阅读说明：本技术 基于交指结构的小型化人工表面等离激元传输线 (Miniaturized artificial surface plasmon transmission line based on interdigital structure ) 是由 潘柏操 罗国清 祝文涛 蔡佳林 廖臻 于 2019-10-15 设计创作，主要内容包括：本发明涉及一种基于交指结构的小型化人工表面等离激元传输线。包括介质基板、金属槽线、两个匹配单元和两个微带馈线；所述的金属槽线与匹配单元位于介质基板同一侧,微带馈线位于介质基板另一侧；两个匹配单元一端与金属槽线连接,另一端两分别与两个微带馈线重叠。两个匹配单元与两个微带馈线对称设置在金属槽线两端；金属槽线包括多个开槽单元,在开槽单元中排布有多个金属条组成的交指结构。本发明具有高效传输特性,在保持传输线线宽尺寸不变的前提下,实现了更低频率的电磁波截止特性,实现了传输线的小型化设计,可快速实现具体不同程度的小型化人工表面等离激元传输线。具有低串扰、高效特性,提高了空间利用率,便于加工制作、成本低。(The invention relates to a miniaturized artificial surface plasmon transmission line based on an interdigital structure. The microstrip antenna comprises a dielectric substrate, a metal slot line, two matching units and two microstrip feeder lines; the metal slot line and the matching unit are positioned on the same side of the dielectric substrate, and the microstrip feeder line is positioned on the other side of the dielectric substrate; one end of each matching unit is connected with the metal slot line, and the other end of each matching unit is overlapped with the two microstrip feeder lines. The two matching units and the two microstrip feeder lines are symmetrically arranged at two ends of the metal slot line; the metal slot line comprises a plurality of slot units, and an interdigital structure consisting of a plurality of metal strips is arranged in each slot unit. The invention has high-efficiency transmission characteristic, realizes the electromagnetic wave cut-off characteristic of lower frequency on the premise of keeping the line width size of the transmission line unchanged, realizes the miniaturization design of the transmission line, and can quickly realize the miniaturization artificial surface plasmon transmission lines with different degrees. The method has the characteristics of low crosstalk and high efficiency, improves the space utilization rate, is convenient to process and manufacture, and has low cost.)

1. A miniaturized artificial surface plasmon transmission line based on an interdigital structure comprises a dielectric substrate, a metal slot line, two matching units and two microstrip feeder lines; the method is characterized in that: the metal slot line and the matching unit are positioned on the same side of the dielectric substrate, and the microstrip feeder line is positioned on the other side of the dielectric substrate; one end of each matching unit is connected with the metal slot line, and the other end of each matching unit is respectively overlapped with the two microstrip feeder lines; the two matching units and the two microstrip feeder lines are symmetrically arranged at two ends of the metal slot line;

the matching units comprise circular resonant cavities and three groups of slot lines; the circular resonant cavity is positioned at the initial end of the first slot line and is responsible for improving the coupling efficiency and providing the unidirectional transmission performance of the slot line; the first slot line is a slot line with uniform width and is responsible for coupling with the back microstrip feeder line, and the terminal of the first slot line is connected with the starting end of the second slot line; the second slot line is a transition slot line with uniform and gradually changed width, and the terminal of the second slot line is connected with the third slot line and is responsible for impedance matching of the first slot line and the third slot line; five groups of slotting structures with gradually-changed depths, which are vertical to the direction of the slot line, are periodically arranged on one side of the starting end of the third slot line, and are responsible for matching and transition of signals in the slot line to the artificial surface plasmon mode; connecting metal slot lines with uniform slot depth behind the five groups of gradual change slotted structures; the metal slot line comprises a plurality of slot units, and interdigital structures formed by a plurality of metal strips are distributed in the slot units, so that the miniaturization of the complementary artificial surface plasmons is realized.

