A polarization-converting and amplitude-amplifying metasurface antenna

Abstract

A polarization-switching amplitude-amplifying metasurface antenna comprises: a reflective polarization-switching amplitude-amplifying metasurface unit structure uniformly arranged in an xy two-dimensional plane; the metasurface unit structure comprises an upper surface metal layer, a dielectric layer, a metal reflection layer on the back of the dielectric layer, and a metal feeder connected to the bottom of the metal reflection layer; the upper surface metal layer comprises two embedded-fed rectangular microstrip patch antennas and a radio frequency amplification circuit; one of the rectangular microstrip patch antennas receives an incident electromagnetic wave, amplifies the electromagnetic wave through the loaded radio frequency amplification circuit, and radiates the electromagnetic wave through another rectangular microstrip patch antenna in a vertical direction.

Description

Technical Field

[0001] The present invention belongs to the field of artificial electromagnetic materials, and specifically relates to the design of a polarization-conversion amplitude-amplified metasurface in the microwave band (which can be used as an antenna or other various electromagnetic wave receiving application scenarios). Background Art

[0002] Changing the polarization state of the reflected electromagnetic wave to form different beam shapes and improving the efficiency of polarization conversion have always been research hotspots in the field of antennas. In addition, in traditional metasurfaces, due to the existence of factors such as dielectric loss, metal loss, and parasitic impedance of the loaded lumped elements, energy dissipation is inevitable after the incident electromagnetic wave is reflected or transmitted through the artificial electromagnetic surface, which is a major constraint in many application scenarios. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects and propose a polarization amplitude amplification metasurface.

[0004] Technical solution: In order to achieve the above technical effects, the present invention proposes the following technical solution: a polarization conversion amplitude amplification metasurface, characterized in that it includes: a reflective polarization conversion amplitude amplification metasurface unit structure uniformly arranged in the xy two-dimensional plane; the metasurface unit structure includes an upper surface metal layer, a dielectric layer, a metal reflective layer on the back of the dielectric layer, and a metal feeder connected to the bottom of the metal reflective layer, the upper surface metal layer includes two embedded-fed rectangular microstrip patch antennas and a radio frequency amplification circuit, one of the rectangular microstrip patch antennas receives the incident electromagnetic wave, and the electromagnetic wave is amplified by the loaded radio frequency amplification circuit, and finally radiated by another rectangular microstrip patch antenna in the vertical direction, thereby realizing polarization conversion and amplitude amplification functions.

[0005] The dielectric layer is an F4B dielectric layer with a dielectric constant of 2.65.

[0006] The upper surface metal layer is a copper sheet.

[0007] The radio frequency amplification circuit is composed of two DC blocking capacitors, a bypass capacitor, a choke inductor and a microwave amplifier; a positive voltage is applied to each amplifier through a DC voltage source, so that the amplifier works in the amplification area, thereby realizing the amplification function of the metasurface.

[0008] An isolation medium layer is also arranged at the bottom of the metal reflective layer, and the bottom of the isolation medium is connected to a metal feed line.

[0009] The polarization conversion is only for a single linear polarization.

[0010] The polarization amplitude is +5.2 dB compared to the metal plate, and the co-polarization amplitude is -5.2 dB compared to the metal plate.

[0011] The central operating frequency of the polarization conversion amplitude amplification is 4 GHz.

[0012] Optionally, the upper surface metal layer is a copper sheet.

[0013] Optionally, the dielectric layer is a F4B dielectric layer (ie, a F4B dielectric plate with a dielectric constant of 2.65).

[0014] Beneficial effects: The present invention fills the gap in the prior art and has at least the following beneficial effects:

[0015] 1) At around 4 GHz, the metasurface designed by the present invention can achieve polarization conversion of single linear polarization, with the cross-polarization amplitude amplified to 5.2 dB and the co-polarization amplitude suppressed to -5.2 dB.

