Artificial surface plasmon conformal leaky-wave antenna

Abstract

The invention discloses an artificial surface plasmon conformal leaky-wave antenna. The antenna comprises a substrate and at least one radiation assembly. The base is a hollow cylinder; the radiation assembly is arranged on the substrate, and the radiation assembly is provided with a first symmetry axis parallel to the axis of the substrate and a second symmetry axis perpendicular to the first symmetry axis; the radiation assembly comprises a radiation part attached to the surface of a substrate, and the radiation part comprises a radiation section; the radiation section comprises a plurality of leaky wave units which are sequentially connected in series. Each leaky-wave unit comprises an upper-layer radiation part and a lower-layer radiation part, and a gap is formed between the upper-layer radiation part and the lower-layer radiation Two adjacent side edges of the upper-layer radiation piece and the lower-layer radiation piece are respectively provided with a plurality of radiation teeth, and gaps are arranged between adjacent radiation teeth in the upper-layer radiation piece and between adjacent radiation teeth in the lower-layer radiation piece; the gap of the upper layer radiation part and the gap of the corresponding lower layer radiation part form a transmission groove belt, and the lengths of the transmission groove belts in the leaky wave units are equal.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and specifically to an artificial surface plasmon conformal leaky wave antenna. Background Technology

[0002] An antenna is a device that transmits and receives electromagnetic waves. With the development of wireless communication technology, the requirements for antenna weight and size are becoming increasingly stringent, and more and more application scenarios require conformal antennas. Conformal antennas not only do not affect the aerodynamic characteristics of the carrier, but their thin and light characteristics also help improve the miniaturization and weight reduction of the overall system. Traditional leaky wave antennas include waveguide slot antennas, microstrip antennas, and substrate integrated waveguide antennas. They are antennas that continuously radiate outwards while transmitting electromagnetic waves along a transmission line, exhibiting excellent characteristics in broadband and wide-angle frequency beam scanning. Although microstrip leaky wave antennas or substrate integrated waveguide leaky wave antennas fabricated using traditional PCB (Printed Circuit Board) methods have significant advantages in longitudinal dimensions compared to leaky wave antennas with waveguide slots, the copper layer of the antenna is attached to a planar high-frequency microstrip board, making it unsuitable for some curved carrier spaces. Therefore, to reduce the space occupied by wireless equipment, the design and fabrication of conformal leaky wave antennas is particularly important.

[0003] Furthermore, since leaky wave antennas radiate by electromagnetic wave leakage from transmission lines, they have a closed transmission carrier structure and typically have a large metal base plate. Existing antenna structures cannot achieve end-fire radiation characteristics consistent with the radial propagation direction. This invention utilizes the special surface wave mode of artificial surface plasmon resonance elements to design a leaky wave antenna, enabling flexible beam pointing design, especially with significant advantages in beam pointing in the end-fire direction. Summary of the Invention

[0004] The purpose of this invention is to provide an artificial surface plasmon conformal leaky antenna to overcome the shortcomings of existing leaky antennas, such as the inability of the radiating components to conform to the substrate and the inability to form a beam pointing direction for end-fired radiation.

[0005] To achieve the above objectives, the present invention provides an artificial surface plasmon conformal leaky antenna, comprising:

[0006] The base is a hollow cylinder;

[0007] At least one radiating component, the radiating component being disposed on a substrate, and the radiating component having a first axis of symmetry parallel to an axis of the substrate and a second axis of symmetry perpendicular to the first axis of symmetry; the radiating component comprising: a radiating portion, the radiating portion being attached to an outer surface of the substrate, and the radiating portion comprising a radiating segment; the radiating segment comprising a plurality of leakage wave units connected in series.

[0008] Each of the aforementioned leakage wave units includes: an upper radiating element and a lower radiating element attached to the outer surface of a substrate, wherein the upper and lower radiating elements are arranged in parallel and symmetrically, and there is a gap between them; each of the two adjacent sides of the upper and lower radiating elements is provided with a plurality of radiating teeth, and there are gaps between adjacent radiating teeth in the upper radiating element and between adjacent radiating teeth in the lower radiating element; the gaps in the upper radiating element and the corresponding gaps in the lower radiating element together constitute a transmission slot, and the length of the transmission slot in each of the aforementioned leakage wave units is equal.

[0009] Optionally, each of the drain wave units is divided into multiple plasmonic units arranged in sequence. Each plasmonic unit is formed by the radiation teeth of an upper radiator, the radiation teeth of its corresponding lower radiator, and the adjacent transmission slots. The two radiation teeth in each plasmonic unit are symmetrical about a first axis of symmetry, and the multiple plasmonic units in each drain wave unit are arranged symmetrically about the center position of the drain wave unit.

