Conical helical antenna

Abstract

The invention relates to the technical field of helical antennas, and discloses a conical helical antenna, which comprises a supporting cone structure, a continuous helical radiator and a feed body, the continuous spiral radiator is wound on the surface of the supporting cone structure, is positioned through the positioning structure and is fixed through the connecting structure; the feed body is arranged in the supporting cone structure, a feed part of the feed body penetrates through the end face of the first end of the supporting cone structure, and the feed part is integrated with a butterfly-shaped loading structure; the continuous spiral radiator arranged in a winding manner is provided with a protruding exposed copper sheet extending towards the first end of the supporting cone structure, and the protruding exposed copper sheet is folded to the butterfly-shaped loading structure and is connected with the butterfly-shaped loading structure in a welding manner; and the feed body adopts an exponential transformation balun. Through the structure that a supporting body is precisely matched with a flexible radiating body and an index gradient balun integrated with butterfly loading for integrated feeding, the technical problems of complex process, high manufacturing cost, poor stability and the like are solved by utilizing the synergistic effect of structural modularization and feed path optimization.

Description

Conical spiral antenna Technical Field

[0001] This invention relates to the field of helical antenna technology, and in particular, to a conical helical antenna. Background Technology

[0002] As an important circularly polarized radiating device, helical antennas have wide applications in satellite communication, navigation and positioning, and other fields. Traditional cylindrical helical antennas have the advantage of simple structure, but their operating bandwidth is relatively narrow, and their impedance characteristics and radiation pattern often fluctuate significantly with frequency changes, which limits their application in scenarios requiring stable wideband operation.

[0003] To extend the operating bandwidth of antennas, conical spiral antennas (such as conical logarithmic spiral antennas) have been proposed. These antennas are typically based on a self-similar structural design, allowing their effective radiation region to automatically shift along the axis of the cone as the operating frequency changes. This results in relatively stable impedance and radiation characteristics over a wide frequency range (i.e., the so-called "frequency-invariant" characteristics). Compared to planar spiral antennas, conical spiral antennas typically achieve better unidirectional radiation without the need for an additional reflecting cavity and offer advantages in beamwidth and radiation efficiency.

[0004] However, existing conical spiral antennas still have some shortcomings in terms of engineering implementation and performance optimization, specifically:

[0005] First, in terms of structure and manufacturing process, conventional conical spiral antennas typically require precision machining or etching processes to form spiral radiating arms on the surface of a conical dielectric support. This type of process is not only costly and difficult to manufacture, but also limits the flexibility of adjusting the antenna's geometric parameters (such as cone angle, pitch, and spiral arm width) once they are determined and fabricated. This restricts the optimization space for antenna performance and the ability to respond quickly to different application requirements.

[0006] Secondly, regarding the feeding method, existing conical spiral antennas typically rely on a complex balun to achieve matching between the unbalanced transmission line (like a coaxial cable) and the balanced antenna spiral arm. This separate balun structure not only increases the overall size and weight of the antenna but may also introduce additional insertion loss. More importantly, the balun itself may generate unwanted electromagnetic radiation or leakage, which can interfere with the antenna's main radiation field, thus adversely affecting the antenna's axial ratio performance, gain, and pattern purity.

[0007] In summary, while pursuing wideband performance, existing conical spiral antennas suffer from problems such as complex structure, high manufacturing cost, cumbersome assembly process, and additional losses and interference introduced by the feed network. Therefore, there is a need in the field for a conical spiral antenna implementation scheme with a simpler structure, easier manufacturing and adjustment, and superior feed performance, in order to further improve its wideband performance and engineering practicality. Summary of the Invention

[0008] This invention provides a conical spiral antenna that solves the problems of existing conical spiral antennas caused by complex traditional processing and assembly processes, losses and leakage introduced by discrete baluns, poor broadband impedance matching stability, and deterioration of circular polarization axial ratio. It utilizes the synergistic effect of structural modularity and optimized feeding path to solve the problems of complex traditional processing and assembly processes, losses and leakage introduced by discrete baluns, poor wideband impedance matching stability, and deterioration of circular polarization axial ratio.

[0009] This invention provides a conical spiral antenna, comprising a supporting conical structure, a continuous spiral radiator, and a feed element; the continuous spiral radiator is wound around the surface of the supporting conical structure and positioned by a positioning structure and fixed by a connecting structure; the feed element is disposed within the supporting conical structure, and the feed portion of the feed element is disposed through the end face of the first end of the supporting conical structure, the feed portion integrating a butterfly loading structure; the wound continuous spiral radiator has a protruding exposed copper sheet extending toward the first end of the supporting conical structure, the protruding exposed copper sheet being folded onto the butterfly loading structure and welded together; the feed element employs an exponential transformation balun.

[0010] Furthermore, the butterfly-shaped loading structure is a combined structure consisting of two fan-shaped structures with their small arc ends arranged opposite each other.

[0011] Furthermore, a first positioning structure is provided on the supporting cone structure, and the first positioning structure is arranged along the generatrix of the supporting cone structure; the continuous spiral radiator is fan-shaped, and a second positioning structure and a third positioning structure are respectively provided on both sides of the continuous spiral radiator. The first side of the continuous spiral radiator is positioned by matching and connecting with the first positioning structure through the second positioning structure, and the second side of the continuous spiral radiator is wrapped around the supporting cone structure and positioned by matching and connecting with the first positioning structure through the third positioning structure, so that the exposed copper area on the second side of the radiator overlaps with the exposed copper area on the first side and is welded together; the edge of the first side of the continuous spiral radiator that is attached to the supporting cone structure is provided with adhesive, and the continuous spiral radiator is fixed to the supporting cone structure by adhesive.

