Method for shortening omni-directional antenna length using director and omni-directional antenna

Abstract

The application belongs to the field of wireless communication, and discloses a method for shortening the length of an omnidirectional antenna using a director and an omnidirectional antenna, the method comprising: using an omnidirectional antenna element as an excited unit; uniformly arranging a plurality of directors around the excited unit in a circumferential direction; wherein the directors and the excited unit are placed vertically or horizontally; by optimizing the length of the directors and the distance between the directors and the excited unit, the secondary radiation electromagnetic waves generated by the space electromagnetic coupling of the directors and the direct electromagnetic waves of the excited unit are phase superposed, the antenna gain is improved while keeping the horizontal plane omnidirectional radiation characteristics, and the length of the omnidirectional antenna required to achieve the target gain is shortened. The application can significantly improve the radiation gain while keeping the length of the antenna unchanged, effectively solves the problem that the antenna gain and the physical length are restricted by each other in engineering application, and is especially suitable for use in scenarios where the diameter of the antenna is allowed to be increased to reduce the length of the antenna.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and in particular to a method for shortening the length of an omnidirectional antenna using a director and an omnidirectional antenna. Background Technology

[0002] Horizontal omnidirectional antennas can achieve uniform electromagnetic wave radiation in a horizontal plane of 360°, and are widely used in outdoor signal coverage scenarios for wireless communication. These antennas have a narrow beamwidth in the vertical plane, enabling precise control of the longitudinal coverage area and effectively suppressing unwanted radiated signals in the upper and lower airspace.

[0003] Antenna gain is a key performance indicator for measuring an antenna's signal focusing capability, directly affecting the system's communication transmission distance, anti-interference level, and weak signal reception performance. Existing horizontal omnidirectional antennas have inherent constraints: antenna gain is positively correlated with its physical length; the larger the antenna's longitudinal dimension, the higher the gain performance; conversely, a reduction in size leads to a corresponding decrease in gain. To achieve high gain, the industry standard solution is to use a multi-element longitudinal linear array, increasing the overall antenna length by adding radiating elements to narrow the vertical beam.

[0004] Currently, most mainstream miniaturization methods use inductive loading. Although this approach can shorten the physical size of the vibrator, it can lead to negative effects such as antenna gain attenuation and operating bandwidth compression, making it impossible to simultaneously achieve miniaturization and radiation performance.

[0005] The aforementioned inherent contradictions create irreconcilable technical challenges in engineering applications: short-sized antennas are lightweight and easy to install, but have low gain and limited signal coverage; long-sized antennas have high gain and long transmission distance, but have the disadvantages of large windward area and high weight, which imposes strict requirements on the structural strength and erection length of the matching mounting bracket, making it difficult to implement in field conditions with limited installation space and insufficient load-bearing capacity of the support rod.

[0006] Therefore, how to provide a method for shortening the length of an omnidirectional antenna using a director and how to design an omnidirectional antenna are problems that urgently need to be solved. Summary of the Invention

[0007] This invention provides a method for shortening the length of an omnidirectional antenna using a director and an omnidirectional antenna, to solve the problems mentioned above in the prior art.

[0008] According to a first aspect of the present invention, a method for shortening the length of an omnidirectional antenna using a director and an omnidirectional antenna are provided.

[0009] In one embodiment, the method for shortening the length of an omnidirectional antenna using a director includes: An omnidirectional antenna vibrator is used as the stimulated element; Several directors are evenly arranged circumferentially around the stimulated unit; wherein the directors are placed vertically or horizontally relative to the stimulated unit. By optimizing the length of the director and the distance between it and the stimulated unit, the secondary radiated electromagnetic wave generated by the director through spatial electromagnetic coupling is superimposed with the direct electromagnetic wave of the stimulated unit. This improves the antenna gain while maintaining the omnidirectional radiation characteristics in the horizontal plane, thereby shortening the omnidirectional antenna length required to achieve the target gain.

[0010] According to a second aspect of the present invention, an omnidirectional antenna is provided.

[0011] In one embodiment, the omnidirectional antenna includes: An omnidirectional antenna element serves as the stimulated unit. Several directors are evenly distributed around the excited unit in the circumferential direction; An insulating support structure is provided for securing the stimulated unit and the director.

[0012] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: 1) The present invention adopts an omnidirectional guiding array structure, which can effectively reduce the overall length of the antenna while keeping the antenna gain unchanged; it can also significantly improve the radiation gain while keeping the antenna length unchanged, effectively solving the problem of mutual constraint between antenna gain and physical length in engineering applications, and is especially suitable for application scenarios that allow the antenna diameter to be increased to reduce the antenna length.