[0010] Optionally, each drain wave unit has a length of 5.5 mm and a thickness of 0.018 mm, and each drain wave unit is divided into 11 plasmonic units. The width of the radiation teeth in each plasmonic unit is 0.3 mm, and the width of the transmission slot is 0.2 mm. The distances between the symmetrical radiation teeth in the 11 plasmonic units in each drain wave unit are 1.45 mm, 1.65 mm, 2.00 mm, 2.45 mm, 2.93 mm, 3.2 mm, 2.93 mm, 2.45 mm, 2.00 mm, 1.65 mm, and 1.45 mm, respectively.

[0011] Optionally, the radiating component further includes:

[0012] Two feeding sections are located at opposite ends of the substrate. Each feeding section includes an upper feeding component and a lower feeding component. The upper feeding component is a microstrip line with a gradually changing width, attached to the outer surface of the substrate. The lower feeding component is a microstrip line with a gradually changing width, located directly below the upper feeding component and attached to the inner surface of the substrate. The direction of the gradually changing width in the lower feeding component is the same as the direction of the gradually changing width in the upper feeding component.

[0013] The system comprises two transition sections, each including an upper transmission component and a lower transmission component. The upper transmission component is attached to the outer surface of the substrate, with one end connected to the upper feed component and the other end connected to the radiating component. The lower transmission component is attached to the outer surface of the substrate, with one end connected to the lower feed component via a connector penetrating the substrate wall and the other end connected to the radiating component. The upper and lower transmission components are of the same length, and a gap exists between them on the outer surface of the substrate, forming a first transmission line. The width of the first transmission line gradually increases towards the radiating component.

[0014] Optionally, in each feeding section, the upper feeding element has a length of 8 mm and a thickness of 0.018 mm, and its length gradually changes from 1.992 mm to 1.2 mm in the direction towards the radiating part; the lower feeding element has a length of 8 mm and a thickness of 0.018 mm, and its length gradually changes from 4.44 mm to 1.2 mm in the direction towards the radiating part.

[0015] In each transition section, the length of the upper transmission element and the lower transmission element are both 6.6 mm and the thickness is both 0.018 mm. The width of the extension end of the upper transmission element away from the power supply section and the width of the extension end of the lower transmission element away from the power supply section are both 2.6 mm. The width of the first transmission line gradually changes from 0.15 mm to 1.3 mm.

[0016] Optionally, the radiating portion further includes two edge segments respectively disposed at both ends of the radiating segment;

[0017] Each edge segment includes: an upper edge member and a lower edge member symmetrically arranged; the two ends of the upper edge member are respectively connected to an upper radiating member and an upper transmitting member, and the width of the upper edge member is equal to the width of the extended end of the upper radiating member; the two ends of the lower edge member are respectively connected to a lower radiating member and a lower transmitting member, and the width of the lower edge member is equal to the width of the extended end of the lower transmitting member; the spacing between the upper edge member and the lower edge member is equal to the width of the first transmission line away from the feeding portion.

[0018] Optionally, in each edge segment, a plurality of edge slots are respectively provided on the two adjacent sides of the upper edge component and the lower edge component. The edge slot of the upper edge component and the edge slot of the corresponding lower edge component form a transition slot band. The length of the plurality of transition slot bands increases in a stepwise manner towards the radiation segment, and the length of the transition slot band near the radiation segment is equal to the length of the transmission slot band in the leakage wave unit.

[0019] Optionally, in each edge segment, the width of both ends of the upper edge member and the lower edge member is 2.6 mm and the thickness is 0.018 mm, the width of the radiating portion is 6.5 mm, and the interval between the upper edge member and the lower edge member is 1.3 mm; each edge segment includes 8 transition grooves arranged sequentially in the direction of the radiating segment, and the length of the 8 transition grooves increases stepwise from 1.3 mm to 3.9 mm in the direction of the radiating segment.

[0020] Optionally, the substrate is made of a material with a dielectric constant of less than or equal to 5.

[0021] Optionally, the substrate is made of a ceramic material with a dielectric constant of 3.55, and the substrate has a thickness of 1 mm, an inner diameter of 9 mm, and a length of 190 mm.

[0022] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0023] This invention constructs a novel leaky wave antenna using a series structure of periodically arranged plasmonic units (i.e., leaky wave units). By periodically varying the distance between the symmetrical radiating teeth in the multiple plasmonic units within each leaky wave unit, the surface impedance of the electromagnetic wave transmitted on the second transmission line formed by the radiating portion is periodically modulated, thereby inducing efficient radiation. One end of the antenna is used as the input signal, and the other end is connected to a load. The signal transmitted on the radiating portion forms an electromagnetic wave in free space, and the radiation direction is along the radial line direction of the base (hollow annular cylinder) (e.g.,...). Figure 8 As shown, this achieves excellent end-fire high-gain radiation characteristics. Simultaneously, the radiating components, including the radiating part, are conformally fitted to the base, and the single-layer antenna structure (i.e., a transmission line structure composed of a single metal layer) is directly etched onto the outer surface of the base. This gives the antenna of the present invention the advantages of being thin, light, and having an ultra-low profile, realizing an integrated structural and functional design for the antenna.