2. A miniaturized artificial surface plasmon transmission line based on an interdigital structure comprises a dielectric substrate, an artificial surface plasmon transmission line positioned on the surface of the dielectric substrate, and a microstrip feeder line and a ground plate which are symmetrically arranged at two ends of the transmission line; the method is characterized in that: the artificial surface plasmon transmission line comprises a metal strip and a third ground plate; the first microstrip feeder line, the second microstrip feeder line and the metal strip are positioned on the front surface of the dielectric substrate, and the first ground plate, the second ground plate and the third ground plate are positioned on the back surface of the dielectric substrate; the first microstrip feeder line, the second microstrip feeder line and the metal strip are in one-to-one correspondence with the mounting positions of the first ground plate, the second ground plate and the third ground plate; the first microstrip feeder line and the second microstrip feeder line are both provided with two, and are symmetrically arranged at two ends of the metal strip, and the second microstrip feeder line is used for connecting the first microstrip feeder line and the metal strip; the first grounding plate and the second grounding plate are both provided with two parts and symmetrically arranged at two sides of the third grounding plate, and the second grounding plate is used for connecting the first grounding plate and the third grounding plate;

the first microstrip feeder line and the first ground plate form a microstrip feeder line with characteristic impedance of 50 omega; the second microstrip feeder line and the ground plate are in gradual transition design, and the first microstrip feeder line and the metal strip are in gradual transition connection through the second microstrip feeder line; one side of the second microstrip feeder line is connected with the first microstrip feeder line, and the other side of the second microstrip feeder line is connected with the metal strip; one side of the second grounding plate is connected with the first grounding plate, and the other side of the second grounding plate is connected with the second grounding plate; the metal strip and the third ground plate form an artificial surface plasmon transmission line, and the metal strip and the third ground plate are equal in width;

matching units with the period length of 7 units are symmetrically arranged on two sides of the metal strip, a four-period unit close to the second microstrip feeder line is of a slotted structure with the depth gradually changed in an equal proportion, and a three-period unit far away from the second microstrip feeder line is of a slotted unit with the same depth; 1-3 interdigital metal arms are respectively arranged in the three slotting units; the metal arms are connected to the two walls of the groove structure in a staggered manner; the middle of the metal strip is of a structure with a plurality of periodic uniform composite slotting units, and a plurality of interdigital metal arms are uniformly distributed in each uniform composite slotting unit in a staggered manner;

the second microstrip feeder line and the second ground plate are responsible for uniform broadband impedance matching between the first microstrip feeder line and the metal strip; the front period unit and the rear period unit of the matching unit are of a slotted structure with depth gradient in equal proportion and are responsible for conversion and matching of signals from a microstrip waveguide mode to an artificial surface plasmon mode; and the last three periods of the matching unit are responsible for mode matching between the artificial surface plasmons and the miniaturized design.

3. The miniaturized artificial surface plasmon transmission line based on interdigital structures of claim 1, wherein: and five groups of slotting structures with gradually changed depths, which are vertical to the direction of the slot line, are periodically etched on one side of the starting end of the third slot line.

4. The miniaturized artificial surface plasmon transmission line based on interdigital structures of claim 1, wherein: in the uniformly slotted metal slot line, one, two and three metal strip structures are respectively arranged in the first three slotting units and are responsible for the mode matching between the periodic slotting units and the slotting structures with the interdigital structures; and starting from the fourth uniform slotting unit, four metal strips which are arranged in a staggered manner are arranged in the slotting unit.

5. The miniaturized artificial surface plasmon transmission line based on interdigital structures of claim 2, wherein: the first grounding plate is a complete metal grounding surface.

6. The miniaturized artificial surface plasmon transmission line based on interdigital structures of claim 2, wherein: one, two and three interdigital metal arms are respectively arranged in the three-period slotting unit of the matching unit, which is far away from the second microstrip feeder line, in sequence; the middle of the metal strip is of a plurality of periodic uniform composite slotting unit structures, and four interdigital metal arms are uniformly and alternately distributed in each uniform composite slotting unit.

Technical Field

The invention belongs to the field of novel artificial electromagnetic materials, and particularly relates to a miniaturized artificial surface plasmon transmission line based on an interdigital structure.

Background

Surface plasmons (surface plasmon polaritons) are a particular electromagnetic response that occurs at the interface between a metal and a medium. In the natural state, it generally exists in high frequency bands such as near infrared, optical band, etc., and is represented as a surface wave form propagating along the metal surface at the interface between the metal and the medium. The electric field of the surface wave is exponentially attenuated along the normal direction of the interface, and the surface wave has strong binding property. Due to this high intensity confinement of light at sub-wavelength dimensions, surface plasmons are widely used to break through the diffraction limit and build various highly integrated optical elements and circuits. This particular surface wave mode can be successfully introduced into lower frequency bands using Metamaterials (Metamaterials) artificial surface units with specific structures. The realization of the high-efficiency excitation of the artificial surface plasmon greatly promotes the development of the artificial surface plasmon in engineering application. A series of active and passive devices based on artificial surface plasmons, including high-efficiency transmission lines, multi-band and broadband filters, power dividers, antennas, directional transmission, slow-wave local confinement, power amplifiers, mixers and the like, are proposed in succession. The comb-corrugated metal structure transmission line as referred to herein is a model for efficiently transmitting the above-mentioned surface waves in the terahertz and microwave frequency bands. Which realizes surface wave dispersion characteristics like surface plasmons.

