the above embodiment, in this embodiment, the metal line widths on the left and right sides of each SSPPs are lw / 2, and the other metal line widths are lw;

[0052] The transverse metal line width and the longitudinal metal line width on the central conductor both decrease linearly to the other metal line widths lw of the SSPPs.

[0053] The impedance and radiation characteristics of the transparent SSPPs end-fire antenna provided in this embodiment are as follows: Figure 3 As shown. Among them, Figure 3 (a) is the simulation S parameter result diagram, Figure 3 (b) is the simulated gain and radiation efficiency diagram. The normalized radiation pattern at the center frequency of 15 GHz is as follows: Figure 4 (a) and Figure 4 (b). Among them, Figure 4 (a) is the normalized orientation diagram of the xoy plane, Figure 4 (b) is the normalized radiation pattern of the xoz plane. It can be seen that the transparent end-fire SSPPs antenna can achieve good working performance in the 14.5 to 15.5 GHz frequency band, with a reflection coefficient of less than -10 dB, an end-fire radiation form, and an overall radiation efficiency of more than 70%.

[0054] Based on the above embodiment, the optical transmittance OR and reflectance OT of each SSPPs are calculated by the following formula in this embodiment:

[0055]

[0056]

[0057] Among them, A metal is the area occupied by the metal wire in SSPPs, A unitis the area of ​​the entire quasi-one-dimensional SSPPs unit, d is the lateral width of the entire quasi-one-dimensional SSPPs unit, p is the longitudinal width of the entire quasi-one-dimensional SSPPs unit, a is the width of the metal grooves on the upper and lower sides of the SSPPs, h1 is the depth of the metal grooves on the upper side of the SSPPs, h2 is the depth of the metal grooves on the lower side of the SSPPs, w is the lateral width of the dielectric substrate, r1 is the major semi-axis of the quasi-one-dimensional elliptical matching structure, and r2 is the minor semi-axis of the quasi-one-dimensional elliptical matching structure.

[0058] The above formula shows that the optical transmittance and reflectance of the quasi-one-dimensional SSPPs antenna radiating part change with the metal line width, which can accurately show the optical transparency of the quasi-one-dimensional SSPPs antenna. For the optical frequency band, the percentage of opaque material in the main radiating part area can be used to evaluate the transmittance (OT) and reflectance (OR) of structures whose size is much larger than the wavelength of light.

[0059] On the basis of the above embodiments, in this embodiment, the thinner the metal wire of the SSPPs is, the higher the optical transmittance is.

[0060] Figure 5 The optical transmittance and reflectance of the quasi-one-dimensional SSPPs antenna radiation part with different metal wire widths are plotted. It can be seen that the thinner the metal wire, the higher the transmittance, so this can be used as a guide to obtain different transmittances as needed.

[0061] Specifically, when the metal line width is less than 80 μm, without considering the dielectric substrate, a visible light transmittance of more than 90% can be obtained, and correspondingly, the visible light reflectivity at this time is less than 10%.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transparent antenna for use in marine communication buoys, characterized in that: It includes coplanar waveguides, impedance matching structures, mode matching structures, asymmetric quasi-one-dimensional SSPPs transmission structures and quasi-one-dimensional elliptical matching structures arranged in parallel; The coplanar waveguide is used to sequentially excite the impedance matching structure, the mode matching structure, the quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure; The central conductor width of the impedance matching structure transitions from the central conductor width of the coplanar waveguide to the unit width of the quasi-one-dimensional SSPPs transmission structure to achieve impedance matching; The mode matching structure is used to obtain mode matching between the coplanar waveguide and the SSPPs; The quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are the main radiation parts. The quasi-one-dimensional SSPPs transmission structure performs phase modulation to form end-fire radiation, which is then radiated into free space through the quasi-one-dimensional elliptical matching structure.

2. The transparent antenna for use in marine communication buoys according to claim 1, characterized in that: The quasi-one-dimensional SSPPs transmission structure comprises a plurality of asymmetric quasi-one-dimensional SSPPs units arranged in parallel and a dielectric substrate.

3. The transparent antenna for marine communication buoy according to claim 1, characterized in that: The quasi-one-dimensional SSPPs transmission structure and the quasi-one-dimensional elliptical matching structure are both composed of quasi-one-dimensional conductive metal wires, the percentage of opaque conductive material in the main radiation part area is much less than 10%, and the optical transmittance reaches more than 90%.

4. The transparent antenna for use in marine communication buoys according to claim 2, characterized in that: The upper and lower sides of each quasi-one-dimensional SSPPs unit are metal grooves of different depths, so that the upper and lower sides of each quasi-one-dimensional SSPPs unit respectively obtain propagation modes with different phase propagation constants.

5. The transparent antenna for use in marine communication buoys according to claim 4, characterized in that: The conductor lines at the bottom of the metal grooves on the upper and lower sides of each quasi-one-dimensional SSPPs unit extend to the outer contour conductor structure of the unit, so that the electric field of the redundant mode flows into the outer contour in the form of current to eliminate the redundant mode and ensure that the transmission modes on the upper and lower sides of each quasi-one-dimensional SSPPs unit do not interfere with each other.

6. The transparent antenna for use in marine communication buoys according to claim 4, characterized in that: The mode matching structure includes a coplanar waveguide floor and a central conductor. The coplanar waveguide floor is located at two sides of the central conductor and is exponentially away from the central conductor.

7. The transparent antenna for use in ocean communication buoys according to claim 6, characterized in that: The depth of the metal grooves on the upper and lower sides of the central conductor increases linearly to the corresponding metal groove depths on the upper and lower sides of the SSPPs, and the transverse metal line width and the longitudinal metal line width on the central conductor both decrease linearly to the metal line width of the SSPPs.

8. The transparent antenna for use in marine communication buoys according to claim 7, characterized in that: The metal line widths on the left and right sides of each quasi-one-dimensional SSPPs unit are lw / 2, other metal line widths are lw .

9. The transparent antenna for use in marine communication buoys according to claim 8, characterized in that: The metal line width of the quasi-one-dimensional SSPPs unit lw Adjustable, within the range of 5-500 μm, it can support SSPPs mode, and the finer the line width, the higher the optical transmittance and the lower the optical reflectivity; When the metal line width is less than 80 μm, without considering the dielectric substrate, a visible light transmittance of more than 90% is obtained, and correspondingly, the visible light reflectivity is less than 10%.

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