A microstrip rectifier metasurface antenna for energy-carrying communications

Abstract

The present invention discloses a microstrip / rectifying metasurface antenna for energy-carrying communication, comprising a first dielectric substrate, a radiating structure and a second dielectric substrate arranged in sequence from top to bottom; a metasurface structure is arranged on the surface of the first dielectric substrate; a metal floor is arranged directly below the second dielectric substrate, and an air gap is formed between the metal floor and the second dielectric substrate; the radiating structure is connected to a feeding network via a feeding point; the metasurface structure comprises structural units arranged in a periodic array; structural units arranged at corresponding positions of the radiating structure are connected to each other via rectifier diodes; structural units arranged on the side of the metasurface structure and connected to rectifier diodes are connected to an LC filtering circuit; high gain is achieved by using a metasurface unit structure, and high gain is achieved by reasonable structural design and arrangement.

Description

Technical Field

[0001] The present invention relates to the technical field of metasurface rectifying antennas, and in particular to a microstrip rectifying metasurface antenna for energy-carrying communication. Background Art

[0002] Generally speaking, in order to improve the gain of the antenna, the purpose can be achieved by loading a metasurface on the antenna. Under the same conditions, the higher the gain of the antenna means the longer the transmission distance of the electromagnetic wave, which is very meaningful in the fields of mobile communications, radar, satellite communications, etc. The propagation mode of electromagnetic waves in the antenna can be divided into TE mode waves and TM mode waves. At certain frequencies, TE mode waves or TM mode waves appear in the form of surface waves. These surface waves exist in the gaps between the metasurface units, which will affect the gain and reflection coefficient of the antenna. The microstrip rectifying metasurface shared antenna used in energy-carrying communications plays two roles: first, it can effectively collect the surface waves of the antenna, enhance the gain of the antenna, and reduce the size of the antenna; second, the metasurface with integrated rectification function can directly convert the transmitted RF / MW energy into DC energy.

[0003] Existing technologies such as "Wide Bandwidth and Enhanced Gain of a Low-Profifile DipoleAntenna Achieved by Integrated Suspended Metasurface" disclose a suspended metasurface dipole antenna that can operate in a broadband range with high gain. The antenna has a dipole on the top, and the metasurface is located below the dipole with an air gap at a certain distance from the ground. The antenna uses the air gap to separate TE mode surface waves and TM mode waves. The wide working bandwidth is attributed to the simultaneous excitation of the transverse electric surface wave resonance of the suspended metasurface and the adjacent dipole resonance. However, although the antenna has improved the gain, it does not consider how to utilize the surface wave.

[0004] Existing technologies such as "Polarization-insensitive wide-angle-reception metasurface with simplified structure for harvesting electromagnetic energy" disclose a single-hole polarization-insensitive energy harvesting surface. The antenna proposes a metasurface unit with a rotationally symmetrical shape, which can achieve polarization-insensitive characteristics through only one metal through-hole. The metasurface can collect electromagnetic energy through a metal through-hole, which is convenient for further rectification into direct current. Since a rectification circuit is introduced in the process of rectifying to direct current, the complexity of the antenna design is increased.

[0005] The prior art "Compact Dual-Band, Wide-Angle, Polarization-Angle-Independent Rectifying Metasurface for Ambient Energy Harvesting and Wireless Power Transfer" discloses a rectifying metasurface. By using the UC-BPG unit structure, the proposed metasurface structure is also composed of square metal sheets and 4 connecting wires; the rectifying diode is connected between the metasurface units to convert energy into a DC signal. It can achieve wide-range and large-angle energy collection and conversion into DC within a specific frequency band, but it is only an energy collector and does not have the ability of antenna communication. Summary of the invention

[0006] The present invention aims at solving the problems in the prior art and provides a microstrip rectifier metasurface antenna for energy-carrying communication.

[0007] The technical solution adopted by the present invention is:

[0008] A microstrip rectifier metasurface antenna for energy-carrying communication, comprising a first dielectric substrate, a radiation structure, and a second dielectric substrate arranged in sequence from top to bottom; the metasurface structure is arranged on the surface of the first dielectric substrate; a metal floor is arranged directly below the second dielectric substrate, and an air gap is formed between the metal floor and the second dielectric substrate; the radiation structure is connected to a feeding network through a feeding point;

[0009] The metasurface structure includes structural units arranged in a periodic array; the structural units arranged at corresponding positions of the radiation structure are connected to each other through rectifier diodes; and the structural units arranged on the side of the metasurface structure and connected to the rectifier diodes are connected to the LC filtering circuit.

[0010] Furthermore, the structural unit is a square structure, and the center positions of the four sides of the square extend outward to form a connecting portion of a rectangular structure; the rectifier diode is connected to the structural unit through the connecting portion.

