Asymmetric high-gain end-on-fire antenna based on artificial surface plasmon

Abstract

The invention relates to the technical field of microwaves, in particular to an asymmetric high-gain end-on-fire antenna based on artificial surface plasmon, which comprises a dielectric substrate bottom layer and a dielectric substrate top layer, a trapezoidal metal layer is arranged on the dielectric substrate bottom layer along the end part; a microstrip line is arranged on the dielectric substrate top layer, the trapezoidal metal layer is arranged at the grounding end of the microstrip line, the microstrip line comprises a transition section and an artificial surface plasmon radiation strip which are sequentially arranged close to the trapezoidal metal layer, and the trapezoidal metal layer, the transition section and the artificial surface plasmon radiation strip form a feed network; the artificial surface plasmon radiation strip comprises a trapezoidal gradual change groove and a rectangular gradual change groove which are sequentially arranged along the transition section, the trapezoidal gradual change groove and the rectangular gradual change groove are coupled, and the artificial surface plasmon radiation strip is of an asymmetric structure; electromagnetic waves can be propagated near the artificial surface plasmon structure, radiation is achieved at the end through the microstrip line, and the antenna has high gain, good radiation directivity and low waveguide loss.

Description

Technical Field

[0001] The invention relates to the field of microwave technology, and in particular to an asymmetric high-gain end-fire antenna based on artificial surface plasmons. Background Art

[0002] As a new type of electromagnetic surface wave mode, artificial surface plasmon has attracted widespread attention in the microwave and terahertz fields in recent years. It regulates the electromagnetic field distribution through periodic subwavelength structures, has the characteristics of strong field localization, low loss and flexible dispersion, and provides new ideas for the design of high-performance antennas. Traditional SSPPs (Spoof Surface PlasmonPolaritons) antennas mostly adopt a symmetrical structure design. The surface wave mode is restricted by symmetrical boundary conditions, resulting in a broadened main lobe of the radiation pattern and insufficient gain, which makes it difficult to meet the needs of modern communication systems for highly directional radiation. End-fire antennas are widely used in directional communications and radar systems due to their high gain and narrow beam characteristics. However, the combination of existing SSPPs antennas and end-fire radiation modes has not been fully studied, and there are common problems such as low end-fire efficiency and beam tilt. Traditional end-fire antennas, such as the Yagi-Uda antenna, rely on multi-unit arrays or complex feeding structures, and have the defects of large size and low integration, making them difficult to adapt to compact RF front ends. To change this situation, attempts are now usually made to combine the SSPPs slow-wave characteristics with end-fire radiation, but their settings are mostly symmetrical structures, which limits gain improvement and makes feeding more complicated. Summary of the invention

[0003] In order to solve the technical problems that the existing SSPPs antennas usually adopt a symmetrical structure, limited gain improvement and complex feeding, the purpose of the present invention is to provide an asymmetric high-gain end-fire antenna based on artificial surface plasmons, and the technical solutions adopted are as follows: The end-fire antenna comprises a dielectric substrate bottom layer and a dielectric substrate top layer; a trapezoidal metal layer is arranged along the end of the dielectric substrate bottom layer; a microstrip line is arranged on the dielectric substrate top layer, the trapezoidal metal layer is arranged at the ground end of the microstrip line, and the microstrip line comprises a transition section and an artificial surface plasmon radiation strip which are sequentially arranged close to the trapezoidal metal layer, and the trapezoidal metal layer, the transition section and the artificial surface plasmon radiation strip form a feeding network; the artificial surface plasmon radiation strip comprises a trapezoidal gradient groove and a rectangular gradient groove which are sequentially arranged along the transition section, the trapezoidal gradient groove and the rectangular gradient groove are coupled, and the artificial surface plasmon radiation strip presents an asymmetric structure.