[0024] The antenna of the present invention adopts high-precision inkjet printing technology to form a radiating component by etching a metal layer (such as copper foil) on a cylindrical ceramic substrate. This gives the antenna of the present invention advantages such as high temperature resistance, thinness, simple processing, high reliability, low cost, and high temperature resistance. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0026] Figure 2 This is a schematic diagram of the radiating component in the artificial surface plasmon conformal leaky antenna described in this invention.

[0027] Figure 3This is a schematic diagram of the feeding section and the transition section in the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0028] Figure 4 This is a three-dimensional structural diagram of the feeding section in the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0029] Figure 5 This is a schematic diagram of the transition section in the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0030] Figure 6 This is a schematic diagram of the radiating section in the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0031] Figure 7 This is a schematic diagram of the structure of the leaky wave unit in the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0032] Figure 8 This is a simulated three-dimensional radiation pattern of the artificial surface plasmon conformal leaky wave antenna described in this invention.

[0033] In the figure, 1-substrate, 2-radiating component, 201-feeding section, 203-radiating section, 2031-edge segment, 2032-radiating segment, 204-transition section, 301-upper layer feeder, 302-lower layer feeder, 303-connector, 304-upper layer transmission component, 305-lower layer transmission component, 306-upper layer radiating component, 307-lower layer radiating component, 308-upper layer edge component, 309-lower layer edge component, 401-first transition groove, 402-second transition groove, 403-third transition groove, 404-fourth transition groove, 405-fifth transition groove, 406-sixth transition groove. Transition slot strip, 407-Seventh transition slot strip, 408-Eighth transition slot strip, 409-Radiation tooth, 410-Gap, 411-Edge slot, 5-Leakage wave unit, 501-First plasmonic unit, 502-Second plasmonic unit, 503-Third plasmonic unit, 504-Fourth plasmonic unit, 505-Fifth plasmonic unit, 506-Sixth plasmonic unit, 507-Seventh plasmonic unit, 508-Eighth plasmonic unit, 509-Ninth plasmonic unit, 510-Tenth plasmonic unit, 511-Eleventh plasmonic unit, 512-Transmission slot strip. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] like Figure 1 As shown, the present invention provides an artificial surface plasmon conformal leaky wave antenna, comprising: a substrate 1 and at least one radiating component 2. The substrate 1 is a hollow cylinder, the radiating component 2 is attached to the outer surface of the substrate 1, and the radiating component 2 extends along the axial direction of the substrate 1, so that the radiating component 2 forms electromagnetic waves radiated along the radial direction of the substrate 1.

[0038] The substrate 1 is made of a high-temperature resistant material with a dielectric constant of less than or equal to 5, typically a ceramic material with a dielectric constant of 3.55. To improve the radiation efficiency of the antenna of the present invention, the length of the substrate 1 should be sufficiently long to allow electromagnetic waves to radiate fully into free space; and the radius of the substrate 1 should not be too small to prevent distortion and deterioration of the antenna pattern formed based on the electromagnetic waves.

[0039] In a preferred embodiment, the base 1 is a hollow cylinder with a thickness of 1 mm, an inner diameter of 9 mm, and a length of 190 mm.

[0040] like Figure 1 and Figure 2As shown, the radiating component 2 is made of a metallic material, typically a copper layer covering the outer surface of the base, with a thickness of 0.018 mm. The radiating component 2 includes two feed sections 201, two transition sections 204, and a radiating section 203. The radiating component 2 has a first axis of symmetry parallel to the base and a second axis of symmetry perpendicular to the first axis of symmetry, with the intersection of the second and first axes of symmetry located at the center of the radiating component 2. The two feed sections 201 are respectively disposed at both ends of the base 1. Each transition section 204 connects to both ends of the radiating section 203 and the corresponding feed section 201, and the radiating section 203 is symmetrical about the second axis of symmetry. In use, one end of the radiating component 2 (one feed section 201) receives a signal, and the other end (the other feed section 201) is connected to a load. The symmetrical structure of the radiating component 2 absorbs unradiated energy from the antenna, preventing the reflection of unradiated energy.

