阅读说明：本技术 一种双频段极化敏感带阻滤波器及其制备方法 (Dual-band polarization sensitive band-stop filter and preparation method thereof ) 是由 阮久福 孟子凡 邹睿智 兰凤 于 2021-09-03 设计创作，主要内容包括：本发明公开了一种双频段极化敏感带阻滤波器及其制备方法,滤波器包括：M×N个由谐振层及介质基底组成的相同单元,谐振层由周期性排列的E字型阵列组成,谐振层和介质基底的材料分别是Ti3C2Tx和聚对苯二甲酸乙二醇酯(PET)；制备方法为依次在基底上旋涂光刻胶、光刻、旋涂Ti3C2Tx分散液及去除光刻胶胶膜。本发明滤波器结构简单,具有良好的频率选择性,且对不同的极化电磁波具有不同的频率响应；制备方法工艺简单,易于实现。(The invention discloses a dual-band polarization sensitive band-stop filter and a preparation method thereof, wherein the filter comprises: m x N identical units composed of resonance layer and medium substrate, the resonance layer is composed of periodically arranged E-shaped array, the materials of resonance layer and medium substrate are Ti3C2Tx and polyethylene terephthalate (PET); the preparation method comprises the steps of spin coating photoresist on a substrate, photoetching, spin coating Ti3C2Tx dispersion liquid and removing the photoresist film in sequence. The filter has simple structure, good frequency selectivity and different frequency responses to different polarized electromagnetic waves; the preparation method has simple process and is easy to realize.)

1. A dual-band polarization sensitive band-stop filter and a preparation method thereof are characterized in that: the filter is of a periodic structure, M is multiplied by N units, adjacent units have no space, M, N is a positive integer greater than or equal to 2, and M can be smaller than, equal to or larger than N;

the unit comprises a resonance layer and a substrate; along the incident direction of the wave, a resonance layer and a substrate are arranged in sequence;

the side length of the unit is 4 cm;

the material of the resonance layer is Ti₃C₂T_xMXene; the material of the substrate is polyethylene terephthalate (PET);

the thickness of the resonance layer is between 2um and 10 um;

the resonance layer comprises an E-shaped patch, a first right trapezoid strip, a second right trapezoid strip, a third right trapezoid strip and a fourth right trapezoid strip; the E-shaped patch consists of three transverse edges and 1 vertical edge; the three transverse sides are equal in size, namely the length and the width of the three transverse sides are equal; the first right trapezoid strip and the third right trapezoid strip are horizontally arranged above and below the E-shaped patch and connected with the lower bottom of the E-shaped patch, the second right trapezoid strip and the fourth right trapezoid strip are vertically arranged on the left side of the E-shaped patch, and the lower bottom of the E-shaped patch is connected with the E-shaped patch; the lower bottoms of the first right-angle trapezoidal strips are connected with the right-angle sides of the second right-angle trapezoidal strips, and the lower bottoms of the third right-angle trapezoidal strips are connected with the right-angle sides of the fourth right-angle trapezoidal strips; the first right-angle trapezoid strip and the third right-angle trapezoid strip are as large as each other, and the second right-angle trapezoid strip and the fourth right-angle trapezoid strip are as large as each other;

the length of 3 transverse edges of the E-shaped patch is 1.85cm, the width of the E-shaped patch is 0.40cm, the vertical edge of the E-shaped patch is 2.80cm, and the width of the E-shaped patch is 0.35 cm;

the upper bottoms of the first right trapezoid strips and the third right trapezoid strips are 0.85cm, the lower bottoms of the first right trapezoid strips and the third right trapezoid strips are 1.05cm, and the height of the first right trapezoid strips and the third right trapezoid strips is 0.25 cm;

the upper bottoms of the second right-angle trapezoidal strip and the fourth right-angle trapezoidal strip are 0.65cm, the lower bottoms of the second right-angle trapezoidal strip and the fourth right-angle trapezoidal strip are 0.80cm, and the height of the second right-angle trapezoidal strip is 0.25 cm;

the filter has a resonance depth of about 30dB around two frequencies of 2.4GHz and 4.9GHz, and has a stop band around the two frequencies; the filter has insertion loss of more than-10 dB to electromagnetic waves in the ranges of 2.2-2.55GHz and 4.83-4.99 GHz; the filter has insertion loss of more than-20 dB to electromagnetic wave in the range of 2.33-2.43GHz and 4.89-4.93GHz,

the filter has different frequency responses to electromagnetic waves with different polarizations, namely TE polarized electromagnetic waves and TM polarized electromagnetic waves;