[0011] Furthermore, the radiation structure is a square structure.

[0012] Furthermore, the LC filter circuit includes an inductor connected to the structural unit and a resistor and a capacitor arranged in parallel with each other.

[0013] Furthermore, the structural unit is made of copper foil with a thickness of 0.035 mm, a side length of 9 mm, and a distance between adjacent structural units of 1.8 mm.

[0014] Furthermore, the thickness of the first dielectric substrate is 0.254 mm, the thickness of the second dielectric substrate is 0.635 mm, and the air gap is 3 mm.

[0015] Furthermore, the radiation structure is made of 0.035 mm copper foil, and the radiation structure is fed by a 50Ω coaxial feeding method.

[0016] The beneficial effects of the present invention are:

[0017] (1) The air gap in the antenna of the present invention can realize TE mode waves and TM mode surface waves, so that the diode can absorb the surface waves and realize energy utilization;

[0018] (2) The metasurface structure of the present invention can achieve high gain through reasonable structural design and arrangement. The diode collects the energy in the gaps between the metasurface units and achieves the purpose of rectification through the LC filtering circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the front view of the structure of the present invention.

[0020] Figure 2 It is a side view of the structure of the present invention.

[0021] Figure 3 It is an S parameter curve obtained by simulating the structure of the present invention.

[0022] Figure 4 The E-plane and H-plane directional diagrams obtained by simulating the structure of the present invention are shown.

[0023] Figure 5 The figure is a graph showing the change of rectification efficiency with input power obtained by simulation using the structure of the present invention.

[0024] In the figure: 1-inductor, 2-resistor, 3-capacitor, 4-rectifier diode, 5-super surface structure, 6-metal floor, 7-first dielectric substrate, 8-radiation structure, 9-second dielectric substrate. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figure 1-Figure 2 As shown, a microstrip rectifier metasurface antenna for energy-carrying communication includes a first dielectric substrate 7, a radiating structure 8 and a second dielectric substrate 9 arranged in sequence from top to bottom; a metasurface structure 5 is arranged on the surface of the first dielectric substrate 7; a metal floor 6 is arranged directly below the second dielectric substrate 9, and an air gap is formed between the metal floor 6 and the second dielectric substrate 9; the radiating structure 8 is connected to a feeding network through a feeding point.

[0027] The metasurface structure 5 includes structural units arranged in a periodic array, N×bottles, N and P are both positive integers greater than or equal to 2; the metasurface structure 5 is located at the top, close to the first dielectric substrate 7, and a 3×5 structure is adopted in this embodiment. The structural unit is a square structure, and the center position of the four sides of the square extends outward to form a connecting portion of a rectangular structure; the rectifier diode 4 connects the structural unit through the connecting portion. The rectangular connecting portion is designed according to the size of the rectifier diode 4 in order to place the rectifier diode 4 during the later processing of the physical object. The structural unit in the metasurface structure 5 is not limited to a square structure, and other structures can be selected, such as a circular, square ring or Jerusalem cross oscillator structure. When electromagnetic waves are radiated to the metasurface structure 5, the structural units of the metasurface structure 5 can be equivalent to a parallel LC circuit, where the values ​​of L and C can be changed by adjusting the length of the unit and the period spacing.

[0028] The structural units arranged at the corresponding positions of the radiation structure 8 are connected to each other through the rectifier diode 4; the rectifier diode 4 adopts the SMS-7630 model, and the rectangular connection parts around the structural unit are conducive to the accurate placement of the rectifier diode 4. The rectifier diode 4 has the ability to rectify AC into DC and absorb the energy of the TM mode surface wave at the working frequency. The rectifier diode is not limited to the above-mentioned models, and models with different powers are selected according to different power requirements; the rectifier diode is directly connected between the metasurface units, eliminating the step of separately designing the rectifier circuit and simplifying the overall design of the antenna.

[0029] The structural unit arranged on the side of the metasurface structure 5 and connected with the rectifier diode 4 is connected to the LC filter circuit. The LC filter circuit includes an inductor 1 connected to the structural unit and a resistor 2 and a capacitor 3 arranged in parallel with each other.

[0030] The radiation structure 8 is a square structure. Of course, the radiation structure 8 is not limited to the square structure, and radiation structures such as dipole, monopole, and slot coupling feeding can also be used. The radiation structure 8 is set directly below the metasurface structure 5. Due to the introduction of the radiation structure, the energy is unevenly distributed on the metasurface. The rectifier diode 4 is set in a place with strong electric field strength, which is conducive to collecting relatively high energy. At the same time, the energy output by the previous unit is transmitted to the next unit through the rectifier diode 4. The transmitted energy is superimposed with the energy absorbed by itself and converted into DC power. At the same time, it is transmitted to the next unit to improve the overall collection efficiency.