[0041] Specifically, such as Figure 1-4 As shown, each of the feeding sections 201 is a connection point for current to enter / exit the radiation component 2, including: an upper feeding element 301 and a lower feeding element 302. The upper feeding element 301 is a microstrip line with a gradually changing width, attached to the outer surface of the substrate 1. The lower feed element 302 is a microstrip line with a gradually changing width and is attached to the inner surface of the substrate 1. The substrate 1 isolates the lower feed element 302 from the upper feed element 301, preventing short circuits and reducing electromagnetic interference between them. The lower feed element 302 is located directly below the upper feed element 301, and the direction of the gradually changing width in the lower feed element 302 is the same as that in the upper feed element 301, resulting in an overlap between the two feed elements. By adjusting the length of this overlap, the coupling capability of the feed element 201 can be changed, allowing it to meet different impedance requirements.

[0042] In one specific embodiment, to achieve impedance matching with a 50Ω RF connector, such as Figure 3 and Figure 4 As shown, the upper feeder 301 has a length of 8 mm, and its length gradually changes from 1.992 mm to 1.2 mm in the direction toward the radiating portion 203; the lower feeder 302 has a length of 8 mm, and its length gradually changes from 4.44 mm to 1.2 mm in the direction toward the radiating portion 203.

[0043] like Figure 3As shown, each transition portion 204 includes an upper transmission element 304 and a lower transmission element 305. The upper transmission element 304 is attached to the outer surface of the substrate 1, with one end connected to the upper feed element 301 and the other end connected to the radiation portion 203. The lower transmission element 305 is attached to the outer surface of the substrate 1, and one end of it is connected to a connector 303 penetrating the wall of the substrate 1 (e.g., ...). Figure 4 The connector 303 (as shown) is connected to the lower feeder 302 at one end and to the radiation part 203 at the other end; the connector 303 is made of a conductive metal material and passes through the wall of the substrate 1 radially to transmit the signal of the lower feeder 302 to the lower transmission part 305.

[0044] Furthermore, in each transition section 204, the upper transmission member 304 and the lower transmission member 305 have the same length, and a gap exists between them on the outer surface of the substrate 1. This gap forms a first transmission line, allowing electromagnetic waves generated by the signal between the upper transmission member 304 and the lower transmission member 305 to be transmitted through the first transmission line. Since the width of the transmission line affects radiation loss, a wider transmission line makes it easier for electromagnetic waves to radiate into space. Therefore, to achieve efficient radiation in the radiating section 203, the width of the first transmission line (i.e., the distance between the upper transmission member 304 and the lower transmission member 305) gradually widens towards the radiating section 203 to connect with it, ensuring that the radiating section 203 has sufficient radiation capability to radiate electromagnetic waves into free space.

[0045] In one specific embodiment, such as Figure 3 As shown, in each transition section 204, the upper transmission element 304 extends axially from the upper feed element 301 along the base 1 with a length of 6.6 mm; the lower transmission element 305 extends axially from the connector 303 along the base 1 with a length of 6.6 mm; and the distance between the upper transmission element 304 and the lower transmission element 305 on the side near the feed section 201 is 0.15 mm. Simultaneously, the extension ends of the upper transmission element 304 and the lower transmission element 305 away from the feed section 201 are flush, and the width of both extension ends is 2.6 mm, allowing them to connect together to the radiation section 203. The distance between the two closest points on the extension ends of the upper transmission element 304 and the lower transmission element 305 is 1.3 mm. At this time, the gap between the upper transmission component 304 and the lower transmission component 305 and the width of the first transmission line formed by the substrate 1 gradually change from 0.15mm to 1.3mm, and the signal received by the power supply section 201 is transmitted through the first transmission line.

[0046] Furthermore, such as Figure 3As shown, in each transition section 204, both the upper transmission component 304 and the lower transmission component 305 have a gradually changing width. The width of the upper transmission component 304 at the connection to the feed section 201 is smaller than the width at the connection to the radiation section 203, and the width of the lower transmission component 305 at the connection to the feed section 201 is smaller than the width at the connection to the radiation section 203, so that the transition section 204 and the radiation section 203 are connected in a transitional manner.

[0047] The radiating portion 203 is attached to the outer surface of the substrate 1 and serves as the main body for transmitting electromagnetic waves. For example... Figure 2 , Figure 3 and Figure 5 As shown, the radiating section 203 includes a radiating segment 2032 and two edge segments 2031 respectively disposed at both ends of the radiating segment 2032. Each edge segment 2031 is connected to the feeding section 201 through a transition section 204. The radiating segment 2032 includes a plurality of leakage wave units 5 connected in series. The number of leakage wave units 5 is determined according to actual needs.

[0048] Specifically, such as Figure 3 and Figure 6 As shown, each leaky wave unit 5 includes an upper radiator 306 and a lower radiator 307. The upper radiator 306 is attached to the outer surface of the substrate 1 to connect with the extension end of the upper transmission element 304. The lower radiator 307 is attached to the outer surface of the substrate 1 to connect with the extension end of the lower transmission element 305.

