A three-frequency-band high-transmission 1-bit phase control type metasurface unit

Abstract

This invention discloses a three-band high-transmission 1-bit phase-controlled metasurface unit. The metasurface unit comprises four identical metal layers (4) arranged sequentially and separated by air layers. Each metal layer (4) has three types of symmetrically arranged square-opening ring slots: a first square-opening ring slot (1), a second square-opening ring slot (2), and a third square-opening ring slot (3), which control the transmission phase of three different frequency bands respectively. In the upper half, the three types of square-opening ring slots are arranged from bottom to top, while in the lower half, they are arranged symmetrically from top to bottom. This invention integrates 1-bit transmission phase control functionality across three frequency bands: 8GHz, 11.8GHz, and 18.85GHz. It is more powerful than existing dual-band transmission phase-controlled metasurfaces, filling the gap in three-band transmission metasurfaces, and can be applied in fields such as multi-frequency transmission array antennas, frequency-hopping communication, and multi-target communication.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of novel artificial electromagnetic materials and antenna technology, and relates to a three-band high-transmittance 1-bit phase-modulated metasurface unit. More specifically, it is a transmissive metasurface unit that can operate simultaneously in three frequency bands: 8 GHz, 11.8 GHz, and 18.85 GHz. It achieves a 1-bit operating state with a 180° phase difference in each frequency band and can guarantee a high transmittance of not less than -1 dB. It can be applied in the fields of antennas and imaging. Background Technology

[0002] Metasurface technology is one of the rapidly developing new electromagnetic control technologies in recent years. By modulating parameters such as amplitude, phase, and polarization of reflected or transmitted waves using metasurface units, functions such as electromagnetic beamforming, beam scanning, and near-field electric field distribution reconstruction can be achieved. Compared with reflective units, transmissive metasurface units are not affected by feed source obstruction, providing a completely new solution for array antenna and radar front-end design. Recently, digitally coded metasurface technology has also emerged, which uses several discrete digital bit units for electromagnetic control, reducing design complexity compared to continuous phase control. With the increasing demand for high integration in communication technology, the concept of multi-band metasurfaces has also emerged. As the name suggests, these are metasurface units and arrays that can operate simultaneously in multiple frequency bands. For reflective metasurfaces, several dual-band, tri-band, and even quad-band metasurface designs have appeared, demonstrating the necessity of multi-band metasurface research. However, for transmissive metasurfaces, since high transmission amplitude must be ensured while achieving transmission phase modulation, most designs are single-band, and only a limited number of designs have achieved dual-band. Research on more frequency bands has not yet been reported. Therefore, it is urgent to start the research and development of three-band and more frequency band transmissive metasurface units. Summary of the Invention

[0003] Technical Problem: The purpose of this invention is to provide a three-band high-transmission 1-bit phase-tunable metasurface unit. By designing three specifications of square-opening annular slots and independently changing their longitudinal slot lengths Ly1, Ly2 and Ly3, 1-bit control of the transmission phase of the three frequency bands can be achieved, while ensuring a high transmittance of not less than -1dB, thereby achieving the purpose of controlling the far-field radiation pattern.

[0004] Technical solution: The present invention discloses a three-band high-transmission 1-bit phase-controlled metasurface unit comprising four identical metal layers arranged sequentially and separated by an air layer. Each metal layer has three types of square open ring slots symmetrically arranged vertically: a first square open ring slot, a second square open ring slot, and a third square open ring slot, which control the transmission phase of three different frequency bands respectively. In the upper half, the three types of square open ring slots are arranged from bottom to top, and in the lower half, they are arranged symmetrically from top to bottom.

[0005] The first open annular groove is located at the bottom of the upper half and the top of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

[0006] The second square opening annular groove is located in the middle of the upper half and the middle of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

[0007] The third-party open ring groove is located at the top of the upper half and the bottom of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

[0008] The third-party open ring slot is located inside the opening of the second-party open ring slot, and the second-party open ring slot is located inside the opening of the first-party open ring slot.

[0009] The longitudinal slot length Ly and the transverse slot length Ls of the first, second, and third open-ring slots can be designed independently. The transmission phase at frequency bands 1, 2, and 3 can be adjusted by changing the longitudinal slot lengths Ly1, Ly2, and Ly3.