[0012] Furthermore, adhesive is also applied to the overlapping areas of the continuous spiral radiators to assist in fixing the overlapping areas.

[0013] Furthermore, the first positioning structure adopts a positioning protrusion, while the second and third positioning structures adopt positioning holes; multiple positioning protrusions are arranged along the generatrix direction of the supporting cone structure; the first positioning structure and the second positioning structure, as well as the first positioning structure and the third positioning structure, are arranged in a one-to-one correspondence.

[0014] Furthermore, the size of the first positioning structure gradually increases from the small end to the large end of the supporting cone structure; and / or the spacing between the first positioning structures gradually increases from the small end to the large end of the supporting cone structure.

[0015] Furthermore, the continuous spiral radiator adopts a flexible printed circuit board, and the front and / or back of the flexible printed circuit board are provided with spiral lines, and the spiral lines of the continuous spiral radiator are arranged continuously; the spiral lines are staggered with the second positioning structure and the third positioning structure.

[0016] Furthermore, the pitch of the spiral circuit gradually increases from the small end to the large end of the supporting cone structure.

[0017] Furthermore, the butterfly loading structure uses a printed circuit board with a thickness of 0.2mm-0.6mm; the printed circuit board integrates a butterfly loading piece, and the protruding exposed copper piece is soldered onto the butterfly loading piece, and the butterfly loading piece is soldered to the power supply part.

[0018] Furthermore, an RF head is connected to one end of the feed body facing the second end of the supporting cone structure to achieve a matching connection between the feed end and the outside.

[0019] Furthermore, the first end of the supporting cone structure is the small end, and the second end of the supporting cone structure is the large end.

[0020] Furthermore, the supporting cone structure is made of 3D printed parts.

[0021] The present invention has the following beneficial effects: 1. It achieves high-precision positioning and convenient assembly of the radiator: The positioning structure on the surface of the supporting cone structure cooperates with the continuous spiral radiator to ensure that the winding position of the continuous spiral radiator on the cone surface is accurate and consistent; the connection structure (such as snap-fit, adhesive point, etc.) further provides a fixing effect, so that the spiral radiator, which originally needs to be precisely machined, can be quickly and accurately assembled with the supporting cone structure with positioning features through the prefabricated flexible radiator, thereby significantly reducing the process difficulty and manufacturing cost of directly etching or depositing metal spirals on the cone surface, and improving production efficiency and consistency.

[0022] 2. Optimize wideband impedance matching and simplify the feed structure: The feed body adopts an exponential transformation balun, whose characteristic impedance gradually changes exponentially along the length direction, which can achieve good impedance transformation and balance conversion from the feed line (such as an unbalanced transmission line) to the antenna radiator (balanced structure) over a wide frequency range; the butterfly loading structure integrated in the feed part is equivalent to introducing a capacitive matching network at the antenna input end, which can further optimize the reactance component at the high frequency end; the combination of the two constitutes an integrated wideband matching feed network integrated inside the supporting cone structure, replacing the traditional external independent balun component, which not only simplifies the overall structure and reduces volume and weight, but more importantly, avoids the additional insertion loss, electromagnetic leakage and possible interference to the antenna radiation field (especially the circular polarization axial ratio) caused by the external balun.

[0023] 3. Establishing a robust and low-loss electrical and mechanical connection: The protruding exposed copper sheet extending from the end of the continuous helical radiator is folded and directly welded to the butterfly loading structure, providing a stable electrical path with low contact resistance, ensuring efficient transmission of RF signals from the feed network to the radiator; at the same time, the welding point itself also constitutes a robust mechanical fixing point, working together with the positioning and connection structures to ensure that the continuous helical radiator, especially its critical feed input end, does not shift or loosen under long-term use or environmental stress, ensuring the long-term reliability of the antenna's electrical performance.

[0024] 4. Enhance overall performance by leveraging the synergistic effect between structures: The supporting conical structure not only serves as a physical carrier, but its internal cavity provides space and shielding protection for the placement of the feed element (exponential transformation balun), while its end face provides positioning for the feed section (integrated butterfly loading structure) to pass through. The continuous spiral radiator is precisely wound around the surface of the supporting conical structure through a positioning structure, and its protruding copper sheet is welded to the butterfly loading structure, thus firmly and precisely integrating the radiator, support, and feed grid into a whole. This ensures a high degree of consistency between the antenna's geometry and electrical design, allowing the inherent wideband and circular polarization theoretical radiation characteristics of the conical spiral antenna to be more fully realized in the physical object. At the same time, it has the engineering advantages of compact structure, simple assembly, and high reliability.

[0025] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 is a structural schematic diagram of a conical spiral antenna according to a preferred embodiment of the invention; Figure 2 is a structural schematic diagram of a continuous spiral radiator according to a preferred embodiment of the invention, Figure 2(a) being a front spiral circuit diagram in the unfolded state, and Figure 2(b) being a rear spiral circuit diagram in the unfolded state; Figure 3 is a structural schematic diagram of the top structure of the conical spiral antenna according to a preferred embodiment of the invention; Figure 4 is a structural schematic diagram of the feed element and RF head within the supporting conical structure according to a preferred embodiment of the invention.