[0049] Among them, such as Figure 3 , Figure 5 and Figure 6 As shown, in each leaky wave unit 5, the upper radiator 306 and the lower radiator 307 are mirror-symmetrical about the first axis of symmetry. The upper radiator 306 and the lower radiator 307 are arranged in parallel and have a gap between them. The gap between the upper radiator 306 and the lower radiator 307 in several series-connected leaky wave units 5 together forms a second transmission line. The two ends of the second transmission line are respectively connected to the first transmission line of the two transition sections 204 through two transition sections, which are used to transmit signals and modulate the signals into electromagnetic waves that can be radiated into free space.

[0050] Furthermore, such as Figure 6 and Figure 7As shown, in each leaky wave unit 5, the upper radiator 306 and the lower radiator 307 have several radiating teeth 409 on their two adjacent sides, and there are gaps 410 between adjacent radiating teeth 409 on the same radiator (i.e., upper radiator 306 and lower radiator 307). Since the upper radiator 306 and the lower radiator 307 are symmetrical about the first axis of symmetry, the radiating teeth 409 on the upper radiator 306 correspond one-to-one with the 409 on the lower radiator 307, and the gaps 410 on the upper radiator 306 correspond one-to-one with the gaps 410 on the lower radiator 307. At this time, the gaps 410 of the upper radiator 306 and the corresponding gaps 410 of the lower radiator 307 together constitute the transmission slot 512, and the length of the transmission slot 512 in each leaky wave unit 5 is equal. By changing the distance H between the radiation teeth 409 of the upper radiator 306 and the radiation teeth 409 of the lower radiator 307, the width of the second transmission line is changed, and the signal transmitted by the radiation part 203 is modulated into an electromagnetic wave that can be radiated into free space.

[0051] Specifically, such as Figure 6 and Figure 7 As shown, the radiating teeth 409 of an upper radiator 306, the corresponding radiating teeth 409 of a lower radiator 307, and the adjacent transmission slots 512 on the same side together form a plasmonic unit. That is, each leaky wave unit 5 is divided into multiple plasmonic units arranged sequentially. The number of plasmonic units is determined according to design requirements. If the number of plasmonic units is too small, the radiation efficiency of the radiating part 203 will be poor; if the number of plasmonic units is too large, the signal transmitted by the antenna will be completely radiated, resulting in a waste of the redundant plasmonic unit structure.

[0052] To ensure that the leaky wave unit 5 can modulate the signal transmitted through the first transmission line (i.e., the transition section 204) into an electromagnetic wave that can radiate into free space, the distance between the radiation teeth 409 in each plasmonic unit of a leaky wave unit 5 (i.e., the distance between the radiation teeth 409 of the upper radiator 306 and the corresponding radiation teeth 409 of the lower radiator 307) is calculated as follows:

[0053] The operating frequency f of the antenna described in this invention, and the electromagnetic beam pointing angle θ at this operating frequency, are determined. The electromagnetic beam of the antenna described in this invention is in the end-fire direction, i.e., along the axial direction of the circular cylinder, θ = 90°. The phase β of the -1st spatial harmonic is then obtained using Equation 1. -1 .

[0054] sin(θ)=β -1 / k0 (Equation 1)

[0055] In the formula, k0 is the wavenumber in free space, and β -1The phase of the -1st spatial harmonic of the modulated antenna on each leaky wave element 5.

[0056] The phase β of the -1st spatial harmonic obtained based on Equation 1 -1 The average surface impedance Xs on the second transmission line is obtained as shown in Equation 2.

[0057]

[0058] Based on the principle of sinusoidal modulation of surface impedance, the surface impedance at different locations along the second transmission line should exhibit a sinusoidal distribution. Therefore, the surface impedance X at different plasmonic units in each leaky wave unit 5 can be calculated. s (y). That is, as shown in the following formula:

[0059] X s (y)=X s [1+Msin(2πy / T)] (Equation 3)

[0060] In the formula, y is the coordinate of each plasmonic unit along the signal propagation direction on one leaky element 5; M is the modulation factor of the periodic modulation antenna, which is selected as 0.4 in this invention; and T is the length of each leaky element 5.

[0061] Equation 4 is used to obtain the expected wavenumber k(y) of each plasmonic unit under the current design.

[0062]

[0063] An antenna model with the same structure as the antenna described in this invention is established using simulation software (e.g., Ansys HFSS). The gap length of each plasmonic element in the model is adjusted so that the beam of the plasmonic element at each position reaches the expected beam k(y), thereby obtaining the gap length of the plasmonic element that satisfies the antenna radiation efficiency.