[0010] The electrical dimension thickness of the metal layer ranges from 0.0001 wavelengths to 0.1 wavelengths.

[0011] The lateral lengths of the first, second, and third open-ring slots range from 0.0001 wavelengths to 1 wavelength.

[0012] The air layer is a separator, and the electrical dimension thickness H0 of the air layer ranges from 0.0001 wavelengths to 0.5 wavelengths.

[0013] The width P of the metal layer is from 0.0001 wavelengths to 1 wavelength.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following advantages.

[0015] 1. Compared with single-band and dual-band transmissive metasurface units, the present invention can operate independently in three frequency bands, which has not been reported before.

[0016] 2. The three frequency bands in which this invention can operate cover both the X and Ku bands, and the designed unit has high isolation between the three frequency bands, so that they do not interfere with each other.

[0017] 3. The unit transmittance of the present invention is better than -1dB, which is far higher than the existing -3dB standard.

[0018] 4. The phase modulation of the present invention is a 1-bit digital modulation method, which is simple to design and has good electromagnetic modulation effect.

[0019] 5. This invention uses an all-metal structure, which is lighter and easier to integrate than the more common dielectric-metal structure. Attached Figure Description

[0020] Figure 1 This is a front view of the unit structure of the present invention.

[0021] Figure 2 This is a side view of the unit structure of the present invention.

[0022] Figure 3 This is a schematic diagram of the induced electric field of the unit in this invention.

[0023] Figure 4 This is a 1-bit transmission phase versus size relationship diagram of the unit of the present invention at 8GHz.

[0024] Figure 5 This is a graph showing the relationship between the 1-bit transmission amplitude and size of the unit of the present invention at 8GHz.

[0025] Figure 6 This is a diagram showing the relationship between the 1-bit transmission phase modulation and size of the unit of the present invention at 11.8 GHz.

[0026] Figure 7 This is a graph showing the relationship between the 1-bit transmission amplitude and size of the unit of the present invention at 11.8 GHz.

[0027] Figure 8 This is a diagram showing the relationship between the 1-bit transmission phase modulation and size of the unit of this invention at 18.85 GHz.

[0028] Figure 9 This is a graph showing the relationship between the 1-bit transmission amplitude and size of the unit of the present invention at 18.85 GHz.

[0029] The diagram shows: a first open annular groove 1, a second open annular groove 2, a third open annular groove 3, and a metal layer 4. Detailed Implementation

[0030] The three-band high-transmittance 1-bit phase-controlled metasurface unit of the present invention includes four identical metal layers 4 separated by air layers. Each metal layer 4 can be divided into two symmetrical parts, each part containing three types of square open ring slots: a first square open ring slot 1, a second square open ring slot 2, and a third square open ring slot 3. In the upper part, the three types of square open ring slots are arranged from bottom to top, and each slot includes two longitudinal slots and one transverse slot. The lower part is completely symmetrical with the upper part. The transverse slot lengths Ls1, Ls2, and Ls3 of each slot remain unchanged, while the longitudinal slot lengths Ly1, Ly2, and Ly3 are set independently, realizing independent 1-bit transmission phase control in three frequency bands and ensuring that its transmittance is not lower than -1dB.

[0031] in,

[0032] The material of the metal layer 4 has excellent electrical conductivity, and its electrical dimension thickness ranges from 0.0001 wavelengths to 0.1 wavelengths.

[0033] All slots range in length from 0.0001 wavelengths to 1 wavelength.

[0034] The air gap thickness H0 ranges from 0.0001 wavelengths to 0.5 wavelengths.

[0035] The width P of the metal layer is from 0.0001 wavelengths to 1 wavelength.

[0036] This invention discloses a three-band high-transmittance 1-bit phase-tunable metasurface unit that can simultaneously achieve independent transmission phase tuning in three frequency bands while ensuring high transmittance. It achieves independent 1-bit transmission phase tuning in the 8GHz, 11.8GHz, and 18.85GHz frequency bands by designing three types of square-opening annular slots arranged from top to bottom. The transverse slot lengths Ls1, Ls2, and Ls3 remain constant, while the longitudinal slot lengths Ly1, Ly2, and Ly3 are independently set. This ensures that the transmittance is not lower than -1dB.