[0027] Legend: 100, supporting cone structure; 101, first positioning structure; 200, continuous spiral radiator; 201, protruding exposed copper sheet; 202, second positioning structure; 203, third positioning structure; 204, spiral circuit; 300, power supply body; 301, power supply section; 400, butterfly loading structure; 500, radio frequency head. Detailed Implementation

[0028] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0029] As shown in Figures 1 and 2, the conical spiral antenna of this embodiment includes a supporting conical structure 100, a continuous spiral radiator 200, and a feed element 300. The continuous spiral radiator 200 is wound around the surface of the supporting conical structure 100 and positioned by a positioning structure and fixed by a connecting structure. The feed element 300 is arranged inside the supporting conical structure 100, and the feed portion 301 of the feed element 300 passes through the end face of the first end of the supporting conical structure 100. The feed portion 301 integrates a butterfly loading structure 400. The wound continuous spiral radiator 200 has a protruding exposed copper sheet 201 extending toward the first end of the supporting conical structure 100. The protruding exposed copper sheet 201 is folded onto the butterfly loading structure 400 and welded together. The feed element 300 adopts an exponential transformation balun. The conical spiral antenna of the present invention has a positioning structure on the surface of the supporting conical structure 100 that cooperates with the continuous spiral radiator 200 to ensure that the winding position of the continuous spiral radiator 200 on the conical surface is accurate and consistent. The connection structure (e.g., snap-fit, adhesive point, etc.) further provides a fixing function, so that the spiral radiator, which originally needs to be precisely machined, can be quickly and accurately assembled with the supporting conical structure 100 with positioning features through a prefabricated flexible radiator. This significantly reduces the process difficulty and manufacturing cost of directly etching or depositing metal spirals on the surface of the conical structure, and improves production efficiency and consistency. The feed element 300 employs an exponential transformation balun, whose characteristic impedance gradually changes exponentially along its length, enabling excellent impedance transformation and balance conversion from the feed line (such as an unbalanced transmission line) to the antenna radiator (balanced structure) over a wide frequency range. The butterfly loading structure 400 integrated in the feed section 301 is equivalent to introducing a capacitive matching network at the antenna input, which can further optimize the reactance component at the high frequency end. The combination of the two forms an integrated wideband matching feed network inside the supporting cone structure 100, replacing the traditional external independent balun component. This not only simplifies the overall structure and reduces volume and weight, but more importantly, it avoids the additional insertion loss, electromagnetic leakage, and potential interference to the antenna radiation field (especially the circular polarization axial ratio) caused by the external balun. The protruding exposed copper sheet 201 extending from the end of the continuous spiral radiator 200 is folded and directly welded to the butterfly loading structure 400, providing a stable electrical path with low contact resistance and ensuring efficient transmission of radio frequency signals from the feed network to the radiator. At the same time, the welding point itself also constitutes a robust mechanical fixing point, which, together with the positioning and connection structures, ensures that the continuous spiral radiator 200, especially its critical feed input end, does not shift or loosen under long-term use or environmental stress, thus guaranteeing the long-term reliability of the antenna's electrical performance.The supporting conical structure 100 not only serves as a physical carrier, but its internal cavity also provides space and shielding protection for the placement of the feed element 300 (exponential transformation balun). Its end face provides positioning for the feed section 301 (integrated butterfly loading structure 400) to pass through. The continuous spiral radiator 200 is precisely wound around the surface of the supporting conical structure 100 through the positioning structure, and its protruding exposed copper sheet 201 is welded to the outgoing butterfly loading structure 400. This firmly and precisely integrates the radiator, support, and feed grid into a whole, ensuring a high degree of consistency between the antenna's geometry and electrical design. This allows the inherent wideband and circular polarization theoretical radiation characteristics of the conical spiral antenna to be more fully realized in the physical object, while also possessing the engineering advantages of compact structure, simple assembly, and high reliability. The conical spiral antenna of this invention, through structural design such as the positioning and matching of the supporting conical structure 100 and the continuous spiral radiator 200, the built-in integrated butterfly-loaded exponential transformation balun, and the direct welding connection between the continuous spiral radiator 200 and the feed section 301, effectively simplifies the antenna structure, facilitates assembly, reduces manufacturing costs, and optimizes feed matching performance while ensuring the wideband radiation performance of the conical spiral antenna. It solves the problems of complex manufacturing processes, reliance on external baluns leading to structural redundancy and performance degradation in the prior art.