[0064] In one specific embodiment, such as Figure 7As shown, the radiating portion 203 has a length of 157.8 mm and a width of 6.5 mm. The radiating segment 2032 of the radiating portion 203 is composed of 27 leakage wave units 5, and each leakage wave unit 5 has a length of 5.5 mm. Each leakage wave unit 5 is divided into 11 plasmonic units, namely, the first plasmonic unit 501, the second plasmonic unit 502, the third plasmonic unit 503, the fourth plasmonic unit 504, the fifth plasmonic unit 505, the sixth plasmonic unit 506, the seventh plasmonic unit 507, the eighth plasmonic unit 508, the ninth plasmonic unit 509, the tenth plasmonic unit 510, and the eleventh plasmonic unit 511. Furthermore, for ease of simulation calculation, the width of each radiating tooth 409 and the width of each slot 410 in the leaky wave unit 5 are equal; in this embodiment, the width b of the radiating tooth 409 is 0.3 mm, and the width a of the slot 410 (i.e., the width of the transmission slot 512) is 0.2 mm, that is, the width of each plasmon element is a + b = 0.5 mm. Moreover, to further ensure the symmetry and stability of the antenna radiation pattern, the multiple plasmon elements in each leaky wave unit 5 are symmetrically arranged about the center position of the leaky wave unit 5 (e.g., ...). Figure 7 (As shown); that is, the distance H1 between the symmetrical radiation teeth 409 in the first plasmonic unit 501 is equal to the distance H11 between the symmetrical radiation teeth 409 in the eleventh plasmonic unit 511; the distance H2 between the symmetrical radiation teeth 409 in the second plasmonic unit 502 is equal to the distance H10 between the symmetrical radiation teeth 409 in the tenth plasmonic unit 510; and the distance H11 between the symmetrical radiation teeth 409 in the third plasmonic unit 503 is equal to the distance H10 between the symmetrical radiation teeth 409 in the eleventh plasmonic unit 511. The distance H9 between H3 and the symmetrical radiation teeth 409 in the ninth plasmonic unit 509 is equal. The distance H4 between the symmetrical radiation teeth 409 in the fourth plasmonic unit 504 is equal to the distance H8 between the symmetrical radiation teeth 409 in the eighth plasmonic unit 508. The distance H5 between the symmetrical radiation teeth 409 in the fifth plasmonic unit 505 is equal to the distance H7 between the symmetrical radiation teeth 409 in the seventh plasmonic unit 507. After the above simulation calculations, the distances between the symmetrical radiation teeth 409 in each leaky wave unit 5 are obtained as follows: H1 = H11 = 1.45 mm, H2 = H10 = 1.65 mm, H3 = H9 = 2.00 mm, H4 = H8 = 2.45 mm, H5 = H7 = 2.93 mm, and H6 = 3.2 mm.

[0065] Furthermore, such as Figure 3 and Figure 5As shown, the edge segment 2031 in the radiating portion 203 is used to achieve a good transition between the leakage unit 5 and the transition portion 204, as well as good impedance matching between them. Each edge segment 2031 includes: an upper edge member 308 and a lower edge member 309 symmetrically arranged. The two ends of the upper edge member 308 are respectively connected to the upper radiating member 306 and the upper transmitting member 304, and the width of the upper edge member 308 is equal to the width of the extended end of the upper radiating member 306. The two ends of the lower edge member 309 are respectively connected to the lower radiating member 307 and the lower transmitting member 305, and the width of the lower edge member 309 is equal to the width of the extended end of the lower transmitting member 305. At the same time, the interval between the upper edge member 308 and the lower edge member 309 is equal to the width of the first transmission line away from the feed portion 201, completing the transition between the transition portion 204 and the radiating segment 2032 in the radiating portion 203.

[0066] Specifically, such as Figure 3 and Figure 5 As shown, in each edge segment 2031, several edge slots 411 are respectively provided on the two adjacent sides of the upper edge member 308 and the lower edge member 309; wherein, the edge slots 411 on the upper edge member 308 and the edge slots 411 on the lower edge member 309 are symmetrical about the first axis of symmetry, and the edge slots 411 of each upper edge member 308 and the corresponding edge slots 411 of the lower edge member 309 form a transition slot band. The length of the several transition slot bands increases stepwise towards the radiation segment 2032, and the length of the transition slot band near the radiation segment 2032 is equal to the length of the transmission slot band 512 in the leakage wave unit 5, realizing the transition between the first transmission line and the second transmission line.