For a conventional transmission line with a corrugated metal structure, the cut-off frequency depends mainly on the groove depth, and the cut-off frequency is obviously reduced along with the increase of h of the groove depth. But at the same time as the cutoff frequency is lowered, the confinement of the transmission line to the wave is enhanced due to the increase of h, resulting in a reduction of the transmission distance. Adjusting the cutoff frequency by increasing h, or additional structures, tends to increase the lateral dimensions of the transmission line; affecting the transmission efficiency of the transmission line.

Disclosure of Invention

An object of the present invention is to provide a miniaturized artificial surface plasmon transmission line based on an interdigital structure, which addresses the deficiencies of the prior art. A group of interdigital metal arm structures are additionally arranged in a groove structure unit of a common periodic grooved artificial surface plasmon structure, so that the effective control on the cut-off frequency can be realized under the condition of not influencing the transmission efficiency, and the miniaturization design of the artificial surface plasmon is realized.

The invention comprises a dielectric substrate, a metal slot line, two matching units and two microstrip feeder lines; the metal slot line and the matching unit are positioned on the same side of the dielectric substrate, and the microstrip feeder line is positioned on the other side of the dielectric substrate; one end of each matching unit is connected with the metal slot line, and the other end of each matching unit is overlapped with the two microstrip feeder lines. The two matching units and the two microstrip feeder lines are symmetrically arranged at two ends of the metal slot line;

the matching units comprise circular resonant cavities and three groups of slot lines; the circular resonant cavity is positioned at the initial end of the first slot line and is responsible for improving the coupling efficiency and providing the unidirectional transmission performance of the slot line; the first slot line is a slot line with uniform width and is responsible for coupling with the back microstrip feeder line, and the terminal of the first slot line is connected with the starting end of the second slot line; the second slot line is a transition slot line with uniform and gradually changed width, and the terminal of the second slot line is connected with the third slot line and is responsible for impedance matching of the first slot line and the third slot line; five groups of slotting structures with gradually-changed depths, which are vertical to the direction of the slot line, are periodically arranged on one side of the starting end of the third slot line, and are responsible for matching and transition of signals in the slot line to the artificial surface plasmon mode; connecting metal slot lines with uniform slot depth behind the five groups of gradual change slotted structures; the metal slot line comprises a plurality of slot units, and interdigital structures formed by a plurality of metal strips are distributed in the slot units, so that the miniaturization of the complementary artificial surface plasmons is realized.

Preferably, five groups of groove structures with gradually changed depths are periodically etched on the starting end side of the third groove line, wherein the depths of the five groups of groove structures are vertical to the direction of the groove line.

Preferably, in the uniformly grooved metal grooved wire, one, two and three metal strip structures are respectively arranged in the first three grooving units and are responsible for the mode matching between the periodic grooving units and the grooving structures with the interdigital structures; and starting from the fourth uniform slotting unit, four metal strips which are arranged in a staggered manner are arranged in the slotting unit.

The invention can also comprise a dielectric substrate, an artificial surface plasmon transmission line positioned on the surface of the dielectric substrate, and a microstrip feeder line and a ground plate which are symmetrically arranged at the two ends of the transmission line; the artificial surface plasmon transmission line comprises a metal strip and a third ground plate; the first microstrip feeder line, the second microstrip feeder line and the metal strip are positioned on the front surface of the dielectric substrate, and the first ground plate, the second ground plate and the third ground plate are positioned on the back surface of the dielectric substrate; the first microstrip feeder line, the second microstrip feeder line and the metal strip are in one-to-one correspondence with the mounting positions of the first ground plate, the second ground plate and the third ground plate. The first microstrip feeder line and the second microstrip feeder line are respectively provided with two, are symmetrically arranged at two ends of the metal strip, and are used for connecting the first microstrip feeder line and the metal strip. The first grounding plate and the second grounding plate are both provided with two parts and symmetrically arranged at two sides of the third grounding plate, and the second grounding plate is used for connecting the first grounding plate and the third grounding plate;

the first microstrip feeder line and the first ground plate form a microstrip feeder line with characteristic impedance of 50 omega; the second microstrip feeder line and the ground plate are in gradual transition design, and the first microstrip feeder line and the metal strip are connected through gradual transition through the second microstrip feeder line. One side of the second microstrip feeder line is connected with the first microstrip feeder line, and the other side of the second microstrip feeder line is connected with the metal strip; one side of the second grounding plate is connected with the first grounding plate, and the other side of the second grounding plate is connected with the second grounding plate. The metal strip and the third ground plate form an artificial surface plasmon transmission line, and the metal strip and the third ground plate are equal in width.