[0004] Preferably, the trapezoidal gradient groove and the rectangular gradient groove are respectively defined as the first period segment and the second period segment of the artificial surface plasmon radiation strip; The depth of the trapezoidal gradient groove gradually deepens toward the rectangular gradient groove to the center of the first period segment, and gradually decreases from the center of the first period segment to the second period segment; the depths of the rectangular gradient grooves in the second period segment are all different.

[0005] Preferably, the depth of the rectangular gradient groove ranges from 0.5 mm to 3.5 mm.

[0006] Preferably, the length of the artificial surface plasmon radiation strip is in the range of 48 mm to 52 mm.

[0007] Preferably, the width of the artificial surface plasmon radiation strip is in the range of 1.1 mm to 1.7 mm, and the width of the trapezoidal gradient groove is the same as that of the rectangular gradient groove.

[0008] The present invention has the following beneficial effects: The high-gain end-fire antenna based on artificial surface plasmon proposed in the present application adopts an asymmetric structure, so that electromagnetic waves can be better propagated near the artificial surface plasmon structure, and effective radiation is achieved at the end through the microstrip line, that is, after the current enters, the current is transported upward to the microstrip line on the top layer of the dielectric substrate through the trapezoidal metal layer on the bottom layer of the dielectric substrate, so that the current can be accurately fed to the microstrip line, which can not only effectively save metal materials, but also has high gain and good radiation directivity, and can maintain energy integrity and low waveguide loss; according to the coordination of the first period segment and the second period segment, impedance matching can be achieved faster to improve the efficiency of the end-fire antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 A schematic structural diagram of a dielectric substrate bottom layer of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by an embodiment of the present invention; Figure 2 A schematic structural diagram of a top layer of a dielectric substrate of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by an embodiment of the present invention; Figure 3 An S-parameter diagram of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by one embodiment of the present invention; Figure 4A schematic diagram of the 11G direction of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by an embodiment of the present invention; Figure 5 A schematic diagram of the 11.2G direction of an asymmetric high-gain end-fire antenna based on artificial surface plasmon provided by an embodiment of the present invention; Figure 6 A schematic diagram of the 11.4G direction of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by an embodiment of the present invention; Figure 7 A schematic diagram of gain and efficiency of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by one embodiment of the present invention; In the figure: 7, bottom layer of dielectric substrate; 6, trapezoidal metal layer; 12, top layer of dielectric substrate; 8, transition section; 9, artificial surface plasmon radiation strip; 10, trapezoidal gradient groove; 11, rectangular gradient groove. DETAILED DESCRIPTION

[0011] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation, structure, features and effects of an asymmetric high-gain end-fire antenna based on artificial surface plasmon proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0012] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0013] A specific solution of an asymmetric high-gain end-fire antenna based on artificial surface plasmons provided by the present invention is described in detail below with reference to the accompanying drawings.

[0014] Please combine Figure 1 and Figure 2 , which respectively show the structural schematic diagrams of the dielectric substrate bottom layer 7 and the dielectric substrate top layer 12 of an asymmetric high-gain end-fire antenna based on artificial surface plasmons of the present invention.

[0015] Furthermore, an asymmetric high-gain end-fire antenna based on artificial surface plasmons includes a dielectric substrate bottom layer 7 and a dielectric substrate top layer 12; a trapezoidal metal layer 6 is arranged along the end of the dielectric substrate bottom layer 7; a microstrip line is arranged on the dielectric substrate top layer 12, the trapezoidal metal layer 6 is arranged at the ground end of the microstrip line, and the microstrip line includes a transition section 8 and an artificial surface plasmon radiation strip 9 arranged in sequence near the trapezoidal metal layer 6, the trapezoidal metal layer 6, the transition section 8 and the artificial surface plasmon radiation strip 9 form a feeding network; the artificial surface plasmon radiation strip 9 includes a trapezoidal gradient groove 10 and a rectangular gradient groove 11 arranged in sequence along the transition section 8, the trapezoidal gradient groove 10 and the rectangular gradient groove 11 are coupled, and the artificial surface plasmon radiation strip 9 has an asymmetric structure.

