Artificial Surface Plasmon High Aperture Efficiency End-Fire Antenna

Abstract

The present invention provides an artificial surface plasmon high-aperture efficiency end-fire antenna, which includes a dielectric substrate. The upper and lower surfaces of the dielectric substrate respectively form a dielectric substrate top layer and a dielectric substrate bottom layer. The dielectric substrate bottom layer is provided with a grounding metal layer, and the dielectric substrate top layer is provided with a top surface metal layer. The top surface metal layer is provided with a balun structure, a tapered parallel two-wire line, a transitional parallel two-wire line, and artificial surface plasmon radiation strips. One end of the balun structure is a feeding port, and the other end of the balun structure is connected to the end of the transitional parallel two-wire line through a connecting tapered parallel two-wire line. The other end of the transitional parallel two-wire line is connected to a pair of artificial surface plasmon radiation strips. This artificial surface plasmon high-aperture efficiency end-fire antenna has the advantages of high aperture efficiency, low profile, wide operating bandwidth, high directivity, high gain, and relatively small overall size.

Description

Technical Field

[0001] The present invention relates to an artificial surface plasmon high-aperture efficiency end-fire antenna, belonging to the technical field of antennas. Background Art

[0002] Artificial surface plasmons are surface waves with dispersive characteristics excited on a periodic metal surface, having strong field confinement. Microwave devices designed using this mode have characteristics such as low transmission loss and easy conformal shaping, and thus have received extensive research. In recent years, end-fire antennas based on artificial surface plasmons have also received a great deal of attention.

[0003] However, the current end-fire antennas based on artificial surface plasmons still have the following problems: 1) The method of achieving end-fire still relies on resonant radiators such as dipole arrays, which will cause the designed antenna to have a relatively large lateral size, occupy a large space, and result in a low aperture efficiency of the antenna; 2) Due to the design using resonant radiators, there is a problem of narrow working bandwidth.

[0004] For example, a broadband high-gain planar end-fire antenna based on artificial surface plasmons disclosed in Chinese Patent Application CN202111621835.5. In this patent, multiple I-shaped resonators are used in the transition part, and a tapered aperture structure is used in the radiation part, resulting in too large electrical sizes in the lateral and longitudinal directions of the antenna and too low aperture efficiency.

[0005] In addition, the existing end-fire antennas relying on artificial surface plasmon radiation will adopt an asymmetric structure, which will cause the maximum radiation direction of the antenna to deviate from the end-fire direction, resulting in poor directivity of the antenna and bringing trouble to the actual antenna assembly. At the same time, using resonant radiators or an asymmetric artificial surface plasmon structure makes the design of the antenna complicated.

[0006] The above problems should be considered and solved in the design and production process of end-fire antennas. Summary of the Invention

[0007] The object of the present invention is to provide an artificial surface plasmon high-aperture efficiency end-fire antenna, which has characteristics such as high aperture efficiency, low profile, wide working bandwidth, and good directivity in the end-fire direction, and solves the problems of low aperture efficiency, high profile, narrow working bandwidth, large size, radiation direction deviation, and complicated design existing in the prior art.

[0008] The technical solution of the present invention is:

[0009] An artificial surface plasmon high-aperture efficiency end-fire antenna, comprising a dielectric substrate. The upper and lower surfaces of the dielectric substrate respectively form a dielectric substrate top layer and a dielectric substrate bottom layer. The dielectric substrate bottom layer is provided with a grounding metal layer, and the dielectric substrate top layer is provided with a top surface metal layer. The top surface metal layer is provided with a balun structure, a tapered parallel twin line, a transitional parallel twin line, and an artificial surface plasmon radiation strip. One end of the balun structure is a feeding port, and the other end of the balun structure is connected to the end of the transitional parallel twin line through a connecting tapered parallel twin line. The other end of the transitional parallel twin line is connected to a pair of artificial surface plasmon radiation strips arranged symmetrically. A gap is formed between the artificial surface plasmon radiation strips and they are arranged axially symmetrically. The balun structure and the grounding metal layer are correspondingly arranged on the upper and lower surfaces of the dielectric substrate. Through the transitional structure composed of the balun structure, the tapered parallel twin line, and the transitional parallel twin line, the currents on both sides of the artificial surface plasmon radiation strip are fed in phase.