[0030] As shown in Figure 3, in this embodiment, the butterfly loading structure 400 is a combined structure consisting of two fan-shaped structures with their small arc ends arranged opposite each other. The butterfly loading structure 400 constitutes a planar capacitor. When the butterfly loading structure 400 is integrated at the top of the feed section 301 of the exponential transformation balun, it forms a specific distributed capacitance with the continuous spiral radiator 200 (welded together via the protruding exposed copper sheet 201). This capacitive loading can compensate for the inductive impedance component that the continuous spiral radiator 200 may exhibit when operating at high frequencies, thereby improving the input impedance at the high-frequency end, making it closer to the characteristic impedance of the feed system, and extending the high-frequency operating bandwidth of the antenna. The small arc ends of the two fan-shaped structures are arranged opposite each other, forming a concentrated electric field region in the central area, while the large arc ends on the outer sides provide a relatively wide connection or coupling area. The protruding exposed copper sheet 201 is folded and soldered onto this structure, allowing the feed current to be efficiently fed from the feed network (balun) to the starting end of the continuous spiral radiator 200 through a low inductive reactance path, minimizing the parasitic inductance introduced by traditional cable or probe connections, which is beneficial for maintaining good matching over a wide bandwidth. The butterfly loading structure 400, as a whole (formed by etching the metal layer on a copper-clad dielectric board, such as a PCB), has a certain mechanical strength due to its planar structure. The fan-shaped structure provides a better pad attachment area and shape than a simple rectangle or line. When the protruding exposed copper sheet 201 of the continuous spiral radiator 200 is folded and soldered onto it, the larger solder contact area and optimized structural shape can form a stronger mechanical connection and a more stable electrical contact, improving the long-term reliability of the antenna feed point.

[0031] As shown in Figures 1 and 2, in this embodiment, a first positioning structure 101 is provided on the supporting cone structure 100, and the first positioning structure 101 is arranged along the generatrix of the supporting cone structure 100; the continuous spiral radiator 200 is fan-shaped, and a second positioning structure 202 and a third positioning structure 203 are respectively provided on both sides of the continuous spiral radiator 200. The first side of the continuous spiral radiator 200 is matched and positioned with the first positioning structure 101 through the second positioning structure 202, and the second side of the continuous spiral radiator 200 is wrapped around the supporting cone structure 100 and matched and positioned with the first positioning structure 101 through the third positioning structure 203, so that the exposed copper area on the second side of the radiator overlaps with the exposed copper area on the first side and is welded together; the edge of the first side of the continuous spiral radiator 200 that is attached to the supporting cone structure 100 is provided with adhesive, and the continuous spiral radiator 200 is fixed to the supporting cone structure 100 by adhesive. The first positioning structure 101, arranged along the generatrix on the supporting cone structure 100, is matched and connected to the second positioning structure 202 and the third positioning structure 203 on both sides of the continuous spiral radiator 200, respectively, to ensure that the flexible continuous spiral radiator 200 can be precisely wrapped around the cone surface at a predetermined angle and trajectory. In particular, through the cooperation of the two side structures, the starting position, winding pitch and ending position of the radiator can be accurately controlled, ensuring the geometric accuracy of the spiral shape, which in turn helps to maintain the wide bandwidth and circular polarization radiation characteristics of the conical spiral antenna, and makes each antenna element highly consistent during mass production. The exposed copper area on the second side of the continuous spiral radiator 200 overlaps with and is welded to the exposed copper area on the first side. After the continuous spiral radiator 200 wraps around and covers its starting end, it forms a strong and low-resistance electrical connection point through the overlapping welding of the exposed copper areas (metal conductors) on both sides. This constitutes a truly electrically continuous spiral conductor, which solves the problem of unreliable electrical connection that may occur when flexible radiators are wound and spliced. It ensures the smooth flow of radio frequency current along the spiral path and realizes effective antenna radiation. In addition to the mechanical limiting of the positioning structure, adhesive is applied to the edge of the supporting cone structure 100 on the first side of the continuous spiral radiator 200. This allows the continuous spiral radiator 200 to be pre- or assistedly fixed to the cone surface by adhesive bonding after initial positioning. This method, which combines the precision guidance of the positioning structure with the local fixation of the adhesive, simplifies the assembly process. One side of the continuous spiral radiator 200 can be aligned with the positioning structure and initially attached with adhesive, then wound along the cone surface, and finally the other side can be locked with the positioning structure and the welding of the overlapping exposed copper areas can be completed. This greatly reduces the difficulty of manually aligning and fixing the precision spiral conductor on complex curved surfaces, and improves assembly efficiency and yield.The first positioning structure 101, the second positioning structure 202, and the third positioning structure 203 together constitute a three-dimensional spatial constraint system, which precisely positions the spatial trajectory of the continuous spiral radiator 200 on the supporting cone structure 100. Based on this precise positioning, the adhesive backing provides a temporary or permanent fixing method without additional mechanical fasteners or damage to the integrity of the radiator, ensuring that the radiator remains stable in position before subsequent processes such as welding. The final welding of the overlapping exposed copper area completes the electrical closure and mechanical reinforcement of the spiral conductor. The three work together to form a complete assembly solution that ensures electrical and mechanical performance, from "precise positioning" to "temporary fixing" to "permanent connection".

[0032] As shown in Figures 1 and 2, in this embodiment, adhesive is also applied to the overlapping area of ​​the continuous spiral radiator 200 to assist in fixing the overlapping area. Applying adhesive to the overlapping area (i.e., the overlap between the exposed copper areas on the second and first sides of the continuous spiral radiator 200) allows for the temporary and secure fixing of the two conductor layers together before the final welding process. This prevents misalignment or separation of the overlapping portion during handling, positioning, or preparation for welding, ensuring high accuracy in the welding position and providing a prerequisite for obtaining a precisely positioned and well-contact welded joint. The adhesive and welding connection complement each other, jointly ensuring the precise positioning, firm connection, and long-term stability of the electrical connection points at the spiral ends of the radiator, further improving the overall structural reliability and performance consistency of the antenna from a process detail perspective.