The two sides of the metal strip are symmetrically provided with matching units with the period length of 7 units, the four-period unit close to the second microstrip feeder line is of a slotted structure with the depth gradually changed in an equal proportion, and the three-period unit far away from the second microstrip feeder line is of a slotted unit with the same depth. 1-3 interdigital metal arms are respectively arranged in the three slotting units. The metal arms are connected to the two walls of the groove structure in a staggered manner. The middle of the metal strip is of a structure with a plurality of periodic uniform composite slotting units, and a plurality of interdigital metal arms are uniformly and alternately distributed in each uniform composite slotting unit.

The second microstrip feeder line and the second ground plate are responsible for uniform broadband impedance matching between the first microstrip feeder line and the metal strip; the front period unit and the rear period unit of the matching unit are of a slotted structure with depth gradient in equal proportion and are responsible for conversion and matching of signals from a microstrip waveguide mode to an artificial surface plasmon mode; and the last three periods of the matching unit are responsible for mode matching between the artificial surface plasmons and the miniaturized design.

Preferably, the first ground plate is a complete metal ground plane.

Preferably, one, two or three interdigital metal arms are respectively arranged in the three-period slotting unit of the matching unit far away from the second microstrip feeder line in sequence; the middle of the metal strip is of a plurality of periodic uniform composite slotting unit structures, and four interdigital metal arms are uniformly and alternately distributed in each uniform composite slotting unit.

The number of the interdigital metal arm structures in the slotted structure is adjusted, so that the cut-off frequency can be effectively changed, and the miniaturized transmission performance of different degrees is realized.

Has the advantages that:

1. the artificial surface plasmon transmission line with the interdigital metal arm structure has high-efficiency transmission characteristics, realizes the electromagnetic wave cut-off characteristics of lower frequency on the premise of keeping the line width size of the transmission line unchanged, and realizes the miniaturization design of the transmission line; the size and the arrangement rule of the interdigital metal arm structure are adjusted, and the miniaturized artificial surface plasmon transmission lines with different degrees can be quickly realized.

2. The invention has the characteristics of low crosstalk and high efficiency. Compared with the traditional artificial surface plasmon polariton transmission line, the designed miniaturized transmission line has the width reduced by 50%, and the space utilization rate is greatly improved.

3. The invention has the characteristics of convenient processing and manufacturing, low cost and the like. The structure is not sensitive to the deformation of the medium substrate, and can be attached to the surface of a spherical surface, a conical surface and other non-planar medium substrates to manufacture conformal devices.

Drawings

FIG. 1 is a schematic diagram of the front and back structures of a miniaturized artificial surface plasmon transmission line;

FIG. 2 is a comparison of dispersion characteristics of periodic slotted structures with different numbers of interdigitated metal arms added;

FIG. 3 is a comparison of transmission efficiency of the miniaturized artificial surface plasmon transmission line of the present invention with that of the conventional design;

FIG. 4 is a schematic diagram of the front, side and back structures of a miniaturized complementary artificial surface plasmon transmission line;

FIG. 5 is a comparison of the dispersion characteristics of complementary unit structures of the present invention with the addition of different numbers of interdigitated metal arms;

FIG. 6 is a S parameter comparison of the miniaturized complementary artificial surface plasmon transmission line of the present invention with a conventional design.