[0010] Further, the balun structure includes a first microstrip line, a double microstrip line, and a parallel twin line. The double microstrip line includes a second microstrip line and a third microstrip line. The second microstrip line and the third microstrip line are respectively microstrip lines bent into a U shape with a total length difference of half a wavelength. One end of the first microstrip line is the feeding port of the antenna, and the other end of the first microstrip line is connected to the second microstrip line and the third microstrip line respectively on both sides. The second microstrip line and the third microstrip line are connected to the tapered parallel twin line.

[0011] Further, the second microstrip line and the third microstrip line are respectively U-shaped microstrip lines with opposite bending directions.

[0012] Further, the artificial surface plasmon radiation strip includes an artificial surface plasmon transition section, a periodic rectangular patch section, an artificial surface plasmon tapered section, and a patch. One end of the periodic rectangular patch section is connected to the tapered parallel twin line through the artificial surface plasmon transition section, and the other end of the periodic rectangular patch section is connected to the artificial surface plasmon tapered section. The patches are arranged at equal intervals on the outside of the artificial surface plasmon radiation strip.

[0013] Further, a gap is provided on the inner side of the artificial surface plasmon radiation strip and they are arranged parallel to each other.

[0014] Further, the patch includes a first periodic patch, a rectangular patch, and a second periodic patch. The top end of the first periodic patch is provided with a first inclined surface. The bottom end of the first periodic patch is arranged on the outside of the artificial surface plasmon transition section. The rectangular patch is arranged on the outside of the periodic rectangular patch section and has the same height. The top end of the second periodic patch is provided with a second inclined surface. The bottom end of the second periodic patch is arranged on the outside of the artificial surface plasmon tapered section.

[0015] Furthermore, the height of the first periodic patch gradually increases from the far periodic rectangular patch end to the near periodic rectangular patch end, and the height of the second periodic patch gradually decreases from the far periodic rectangular patch end to the near periodic rectangular patch end.

[0016] Furthermore, by adjusting the height of the rectangular patches on the artificial surface plasmon radiation strip, the dispersion curve of the artificial surface plasmon radiation strip is regulated, thereby realizing the adjustment of the operating frequency and bandwidth of the antenna: when the height of the rectangular patch increases, the operating frequency of the antenna decreases and the operating bandwidth becomes narrower; when the height of the rectangular patch decreases, the operating frequency of the antenna increases and the operating bandwidth becomes wider.

[0017] Furthermore, by adjusting the number of rectangular patches on the artificial surface plasmon radiation strip, the length of the artificial surface plasmon radiation strip is regulated, thereby realizing the regulation of the antenna gain and beam width: when the number of rectangular patches increases, the gain of the antenna increases and the beam width becomes narrower; when the number of rectangular patches decreases, the gain of the antenna decreases and the beam width becomes wider.

[0018] Furthermore, by adjusting the total length of the second microstrip line and the third microstrip line in the balun structure, the operating frequency of the antenna is regulated: when the difference in the total length between the second microstrip line and the third microstrip line in the balun structure increases, the operating frequency of the antenna becomes smaller; on the contrary, when the difference in the total length decreases, the operating frequency of the antenna becomes larger.

[0019] The technical solution of the present invention is:

[0020] The beneficial effects of the present invention are:

[0021] 1. This kind of artificial surface plasmon high aperture efficiency end-fire antenna has the advantages of high aperture efficiency, low profile, wide operating bandwidth, high directivity, high gain, and small overall size, and is simple in structure and easy to process; it solves the problems existing in the existing end-fire antennas based on artificial surface plasmons, such as low aperture efficiency, high profile, narrow bandwidth, radiation direction deviation, large lateral size, and complex design, and can be applied to the millimeter wave band.