[0013] 2) In this invention, an omnidirectional antenna vibrator is used as the stimulated unit, and a ring of directors is placed uniformly around it. The distance between the directors and the stimulated unit is about one-third of the wavelength, and the length of the directors is about 0.45 times the wavelength. By reasonably optimizing the distance between the directors and the stimulated unit and the length of the directors, the optimal gain improvement can be obtained.

[0014] 3) The number of directors in this invention can be 6, 8, 12, etc., as long as they are evenly arranged around the excited unit, the same effect can be achieved; the diameter of the director and the excited unit is 3.2mm, but this invention is not limited to this diameter, and other diameters can also be achieved.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] Figure 1This is a flowchart illustrating a method for shortening the length of an omnidirectional antenna using a director, according to an exemplary embodiment. Figure 2 This is a top view of a vertically directed array according to an exemplary embodiment; Figure 3 This is a side view of a vertically directed array according to an exemplary embodiment; Figure 4 This is a schematic diagram of a half-wave dipole antenna structure according to an exemplary embodiment; Figure 5 This is a diagram of an insulating support structure according to an exemplary embodiment; Figure 6 This is a vertically directed array pattern shown according to an exemplary embodiment; Figure 7 This is a diagram illustrating a directorless half-wave dipole antenna structure according to an exemplary embodiment; Figure 8 This is a radiation pattern of a half-wave dipole antenna according to an exemplary embodiment; Figure 9 This is a schematic diagram of a two-array half-wave dipole antenna structure according to an exemplary embodiment; Figure 10 This is a radiation pattern of a two-array half-wave dipole antenna according to an exemplary embodiment; Figure 11 This is a top view of a vertically oriented two-layer array design according to an exemplary embodiment; Figure 12 This is a side view of a vertically oriented two-layer upper and lower array design according to an exemplary embodiment; Figure 13 This is a vertically directed two-layer upper and lower array pattern shown according to an exemplary embodiment; Figure 14 This is a side view of a three-array half-wave dipole antenna according to an exemplary embodiment; Figure 15 This is a radiation pattern of a three-array half-wave dipole antenna according to an exemplary embodiment; Figure 16 This is a top view of a first-level horizontally directed single-layer design according to an exemplary embodiment; Figure 17 This is a side view of a single-story design with a first-level horizontal orientation, as shown in an exemplary embodiment. Figure 18 This is a first-level horizontal directional single-layer design orientation diagram illustrated according to an exemplary embodiment; Figure 19 This is a schematic diagram illustrating the clearance length of a metal mounting surface according to an exemplary embodiment; Figure 20This is a concentric circle horizontally directed antenna structure shown according to an exemplary embodiment; Figure 21 This is a top view of a secondary horizontal guide structure shown according to an exemplary embodiment; Figure 22 This is a side view of a secondary horizontal guide structure shown according to an exemplary embodiment; Figure 23 This is a radiation pattern of a two-stage horizontally directed antenna according to an exemplary embodiment; Figure 24 This is a top view of a horizontally directed upper and lower array according to an exemplary embodiment; Figure 25 This is a side view of the horizontally directed upper and lower arrays according to an exemplary embodiment; Figure 26 This is a horizontally directed upward and downward array pattern shown according to an exemplary embodiment; Figure 27 This is a top view of a horizontally directed four-layer array according to an exemplary embodiment; Figure 28 This is a side view of a horizontally directed four-layer array according to an exemplary embodiment; Figure 29 This is a horizontally directed four-layer array pattern shown according to an exemplary embodiment; Figure 30 This is a schematic diagram of the Yagi antenna principle structure according to an exemplary embodiment.

[0018] In the picture: 1. Excited unit; 2. Director; 3. Insulating support structure; 4. Feed source; 5. Center equal amplitude and equal phase feed; 6. Mounting plane; 7. Clearance length; 8. Reflector. Detailed Implementation

[0019] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some portions and features of certain embodiments may be included in or replace portions and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims and all available equivalents thereof. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0020] The design inspiration of this invention comes from the Yagi antenna. A ring of directors 2 is added at equal intervals around the omnidirectional dipole, and the reflector 8 in the Yagi antenna is discarded. The omnidirectional antenna dipole is used as the stimulated unit 1 (this invention takes a half-wave dipole as an example). In this way, the gain of the omnidirectional antenna can be improved without increasing the antenna length.

[0021] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0022] Figure 1 An embodiment of a method of shortening the length of an omnidirectional antenna using a director is shown.

[0023] In this optional embodiment, the method for shortening the length of an omnidirectional antenna using a director includes: Step S101: Use an omnidirectional antenna vibrator as the stimulated element 1; Step S102: A plurality of guides 2 are evenly arranged around the stimulated unit 1 along the circumferential direction; wherein the guides 2 are placed vertically or horizontally relative to the stimulated unit 1. Step S103: By optimizing the length of the director 2 and the distance between it and the stimulated unit 1, the secondary radiated electromagnetic wave generated by the director 2 through spatial electromagnetic coupling is phase-superimposed with the direct electromagnetic wave of the stimulated unit 1. While maintaining the omnidirectional radiation characteristics of the horizontal plane, the antenna gain is improved, thereby shortening the omnidirectional antenna length required to achieve the target gain.