[0033] As shown in Figures 1 and 2, in this embodiment, the first positioning structure 101 uses a positioning protrusion, and the second positioning structure 202 and the third positioning structure 203 use positioning holes. Multiple positioning protrusions are arranged along the generatrix direction of the supporting cone structure 100. The first positioning structure 101 and the second positioning structure 202, as well as the first positioning structure 101 and the third positioning structure 203, are arranged in a one-to-one correspondence. By using the matching method of positioning protrusions and positioning holes, the positioning protrusions are arranged along the generatrix direction of the supporting cone structure 100, forming a clear physical guide trajectory. When the positioning holes on the continuous spiral radiator 200 are aligned with and fitted into the positioning protrusions, the flexible, sheet-like continuous spiral radiator 200 can be quickly and accurately constrained on a predetermined three-dimensional spatial path. This protrusion-hole matching has clear guidance and constraint, effectively preventing the radiator from laterally sliding or circumferentially twisting on the cone surface, ensuring the accuracy of the winding position and angle. The positioning protrusions and positioning holes are arranged in a one-to-one correspondence. Each positioning hole on both sides of the continuous helical radiator 200 has a unique corresponding positioning protrusion on the conical surface. This "one-to-one" deterministic relationship eliminates positional uncertainty during assembly, ensuring that each assembly operation can install the continuous helical radiator 200 onto the supporting conical structure 100 with exactly the same geometric relationship. This guarantees that mass-produced antenna products have highly consistent electrical performance (such as radiation pattern, impedance, and axial ratio). Compared to relying on manual alignment and pasting or measuring and drawing lines on curved surfaces, the protrusion-hole matching is a simpler and more precise assembly aid. Simply align the positioning holes on both sides of the continuous helical radiator 200 in sequence and fit the corresponding positioning protrusions to achieve precise positioning naturally. No special tools or advanced skills are required, significantly reducing the technical requirements for assembly personnel, improving assembly efficiency, and reducing the scrap rate caused by human error. After the positioning holes and positioning protrusions are fitted together, the continuous spiral radiator 200 is initially fixed in the correct position, providing a stable and reliable working foundation for subsequent steps (such as using adhesive for bonding or welding overlapping areas); the positioning protrusions themselves can also resist, to some extent, any accidental displacement of the continuous spiral radiator 200 that may occur before the adhesive cures or during the welding process.

[0034] As shown in Figures 1 and 2, in this embodiment, the size of the first positioning structure 101 gradually increases from the small end to the large end of the supporting cone structure 100; and / or the spacing of the first positioning structures 101 gradually increases from the small end to the large end of the supporting cone structure 100. When the flexible, sheet-like continuous spiral radiator 200 is wound around the conical surface, its unfolded length and stress distribution under winding state change as it extends from the small end (small radius of curvature, short circumference) to the large end (large radius of curvature, long circumference). From the small end to the large end of the supporting cone structure 100, the size (such as the diameter or height of the protrusion) of the first positioning structure 101 gradually increases, which can provide stronger mechanical limiting force and a larger contact area in the large end area where the stress is relatively large, so as to better resist the displacement tendency of the radiator due to its own tension or external stress, thereby improving the positioning stability along the entire winding path. The space at the small end of the cone is compact. If the size or spacing of the positioning protrusions is too large, it may cause interference or make it difficult to process. The arrangement of the first positioning structure 101 gradually increases from the small end to the large end, which conforms to the geometric feature of the cone surface circumference gradually increasing. This can make the distribution of positioning points on the cone surface more uniform and reasonable. The denser arrangement of positioning points in the small end area helps to provide more precise guidance in positions with large curvature and difficult positioning. The appropriate increase of the spacing in the large end area can not only meet the positioning requirements, but also avoid structural redundancy, thus optimizing the space utilization and strength of the supporting cone structure 100. During the winding process, the intensity of the bending deformation mode (such as stretching and shearing) of the continuous helical radiator 200 on the conical surface generally decreases from the small end to the large end. The gradual design of size and / or spacing can also be an adaptive adjustment of the "constraint stiffness" or "positioning density" provided by the first positioning structure 101 along the generatrix direction. In the small end region where deformation is severe, a tighter constraint is provided by protrusions of smaller size and denser spacing, which is beneficial to control the initial winding shape. In the large end region where deformation tends to be gentle, a looser but more stable positioning is provided by protrusions of larger size and sparser spacing, which is beneficial to release some stress and ensure that the radiator fits smoothly and without wrinkles on the entire conical surface. The gradient size or spacing design creates an asymmetrical positioning system, which makes it easier to judge whether the winding direction and position of the continuous spiral radiator 200 are correct when assembling it (for example, the positioning holes on the continuous spiral radiator 200 can only be fully fitted onto the gradient protrusions from a specific direction and in a specific order), thus playing a certain role in preventing incorrect assembly and further improving the accuracy and efficiency of assembly.