[0022] 2. This kind of artificial surface plasmon high aperture efficiency end-fire antenna uses the opposite currents realized by the balun structure to form a dipole array with the artificially surface plasmon radiation strips symmetrically arranged up and down, thereby realizing the end-fire radiation of the antenna. At the same time, using the artificial surface plasmon radiation strip as the radiation source of the antenna reduces the overall size of the antenna, decreases the metal occupation area, realizes the small aperture of the antenna, and achieves high gain while reducing the antenna aperture, thereby realizing high aperture efficiency.

[0023] III. For this kind of artificial surface plasmon high-aperture efficiency end-fire antenna, the impedance matching of the antenna is achieved through the transition of the current in the balun structure through the tapered parallel twin lines, the transitional parallel twin lines and the artificial surface plasmon transition section, thus achieving a relatively wide bandwidth.

[0024] IV. The present invention uses a balun structure to feed a pair of completely symmetric artificial surface plasmon radiation strips, avoiding the problem of pattern tilt caused by the asymmetric structure, thus achieving highly directive radiation in the end-fire direction.

[0025] V. For this kind of artificial surface plasmon high-aperture efficiency end-fire antenna, the matching of electromagnetic waves is achieved through the tapering of the artificial surface plasmon tapered section, so that the electromagnetic waves can be effectively radiated into free space, achieving a relatively high gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the artificial surface plasmon high-aperture efficiency end-fire antenna according to an embodiment of the present invention;

[0027] Figure 2 is a schematic top view structure diagram of the artificial surface plasmon high-aperture efficiency end-fire antenna according to the embodiment.

[0028] Figure 3 is Figure 2 a partial enlarged schematic diagram of A in

[0029] Figure 4 is Figure 2 a partial enlarged schematic diagram of B in

[0030] Figure 5 is Figure 2 a partial enlarged schematic diagram of C in

[0031] Figure 6 is Figure 2 a partial enlarged schematic diagram of D in

[0032] Figure 7 is a schematic bottom view structure diagram of the artificial surface plasmon high-aperture efficiency end-fire antenna according to the embodiment.

[0033] Figure 8 is a schematic diagram of the simulated and measured S parameters of the artificial surface plasmon high-aperture efficiency end-fire antenna according to the embodiment.

[0034] Figure 9 is a schematic diagram of the 9G pattern of the artificial surface plasmon high-aperture efficiency end-fire antenna according to the embodiment, where Figure 9 (a) is the coplanar polarization and cross-polarization diagrams of the E-plane in simulation and measurement, Figure 9 (b) is the coplanar polarization and cross-polarization diagrams of the H-plane in simulation and measurement.

[0035] Figure 10 It is a schematic diagram of the 10G radiation pattern of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiment. Among them, Figure 10 (a) is the coplanar polarization and cross-polarization diagrams of simulation and measurement in the E-plane, Figure 10 (b) is the coplanar polarization and cross-polarization diagrams of simulation and measurement in the H-plane.

[0036] Figure 11 It is a schematic diagram of the 11G radiation pattern of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiment; among them, Figure 11 (a) is the coplanar polarization and cross-polarization diagrams of simulation and measurement in the E-plane, Figure 11 (b) is the coplanar polarization and cross-polarization diagrams of simulation and measurement in the H-plane.

[0037] Figure 12 It is a schematic diagram of the simulated and measured gain and efficiency of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiment.

[0038] Among them: 11 - top layer of the dielectric substrate, 12 - top surface metal layer, 13 - balun structure, 14 - tapered parallel twin lines, 15 - transitional parallel twin lines, 16 - artificial surface plasmon radiation strip, 17 - gap;

[0039] 131 - first microstrip line, 132 - second microstrip line, 133 - third microstrip line, 134 - parallel twin lines;

[0040] 161 - artificial surface plasmon transition section, 162 - periodic rectangular patch segment, 163 - artificial surface plasmon tapered section, 164 - first periodic patch, 165 - rectangular patch, 166 - second periodic patch, 167 - first inclined plane, 168 - second inclined plane;

[0041] 21 - bottom layer of the dielectric substrate, 22 - ground metal layer. Detailed implementation manners

[0042] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Embodiment

[0044] An artificial surface plasmon high-aperture efficiency end-fire antenna, such as Figure 1 、 Figure 2 and Figure 7 , includes a dielectric substrate. The upper and lower surfaces of the dielectric substrate respectively form the top layer 11 of the dielectric substrate and the bottom layer 21 of the dielectric substrate, and the bottom layer 21 of the dielectric substrate is provided with a ground metal layer 22.