[0016] As an optional implementation, in this embodiment, the end-fire antenna can be manufactured using any one of a planar printed circuit board (PCB) process, a chip process, a high temperature co-fired ceramic (HTCC) process, or a low temperature co-fired ceramic (LTCC) process; among them, the planar printed circuit board process is widely used in various radio frequency and microwave devices due to its high cost-effectiveness and design flexibility; the chip process can achieve extremely high integration and performance, and is suitable for occasions with strict requirements on size and weight; the high temperature co-fired ceramic process and the low temperature co-fired ceramic process are often used in radio frequency modules that need to withstand extreme environmental conditions due to their excellent thermal stability and mechanical strength; in actual applications, the most suitable preparation method can be selected according to specific application requirements and performance indicators.

[0017] It can be explained that the trapezoidal tapered groove 10 and the rectangular tapered groove 11 are coupled, and the trapezoidal tapered groove 10 and the rectangular tapered groove 11 in the artificial surface plasmon radiation strip 9 are coupled and fed through the trapezoidal metal layer 6 of the bottom layer 7 of the dielectric substrate, and impedance matching is achieved through the transition section 8 to maintain energy integrity and reduce waveguide losses. That is, the end-fire antenna feeding is directly achieved through the microstrip line combined with the trapezoidal metal layer 6 on the back thereof to simplify the feeding process and facilitate feeding, so that the entire end-fire antenna can be more efficient, have high gain and good radiation directivity.

[0018] See also Figure 3 , which shows the S-parameter diagram of an asymmetric high-gain end-fire antenna based on artificial surface plasmon provided by an embodiment of the present invention; it reflects that the end-fire antenna works in the slow-wave region, and the phase constant is larger than the phase constant in the fast-wave region, making it easier for the slow-wave region to radiate the end-fire beam.

[0019] Further, the trapezoidal gradient groove 10 and the rectangular gradient groove 11 are respectively defined as the first period segment and the second period segment of the artificial surface plasmon radiation strip 9; The depth of the trapezoidal gradient groove 10 gradually increases toward the rectangular gradient groove 11 to the center of the first period segment, and gradually decreases from the center of the first period segment to the second period segment; the depths of the rectangular gradient grooves 11 in the second period segment are all different.

[0020] Specifically, in the structural layout, the part close to the transition section 8 is set as a trapezoidal tapered groove 10, that is, the first periodic segment is used to arrange the trapezoidal tapered groove 10, which is in the shape of a horn, and it cooperates with the transition section 8 to achieve impedance matching, which can achieve impedance matching faster and improve the efficiency of the end-fire antenna. In addition, in the second periodic segment, the direction of the rectangular tapered groove 11 constitutes an asymmetric structure. At this time, the phase difference on both sides of the asymmetric modulation even mode TL (Transmission Line) is obtained, and the corresponding logical formula is:

[0021] in, Indicates phase difference; represents the scattering parameter; Represents the coherence length.

[0022] when yes When it is an even multiple of for The phase values ​​on both sides are in opposite phases, and end-fire cannot be achieved. yes When it is an odd multiple of for An even multiple of , corresponding to being in phase, then end-fire is achieved at the end of the TL; in this embodiment, the artificial surface plasmon radiation strip 9 used in the end-fire antenna has an asymmetric structure and is in phase, which can achieve end-fire while improving gain.

[0023] Furthermore, the depth range of the rectangular tapered groove 11 is 0.5 mm to 3.5 mm. This setting is used to adjust the high-frequency cutoff frequency of the end-fire antenna to ensure that the end-fire antenna can work effectively within a specific frequency range. For example, when the end-fire antenna needs to cover a wider frequency band, the high-frequency cutoff frequency is reduced by increasing the depth of the tapered groove.