[0035] As shown in Figures 1 and 2, in this embodiment, the continuous spiral radiator 200 uses a flexible printed circuit board (FPC). Spiral lines 204 are arranged on the front and / or back of the FPC, and the spiral lines 204 of the wound continuous spiral radiator 200 are arranged continuously. The spiral lines 204 are staggered with the second positioning structure 202 and the third positioning structure 203. Using a flexible printed circuit board (FPC) as the substrate of the continuous spiral radiator 200 allows for the use of mature PCB manufacturing processes. Through precise patterning processes such as photolithography and etching, spiral lines 204 can be formed on the front and / or back of the flexible substrate. This enables precise control over the linewidth, spacing, edge accuracy, and overall geometry of the spiral lines 204. The precision is far superior to traditional methods such as manual winding, attaching metal strips, or direct processing on a three-dimensional conical surface. This ensures excellent consistency and repeatability of the spiral conductor, which serves as the core radiating element of the antenna, thereby ensuring the stability of the antenna's electrical performance. The spiral line 204 of the continuously spiral radiator 200 is continuously arranged. Although the continuous spiral radiator 200 has non-radiative structures such as positioning structures, the spiral line 204 itself, as a radiating conductor, is continuous and uninterrupted. This electrical continuity avoids contact resistance, parasitic inductance and discontinuous reflection that may be introduced at the connection of segmented conductors, and ensures that the radio frequency current can flow smoothly along the designed spiral path, thereby ensuring that the antenna has the expected radiation efficiency, impedance characteristics and radiation pattern. The spiral circuit 204 is staggered with the second positioning structure 202 and the third positioning structure 203. The second positioning structure 202 and the third positioning structure 203 (such as positioning holes) are necessary structures for achieving mechanical positioning. However, they are usually non-metallic (such as openings on the substrate) or metal connection points. If they overlap with or are too close to the radiating circuit, they may change the local capacitance and inductance distribution at that location, or even hinder the current path, becoming a "disturbance source" that affects the antenna performance. By staggering the spiral circuit 204 with these positioning structures, that is, by avoiding each other in space, the influence of the positioning structures on the high-frequency current distribution on the spiral conductor is minimized, and the uncertainty and deterioration risk of electrical performance introduced by mechanical positioning requirements are reduced. Thus, while achieving precise positioning, the purity of the electromagnetic performance of the spiral radiator is maintained. Flexible printed circuit board technology allows for the realization of complex circuit patterns on a single or multiple layers. In addition to the main radiating spiral circuit 204, other auxiliary circuits, matching branches, or sensing elements can be easily integrated on the same flexible printed circuit board. This integrated design improves the functional integration and design flexibility of the antenna. The properties of the flexible substrate enable it to fit well with conical curved surfaces and adapt to three-dimensional structures.

[0036] As shown in Figures 1 and 2, in this embodiment, the pitch of the spiral circuit 204 gradually increases from the small end to the large end of the supporting conical structure 100. The working principle of the conical spiral antenna relies on the current wave traveling along the spiral conductor; when the pitch changes along the axial direction, the phase velocity of the current propagating along the spiral path will change accordingly; the pitch gradually increases from the small end (feed end) to the large end (radiating end), which can adjust the phase relationship of the current propagating from the feed point to different positions at the end of the spiral. This can be used to compensate for the path difference caused by the geometric expansion of the cone, making the electromagnetic waves radiated from different turns of the spiral more likely to be superimposed in phase in the axial direction, thereby optimizing the directivity of the main beam, improving the gain, and possibly improving the symmetry of the radiation pattern. The input impedance of a conical spiral antenna is closely related to its geometric parameters, especially the pitch. Using a gradually changing pitch from the small end to the large end is equivalent to changing the equivalent inductance and capacitance distribution of the spiral conductor along the axial direction. This gradually changing structure can be regarded as a distributed impedance transformer. Starting with a smaller pitch at the feed end (small end) helps to achieve a smoother impedance transition with the feed network (such as an exponential transform balun). As the pitch gradually increases, the characteristic impedance of the spiral also changes, which can achieve a good match between the antenna input impedance and the feed line characteristic impedance over a wider frequency band, thereby expanding the antenna's operating bandwidth. On the conical surface, the helical circuit 204 gradually increases in circumference from the apex (small end) to the bottom (large end). A helix with a constant pitch is wound around the conical surface, and the physical dimensions and tilt angle of its radiating elements (each helix turn) vary. Designing the pitch to gradually increase from the small end to the large end synergizes with the increase in the conical surface circumference, helping to maintain a relatively stable ratio between the geometric dimensions of the effective radiation region (one or more helix turns) and the operating wavelength over a wider frequency range. This is beneficial for achieving more stable radiation pattern characteristics (such as beamwidth and sidelobe levels) and is one means of obtaining "non-frequency-varying" or broadband radiation characteristics. Compared to a constant-pitch helix, a gradually increasing pitch adds a key optimization dimension to antenna design. By rationally designing the pitch variation law (such as linear increase, exponential increase, etc.), multiple key performance indicators of the antenna can be more flexibly balanced and optimized, including input impedance, voltage standing wave ratio, axial ratio, gain, and beamwidth. This allows designers to control antenna performance for specific application requirements to achieve better overall performance. The pitch of the spiral circuit 204 gradually increases from the small end to the large end. This is a design that optimizes the electromagnetic performance of the antenna through structural gradient. By changing the spatial configuration of the spiral conductor, the phase and impedance distribution of the current propagating along the spiral can be actively adjusted. This can more effectively control the wavefront of the radiated electromagnetic wave, improve impedance matching in a wide bandwidth, and enhance the stability of the radiation pattern, thus facilitating the realization of a high-performance, wide-bandwidth conical spiral antenna.

