Terahertz phase shifter based on Huygens metasurface

Abstract

The invention discloses a Huygens metasurface-based terahertz phase shifter, which relates to the technical field of terahertz propagation and phase modulation and is composed of a plurality of terahertz units of rectangular resonant rings. Each resonance unit comprises a dielectric substrate PI (polyimide) and a metal structure. The metal structure in each resonance unit is composed of a plurality of metal strips. According to the terahertz phase shifter based on the Huygens metasurface, the stable high transmission coefficient can be achieved within the working frequency band of 0.4-1.0 THz, meanwhile, the transmission phase of the resonance unit covers the wide adjustment range of over 350 degrees, and therefore flexible and accurate terahertz wave phase adjustment and control are achieved. The structure is simple and fixed, the manufacturing process is mature and reliable, and important application prospects are achieved in the fields of terahertz components, terahertz imaging, terahertz communication and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of terahertz propagation and phase modulation, and particularly relates to a terahertz phase shifter based on a Huygens super surface. BACKGROUND

[0002] Terahertz (THz) technology has broad application prospects in the fields of security imaging, satellite-ground communication, industrial non-destructive testing, etc. due to its unique penetration, low energy and high resolution characteristics. It is an important driving force for promoting the upgrading of the technology industry. With the development of terahertz systems towards high integration, high performance and low cost, the performance of the phase control module as a core component directly determines the overall performance of the system. Existing terahertz phase shifting techniques have problems such as low phase shifting amount (usually not more than 180°), large insertion loss, poor environmental adaptability, etc., which limit the large-scale application of terahertz technology. Huygens super surface has the advantages of compact structure, large phase variation, small insertion loss, high transmittance, strong compatibility, etc. The terahertz phase shifter based on it can effectively solve the above problems and provide key technical support for the practical application of terahertz technology.

[0003] The inventor's prior application CN119481719A, a terahertz beam steering device based on a Huygens super surface, is composed of five resonant units with different shapes and sizes in the horizontal direction, and the vertical direction is a periodic arrangement of identical units. Each resonant unit includes a dielectric substrate PI (polyimide) and a metal structure. The metal structure in each resonant unit is composed of multiple metal strips, and a metal opening is designed between specific metal strips in each metal structure.

[0004] The prior application (CN119481719A) has defects such as complex structure (five resonant units with different shapes and sizes need to be horizontally spliced, long design iteration and difficult to control consistency in mass production), energy loss caused by metal openings, phase control of only about 300° (which cannot meet the high precision requirement), narrow working frequency band (focusing on 0.8618 THz, limited scene adaptation), poor material adaptation (dielectric constant of dielectric substrate PI is 3.9, which is too high, copper is used for metal, which has large transmission loss in wide frequency band and weak environmental adaptability). The present application simplifies the structure for mass production by periodically arranging rectangular resonant ring units with a unified structure, eliminates the metal opening, uses a closed rectangular resonant ring with front and back symmetry to reduce loss (transmission coefficient is stable at more than 0.6 in the 0.8-1.0 THz frequency band), expands the phase control to more than 350°, optimizes the materials (dielectric constant of PI is 2.68, and gold is used for metal) and structure parameters, widens the working frequency band to 0.4-1.0 THz to improve transmission efficiency and scene compatibility, and focuses on the phase control core. By covering a wide phase, the "frequency-phase" direct matching is realized, and the beam pointing direction can be flexibly adjusted without unit splicing. The function is more focused, and the control efficiency is higher. SUMMARY

[0005] The present application aims to solve the above problems of the prior art. A terahertz phase shifter based on a Huygens super surface is proposed. The technical scheme of the present application is as follows:

[0006] A terahertz phase shifter based on a Huygens super surface, which is composed of a plurality of rectangular resonant ring terahertz unit periodic arrangement; the rectangular resonant ring terahertz unit contains a dielectric substrate (1) and two groups of metal structures, the metal structure includes the first group of metal structure and the second group of metal structure, the first group of metal structure is arranged on the front side of the dielectric substrate (1) above the position, the second group of metal structure is symmetrically arranged on the back side of the dielectric substrate (1) below the position, the first group of metal structure includes the first metal strip (2), the second metal strip (3), the third metal strip (4) and the fourth metal strip (5) four metal strips, wherein the first metal strip (2) and the third metal rod (4) are arranged in parallel, the second metal rod (3) and the fourth metal rod (5) are arranged vertically between the first metal rod (2) and the third metal rod (4), and the second metal rod (3) and the fourth metal rod (5) are arranged in parallel; the length of the first metal rod (2) and the third metal strip (4) is the same as the length of the dielectric substrate (1).