[0045] Such as Figure 1 and Figure 2, on the top layer 11 of the dielectric substrate, there is a top surface metal layer 12. The top surface metal layer 12 is provided with a balun structure 13, a tapered parallel twin line 14, a transitional parallel twin line 15, and an artificial surface plasmon radiation strip 16. One end of the balun structure 13 is a feeding port. The other end of the balun structure 13 is connected to the end of the transitional parallel twin line 15 through the connecting tapered parallel twin line 14. The other end of the transitional parallel twin line 15 is connected to the pair - set artificial surface plasmon radiation strips 16. A gap 17 is formed between the artificial surface plasmon radiation strips 16 and they are axially symmetrically arranged. The balun structure 13 and the grounding metal layer 22 are correspondingly arranged on the upper and lower surfaces of the dielectric substrate. Through the transitional structure composed of the balun structure 13, the tapered parallel twin line 14, and the transitional parallel twin line 15, the currents on both sides of the artificial surface plasmon radiation strip 16 are fed in - phase.

[0046] This kind of artificial surface plasmon high - aperture - efficiency end - fire antenna has the advantages of high aperture efficiency, low profile, wide operating bandwidth, high directivity, high gain, and relatively small overall size, and is simple in structure and easy to process. It solves the problems existing in the existing end - fire antennas based on artificial surface plasmons, such as high profile, low aperture efficiency, narrow bandwidth, radiation direction deviation, large lateral size, and complex design, and can be applied to the millimeter - wave band.

[0047] As Figure 2 and Figure 3 , the balun structure 13 includes a first microstrip line 131, a double - microstrip line, and a parallel twin line 134. The double - microstrip line includes a second microstrip line 132 and a third microstrip line 133. The second microstrip line 132 and the third microstrip line 133 are respectively microstrip lines bent into a U - shape with a length difference of half a wavelength. One end of the first microstrip line 131 is the feeding port of the antenna. The other end of the first microstrip line 131 is connected to the second microstrip line 132 and the third microstrip line 133 on both sides respectively. The second microstrip line 132 and the third microstrip line 133 are connected to the tapered parallel twin line 14.

[0048] As Figure 2 , the opposite currents realized by the balun structure 13 make the artificially - surface - plasmon - radiation strips 16 arranged symmetrically up and down form a dipole array, thus realizing the end - fire radiation of the antenna. At the same time, taking the artificial surface plasmon radiation strip 16 as the radiation source of the antenna reduces the overall size of the antenna, decreases the metal occupation area, realizes the small aperture of the antenna, and thus realizes the high aperture efficiency.

[0049] As Figure 1 and Figure 2, the feeding part adopts a balun structure 13 with a 180° phase shift. In the balun structure 13, the first microstrip line 131 is connected to the parallel twin line 134 through two high-impedance second microstrip lines 132 and third microstrip lines 133. The second microstrip line 132 and the third microstrip line 133 are composed of bent microstrip lines with a U-shaped structure, and the lengths of the second microstrip line 132 and the third microstrip line 133 differ by half a wavelength. The feeding at the front end of the first microstrip line 131 forms two currents with a 180° phase difference at the end of the parallel twin line 134 after passing through the double microstrip lines, and then transitions to the artificial surface plasmon radiation strip 16 through the tapered parallel twin line 14 and the transition parallel twin line 15, achieving end-fire direction radiation.

[0050] Such as Figure 2 And Figure 3 , the second microstrip line 132 and the third microstrip line 133 respectively adopt U-shaped microstrip lines with opposite bending directions, which can avoid the coupling between the two microstrip lines caused by bending in the same direction. The first microstrip line 131 is preferably a 50-ohm microstrip line.

[0051] Such as Figure 1 And Figure 7 , by setting the tapered parallel twin line 14 and the transition parallel twin line 15, the structure is simple, the electrical size is small, and it is easy to process. The bottom layer 21 of the dielectric substrate is provided with a grounding metal layer 22 with a length corresponding to that of the balun structure 13.