[0016] 2) The metasurface designed by the present invention has a simple structure, is easy to design, and is thin, and has great application potential.

[0017] 3) The metasurface with amplified polarization conversion amplitude of the present invention has important application prospects in the fields of wireless communications, electromagnetic wave spatial isolation, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structural unit of the present invention.

[0019] Figure 2 This is a sample diagram of the metasurface of the present invention.

[0020] Figure 3 It is a schematic diagram of a radio frequency amplifying circuit in a unit structure of the present invention.

[0021] Figure 4 This is a diagram of a test board for a radio frequency amplifier circuit in a unit structure of the present invention.

[0022] Figure 5 It is a result diagram of the test and calibration of the radio frequency amplification circuit in the unit structure of the present invention.

[0023] Figure 6 It is a simulation result diagram of the present invention.

[0024] Figure 7 It is a diagram of experimental test results of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below by specific embodiments in conjunction with the accompanying drawings. However, it should be understood that the present invention can be implemented in various forms, and some exemplary and non-limiting embodiments shown in the accompanying drawings and described below are not intended to limit the present invention to the specific embodiments described.

[0026] It should be understood that, where technically feasible, the technical features listed above for different embodiments can be combined with each other to form other embodiments within the scope of the present invention. In addition, the specific examples and embodiments described in the present invention are non-limiting, and the structures, steps, and sequences described above can be modified accordingly without departing from the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] Figure 1 It is a schematic diagram of the unit structure of a polarization-converted amplitude-amplified metasurface. An embodiment of the present invention provides a polarization-converted amplitude-amplified metasurface formed by periodic extension of basic units in an xy two-dimensional plane, and the xy two-dimensional plane is a square plane. Its basic unit includes an upper surface metal layer, an F4B dielectric layer (dielectric constant 2.65, loss tangent 0.015), a metal reflective layer on the back of the dielectric layer, and a metal feeder connected to the bottom of the metal reflective layer. In this embodiment, the upper surface metal layer is made of copper, and the thickness of the dielectric layer is 2 mm. The entire upper surface metal layer, except for the RF amplification circuit part, is along the diagonal direction of the xy two-dimensional plane, that is, the +45° diagonal in the xy coordinate system.

[0029] This embodiment adopts the working mechanism of receiving-amplifying-polarization conversion-radiating, that is, firstly, a microstrip patch antenna is formed by feeding along the x direction in the upper surface metal layer, the dielectric layer and the back metal reflective layer to receive electromagnetic waves, and the current in the x direction is formed to be amplified by the radio frequency amplification circuit part, and then the current in the x direction is converted into the current in the y direction to realize polarization conversion through the rectangular metal guide in the y direction, and finally a microstrip patch antenna is formed by feeding along the y direction, the dielectric layer and the back metal reflective layer to radiate electromagnetic waves.

[0030] This embodiment adopts the column feeding method. In order to facilitate column control feeding, a 0.5mm isolation dielectric layer is loaded on the back of the metal reflective layer, and then a metal feed line is added to the bottom of the isolation dielectric layer. In order to obtain a good polarization conversion amplitude amplification effect, it is appropriate to form a periodic unit with multiple reflective super unit structures and then form an overall metasurface. The more periods and the larger the size of the whole board, the better the polarization conversion amplitude amplification effect of the whole board. However, based on cost considerations, this embodiment adopts Figure 2 The 5*5 periodic unit size board shown. The rectangular block is a microstrip patch antenna, and its connection relationship is as follows Figure 1 The schematic diagram is given, and the period is 50mm.

