Multifunctional transmission polarization conversion metasurface suitable for S wave band

Abstract

The utility model discloses a multifunctional transmission polarization conversion metasurface suitable for an S wave band, the metasurface is provided with a sandwich layered composite structure, the sandwich layered composite structure comprises an upper layer and a lower layer which are metal grid structures integrated with PIN diodes, and a middle layer which is a metal strip array periodically arranged at an inclination angle of 45 degrees, and dielectric substrates are arranged between the upper layer and the middle layer and between the middle layer and the lower layer. The metasurface has broadband working and dynamic reconfigurable characteristics, and has wide application potential in the fields of communication, radar, satellite systems, electronic countermeasures and the like.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the microwave and radio frequency technical field, concretely relates to a kind of multifunctional transmission polarized conversion metasurface suitable for S wave band. BACKGROUND

[0002] Metasurface is a kind of two-dimensional structural material designed artificially, its thickness is far less than working wavelength, and it is usually arranged by a series of subwavelength scale micro-nano structural units according to specific coding rule.Metasurface can control the wavefront characteristics of incident wave with extremely high precision due to the design of these micro-nano units, especially in polarization conversion, propagation phase modulation and asymmetric transmission, etc., and it shows unprecedented flexibility and adjustability.These characteristics endow metasurface with excellent control ability in optical and electromagnetic wave field, so that it becomes a kind of extremely potential technology in changing light wave propagation characteristics and realizing complex optical function.

[0003] In particular, metasurface has unique advantages in polarization conversion.This advantage makes metasurface show wide application prospect in multiple frontier fields such as optoelectronic devices, sensors, display technology, optical imaging and next-generation communication technology.However, although a series of remarkable achievements have been made, existing metasurface technology still faces many challenges.For example, the working bandwidth of many metasurface designs is limited, showing narrowband characteristics;In addition, the functional integration degree of existing metasurface is usually low, and multiple functions cannot be realized simultaneously in a small space;At the same time, the material loss problem also causes not small limitation to the practical application of metasurface.Therefore, how to break through the existing bottleneck in expanding working bandwidth, improving integration degree and reducing loss, etc., is still the core challenge in metasurface research. UTILITY MODEL CONTENT

[0004] In view of the above problems, the utility model provides a kind of multifunctional transmission polarized conversion metasurface suitable for S wave band, solves the multifunctional transmission polarized conversion of metasurface, and simultaneously has broadband characteristics.

[0005] The utility model solves the above technical problem using the following technical scheme:

[0006] The utility model provides a kind of multifunctional transmission polarized conversion metasurface suitable for S wave band,

[0007] A kind of multifunctional transmission polarized conversion metasurface suitable for S wave band, it is characterized in that, the metasurface has sandwich layered composite structure, and the structure includes: the metal grid structure of integrated PIN diode for upper layer and lower layer, the metal strip array periodically arranged with 45° inclination angle for middle layer, wherein, upper layer and middle layer and middle layer and lower layer are all provided with dielectric substrate between.

[0008] Further, the upper layer and the lower layer comprise a central patch, the central patch is square, the side length is 6mm, four square metal strips are arranged around the central patch, the length of the four square metal strips is 5mm, and the width is 0.4mm; and a PIN diode is arranged to connect the central patch and the four metal strips.

[0009] Further, the PIN diode used is NXP BA591; when the PIN diode is turned off, the equivalent capacitance is 0.65 pF, and when the PIN diode is turned on, the equivalent resistance is 0.36Ω.

[0010] Further, the width of the metal strip arranged periodically at the 45°inclination angle of the intermediate layer is 2.5mm, and the strip interval is 1mm.

[0011] Further, the medium substrate adopts Rogers RT5880, the relative dielectric constant is 2.2, and the loss tangent is 0.0009.

[0012] Further, the period of the medium substrate is 10mm, and the thickness is 20mm.