[0052] Such as Figure 1 And Figure 2 , the artificial surface plasmon radiation strip 16 includes an artificial surface plasmon transition section 161, a periodic rectangular patch section 162, an artificial surface plasmon tapered section 163 and patches. One end of the periodic rectangular patch section 162 is connected to the tapered parallel twin line 14 through the artificial surface plasmon transition section 161, and the other end of the periodic rectangular patch section 162 is connected to the artificial surface plasmon tapered section 163. The patches are arranged at equal intervals on the outside of the artificial surface plasmon radiation strip 16.

[0053] Such as Figure 2 , a gap 17 is provided on the inner side of the artificial surface plasmon radiation strip 16 and is arranged in parallel. By setting two completely parallel artificial surface plasmon radiation strips 16, and the gap 17 between the two artificial surface plasmon radiation strips 16 is an equal-width gap, it is possible to achieve a small antenna lateral size, high aperture efficiency, and avoid problems such as increasing the antenna lateral size, reducing the aperture efficiency, and complex processing.

[0054] Such as Figure 2 , Figure 4 , Figure 5 And Figure 6, the patch includes a first periodic patch 164, a rectangular patch 165, and a second periodic patch 166. A first inclined surface 167 is provided at the top of the first periodic patch 164. The bottom end of the first periodic patch 164 is disposed outside the artificial surface plasmon transition section 161. The rectangular patch 165 is disposed outside the periodic rectangular patch section 162, and the heights of the rectangular patches 165 are the same. A second inclined surface 168 is provided at the top of the second periodic patch. The bottom end of the second periodic patch 166 is disposed outside the artificial surface plasmon gradient section 163. The first inclined surface 167 can better achieve the transition from the parallel twin lines 15 to the artificial surface plasmon radiation strip 16. The second inclined surface 168 realizes the phase matching between the antenna and the free space through the artificial surface plasmon with gradually decreasing height, enabling the electromagnetic wave to better radiate into the free space.

[0055] Such as Figure 2 , Figure 4 and Figure 6 , the height of the first periodic patch 164 gradually increases from the far periodic rectangular patch section 162 end to the near periodic rectangular patch section 162 end. The height of the second periodic patch 166 gradually decreases from the far periodic rectangular patch section 162 end to the near periodic rectangular patch section 162 end. The first periodic patch 164 can better achieve the transition from the parallel twin lines 15 to the artificial surface plasmon radiation strip 16 without the need to additionally set an I-shaped resonator, and at the same time can achieve a shorter length ratio, reducing the overall size of the antenna; the second periodic patch 166 realizes the phase matching between the antenna and the free space through the artificial surface plasmon with gradually decreasing height, enabling the electromagnetic wave to better radiate into the free space.

[0056] Such as Figure 1 and Figure 2 , radiation is carried out using the artificial surface plasmon radiation strip 16, and the traveling wave mode is transmitted, which enables the antenna to have a relatively wide operating bandwidth. The current passing through the balun structure 13 undergoes transitions through the tapered parallel twin lines 14, the transition parallel twin lines 15, and the artificial surface plasmon transition section 161, achieving the impedance matching of the antenna, and thus further enabling a relatively wide bandwidth; through the gradient of the artificial surface plasmon gradient section 163, the matching of the electromagnetic wave is achieved, enabling the electromagnetic wave to effectively radiate into the free space and achieving a relatively high gain.

[0057] In the embodiment, by adjusting the height of the rectangular patch 165 on the artificial surface plasmon radiation strip 16, the regulation of the dispersion curve of the artificial surface plasmon radiation strip 16 is realized, thereby realizing the adjustment of the operating frequency and bandwidth of the antenna: when the height of the rectangular patch 165 increases, the operating frequency of the antenna decreases and the operating bandwidth becomes narrower; when the height of the rectangular patch 165 decreases, the operating frequency of the antenna increases and the operating bandwidth becomes wider.