[0007] The second group of metal structure includes the fifth metal strip (6), the sixth metal strip (7), the seventh metal strip (8) and the eighth metal strip (9), the fifth metal strip (6) and the sixth metal strip (7) are arranged in parallel, the seventh metal strip (8) and the eighth metal strip (9) are arranged vertically between the fifth metal strip (6) and the sixth metal strip (7), and the seventh metal strip (8) and the eighth metal strip (9) are arranged in parallel; the length of the fifth metal strip (6) and the sixth metal strip (7) is the same as the length of the dielectric substrate (1).

[0008] Further, the shape of the dielectric substrate (1) of each unit is a square with a side length of 224 um.

[0009] Further, the width of the metal strip in the metal structure is 19 um, the left side distance of the second metal strip (3) and the eighth metal strip (9) to the left side of the substrate is 46.5 um, the right side distance of the fourth metal strip (5) and the seventh metal strip (8) to the right side of the substrate is 46.5 um, the width between the second metal strip (3) and the fourth metal strip (5) is 93 um, the width between the seventh metal strip (8) and the eighth metal strip (9) is 93 um, the length of the first metal rod (2), the third metal rod (4), the fifth metal strip (6) and the sixth metal strip (7) is 224 um, the distance between the first metal strip (2) and the top of the dielectric substrate is 10 um, and the distance between the sixth metal strip (7) and the bottom of the dielectric substrate is 10 um.

[0010] Further, the medium substrate (1) is a PI (polyimide) substrate, the dielectric constant is 2.68, and the thickness is 50 um.

[0011] Further, the material of each group of metal structure is gold, the conductivity is 4.561*107 S / m, and the thickness is 0.2 um.

[0012] Further, in the working frequency band of 0.8-1.0 THz, the transmission coefficient of the terahertz phase shifter can be stably kept above 0.6.

[0013] Further, in the frequency range of 0.4-1.0 THz, the phase of the outgoing terahertz wave of the terahertz phase shifter realizes a continuous change from about-50° to about-400°, and the phase control range covers more than 350°.

[0014] The advantages and beneficial effects of the present application are as follows:

[0015] 1. The present application has a higher transmission coefficient in the working frequency band of 0.8-1.0 THz, and compared with the traditional terahertz phase shifter, the loss is smaller, and the influence on the subsequent work is smaller;

[0016] 2. The present application has a wide phase change coverage of more than 350° in the working frequency band of 0.4-1.0 THz, so the present application can directly match the phase output of the corresponding frequency band according to the required terahertz beam deflection requirement, and the beam pointing is flexible and adjustable;

[0017] 3. The metal layer pattern in the present application is simple in geometry, the processing technology is mature, the manufacturing cost is low, and it is easy to integrate;

[0018] 4. The material property of the present application is flexible, and has high universality.

[0019] 5. The present application adopts a non-opening rectangular resonant ring structure, instead of the split ring, opening structure or multi-layer heterostructure of the traditional Huygens super surface, and the structure is more compact and has no energy leakage channel.

[0020] 6. The present application does not need to optimize parameters for different units separately, reduces the simulation and processing iteration period, and reduces the research and development cost;

[0021] 7. The unit size of the present application is uniform, and can be mass-produced through mature micro-nano processing technology, avoiding the precision deviation problem of multi-specification units;

[0022] 8. The present application adopts a closed resonant ring structure without metal opening, reduces the energy leakage of electromagnetic waves at the opening, and lays a structural foundation for high transmission coefficient. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1This is a front view of the rectangular resonant unit according to a preferred embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the reverse side of the rectangular resonant unit of the present invention;

[0025] Figure 3 This is a right view of the rectangular resonant unit of the present invention;

[0026] Figure 4 This is a transmission coefficient diagram of the rectangular resonant unit of the present invention.