[0037] As shown in Figures 1 and 3, in this embodiment, the butterfly loading structure 400 adopts a printed circuit board (PCB) with a thickness of 0.2mm-0.6mm. A butterfly loading piece is integrated on the PCB, and a protruding exposed copper piece 201 is soldered onto the butterfly loading piece. The butterfly loading piece is soldered to the feed section 301. Placing the butterfly loading structure 400 on a PCB with a thickness of 0.2mm to 0.6mm provides sufficient mechanical strength and rigidity, enabling it to maintain its shape stability during soldering operations (such as soldering the protruding exposed copper piece 201 and the feed section 301) and under antenna vibrations. This ensures a stable platform for the integrated butterfly loading piece and guarantees the long-term mechanical reliability of the soldered connection. A substrate that is too thin, such as <0.2mm, may deform easily due to insufficient strength, affecting the soldering quality. A substrate that is too thick, such as >0.6mm, may introduce unnecessary volume and weight and is not conducive to integration with surrounding structures. The butterfly loading structure 400 is manufactured using printed circuit board technology. Mature micro-patterning techniques (such as photolithography and etching) can be used to precisely produce butterfly loading pieces with specific shapes and sizes, ensuring the pattern accuracy, edge quality, and consistency of the butterfly loading pieces. This facilitates accurate control of its electrical performance (such as capacitance value) as a capacitive loading element. At the same time, the butterfly loading piece and the feed lines (i.e., feed section 301) on the printed circuit board can be integrally formed, realizing monolithic integration of the feed network and matching structure, avoiding parasitic parameters and inconsistencies introduced by discrete device connections. The exposed copper sheet 201 is soldered onto the butterfly-shaped loading plate, which is then soldered to the power supply section 301. The 0.2mm-0.6mm thick printed circuit board provides an ideal substrate for this soldering interconnection. The flat surface of the printed circuit board facilitates the soldering operation and makes it easy to form good solder joints. The 0.2mm-0.6mm thick substrate has a moderate heat capacity, which can quickly transfer heat to melt the solder during soldering without causing cold solder joints due to excessive heat capacity. The structural stability of the printed circuit board itself ensures the accuracy and firmness of the solder joint position. Through two soldering points, an electrical connection path is achieved from the power supply section 301 to the butterfly-shaped loading plate, and then to the continuous spiral radiator 200 (through the exposed copper sheet 201). This path has low loss and high reliability.A thickness range of 0.2mm-0.6mm is a common thickness for high-frequency circuit boards, and its dielectric properties (such as dielectric constant and loss tangent) are controllable and stable. Integrating the butterfly loading sheet on such a substrate allows for predictable and repeatable distributed capacitance and inductance parameters. A thinner substrate (such as 0.2mm-0.6mm) helps control the dielectric thickness between the feed section 301 and the reference ground, thereby optimizing transmission line characteristics. The entire butterfly loading structure 400 and the feed section 301 form a compact integrated module, which can be easily built into the support cone structure 100, achieving miniaturization and integration.

[0038] As shown in Figure 4, in this embodiment, an RF connector 500 is connected to one end of the feed body 300 facing the second end of the supporting cone structure 100 to achieve a matching connection between the feed end and the external environment. The RF connector 500 is a universal standardized RF connector. By connecting the RF connector 500 to one end of the feed body 300 facing the second end of the supporting cone structure 100, a standard, reliable, and reusable electrical interface is provided for the entire conical spiral antenna. This allows the antenna to be conveniently connected to external devices (such as signal transmitters, receivers, or test instruments) via a standard RF cable (coaxial cable), improving the antenna's engineering practicality and system integration convenience. The RF connector 500 is physically and electrically connected to the feed element 300 (the output of the exponential converter balun or the end of the transmission line), forming the terminal of the feed network. This not only completes the transmission channel for electrical signals but also provides a robust mechanical termination point for the internal, delicate feed network (such as microstrip lines or striplines printed on a thin substrate). The RF connector 500 itself typically has a metal casing and connection structure, protecting the fragile end of the feed element 300 (such as the PCB edge) from external damage and enhancing the mechanical strength of the entire antenna port. The connection between the RF connector 500 and the feed element 300 is impedance-matched to ensure the transition from the external cable to the internal feed network of the antenna is as smooth as possible, minimizing reflections. This helps maintain the integrity of signal transmission and avoids strong signal reflections at the connection point due to impedance abrupt changes, which would degrade the voltage standing wave ratio (VSWR) performance of the antenna port. Using the RF head 500 as a fixed external interface for the antenna simplifies and standardizes antenna assembly, system integration, performance testing, and subsequent maintenance. It eliminates the need for manual soldering or crimping on the exposed wires of the feed body 300, avoiding damage or performance changes caused by improper operation and improving production efficiency and reliability. Optionally, the RF head 500 uses an SMA KYHD15 RF head.

[0039] As shown in Figures 1 and 4, in this embodiment, the first end of the supporting cone structure 100 is the small end, and the second end of the supporting cone structure 100 is the large end.

[0040] In this embodiment, the supporting cone structure 100 is a 3D printed part.