[0058] In the embodiment, by adjusting the number of rectangular patches 165 on the artificial surface plasmon radiation strip 16, the length of the artificial surface plasmon radiation strip 16 is regulated, so as to regulate the gain and beam width of the antenna: when the number of rectangular patches 165 increases, the gain of the antenna increases and the beam width becomes narrower; when the number of rectangular patches 165 decreases, the gain of the antenna decreases and the beam width becomes wider.

[0059] For this kind of artificial surface plasmon high-aperture efficiency end-fire antenna, by adjusting the lengths of the second microstrip line 132 and the third microstrip line 133 in the balun structure 13, the operating frequency of the antenna is regulated. When the difference in the total lengths of the second microstrip line 132 and the third microstrip line 133 in the balun structure 13 increases, the operating frequency of the antenna becomes smaller; on the contrary, when the difference in the total lengths decreases, the operating frequency of the antenna becomes larger.

[0060] This kind of artificial surface plasmon high-aperture efficiency end-fire antenna is significantly different from the existing artificial surface plasmon end-fire antennas. In terms of structure: the existing artificial surface plasmon end-fire antennas usually adopt an asymmetric structure or use a resonant radiator, while the artificial surface plasmon end-fire antenna in the embodiment adopts a completely symmetric structure; in terms of principle: artificial surface plasmons have strong field confinement and cannot effectively radiate energy into free space. If we want to achieve the radiation of artificial surface plasmons into free space, we must disrupt their field distribution. The existing artificial surface plasmon end-fire antennas use the artificial surface plasmon transmission line as the feed of the antenna, and radiate by coupling the energy on the artificial surface plasmon transmission line to the radiator, or the artificial surface plasmon end-fire antenna with an asymmetric structure excites a differential electric field on the artificial surface plasmon radiation strip 16. The artificial surface plasmon end-fire antenna in the embodiment uses the balun structure 13 to feed the dipole-type artificial surface plasmons, so as to achieve effective energy radiation.

[0061] This kind of artificial surface plasmon high-aperture efficiency end-fire antenna adopts a thin dielectric substrate with a single-layer metal structure to achieve a low profile. The symmetric structure adopted makes the end-fire beam formed by the antenna not inclined. Finally, the antenna has the characteristics of a low profile, a wide operating bandwidth, a high aperture efficiency, good directivity in the end-fire direction, and a small size, etc., and can be applied to the microwave field.

[0062] The simulation and measurement verification results of the embodiment are as follows:

[0063] Figure 8 It is the S-parameter diagram of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiment. The antenna has an operating bandwidth of 9 - 11 GHz and a relative bandwidth of 20%, having a relatively wide operating bandwidth.

[0064] Figure 9, Figure 10 and Figure 11 are the radiation patterns of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiments at 9 GHz, 10 GHz, and 11 GHz, respectively. It can be seen from the radiation patterns that its beam does not tilt in the end-fire direction and has excellent end-fire performance.

[0065] Figure 12 are the gain and radiation efficiency obtained by taking points every 0.1 GHz in the 9-11 GHz frequency band of the artificial surface plasmon high-aperture efficiency end-fire antenna in the embodiment. The antenna has a maximum gain of 13.3 dBi and an average radiation efficiency of 98%, showing high gain and high radiation efficiency.

[0066] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. An artificial surface plasmon high-aperture efficiency end-fire antenna, comprising a dielectric substrate, a dielectric substrate top layer and a dielectric substrate bottom layer are respectively formed on the upper and lower surfaces of the dielectric substrate, and a grounding metal layer is provided on the dielectric substrate bottom layer, characterized in that: The top layer of the dielectric substrate is provided with a top surface metal layer. The top surface metal layer is provided with a balun structure, a tapered parallel two-wire line, a transitional parallel two-wire line, and artificial surface plasmon radiation strips. One end of the balun structure is a feeding port. The other end of the balun structure is connected to the end of the transitional parallel two-wire line through the connecting tapered parallel two-wire line. The other end of the transitional parallel two-wire line is connected to the pair of artificial surface plasmon radiation strips arranged symmetrically. A gap is formed between the artificial surface plasmon radiation strips and they are axially symmetrically arranged. The balun structure and the ground metal layer are correspondingly arranged on the upper and lower surfaces of the dielectric substrate. Through the transitional structure composed of the balun structure, the tapered parallel two-wire line, and the transitional parallel two-wire line, the currents on both sides of the artificial surface plasmon radiation strips are fed in phase. The artificial surface plasmon radiation strips include an artificial surface plasmon transition section, a periodic rectangular patch section, an artificial surface plasmon tapered section, and a number of patches. One end of the periodic rectangular patch section is connected to the tapered parallel two-wire line through the artificial surface plasmon transition section. The other end of the periodic rectangular patch section is connected to the artificial surface plasmon tapered section. The patches are arranged at equal intervals on the outer side of the artificial surface plasmon radiation strips.