[0027] Figure 5 This is the phase diagram of the rectangular resonant unit of the present invention.

[0028] Figure 6 This is a physical image of the metasurface of the present invention.

[0029] The attached diagram shows the markings and corresponding component names:

[0030] 1-Dielectric substrate, 2-First metal strip, 3-Second metal strip, 4-Third metal strip, 5-Fourth metal strip, 6-Fifth metal strip, 7-Sixth metal strip, 8-Seventh metal strip, 9-Eighth metal strip. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of the present invention.

[0032] The technical solution of the present invention to solve the above-mentioned technical problems is:

[0033] like Figures 1 to 6 As shown, a terahertz phase shifter based on a Huygens metasurface is disclosed. The terahertz phase shifter is composed of several rectangular resonant ring terahertz units. Each rectangular resonant ring terahertz unit includes a dielectric substrate 1 and two sets of metal structures. The metal structures include a first set of metal structures and a second set of metal structures. The first set of metal structures is positioned above the front side of the dielectric substrate 1, and the second set of metal structures is symmetrically positioned below the back side of the dielectric substrate 1. The first set of metal structures includes four metal strips: a first metal strip 2, a second metal strip 3, a third metal strip 4, and a fourth metal strip 5. The first metal strip 2 and the third metal strip 4 are arranged parallel to each other, and the second metal strip 3 and the fourth metal strip 5 are perpendicularly arranged between the first metal strip 2 and the third metal strip 4, and are also parallel to each other. The lengths of the first metal strip 2 and the third metal strip 4 are the same as the length of the dielectric substrate 1.

[0034] The second group of metal structures includes a fifth metal strip 6, a sixth metal strip 7, a seventh metal strip 8, and an eighth metal strip 9. The fifth metal strip 6 and the sixth metal strip 7 are arranged in parallel, and the seventh metal strip 8 and the eighth metal strip 9 are arranged perpendicularly between the fifth metal strip 6 and the sixth metal strip 7, and the seventh metal strip 8 and the eighth metal strip 9 are arranged in parallel. The lengths of the fifth metal strip 6 and the sixth metal strip 7 are the same as the length of the dielectric substrate 1.

[0035] Preferably, each unit medium substrate 1 is a square with a side length of 224 μm.

[0036] Preferably, the width of the metal strips in the metal structure is 19 μm. The left side of the second metal strip 3 and the eighth metal strip 9 is 46.5 μm away from the left side of the substrate, and the right side of the fourth metal strip 5 and the seventh metal strip 8 is 46.5 μm away from the right side of the substrate. The width between the second metal strip 3 and the fourth metal strip 5 is 93 μm, and the width between the seventh metal strip 8 and the eighth metal strip 9 is 93 μm. The length of the first metal rod 2, the third metal rod 4, the fifth metal strip 6, and the sixth metal strip 7 is 224 μm. The first metal strip 2 is 10 μm away from the top of the dielectric substrate, and the sixth metal strip 7 is 10 μm away from the bottom of the dielectric substrate.

[0037] Preferably, the dielectric substrate 1 is a PI polyimide substrate with a dielectric constant of 2.68 and a thickness of 50 μm.

[0038] Preferably, the metal structure material of each group is gold, with an electrical conductivity of 4.561×107S / m and a thickness of 0.2um.

[0039] Preferably, within the operating frequency band of 0.8~1.0THz, the transmission coefficient of the terahertz phase shifter can be stably maintained above 0.6.

[0040] Preferably, within a frequency range of 0.4 to 1.0 THz, the phase of the emitted terahertz wave from the terahertz phase shifter achieves a continuous change from approximately -50° to approximately -400°, with a phase adjustment range covering over 350°.