Detailed Description

As shown in fig. 1, the miniaturized artificial surface plasmon transmission line based on the interdigital structure comprises a dielectric substrate, an artificial surface plasmon transmission line positioned on the surface of the dielectric substrate, and microstrip feed lines symmetrically arranged at two ends of the transmission line; the first microstrip feed line M0, the second microstrip feed line M1 and the metal strip M2 are positioned on the front surface of the dielectric substrate, and the first ground plate B0, the second ground plate B1 and the third ground plate B2 are positioned on the back surface of the dielectric substrate. The number of the first microstrip feed line M0 and the number of the second microstrip feed line M1 are two, and the two microstrip feed lines are symmetrically installed at two ends of the metal strip M2, and the second microstrip feed line M1 is used for connecting the first microstrip feed line M0 and the metal strip M2. The first ground plate B0 and the second ground plate B1 are also provided with two ground plates, and are symmetrically arranged on two sides of the third ground plate B2, and the second ground plate B1 is used for connecting the first ground plate B0 and the third ground plate B2; the first microstrip feed line M0, the second microstrip feed line M1 and the metal strip M2 are in one-to-one correspondence with the mounting positions of the first ground plate B0, the second ground plate B1 and the third ground plate B2.

The first microstrip feed line M0 and the first ground plate B0 form a microstrip feed line with characteristic impedance of 50 omega; the microstrip grounding plate B0 is a complete metal grounding surface; the first microstrip feed line M0 has a line width of 1.37 mm. The second microstrip feed line M1 and the ground plate B1 are in gradual transition design, and the first microstrip feed line M0 and the metal strip M2 are connected through gradual transition through the second microstrip feed line M1. The length of the second microstrip feeder line M1 is 20mm, one side of the second microstrip feeder line M1 is connected with the first microstrip feeder line M0, and the other side of the second microstrip feeder line M1 is connected with the metal strip M2; the width of the second microstrip feed line M1 increases continuously and gradually from 1.37mm to 4.4 mm. The second ground plate B1 has one side connected to the first ground plate B0 and another side connected to the second ground plate B2. The width of the second ground plate B1 is continuously tapered from 20mm to 4.4 mm. The metal strip M2 and the third grounding plate B2 form an artificial surface plasmon transmission line; the metal strip M2 and the third ground plate B2 are of equal width.

The two sides of the metal strip M2 are symmetrically provided with a pattern matching design with a 7-unit period length, the unit period is 4mm, and the slot width is 3 mm. The four period units before the pattern matching design are slotted structures S1, S2, S3 and S4 with the depth gradually changed in an equal proportion, and the depth of each slot is 1mm, 2mm, 3mm and 4mm respectively. The last three periodic units are slotted units S5, S6, S7 with the depth of 4 mm. One, two and three interdigital metal arms are respectively arranged in the three slotting units, and the width and the length of each metal arm are 0.2mm and 2.5mm respectively. The metal arms are connected to the two walls of the groove structure in a staggered manner. The middle of the two groups of mode matching designs of the transmission line is a plurality of period uniform composite slotted unit structures, and four interdigital metal arm structures are uniformly distributed in each unit in a staggered mode. The metal strip M2 and the third ground plate B2 together constitute a miniaturized artificial surface plasmon transmission line.

The signal is fed by the first microstrip feed line M0 via the signal source, and is transferred to the metal strip M2 by the second microstrip feed line M1 for impedance matching. At the edge of the metal strip M2, the mode matching of signals is realized through the gradual change slot lines S1-S4, and the traditional microstrip guided wave mode electromagnetic wave is converted into the artificial surface plasmon mode electromagnetic wave. And the conversion between the artificial surface plasmon mode and the miniaturized artificial surface plasmon mode is realized at the groove lines S5-S7, and then the transmission is efficiently carried out in the miniaturized transmission line.

As shown in fig. 2, the dispersion characteristics of the slotted unit of the additional interdigital metal arm structure are compared, and the black curve in the graph is the dispersion characteristics of the conventional periodic slotted structure, and the curve is cut off at 12.4 GHz. The dashed lines, the dotted lines, and the curves with square and circular labels represent the dispersion characteristics of the composite element with one to four interdigitated metal arm structures attached to the inside of the slot, respectively. It can be observed from the figure that the cut-off frequency of the dispersion curve gradually decreases as the number of additional interdigitated metal arm structures increases. For the four-metal-arm slotted composite unit related to the design, the cut-off frequency is 6 GHz.

Fig. 3 shows the comparison result of the transmission efficiency of the designed miniaturized artificial surface plasmon transmission line and the conventional design scheme. It can be seen from the figure that the signal propagation of the conventional design is cut off at 10.4GHz while keeping the widths of the two sets of transmission lines consistent. The cut-off frequency achieved by the novel structure is greatly reduced to 5.7 GHz. The system size is effectively reduced.