[0013] Compared with the prior art, the advantages of the utility model lie in that:

[0014] 1. The utility model realizes the multifunctional transmission polarization conversion of the S wave band, the insertion loss and the bandwidth index of the super surface are better, and four kinds of electromagnetic working modes can be realized by adjusting the bias state of the PIN diode: the first polarization separation mode realizes the duplex transmission of x polarization wave reflection / y polarization wave transmission, the second polarization separation mode realizes the duplex transmission of y polarization wave reflection / x polarization wave transmission; the third polarization conversion mode realizes the polarization conversion of x polarization wave incidence-y polarization wave emission, and the fourth polarization conversion mode realizes the polarization conversion of y polarization wave incidence-x polarization wave emission. The modeling simulation result shows that: in the polarization separation mode, the device insertion loss is less than 3 dB in the S wave band (2-4 GHz) full frequency band; the cross polarization conversion efficiency is more than 92% in the polarization conversion mode, and the relative bandwidth reaches 106% (1.6-5.2 GHz).

[0015] 2. The utility model has polarization stability characteristics.

[0016] 3. The utility model structure is easy to realize, and the processing test of the utility model is convenient. DETAILED DESCRIPTION

[0017] Figure 1 It is a unit structure side view of the multifunctional transmission polarization conversion super surface of the utility model;

[0018] Figure 2The upper and lower layer structure diagram of the multifunctional transmission polarization conversion metasurface of the utility model;

[0019] Figure 3 The middle layer structure diagram of the multifunctional transmission polarization conversion metasurface of the utility model;

[0020] Figure 4 The S parameter of the multifunctional transmission polarization conversion metasurface of the utility model working in the polarization separation mode;

[0021] Figure 5 The S parameter of the multifunctional transmission polarization conversion metasurface of the utility model working in the polarization separation mode under another condition;

[0022] Figure 6 The S parameter of the multifunctional transmission polarization conversion metasurface of the utility model working in the polarization conversion mode;

[0023] Figure 7 The S parameter of the multifunctional transmission polarization conversion metasurface of the utility model working in the polarization conversion mode under another condition;

[0024] Figure 8 The PCR of the multifunctional transmission polarization conversion metasurface of the utility model working in the polarization conversion mode. DETAILED DESCRIPTION

[0025] In order to more clearly and clearly illustrate the purpose, technical scheme and advantages of the utility model, the utility model is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0026] As Figure 1 , 2, 3 respectively are the unit structure side view, upper and lower layer structure diagram and middle layer structure diagram of the utility model. The structure is a sandwich layered composite structure: the upper layer 1 and the lower layer 2 are metal grid structures integrated with PIN diodes, and the middle layer 3 is a metal strip array periodically arranged at an inclination angle of 45°. Wherein, the dielectric substrate 4 is arranged between the upper layer and the middle layer and between the middle layer and the lower layer. The upper layer and the lower layer include a central patch 5, the central patch is square, the side length is 6mm, four square metal strips 6 are provided around the central patch, the length of the square metal strip around is 5mm, and the width is 0.4mm, and the PIN diode 7 connects the central patch with the four metal strips. The on-off of the PIN diode is controlled by the bias line, and the switching of the polarization separation and polarization conversion functions in the S wave band is realized.

[0027] The PIN diode used in the embodiment is NXP BA591; the PIN diode is equivalent to a capacitor of 0.65 pF when turned off and a resistor of 0.36 Ω when turned on.

[0028] The metal strips of the intermediate layer are arranged periodically at an inclination angle of 45° in the embodiment, and the width of the metal strips is 2.5 mm, and the interval between the metal strips is 1 mm.

[0029] With the above structure, the utility model can realize four electromagnetic working modes: in the first polarization separation mode, the utility model realizes the duplex transmission of x polarization wave reflection / y polarization wave transmission, in the second polarization separation mode, the utility model realizes the duplex transmission of y polarization wave reflection / x polarization wave transmission; in the third polarization conversion mode, the utility model realizes the polarization conversion of x polarization wave incidence-y polarization wave emission, and in the fourth polarization conversion mode, the utility model realizes the polarization conversion of y polarization wave incidence-x polarization wave emission. The modeling simulation result shows that in the polarization separation mode, the device has an insertion loss of less than 3 dB in the S waveband (2-4 GHz) full frequency band, and the mode isolation degree is better than 10 dB; in the polarization conversion mode, the cross polarization conversion efficiency is more than 92%, and the relative bandwidth reaches 106% (1.6-5.2 GHz). The super surface has wideband operation and dynamic reconfigurable characteristics, and has wide application potential in the fields of communication, radar, satellite system and electronic countermeasure.