[0031] The amplification effect of the reflective super unit structure is achieved based on the loaded RF amplifier circuit. Figure 3The schematic diagram of the loaded RF amplifier circuit is shown in Figure 1. The amplifier circuit consists of two 3pF DC blocking capacitors, a 100pF bypass capacitor and a 1nH choke inductor connected in series to a microwave amplifier (model GaLi2+). Two 3pF DC blocking capacitors C1 are connected in series to the input and output ports of the amplifier (model GaLi2+) A. The DC bias circuit of the amplifier includes a 1nH choke inductor L connected to the output port of the amplifier and a 100pF bypass capacitor C2 connected to ground. The RF amplifier circuit is made into a Figure 4 The test board shown in the figure is used for measurement and calibration. The calibration parts are a set of calibration parts designed based on the TRL calibration principle. The results after measurement and calibration are shown in Figure 5 As shown, it can be seen that within the frequency range of 1-7GHz, the RF amplifier circuit can achieve an amplitude amplification greater than 10dB.

[0032] Based on the above unit design concept, we use the commercial software CST to simulate the unit, adopting periodic boundary conditions for the unit structure and open boundary conditions in the longitudinal direction. Using CST's field-circuit joint simulation, the scattering parameters after RF amplifier circuit test and calibration are loaded into the unit structure. The simulation results are shown in the figure. Figure 6 As shown in the figure, at 4.07GHz, the cross-polarization amplitude of the x-polarization of the unit reaches 10dB, and the co-polarization amplitude is suppressed to -10dB. As an experimental verification, samples were processed and made for actual measurement. The measurement results are shown in the figure below. Figure 7 As shown, the measurement results are in good agreement with the simulation results, and the metasurface can realize the function of amplifying the polarization conversion amplitude.

[0033] The above description is only a preferred embodiment of the present invention and cannot be used to limit the scope of implementation of the present invention. That is, any simple equivalent changes and modifications made according to the claims and the invention description of the present invention should still fall within the scope of coverage of the patent of the present invention.

Claims

1. A polarization-amplification metasurface, characterized in that: include: A reflective polarization-conversion amplitude-amplified metasurface unit structure uniformly arranged in an xy two-dimensional plane; The metasurface unit structure includes an upper surface metal layer, a dielectric layer, and a metal reflective layer on the back of the dielectric layer. An isolation dielectric layer is also arranged at the bottom of the metal reflective layer, and the bottom, i.e., the back, of the isolation dielectric is connected to a metal feeder. The upper surface metal layer includes two embedded-fed rectangular microstrip patch antennas and an RF amplifier circuit. One of the rectangular microstrip patch antennas receives incident electromagnetic waves, and the electromagnetic waves are amplified by the loaded RF amplifier circuit, and finally radiated by another vertical rectangular microstrip patch antenna to achieve polarization conversion and amplitude amplification.

2. The polarization conversion amplitude amplification type metasurface antenna according to claim 1, characterized in that: The dielectric layer is an F4B dielectric layer with a dielectric constant of 2.

65.

3. The polarization-converted amplitude-amplified metasurface antenna according to claim 1, characterized in that: The upper surface metal layer is a copper sheet.

4. The polarization-converted amplitude-amplified metasurface antenna according to claim 1, characterized in that: The radio frequency amplification circuit is composed of two DC blocking capacitors, a bypass capacitor, a choke inductor and a microwave amplifier; a positive voltage is applied to each amplifier through a DC voltage source, so that the amplifier works in the amplification area, thereby realizing the amplification function of the metasurface.

5. The polarization conversion amplitude amplification type metasurface antenna according to claim 1, characterized in that: The polarization conversion is only for a single linear polarization.

6. The polarization conversion amplitude amplification type metasurface antenna according to claim 1, characterized in that: The polarization amplitude is +5.2 dB compared to the metal plate, and the co-polarization amplitude is -5.2 dB compared to the metal plate.

7. The polarization conversion amplitude amplification type metasurface antenna according to claim 1, characterized in that: The central operating frequency of the polarization conversion amplitude amplification is 4 GHz.

8. The polarization conversion amplitude amplification type metasurface antenna according to claim 1, characterized in that: The isolation dielectric layer is a F4B dielectric layer.

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