Fig. 4 is a schematic diagram of a miniaturized complementary artificial surface plasmon transmission line according to another embodiment. In the figure, the circular resonant cavity C1, the first slot line T1, the second slot line T2 and the third slot line T3 are positioned on the front surface of the dielectric substrate. The microstrip M4 and the stub C2 are located on the back of the dielectric substrate. The microstrip M4 adopts a 50 omega microstrip line design as a transmission line feed end, and the microstrip width is 1.37 mm. The microstrip M4 is orthogonally crossed with the first slot line T1 having a width of 0.2mm, and the microstrip M4 is orthogonal to the slot line extension direction and orthogonal to the first slot line T1 in the z direction, and feeds energy into the slot line T1 by coupling. The front circular open-cell resonant cavity C1 is connected to the terminal of the first slot line T1, and the back circular stub C2 is connected to the terminal of the microstrip M4, which is responsible for improving the coupling matching performance and increasing the feed efficiency. The C1 and C2 radius dimensions were 2mm and 3.5mm, respectively. The energy coupled into the first slot line T1 is transferred into the third slot line T3 through the second slot line T2. According to the transmission line impedance matching principle, the second slot line T2 is 0.6mm wide and 6mm long. And a metal slotted structure is periodically etched on the edge of the third slot line T3 metal plate to form the complementary artificial surface plasmon transmission line. The third slot line T3 bilateral symmetry is provided with 8 unit cycle length's mode matching design, and the unit cycle is 4mm, and the fluting width is 3 mm. The signal propagated to the third slot line T3 realizes the conversion of the conventional slot line guided wave mode to the complementary artificial surface plasmon mode in the first five periodic units of the matching design. The five-period unit is a slotted structure G1, G2, G3, G4 and G5 with the depth gradually changed in equal proportion, and the depth of the slot is 1mm, 2mm, 3mm, 4mm and 5mm respectively. After matching design, the three periodic units are slotted structures G6, G7 and G8 with the depth of 5mm, one, two and three interdigital metal arm structures are respectively arranged in the three slotted structures, the width of each metal arm is 0.2mm, and the length of each metal arm is 2.5 mm. The complementary artificial surface plasmon mode signal is further modulated into a miniaturized mode signal in the transmission line. A plurality of periodic uniform interdigital slotting units are arranged between the two groups of matching designs, and four interdigital metal arm structures are uniformly distributed in each unit slotting structure.

FIG. 5 is a comparison of dispersion characteristics of periodic slotted metal structures. In the figure, a black curve is a dispersion distribution curve of a traditional metal slotted structure, and a dotted line, a dot-dash line and a solid line with circles and direction marks respectively represent composite unit dispersion curves of one to four interdigital metal arm structures additionally arranged in the slotted structure. It can be seen from the figure that as the frequency rises, there is a high frequency limit, i.e. a high frequency transmission cut-off frequency, for all designs. While keeping the groove depth unchanged, different numbers of interdigital metal arm structures are added, and the dispersion cut-off frequency is gradually reduced from 10GHz to 5.5 GHz. This means that the design of the present invention has a lower cut-off frequency while keeping the overall dimensions constant. Since the cut-off characteristic of the artificial surface plasmon is directly related to the depth of the groove, when a certain cut-off frequency is selected to be unchanged, the total width of the design in the invention is far smaller than that of the traditional artificial surface plasmon design. Meanwhile, the cutoff frequency is reduced along with the increase of the number of interdigital structures, and the mode matching of the artificial surface plasmon miniaturized design is feasible by the surface design and arrangement by utilizing the purpose of the gradual change interdigital.

Fig. 6 is a S parameter comparison result of the conventional complementary artificial surface plasmon transmission line and the miniaturized complementary artificial surface plasmon transmission line of the present invention. From the figure, it can be seen that the conventional design has been cut off at about 10GHz while maintaining consistent line width dimensions. While the design is cut off at around 5.5 GHz. The cut-off frequency is greatly reduced, and the correctness and the operation feasibility of the design theory of the invention are directly verified.

In a word, the miniaturized artificial surface plasmon consists of an additional interdigital structure in a periodic slotting unit structure. The introduction of the interdigital structure greatly reduces the dispersion cut-off frequency of the unit structure. Helping to further reduce the overall size of the artificial surface plasmon design.

The periodic slotted structure with the interdigital structure has stronger near field constraint capability, can effectively inhibit crosstalk between devices, and improves the electromagnetic compatibility and the stability of a system.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the embodiments, and various equivalent modifications can be made within the technical spirit of the present invention, and the scope of the present invention is also within the scope of the present invention.