2. The plasmonic end-fire antenna with high aperture efficiency of artificial surface plasmons according to claim 1, characterized in that: The balun structure includes a first microstrip line, a double microstrip line, and a parallel two-wire line. The double microstrip line includes a second microstrip line and a third microstrip line. The second microstrip line and the third microstrip line are respectively microstrip lines bent into a U shape with a total length difference of half a wavelength. One end of the first microstrip line is the feeding port of the antenna. The two sides of the other end of the first microstrip line are respectively connected to the second microstrip line and the third microstrip line. The second microstrip line and the third microstrip line are connected to the tapered parallel two-wire line.

3. The plasmonic end-fire antenna with high aperture efficiency of artificial surface plasmons according to claim 2, characterized in that: The second microstrip line and the third microstrip line are respectively U-shaped microstrip lines with opposite bending directions.

4. The plasmonic high-aperture efficiency end-fire antenna according to any one of claims 1-3, characterized in that: A gap is provided on the inner side of the artificial surface plasmon radiation strips and they are arranged parallel to each other.

5. The plasmonic end-fire antenna with high aperture efficiency according to claim 1, wherein: The patches include a first periodic patch, a rectangular patch, and a second periodic patch. The top end of the first periodic patch is provided with a first inclined surface. The bottom end of the first periodic patch is arranged on the outer side of the artificial surface plasmon transition section. The rectangular patch is arranged on the outer side of the periodic rectangular patch section and has the same height. The top end of the second periodic patch is provided with a second inclined surface. The bottom end of the second periodic patch is arranged on the outer side of the artificial surface plasmon tapered section.

6. The artificial surface plasmon high-aperture efficiency end-fire antenna according to claim 5, wherein: The height of the first periodic patch gradually increases from the end far from the periodic rectangular patch section to the end close to the periodic rectangular patch section. The height of the second periodic patch gradually decreases from the end far from the periodic rectangular patch section to the end close to the periodic rectangular patch section.

7. The plasmonic high-aperture efficiency end-fire antenna with artificial surface as claimed in claim 5 or 6, characterized in that: By adjusting the height of the rectangular patches on the artificial surface plasmon radiation strips, the regulation of the dispersion curve of the artificial surface plasmon radiation strips is realized, thereby realizing the adjustment of the working frequency and bandwidth of the antenna: when the height of the rectangular patches increases, the working frequency of the antenna decreases and the working bandwidth becomes narrower; when the height of the rectangular patches decreases, the working frequency of the antenna increases and the working bandwidth becomes wider.

8. The artificial surface plasmon high-aperture efficiency end-fire antenna according to claim 5 or 6, characterized in that: By adjusting the number of rectangular patches on the artificial surface plasmon radiation strip, the length of the artificial surface plasmon radiation strip is regulated, thereby realizing the regulation of the antenna gain and beam width: when the number of rectangular patches increases, the gain of the antenna increases and the beam width becomes narrower; when the number of rectangular patches decreases, the gain of the antenna decreases and the beam width becomes wider.

9. The plasmonic high-aperture efficiency end-fire antenna with artificial surface according to any one of claims 1-3, characterized in that: By adjusting the total length of the second microstrip line and the third microstrip line in the balun structure, the operating frequency of the antenna is regulated: when the difference in the total length between the second microstrip line and the third microstrip line in the balun structure increases, the operating frequency of the antenna becomes smaller. On the contrary, when the difference in the total length decreases, the operating frequency of the antenna becomes larger.

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