[0024] Specifically, when the stimulated unit 1 radiates electromagnetic waves outward, it will induce an alternating current on the peripheral director 2. By optimizing the length and position of the director 2, the electromagnetic waves radiated by the director 2 in the second phase are kept in phase with the electromagnetic waves directly emitted by the stimulated unit 1.

[0025] In-phase electromagnetic waves are enhanced by spatial superposition, ultimately achieving beam convergence and effectively improving antenna gain. Traditional Yagi antennas rely on the coupling of director 2 to generate secondary radiation, which is superimposed with the emitted phase of stimulated element 1 to contract the beam to a single direction, forming directional radiation. This significantly reduces the horizontal and vertical bandwidth of the antenna pattern compared to when stimulated element 1 is used alone, resulting in a significant increase in maximum gain.

[0026] In this optional embodiment, the placement of the director 2 and the stimulated unit 1 in a vertical configuration includes: The stimulated element 1 is a vertically polarized half-wave dipole antenna; The director 2 is arranged around the stimulated unit 1 in the same horizontal plane, and the axis of the director 2 is parallel to the axis of the stimulated unit 1, forming a vertically directed single-layer antenna structure.

[0027] Specifically, Method 1, vertically directed single-layer design: such as Figure 2 and Figure 3 As shown, a director 2 is placed around the vertically polarized omnidirectional antenna element, which allows the antenna to maintain 360° omnidirectional radiation in the horizontal plane and improve the antenna gain.

[0028] like Figure 4 As shown, the stimulated element 1 at the center of the circle in this invention uses a half-wave dipole antenna. When other types of omnidirectional antennas are used as stimulated elements 1, the same effect can be achieved as long as a ring of directors 2 is added around them according to this invention.

[0029] like Figure 5 As shown, the insulating support structure 3 is as follows: the stimulated unit 1 and the director 2 are fixed on the PCB material. This invention uses a PCB material with a dielectric constant of 2.2, which has almost no impact on antenna performance. The support structure can be designed in various ways according to actual applications. Figure 5 This is only shown as a very simple example and is not limited to this single structural form.

[0030] like Figure 6 As shown in Table 1, after adding a ring of directors 2 around the perimeter according to the above method, the gain is 4.9 dBi.

[0031] Table 1. Vertical Direction Array Gain Table

[0032] As shown in Table 1, this radiation pattern includes two planes: a horizontal plane and a vertical plane. The red circle represents the horizontal plane radiation pattern, which is covered by a 360-degree circle. The center is the vertical plane radiation pattern. The radiation patterns of the cases described later are consistent with this.

[0033] Compared with traditional omnidirectional antennas: Figure 7 , Figure 8 As shown in Table 2, when the conventional omnidirectional antenna is not equipped with directors 2 around its four sides, the antenna length is 83mm and the gain is about 2.3dBi. Compared with the antenna with directors 2, the lengths are almost the same, but the gain difference is about 2.6dB.

[0034] Table 2. Gain Table for Half-Wave Dipole Antennas

[0035] As shown in Table 3, after adding director 2, the antenna diameter increased to 165mm, the length remained basically unchanged, and the gain was improved by 2.6dB, which is a significant effect.

[0036] Table 3. Gain Comparison Table for the Same Length

[0037] Traditional half-wave dipole antennas require two dipole arrays to achieve a gain of 4.9 dBi. The following example uses two sets of half-wave dipoles arranged vertically, fed with equal amplitude and in-phase feed, with a total length of 200 mm and a gain of 4.9 dBi. Figure 9 , Figure 10 As shown in Table 4.

[0038] Table 4 Gain Table for Two-Array Half-Wave Dipole Antennas

[0039] Table 5 Comparison of Lengths of Same Gain and Traditional Omnidirectional Antennas

[0040] As shown in Table 5, the length ratio is the ratio of the antenna length of the present invention to the length of a traditional omnidirectional antenna. The smaller the value, the more significant the effect of the present invention compared to the traditional antenna at the same gain.

[0041] In this optional embodiment, several groups of the vertically directed single-layer antenna structures are arrayed vertically, with each layer of stimulated element 1 using equal-amplitude and in-phase feeding to form a vertically directed multi-layer array structure, thereby further improving the antenna gain.

[0042] Specifically, Method 2, vertically directed two-layer upper and lower array design: Using the antenna with director 2 added as described in method 1, the upper and lower groups form an array antenna. The two stimulated elements 1 are fed with equal amplitude and in-phase power, which can further improve the antenna gain. The antenna structure is as follows: Figures 11-13 As shown.