[0067] In the above embodiments, such as Figure 5As shown, the radiating section 2032 has 27 sequentially connected leakage wave units 5. Two edge segments 2031 are respectively provided at both ends of the radiating section 2032, forming a radiating portion 203 with a length of 157.8 mm, realizing the transition of electromagnetic waves from the first transmission line to the second transmission line. The width of the radiating portion 203 is 6.5 mm, and the interval between the upper edge member 308 and the lower edge member 309 is 1.3 mm, with both the upper and lower edge members 308 having a width of 2.6 mm. The transmission slot strip 512 of the leakage wave unit 5 has a length of 3.9 mm. The upper edge member 308 has eight edge slots 411, and the length of the edge slots 411 increases in a stepped manner towards the leakage wave unit 5. The lower edge member 309 has eight edge slots 411 symmetrical to the upper edge member 308, so that the length of the eight transition slot strips of each edge segment 2031 increases in a stepped manner towards the leakage wave unit 5. Specifically, the eight transition slots are designated as the first transition slot 401, the second transition slot 402, the third transition slot 403, the fourth transition slot 404, the fifth transition slot 405, the sixth transition slot 406, the seventh transition slot 407, and the eighth transition slot 408. The lengths of these eight transition slots increase sequentially towards the radiating section 2032. The first transition slot 401 has a length of 1.3 mm, and the eighth transition slot 408 has a length of 3.9 mm. This step-by-step increase in length from 1.3 mm to 3.9 mm achieves a smooth transition between the radiating section 2032 and the transition portion 204. In this embodiment, the simulated three-dimensional radiation pattern of the antenna is as follows: Figure 8 As shown, the antenna has an end-fire radiation direction along the axis of the annular cylinder, which meets the application requirements of practical scenarios.

[0068] See Figure 1When using the antenna described in this invention, the two feed sections 201 located at both ends of the antenna are respectively connected to the signal and the load. In this configuration, near the signal input end, the upper feeder 301 in the power supply section 201 receives signal excitation and causes the lower feeder 302 to be affected by the signal, generating an induced current. The upper feeder 301 transmits the signal to the upper transmission component 304 connected to it, and the lower feeder 302 transmits the induced current to the lower transmission component 305 connected to it, forming an electromagnetic wave between the upper transmission component 304 and the lower transmission component 305. The electromagnetic wave propagates along the first transmission line. As the upper transmission component 304 transmits the signal to the upper radiating component 306 through the upper edge component 308, and the lower transmission component 305 transmits the induced current to the lower radiating component 307 through the lower edge component 309, the electromagnetic wave propagates sequentially through multiple transition slots and the second transmission line. When the electromagnetic wave propagates on the second transmission line (i.e., the leakage wave unit 5), the periodic arrangement of the leakage wave unit 5 periodically modulates the surface impedance of the electromagnetic wave, resulting in efficient radiation of the electromagnetic wave. Meanwhile, the signal after passing through the radiating part 203 is input to the transition part 204 on the side near the antenna connected to the load, and then the signal is transmitted to the load through the feed part 201 on the side near the antenna connected to the load. The load absorbs the energy of the antenna on the side near the load, so that the radiated energy is concentrated and emitted towards the side near the signal excitation, thereby enhancing the antenna's directivity (increasing gain).

[0069] In summary, the antenna of the present invention periodically modulates the surface impedance of the electromagnetic wave transmitted on the second transmission line formed by the radiating component by periodically changing the gap length of the equipolaron unit in each leaky wave unit, thereby causing the antenna to radiate efficiently and thus achieving good end-fire high-gain radiation characteristics; and the radiating component including the radiating part is conformal with the base, realizing the integrated design of the antenna structure and function.

[0070] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A conformal leaky-wave antenna for artificial surface plasmon resonances, characterized in that, include: The base is a hollow cylinder; At least one radiating component, the radiating component being disposed on a substrate, and the radiating component having a first axis of symmetry parallel to an axis of the substrate and a second axis of symmetry perpendicular to the first axis of symmetry; the radiating component comprising: a radiating portion, the radiating portion being attached to an outer surface of the substrate, and the radiating portion comprising a radiating segment; the radiating segment comprising a plurality of leakage wave units connected in series. Each of the aforementioned leakage wave units includes: an upper radiating element and a lower radiating element attached to the outer surface of a substrate, wherein the upper and lower radiating elements are arranged in parallel and symmetrically, and there is a gap between them; each of the two adjacent sides of the upper and lower radiating elements is provided with a plurality of radiating teeth, and there are gaps between adjacent radiating teeth in the upper radiating element and between adjacent radiating teeth in the lower radiating element; the gaps in the upper radiating element and the corresponding gaps in the lower radiating element together constitute a transmission slot, and the length of the transmission slot in each of the aforementioned leakage wave units is equal.

2. The artificial surface plasmon conformal leaky antenna according to claim 1, characterized in that, Each of the aforementioned leaky wave units is divided into multiple plasmonic units arranged sequentially. Each plasmonic unit is formed by the radiation teeth of an upper radiator, the radiation teeth of its corresponding lower radiator, and the adjacent transmission slots. The two radiation teeth in each plasmonic unit are symmetrical about a first axis of symmetry, and the multiple plasmonic units in each leaky wave unit are arranged symmetrically about the center position of the leaky wave unit.