[0037] Figure 1 and Figure 2 The front and side views of the unit structure of the present invention are given, including four identical metal layers 4 separated by air layers. Each metal layer 4 can be divided into two symmetrical parts, each containing three types of square open ring slots: a first square open ring slot 1, a second square open ring slot 2, and a third square open ring slot 3. In the upper part, the three types of square open ring slots are arranged from bottom to top, and each slot includes two longitudinal slots and one transverse slot. The lower part is completely symmetrical to the upper part. The transverse slot lengths Ls1, Ls2, and Ls3 of each slot remain unchanged, while the longitudinal slot lengths Ly1, Ly2, and Ly3 are set independently, realizing independent 1-bit transmission phase modulation in three frequency bands and ensuring that its transmittance is not lower than -1dB. The slot size ranges from 0.0001 wavelengths to 1 wavelength; the metal layer material has excellent conductivity and its electrical thickness ranges from 0.0001 wavelengths to 0.1 wavelengths; the air gap thickness H0 ranges from 0.0001 wavelengths to 0.5 wavelengths; and the metal layer width P ranges from 0.0001 wavelengths to 1 wavelength.

[0038] Figure 3 A schematic diagram of the induced electric field of the unit of the present invention is given. It can be seen that when the operating frequency is 8 GHz, the resonance mainly occurs in the first open-ring slot 1; when the operating frequency is 11.8 GHz, the resonance mainly occurs in the second open-ring slot 2; and when the operating frequency is 18.85 GHz, the resonance mainly occurs in the third open-ring slot 3.

[0039] Figures 4-9 The diagrams showing the 1-bit transmission phase modulation and transmission amplitude versus size relationship of the unit of this invention at 8 GHz, 11.8 GHz, and 18.85 GHz are provided. The eight units are labeled run1 to run8. It can be seen that a 1-bit response with a transmission phase difference of approximately 180° can be achieved at these three frequency points, while maintaining a high transmittance better than -1 dB. Specific dimensions and transmittance are shown in Tables 1 and 2.

[0040] Table 1. Relationship between digital state and size of a three-band high-transmission 1-bit phase-controlled metasurface unit.

[0041]

[0042]

[0043] Table 2. Transmission phase and amplitude response of a three-band 1-bit high-transmission phase-tuned metasurface unit.

[0044]

Claims

1. A three-band high-transmission 1-bit phase-tuned metasurface unit, characterized in that... The metasurface unit comprises four identical metal layers (4) arranged in sequence and separated by an air layer. Each metal layer (4) has three types of square open ring slots that are symmetrically arranged vertically: a first square open ring slot (1), a second square open ring slot (2), and a third square open ring slot (3), which control the transmission phase of three different frequency bands respectively. In the upper half, the three types of square open ring slots are arranged from bottom to top, and in the lower half, they are arranged from top to bottom in a completely symmetrical manner with the upper half. The third-party open ring groove (3) is located inside the opening of the second-party open ring groove (2), and the second-party open ring groove (2) is located inside the opening of the first-party open ring groove (1).

2. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The first opening ring groove (1) is located at the bottom of the upper half and the top of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

3. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The second open annular groove (2) is located in the middle of the upper half and the middle of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

4. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The third-party open ring groove (3) is located at the top of the upper half and the bottom of the lower half, and includes two longitudinal grooves and one transverse groove to form a U-shaped structure.

5. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The longitudinal slot length Ly and the transverse slot length Ls of the first open ring slot (1), the second open ring slot (2) and the third open ring slot (3) can be designed independently. The transmission phase at frequency band 1, frequency band 2 and frequency band 3 can be adjusted by changing the longitudinal slot lengths Ly1, Ly2 and Ly3.

6. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The electrical thickness of the metal layer (4) ranges from 0.0001 wavelengths to 0.1 wavelengths.

7. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The transverse lengths of the first open ring slot (1), the second open ring slot (2), and the third open ring slot (3) range from 0.0001 wavelengths to 1 wavelength.

8. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The air layer is a separator, and the electrical dimension thickness H0 of the air layer ranges from 0.0001 wavelengths to 0.5 wavelengths.

9. The three-band high-transmission 1-bit phase-tuned metasurface unit according to claim 1, characterized in that: The width P of the metal layer (4) ranges from 0.0001 wavelengths to 1 wavelength.

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