firstly, spin-coating 12um thick positive photoresist on a polyethylene terephthalate (PET) substrate to form a glue film with uniform thickness;

secondly, sequentially exposing and developing to obtain a required cluster plan;

then, spin-coating the dispersion liquid, and standing; baking for 3 minutes after the liquid components in the dispersion liquid are evaporated and the substrate is completely provided with the MXene solid film; the thickness of the MXene film is less than or equal to 10 um; coating pentanone and ethylene glycol on a substrate in sequence, and then standing for finishing natural evaporation of the solvents in the two solutions;

finally, removing the positive photoresist to obtain the dual-band polarization sensitive band-stop filter;

the developing solution is a 3% potassium borate solution diluted by AZ400K developing solution and water according to the volume ratio of 1: 4;

the etching solution for removing the positive photoresist is a solution prepared according to the mixture ratio of 1g of ammonium oxalate, 1.66g of glycine, 0.005g of dodecylbenzene yellow, 1ml of 25% hydrogen peroxide and 100ml of water solution;

the optimal time for removing the positive photoresist is 11 minutes.

2. The dual band polarization sensitive band reject filter of claim 1, wherein the substrate has a thickness in the range of 50-200 um.

3. The method of making a dual band polarization sensitive band reject filter according to claim 1, wherein the positive photoresist is AZ 4562.

Technical Field

The invention relates to the technical field of wireless communication devices and micromachining, in particular to a dual-band polarization sensitive band-stop filter and a preparation method thereof.

Background

The filter is used as a frequency selection device and has the main function of blocking unwanted signals in the field of wireless communication, so that signals with target frequencies pass through, and the signal-to-noise ratio is improved to improve the communication effect. The traditional filter is usually manufactured by Printed Circuit Board (PCB) technology, i.e. 35um thick copper is printed on a dielectric substrate, and the filter manufactured by the method is difficult to meet the performance requirements of being light, thin, flexible, and therefore is not suitable for portable and wearable applications. With the rapid development of wireless communication and internet of things technologies, the demand for light, thin, portable and wearable electronic devices is increasing day by day. Therefore, the design of a flexible, light and thin high-performance filter has important significance for the development and the practicability of wearable electronic equipment. In addition, most of the existing filters for wireless communication can only realize single-frequency filtering. With the increase of communication frequency, the available communication frequency band is increased, and the application range of the dual-band device is wider. In addition, most of the existing filter devices are of symmetrical structures and are insensitive to polarization. In some specific cases, it is necessary to distinguish between two different polarized electromagnetic waves, TE and TM.

Based on the above problems, how to design a thin, light, flexible and wearable dual-band polarization sensitive band-stop filter for a wireless local area network frequency band becomes an urgent problem to be solved in the field.

Disclosure of Invention

Therefore, a dual-band polarization sensitive band-stop filter which is simple in structure and easy to implement is needed.

In order to achieve the purpose, the invention provides the following scheme:

a dual-band polarization sensitive band-stop filter and a preparation method thereof are characterized in that: the filter is of a periodic structure, M is multiplied by N units, adjacent units have no space, M, N is a positive integer greater than or equal to 2, and M can be smaller than, equal to or larger than N;

the unit comprises a resonance layer and a substrate; along the incident direction of the wave, a resonance layer and a substrate are arranged in sequence;

the side length of the unit is 4 cm;

the material of the resonance layer is Ti₃C₂T_xMXene; the material of the substrate is polyethylene terephthalate (PET);

the thickness of the resonance layer is between 2um and 10 um;

the resonance layer comprises an E-shaped patch, a first right trapezoid strip, a second right trapezoid strip, a third right trapezoid strip and a fourth right trapezoid strip; the E-shaped patch consists of three transverse edges and 1 vertical edge; the three transverse sides are equal in size, namely the length and the width of the three transverse sides are equal; the first right trapezoid strip and the third right trapezoid strip are horizontally arranged above and below the E-shaped patch and connected with the lower bottom of the E-shaped patch, the second right trapezoid strip and the fourth right trapezoid strip are vertically arranged on the left side of the E-shaped patch, and the lower bottom of the E-shaped patch is connected with the E-shaped patch; the lower bottoms of the first right-angle trapezoidal strips are connected with the right-angle sides of the second right-angle trapezoidal strips, and the lower bottoms of the third right-angle trapezoidal strips are connected with the right-angle sides of the fourth right-angle trapezoidal strips; the first right-angle trapezoid strip and the third right-angle trapezoid strip are as large as each other, and the second right-angle trapezoid strip and the fourth right-angle trapezoid strip are as large as each other;