[0031] The metal floor 6 is located at the bottom, and an air gap is formed between the metal floor 6 and the second dielectric substrate 9. The air gap causes the wave to be divided into TE mode wave and TM mode surface wave. The generation of surface wave will affect the radiation, gain, efficiency, etc. of the antenna. Reasonable collection of surface waves helps to improve the performance of the antenna. The selection of dielectric substrate properties and the length of the air gap can make the mode surface wave work at different frequencies.

[0032] When used specifically, the radiating structure 8 is fed with 50Ω coaxial feeding. The structural unit is made of copper foil with a thickness of 0.035mm, a side length of 9mm, and a distance of 1.8mm between adjacent structural units. The rectifier diode 4 adopts SMS-7630, and the diode operates in a small power range, less than the power level of 5dBm. The thickness of the first dielectric substrate 7 is 0.254mm, the thickness of the second dielectric substrate 9 is 0.635mm, and the air gap is 3mm. The first dielectric substrate 7 and the second dielectric substrate 9 are both RO3210 substrates, both of which are 45mm×35mm in size and have a dielectric constant of 10.2. The radiating structure 8 is made of 0.035mm copper foil, and the distance between the 50Ω coaxial feeding point and the radiating structure is 1.8mm. The size of the metal floor 6 is also set to 45mm×35mm.

[0033] The antenna with the above parameters is simulated using CST, and the S parameters are as follows Figure 3 As shown, the E-plane and H-plane directional diagrams are as follows Figure 4 As shown. Figure 3 It can be seen that in the 5.8GHZ frequency band, |S_11| = -19.499dB. Figure 4 As shown, the maximum gain can reach 7.056dB at 5.8GHZ.

[0034] Figure 5 The figure is a graph showing the change of rectification efficiency with input power obtained by simulation using the structure of the present invention. Figure 5 It can be seen that the electromagnetic energy receiving efficiency reaches a maximum value of 54.8% at an operating frequency of 5.8 GHz and an input power of 0 dBm.

[0035] The antenna of the present invention can realize TE mode waves and TM mode surface waves by reasonably setting the air gap, so that the diode can absorb the surface wave and realize energy utilization. The high gain is achieved by using the metasurface unit structure, and the high gain is achieved by reasonable structural design and arrangement. The placement of the diode collects the energy of the gaps between the metasurface units, and finally achieves the purpose of rectification through the LC filter circuit.

Claims

1. A microstrip rectifier metasurface antenna for energy-carrying communication, characterized in that: The invention comprises a first dielectric substrate (7), a radiation structure (8) and a second dielectric substrate (9) which are arranged in sequence from top to bottom; a super surface structure (5) is arranged on the upper surface of the first dielectric substrate (7); a metal floor (6) is arranged directly below the second dielectric substrate (9), and an air gap is formed between the metal floor (6) and the second dielectric substrate (9); The radiating structure (8) is connected to a feeding network via a feeding point; the metasurface structure (5) comprises structural units arranged in a periodic array; the radiating structure (8) is arranged directly below the metasurface structure (5), and the structural units arranged at corresponding positions thereof are connected to each other via a rectifier diode (4); any structural unit arranged on a side of the metasurface structure (5) and connected to a rectifier diode (4) is connected to an LC filter circuit; The structural unit is a square structure, and the central positions of the four sides of the square extend outward to form a connecting portion of a rectangular structure; the rectifier diode (4) is connected to the structural unit through the connecting portion; the structural unit is made of copper foil with a thickness of 0.035 mm, a side length of 9 mm, and a distance between adjacent structural units of 1.8 mm.

2. A microstrip rectifier metasurface antenna for energy-carrying communication according to claim 1, characterized in that: The radiation structure (8) is a square structure.

3. A microstrip rectifier metasurface antenna for energy-carrying communication according to claim 1, characterized in that: The LC filter circuit comprises an inductor (1) connected to a structural unit and a resistor (2) and a capacitor (3) which are arranged in parallel with each other.

4. A microstrip rectifier metasurface antenna for energy-carrying communication according to claim 1, characterized in that: The thickness of the first dielectric substrate (7) is 0.254 mm, the thickness of the second dielectric substrate (9) is 0.635 mm, and the air gap is 3 mm.

5. A microstrip rectifier metasurface antenna for energy-carrying communication according to claim 1, characterized in that: The radiation structure (8) is made of 0.035 mm copper foil, and a 50Ω coaxial feeding method is used to feed the radiation structure (8).

Images