[0024] Furthermore, the length range of the artificial surface plasmon radiation strip 9 is 48mm~52mm. This setting is used to adjust the beam width and gain of the end-fire antenna. For example, in situations where wider beam coverage is required, a wider signal propagation range can be achieved by appropriately increasing the strip length; on the contrary, if the directionality of the signal needs to be improved, reducing the strip length will help to reduce the beam width and increase the gain of the end-fire antenna.

[0025] Furthermore, the width of the artificial surface plasmon radiation strip 9 ranges from 1.1 mm to 1.7 mm, and the width of the trapezoidal gradient groove 10 is the same as that of the rectangular gradient groove 11; by adjusting the width of the artificial surface plasmon radiation strip 9, the beam width of the end-fire antenna can be adjusted to optimize the performance of the end-fire antenna.

[0026] See also Figure 4-Figure 7 , which respectively show the 11G direction schematic diagram, 11.2G direction schematic diagram, 11.4G direction schematic diagram, and gain and efficiency schematic diagram of an asymmetric high-gain end-fire antenna based on artificial surface plasmon provided by an embodiment of the present invention; the figure shows that the gain can reach 10.3ghz, indicating that the end-fire antenna has the characteristics of high gain.

[0027] It can be understood that the high-gain end-fire antenna based on artificial surface plasmon proposed in the present application adopts an asymmetric structure, so that electromagnetic waves can better propagate near the artificial surface plasmon structure, and realize effective radiation at the end through the microstrip line, that is, after the current enters, the current is transported upward to the microstrip line on the top layer 12 of the dielectric substrate through the trapezoidal metal layer 6 of the bottom layer 7 of the dielectric substrate, so that the current can be accurately fed to the microstrip line, which can not only effectively save metal materials, but also has high gain and good radiation directivity, and can maintain energy integrity and low waveguide loss; according to the coordination of the first period segment and the second period segment, impedance matching can be achieved faster to improve the efficiency of the end-fire antenna.

[0028] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0029] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. An asymmetric high-gain end-fire antenna based on artificial surface plasmons, characterized in that: The end-fire antenna comprises a dielectric substrate bottom layer and a dielectric substrate top layer; A trapezoidal metal layer is arranged along the end of the bottom layer of the dielectric substrate; A microstrip line is arranged on the top layer of the dielectric substrate, the trapezoidal metal layer is arranged at the ground end of the microstrip line, and the microstrip line includes a transition section and an artificial surface plasmon radiation strip which are sequentially arranged near the trapezoidal metal layer, and the trapezoidal metal layer, the transition section and the artificial surface plasmon radiation strip form a feeding network; The artificial surface plasmon radiation strip comprises a trapezoidal gradient groove and a rectangular gradient groove which are sequentially arranged along the transition section, the trapezoidal gradient groove and the rectangular gradient groove are coupled, and the artificial surface plasmon radiation strip presents an asymmetric structure.

2. The asymmetric high-gain end-fire antenna based on artificial surface plasmon according to claim 1, characterized in that: Respectively defining the trapezoidal gradient groove and the rectangular gradient groove as the first period segment and the second period segment of the artificial surface plasmon radiation strip; The depth of the trapezoidal gradient groove gradually deepens toward the rectangular gradient groove to the center of the first period segment, and gradually decreases from the center of the first period segment to the second period segment; the depths of the rectangular gradient grooves in the second period segment are all different.

3. The asymmetric high-gain end-fire antenna based on artificial surface plasmon according to claim 2, characterized in that: The depth of the rectangular gradient groove ranges from 0.5 mm to 3.5 mm.

4. The asymmetric high-gain end-fire antenna based on artificial surface plasmon according to claim 1, characterized in that: The length of the artificial surface plasmon radiation strip ranges from 48 mm to 52 mm.

5. The asymmetric high-gain end-fire antenna based on artificial surface plasmon according to claim 2, characterized in that: The width of the artificial surface plasmon radiation strip is in the range of 1.1 mm to 1.7 mm, and the width of the trapezoidal gradient groove is the same as that of the rectangular gradient groove.

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