the length of 3 transverse edges of the E-shaped patch is 1.85cm, the width of the E-shaped patch is 0.40cm, the vertical edge of the E-shaped patch is 2.80cm, and the width of the E-shaped patch is 0.35 cm;

the upper bottoms of the first right trapezoid strips and the third right trapezoid strips are 0.85cm, the lower bottoms of the first right trapezoid strips and the third right trapezoid strips are 1.05cm, and the height of the first right trapezoid strips and the third right trapezoid strips is 0.25 cm;

the upper bottoms of the second right-angle trapezoidal strip and the fourth right-angle trapezoidal strip are 0.65cm, the lower bottoms of the second right-angle trapezoidal strip and the fourth right-angle trapezoidal strip are 0.80cm, and the height of the second right-angle trapezoidal strip is 0.25 cm;

the filter has a resonance depth of about 30dB around two frequencies of 2.4GHz and 4.9GHz, and has a stop band around the two frequencies; the filter has insertion loss of more than-10 dB to electromagnetic waves in the ranges of 2.2-2.55GHz and 4.83-4.99 GHz; the filter has insertion loss of more than-20 dB to electromagnetic waves in the ranges of 2.33-2.43GHz and 4.89-4.93 GHz.

The filter has different frequency responses to differently polarized electromagnetic waves, i.e., TE polarized and TM polarized electromagnetic waves.

Firstly, spin-coating 12um thick positive photoresist on a polyethylene terephthalate (PET) substrate to form a glue film with uniform thickness;

secondly, sequentially exposing and developing to obtain a required cluster plan;

then, spin-coating the dispersion liquid, and standing; baking for 3 minutes after the liquid components in the dispersion liquid are evaporated and the substrate is completely provided with the MXene solid film; the thickness of the MXene film is less than or equal to 10 um; coating pentanone and ethylene glycol on a substrate in sequence, and then standing for finishing natural evaporation of the solvents in the two solutions;

finally, removing the positive photoresist to obtain the dual-band polarization sensitive band-stop filter;

the developing solution is a 3% potassium borate solution diluted by AZ400K developing solution and water according to the volume ratio of 1: 4;

the etching solution for removing the positive photoresist is a solution prepared according to the mixture ratio of 1g of ammonium oxalate, 1.66g of glycine, 0.005g of dodecylbenzene yellow, 1ml of 25% hydrogen peroxide and 100ml of water solution;

the optimal time for removing the positive photoresist is 11 minutes.

Optionally, the thickness of the substrate ranges from 50 to 200 um.

Optionally, the positive photoresist is AZ 4562.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a dual-band polarization sensitive band-stop filter and a preparation method thereof, wherein the filter is flexible by using a polyethylene terephthalate (PET) substrate; the Ti3C2Tx Mxene material with small density and metal-like property is used for replacing metal as a resonance layer material, so that the filter has the structural characteristic of lightness and thinness on the premise of not losing the filtering performance; the filter has two working frequency bands, has simple and novel structure, good frequency selectivity and different frequency responses to different polarized electromagnetic waves; the preparation method disclosed by the invention is simple in process, does not need complex and expensive processing equipment, and is easy to realize.

Drawings

FIG. 1 is a schematic structural diagram of a single unit of a dual-band polarization-sensitive band-stop filter according to an embodiment of the present invention;

FIG. 2 is a front view of a 4 x 4 element array of a dual band polarization sensitive band reject filter according to an embodiment of the present invention;

FIG. 3 is a side view of a 4 x 4 array of elements of a dual band polarization sensitive band reject filter according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a resonant layer structure of a single unit of a dual-band polarization-sensitive band-stop filter according to an embodiment of the present invention;

FIG. 5 is a transmission response diagram of a dual band polarization sensitive band reject filter according to an embodiment of the present invention;

fig. 6 shows the transmission response under different polarization angles in the TE mode of the dual-band polarization-sensitive band-stop filter according to the embodiment of the present invention;

FIG. 7 shows the transmission response of the dual-band polarization sensitive band-stop filter in different polarization angles in the TM mode according to the embodiment of the present invention;

fig. 8 is a schematic diagram of a manufacturing method of a dual-band polarization-sensitive band-stop filter according to an embodiment of the present invention.

The structure comprises a substrate 1, a substrate 2, a resonance layer 3, an E-type patch, 4, a first right trapezoid strip, 5, a second right trapezoid strip, 6, a third right trapezoid strip, 7 and a fourth right trapezoid strip.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The invention provides a dual-band polarization sensitive band-stop filter and a preparation method thereof, wherein the dual-band polarization sensitive band-stop filter is of a periodic structure and consists of M N identical units, the adjacent units have no spacing, M, N is integers which are more than or equal to 2, and M can be less than, equal to or more than N. In this embodiment, M ═ N ═ 4 is taken.