3. The artificial surface plasmon conformal leaky antenna according to claim 2, characterized in that, Each drain wave unit is 5.5 mm long and 0.018 mm thick. Each drain wave unit is divided into 11 plasmonic units. The width of the radiation teeth in each plasmonic unit is 0.3 mm, and the width of the transmission slot is 0.2 mm. The distances between the symmetrical radiation teeth in the 11 plasmonic units in each drain wave unit are 1.45 mm, 1.65 mm, 2.00 mm, 2.45 mm, 2.93 mm, 3.2 mm, 2.93 mm, 2.45 mm, 2.00 mm, 1.65 mm, and 1.45 mm, respectively.

4. The artificial surface plasmon conformal leaky antenna according to claim 1, characterized in that, The radiation assembly also includes: Two feeding sections are located at opposite ends of the substrate. Each feeding section includes an upper feeding component and a lower feeding component. The upper feeding component is a microstrip line with a gradually changing width, attached to the outer surface of the substrate. The lower feeding component is a microstrip line with a gradually changing width, located directly below the upper feeding component and attached to the inner surface of the substrate. The direction of the gradually changing width in the lower feeding component is the same as the direction of the gradually changing width in the upper feeding component. The system comprises two transition sections, each including an upper transmission component and a lower transmission component. The upper transmission component is attached to the outer surface of the substrate, with one end connected to the upper feed component and the other end connected to the radiating component. The lower transmission component is attached to the outer surface of the substrate, with one end connected to the lower feed component via a connector penetrating the substrate wall and the other end connected to the radiating component. The upper and lower transmission components are of the same length, and a gap exists between them on the outer surface of the substrate, forming a first transmission line. The width of the first transmission line gradually increases towards the radiating component.

5. The artificial surface plasmon conformal leaky antenna according to claim 4, characterized in that, In each power supply section, the upper power supply component has a length of 8 mm and a thickness of 0.018 mm, and its length gradually changes from 1.992 mm to 1.2 mm in the direction towards the radiating part; the lower power supply component has a length of 8 mm and a thickness of 0.018 mm, and its length gradually changes from 4.44 mm to 1.2 mm in the direction towards the radiating part. In each transition section, the length of the upper transmission element and the lower transmission element are both 6.6 mm and the thickness is both 0.018 mm. The width of the extension end of the upper transmission element away from the power supply section and the width of the extension end of the lower transmission element away from the power supply section are both 2.6 mm. The width of the first transmission line gradually changes from 0.15 mm to 1.3 mm.

6. The artificial surface plasmon conformal leaky antenna according to claim 5, characterized in that, The radiating section further includes two edge segments respectively disposed at both ends of the radiating section; Each edge segment includes: an upper edge member and a lower edge member symmetrically arranged; the two ends of the upper edge member are respectively connected to an upper radiating member and an upper transmitting member, and the width of the upper edge member is equal to the width of the extended end of the upper radiating member; the two ends of the lower edge member are respectively connected to a lower radiating member and a lower transmitting member, and the width of the lower edge member is equal to the width of the extended end of the lower transmitting member; the spacing between the upper edge member and the lower edge member is equal to the width of the first transmission line away from the feeding portion.

7. The artificial surface plasmon conformal leaky antenna according to claim 6, characterized in that, In each edge segment, several edge slots are respectively provided on the two adjacent sides of the upper edge component and the lower edge component. The edge slot of the upper edge component and the edge slot of the corresponding lower edge component form a transition slot band. The length of the several transition slot bands increases in a step-like manner towards the radiation segment, and the length of the transition slot band near the radiation segment is equal to the length of the transmission slot band in the leakage wave unit.

8. The artificial surface plasmon conformal leaky antenna according to claim 7, characterized in that, In each edge segment, the width of both ends of the upper and lower edge components is 2.6 mm and the thickness is 0.018 mm. The width of the radiating portion is 6.5 mm, and the interval between the upper and lower edge components is 1.3 mm. Each edge segment includes 8 transition grooves arranged sequentially in the direction of the radiating segment. The length of the 8 transition grooves increases stepwise from 1.3 mm to 3.9 mm in the direction of the radiating segment.

9. The artificial surface plasmon conformal leaky antenna according to claim 1, characterized in that, The substrate is made of a material with a dielectric constant of less than or equal to 5.

10. The artificial surface plasmon conformal leaky antenna according to claim 9, characterized in that, The substrate is made of a ceramic material with a dielectric constant of 3.55, and the substrate has a thickness of 1 mm, an inner diameter of 9 mm, and a length of 190 mm.

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