[0041] Within the operating frequency band of 0.8~1.0THz, the transmission coefficient of the resonant unit can be stably maintained above 0.6, indicating that the present invention has good terahertz wave transmission efficiency.

[0042] Within a frequency range of 0.4 to 1.0 THz, the phase of the emitted terahertz wave from the resonant unit achieves a continuous change from approximately -50° to approximately -400°, with a phase modulation range covering over 350°. This wide phase modulation range enables flexible and stable terahertz wave phase modulation.

[0043] The terahertz phase shifter based on Huygens metasurface provided in this invention can achieve a stable high transmission coefficient in the 0.4~1.0THz operating frequency band, while ensuring that the transmission phase of the resonant unit covers a wide adjustment range of over 350°. This enables flexible and precise terahertz wave phase control. This invention has strong design adaptability for phase control, and the structure is fixed without additional modifications. The process is mature and reliable, easy to mass-produce, and cost-controllable. It has broad application prospects in future terahertz communication, radar detection, and other systems.

[0044] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions.

[0045] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] The above embodiments should be understood as illustrative only and not as limiting the scope of protection of the present invention. After reading the description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. A terahertz phase shifter based on a Huygens metasurface, characterized in that, It is composed of a periodically arranged terahertz unit of several rectangular resonant rings; the terahertz unit of the rectangular resonant ring includes a dielectric substrate (1) and two sets of metal structures. The metal structures include a first set of metal structures and a second set of metal structures. The first set of metal structures is located above the front of the dielectric substrate (1), and the second set of metal structures is symmetrically located below the back of the dielectric substrate (1). The first set of metal structures includes four metal strips: a first metal strip (2), a second metal strip (3), a third metal strip (4), and a fourth metal strip (5). The first metal strip (2) and the third metal strip (4) are arranged in parallel, and the second metal strip (3) and the fourth metal strip (5) are arranged vertically between the first metal strip (2) and the third metal strip (4), and the second metal strip (3) and the fourth metal strip (5) are arranged in parallel. The lengths of the first metal strip (2) and the third metal strip (4) are the same as the length of the dielectric substrate (1). The second group of metal structures includes a fifth metal strip (6), a sixth metal strip (7), a seventh metal strip (8), and an eighth metal strip (9). The fifth metal strip (6) and the sixth metal strip (7) are arranged in parallel, and the seventh metal strip (8) and the eighth metal strip (9) are arranged vertically between the fifth metal strip (6) and the sixth metal strip (7), and the seventh metal strip (8) and the eighth metal strip (9) are arranged in parallel. The lengths of the fifth metal strip (6) and the sixth metal strip (7) are the same as the length of the dielectric substrate (1).

2. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, Each unit medium substrate (1) is a square with a side length of 224 μm.

3. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, The width of the metal strips in the metal structure is 19um. The second metal strip (3) and the eighth metal strip (9) are 46.5um away from the left side of the substrate. The fourth metal strip (5) and the seventh metal strip (8) are 46.5um away from the right side of the substrate. The width between the second metal strip (3) and the fourth metal strip (5) is 93um. The width between the seventh metal strip (8) and the eighth metal strip (9) is 93um. The length of the first metal rod (2), the third metal rod (4), the fifth metal strip (6), and the sixth metal strip (7) is 224um. The first metal strip (2) is 10um away from the top of the medium substrate. The sixth metal strip (7) is 10um away from the bottom of the medium substrate.

4. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, The dielectric substrate (1) is a PI (polyimide) substrate with a dielectric constant of 2.68 and a thickness of 50 μm.

5. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, Each group of metal structures is made of metallic gold, with an electrical conductivity of 4.561×107S / m and a thickness of 0.2um.

6. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, Within the operating frequency band of 0.8~1.0THz, the transmission coefficient of the terahertz phase shifter can be stably maintained above 0.

6.

7. A terahertz phase shifter based on a Huygens metasurface according to claim 1, characterized in that, Within a frequency range of 0.4 to 1.0 THz, the phase of the emitted terahertz wave from the terahertz phase shifter achieves a continuous change from approximately -50° to approximately -400°, with a phase adjustment range covering over 350°.

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