As shown in fig. 1 and 2, the substrate 1 is made of polyethylene terephthalate (PET), and the resonance layer 2 is made of a two-dimensional material Ti3C2 Tx.

As shown in fig. 3, the thickness b of the substrate 1 is 100um, and the thickness a of the resonance layer 2 is 4.3 um.

As shown in fig. 4, the resonance layer 2 includes: the patch comprises an E-shaped patch 3, a first right trapezoid strip 4, a second right trapezoid strip 5, a third right trapezoid strip 6 and a fourth right trapezoid strip 7, wherein the first right trapezoid strip 4 and the third right trapezoid strip 6 are horizontally arranged above and below the E-shaped patch 3 and are connected with the E-shaped patch 3 at the lower bottom, the second right trapezoid strip 5 and the fourth right trapezoid strip 7 are vertically arranged at the left side of the E-shaped patch 3 and are connected with the E-shaped patch 3 at the lower bottom; the lower bottoms of the first right-angle trapezoidal strips 4 are connected with the right-angle sides of the second right-angle trapezoidal strips 5, and the lower bottoms of the third right-angle trapezoidal strips 6 are connected with the right-angle sides of the fourth right-angle trapezoidal strips 7.

The side length D of the single unit is 4cm in the embodiment; the transverse length d of 3E-shaped patches is 1.85cm, the width w1 is 0.40cm, the vertical length l is 2.80cm, and the width w2 is 0.35 cm; the upper bottom f1 of the first right-angle trapezoid strip and the third right-angle trapezoid strip is 0.85cm, the lower bottom g1 is 1.05cm, and the height w3 is 0.25 cm; the upper bottom f2 of the second and the fourth right-angle trapezoidal strips is 0.65cm, the lower bottom g2 is 0.80cm, and the height w3 is 0.25 cm.

As shown in fig. 5, the center frequency of the first stop band of the filter according to the embodiment of the present invention is 2.4GHz, the insertion loss is-34 dB, and the relative bandwidth is 14%; the second stopband has a center frequency of 4.9GHz, an insertion loss of-30 dB, and a relative bandwidth of 3%.

As shown in fig. 6 and fig. 7, the filters according to the embodiments of the present invention have sensitivities to different polarization angles in the TE mode and the TM mode, that is, the filters according to the embodiments of the present invention are polarization-sensitive, that is, have different transmission responses to electromagnetic waves with different polarizations.

As shown in fig. 8, in the method for manufacturing a dual-band polarization-sensitive band-stop filter according to the embodiment of the present invention, first, a positive photoresist AZ4562 with a thickness of 12um is spin-coated on a polyethylene terephthalate (PET) substrate to form a glue film with a uniform thickness; secondly, sequentially exposing and developing to obtain a required cluster plan; then, spin-coating the dispersion liquid, and standing; after the liquid component in the dispersion is evaporated, the substrate is completely Ti₃C₂T_xAfter the solid film is baked3 minutes; ti₃C₂T_xThe thickness of the film is less than or equal to 10 um; coating pentanone and ethylene glycol on a substrate in sequence, and then standing for finishing natural evaporation of the solvents in the two solutions; finally, removing the positive photoresist to obtain the dual-band polarization sensitive band-stop filter; the developing solution is a 3% potassium borate solution diluted by AZ400K developing solution and water according to the volume ratio of 1: 4; the etching solution for removing the positive photoresist is a solution prepared according to the mixture ratio of 1g of ammonium oxalate, 1.66g of glycine, 0.005g of dodecylbenzene yellow, 1ml of 25% hydrogen peroxide and 100ml of water solution; the optimal time for removing the positive photoresist is 11 minutes.

The dual-band polarization sensitive band-stop filter in the embodiment has two working frequency bands, wherein the working frequency bands below-10 dB are respectively 2.2-2.55GHz and 4.83-4.99GHz, the working frequency bands below-20 dB are respectively 2.33-2.43GHz and 4.89-4.93GHz, resonance frequency points are respectively 2.4GHz and 4.9GHz, insertion loss can respectively reach-34 dB and-30 dB, the frequency selection performance is good, the steep drop characteristic is good, and the dual-band filtering working requirement of electromagnetic wave signals of a wireless local area network can be met. The preparation method of the dual-band polarization sensitive band-stop filter in the embodiment has the advantages of simple process, no need of complex and expensive processing equipment and easiness in implementation.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.