[0041] In implementation, a conical spiral antenna is provided, using a 3D-printed part as the antenna's supporting conical structure 100, the surface of which is provided with positioning protrusions. The continuous spiral radiator 200 is made of a flexible printed circuit board (FPC), which has positioning holes that mate with the positioning protrusions. The FPC is precisely fitted onto the surface of the supporting conical structure 100 through the engagement of the positioning holes and positioning protrusions. After the two ends of the FPC are wound together, the openings at its ends are used to assist in the adhesive backing for fixation, so that the exposed copper areas at both ends overlap and are soldered to form the continuous spiral radiator 200. The feed section 301 is located at the top of the antenna and has a 0.4mm thick printed circuit board (PCB) on it, on which a butterfly loading structure 400 is integrated. A protruding exposed copper sheet 201 extends from the top of the FPC radiator, which is folded onto the butterfly loading sheet of the PCB and soldered together. The power supply uses an exponential conversion balun. The balun passes through the top surface of the antenna and is soldered to a butterfly loading piece on the PCB. Its other end is connected to an SMA KYHD15 RF head to achieve matching connection between the power supply and the external environment.

[0042] By employing 3D-printed components as the support structure, combined with an FPC radiator and a PCB feed network, a simplified and lightweight design of the conical spiral antenna is achieved. Precise matching of protrusions and positioning holes on the FPC and 3D-printed support components ensures the accuracy and consistency of the radiator shape, significantly simplifying the assembly process and reducing manufacturing costs. The top-mounted butterfly loading structure 400, combined with an exponentially graded balun for feeding, not only achieves excellent matching across a wide frequency band but also avoids the size and loss problems associated with traditional complex baluns. The overall structure is compact and easy to feed, achieving stable circularly polarized radiation performance and optimized radiation pattern characteristics across a wide frequency band, demonstrating good engineering practicality and manufacturability.

[0043] Matters not covered in this invention are common knowledge.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A conical spiral antenna, characterized in that, The device includes a supporting cone structure (100), a continuous spiral radiator (200), and a feeder (300). The continuous spiral radiator (200) is wound around the surface of the supporting cone structure (100) and positioned by a positioning structure and fixed by a connecting structure. The feeder (300) is arranged inside the supporting cone structure (100), and the feeder portion (301) of the feeder (300) is arranged through the end face of the first end of the supporting cone structure (100). The feeder portion (301) integrates a butterfly loading structure (400). The wound continuous spiral radiator (200) has a protruding exposed copper sheet (201) extending toward the first end of the supporting cone structure (100). The protruding exposed copper sheet (201) is folded onto the butterfly loading structure (400) and welded together. The feeder (300) adopts an exponential transformation balun.

2. The conical spiral antenna according to claim 1, characterized in that, A first positioning structure (101) is provided on the supporting cone structure (100), and the first positioning structure (101) is arranged along the generatrix of the supporting cone structure (100); the continuous spiral radiator (200) is fan-shaped, and a second positioning structure (202) and a third positioning structure (203) are respectively provided on both sides of the continuous spiral radiator (200). The first side of the continuous spiral radiator (200) is matched and connected to the first positioning structure (101) through the second positioning structure (202) for positioning. The second side of the spiral radiator (200) is wrapped around the support cone structure (100) and positioned by matching and connecting with the first positioning structure (101) through the third positioning structure (203), and the exposed copper area on the second side of the radiator is overlapped with the exposed copper area on the first side and welded together; the edge of the first side of the continuous spiral radiator (200) that is attached to the support cone structure (100) is provided with adhesive, and the continuous spiral radiator (200) is fixed to the support cone structure (100) by adhesive.

3. The conical spiral antenna according to claim 2, characterized in that, The first positioning structure (101) adopts a positioning protrusion, and the second positioning structure (202) and the third positioning structure (203) adopt positioning holes; multiple positioning protrusions are arranged along the generatrix direction of the supporting cone structure (100); the first positioning structure (101) and the second positioning structure (202) and the first positioning structure (101) and the third positioning structure (203) are arranged in a one-to-one correspondence.

4. The conical spiral antenna according to claim 3, characterized in that, The size of the first positioning structure (101) gradually increases from the small end to the large end of the supporting cone structure (100); and / or the spacing of the first positioning structure (101) gradually increases from the small end to the large end of the supporting cone structure (100).

5. The conical spiral antenna according to claim 2, characterized in that, The continuous spiral radiator (200) adopts a flexible printed circuit board, and the front and / or back of the flexible printed circuit board are provided with spiral lines (204), and the spiral lines (204) of the continuous spiral radiator (200) are continuously arranged; the spiral lines (204) are staggered with the second positioning structure (202) and the third positioning structure (203).

6. The conical spiral antenna according to claim 5, characterized in that, The pitch of the spiral circuit (204) gradually increases from the small end to the large end of the supporting cone structure (100).

7. The conical spiral antenna according to claim 1, characterized in that, The butterfly loading structure (400) uses a printed circuit board with a thickness of 0.2mm-0.6mm. The printed circuit board integrates a butterfly loading piece, and the exposed copper piece (201) is soldered to the butterfly loading piece. The butterfly loading piece is soldered to the power supply part (301).

8. The conical spiral antenna according to any one of claims 1 to 7, characterized in that, One end of the feed body (300) facing the second end of the supporting cone structure (100) is connected to an RF head (500) to achieve a matching connection between the feed end and the outside.

9. The conical spiral antenna according to any one of claims 1 to 7, characterized in that, The first end of the supporting cone structure (100) is the small end, and the second end of the supporting cone structure (100) is the large end.

10. The conical spiral antenna according to any one of claims 1 to 7, characterized in that, The supporting cone structure (100) is made of 3D printed parts.

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