[0030] The metal grid structure material of the upper layer of the structure is selected from metal copper which has good conductivity and stable properties.

[0031] The dielectric substrate adopts Rogers RT5880, has a relative dielectric constant of 2.2, a loss tangent of 0.0009, a period of 10 mm and a thickness of 20 mm. The metal grid structure of the upper layer is printed on the upper side of the dielectric substrate.

[0032] The multifunctional transmission polarization conversion super surface suitable for the S waveband is implemented by using a full-wave simulation method. Figure 4 When the upper layer y-direction diode is turned on and the lower layer x-direction diode is turned on, the x polarization electromagnetic wave is converted into a y polarization wave, and the 3 dB bandwidth covers 1.58-5.21 GHz. The transmission coefficient of the x polarization wave is always lower than -10 dB in the S waveband (2-4 GHz), which indicates that the incident x polarization wave is basically converted into a y polarization wave, and the good polarization conversion performance is verified. Figure 5 When the upper layer x-direction diode is turned on and the lower layer y-direction diode is turned on, the simulation result shows that in the 1.57-5.20 GHz frequency band, the y polarization wave is converted into an x polarization wave, and the insertion loss is always lower than 3 dB; at the same time, the transmission coefficient of the y polarization wave is kept to be less than -10 dB in the S waveband, which further verifies the bidirectional polarization conversion capability of the structure. Figure 6For when the upper layer x-direction diode is turned on, the lower layer x-direction diode is turned on, the reflection coefficient of the x-polarized wave and the transmission coefficient of the y-polarized wave. In the target S wave band, the x-polarized reflection coefficient and the y-polarized transmission coefficient are both better than -3 dB. Similarly, Figure 7 For when the upper layer y-direction diode is turned on, the lower layer y-direction diode is turned on, the y-polarized reflection coefficient and the x-polarized transmission coefficient are also better than -3 dB. The above results show that the structure can realize high-efficiency polarization control: when the upper and lower diodes are turned on in different directions, the dominant polarization conversion is realized, and when the upper and lower diodes are turned on in the same direction, polarization separation is realized by suppressing the cross-polarization component. Figure 8 Further disclosed is the super surface polarization conversion rate (PCR), and it can be seen that the polarization conversion rate is above 92%.

[0033] The above only is the preferred embodiment of the utility model patent, and does not use to limit the utility model patent. It should be pointed out: any improvement and decoration within the spirit and principles of the utility model patent should be regarded as the protection scope of the utility model patent.

Claims

1. A multifunctional transmissive polarization conversion metasurface suitable for S-band, characterized in that, The super surface has a sandwich layer composite structure, which comprises: upper and lower layers of metal grid structure integrated with PIN diodes, and an intermediate layer of metal strip array periodically arranged at an inclination angle of 45°.

2. The multifunctional transmissive polarization conversion metasurface suitable for S-band of claim 1, wherein, The upper and lower layers comprise a central patch which is square with a side length of 6 mm, and four square metal strips around the central patch, each with a length of 5 mm and a width of 0.4 mm, and the PIN diode connects the central patch and the four metal strips.

3. The multifunctional transmissive polarization conversion metasurface suitable for S-band of claim 1 or 2, characterized in that, The PIN diode uses a model of NXP BA591; when the PIN diode is off, it is equivalent to a capacitor of 0.65 pF, and when the PIN diode is on, it is equivalent to a resistor of 0.36Ω.

4. The multifunctional transmissive polarization conversion metasurface suitable for S-band of claim 1 or 2, characterized in that, The metal strips of the intermediate layer are periodically arranged at an inclination angle of 45°, with a width of 2.5 mm and a strip spacing of 1 mm.

5. The multifunctional transmissive polarization conversion metasurface suitable for S-band according to claim 1, characterized in that, The dielectric substrate uses Rogers RT5880, with a relative dielectric constant of 2.2 and a loss tangent of 0.0009.

6. The multifunctional transmissive polarization conversion metasurface suitable for S-band according to claim 1 or 5, characterized in that, The period of the dielectric substrate is 10 mm, and the thickness is 20 mm.

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