[0043] Table 6. Vertical Direction Two-Layer Array Gain Table

[0044] As shown in Table 6, the gain after two sets of upper and lower arrays is 7.4 dBi, which is 2.5 dB higher than the gain of the single-layer method 1. If a traditional half-wave dipole antenna is used, three sets of upper and lower arrays with equal amplitude and in-phase feeding are required to achieve this, and the length needs to be 353 mm to achieve a similar gain of 7.3 dBi. Figure 14 , Figure 15 Table 7 shows the results for a conventional half-wave dipole antenna with the same gain.

[0045] Table 7 Gain Table for Three-Array Half-Wave Dipole Antennas

[0046] Table 8 Comparison of this invention and the three-array half-wave dipole antenna

[0047] As shown in Table 8, using this method, the length of a conventional omnidirectional antenna is only 75.9% of the same gain, a reduction of 85mm. Similarly, using more layers in the vertical direction for arraying can further increase the gain, which will not be listed here.

[0048] In this optional embodiment, the placement of the director 2 and the stimulated unit 1 in a horizontal manner includes: N groups of half-wave dipole antennas are placed horizontally and arranged at equal intervals around the same center to form an N-sided structure stimulated unit 1. N sets of directors 2 are arranged circumferentially around the N-sided structure stimulated unit 1. The axis of the horizontal director 2 is parallel to the axis of the half-wave dipole antenna, forming a first-level horizontal director structure.

[0049] Specifically, Method 3, Horizontal-oriented single-layer design: 3.1 Single-layer design with a first-level horizontal guide: such as Figures 16-18 As shown, if the half-wave dipole antenna and the directing structure are made into a structure similar to the Bagua diagram, with several groups of half-wave dipole antennas extending out at equal intervals from the center, this invention is designed with 6 groups. A 1-to-6 power divider is used in parallel to feed the 6 groups of dipoles to the center with equal amplitude and phase, forming a regular hexagonal structure. This invention adds six directors 2 outside the stimulated element 1 at 0.23 times the wavelength. The length of the director 2 is about half the wavelength (this size is only a special case of this invention and the protection scope is not limited to this size). It can also produce a directing effect that forms omnidirectional radiation in the horizontal direction. This method is significantly shorter than the traditional half-wave dipole antenna. All subsequent array antennas are explained using a regular hexagonal straight rod directing as an example, as shown in Table 9.

[0050] Table 9. Gain Table for Single-Layer Horizontal Direction Design

[0051] Table 10 Comparison of the present invention and the half-wave dipole antenna

[0052] As shown in Table 10, the antenna length of 3mm is the length of the antenna itself, excluding the influence of the external environment. The stimulated element 1 uses a quarter-wavelength dipole antenna; the radiation mechanism remains unchanged, only the vertical placement has been changed to a horizontal placement. When the operating environment is free space, the antenna's radiation in all directions is unaffected. If the mounting plane 6 is made of metal, such as… Figure 19 As shown, the antenna needs to be at least a quarter wavelength away from the metal surface as the clearance length 7. If the mounting plane 6 is non-metallic, the clearance length 7 is not limited.

[0053] like Figure 20 As shown, if the director 2 and the stimulated unit 1 are replaced with arcs instead of straight rods to form a concentric circle structure, the same effect can be achieved. In this way, the antenna diameter can be slightly smaller.

[0054] In this optional embodiment, N sets of directors 2 are sequentially added along the radial direction outside the first-level horizontal guiding structure to form a second-level horizontal guiding structure, so as to further improve the antenna gain.

[0055] Specifically, 3.2, Second-level horizontal director single-layer design: If two directors 2 are used on each side to form a second-level director along the radial direction based on method 3.1, a stronger directing effect can be generated, and the gain can be further improved. The structure is as follows. Figures 21-23 As shown in Table 11.

[0056] Table 11 Gain Table of Second-Level Horizontal Directional Antenna

[0057] As shown in Table 12, the gain of the second-level horizontal guide is increased by 0.6dB compared to the first-level guide 2, but the diameter is increased by 164mm, resulting in limited benefits. Multi-layer arrays will not be listed in the following examples.

[0058] Table 12 Comparison of the present invention and the half-wave dipole linear array antenna

[0059] In this optional embodiment, the n-layer first-level horizontal guiding structure is arrayed vertically, and each layer of stimulated unit 1 is fed with equal amplitude and in phase to form a horizontally guiding multi-layer array structure to further improve the antenna gain.

[0060] Specifically, Method 4: Horizontally directed multi-layer array design: 4.1 Horizontal Two-Layer Array: As described in method 3.1, a two-layer array is used. Each layer uses a 1-to-6 power divider with equal amplitude and in-phase feeding. The two layers are connected by a 1-to-2 equal amplitude and in-phase feeding system. This further enhances the antenna gain. The structure is as follows: Figures 24-26 As shown: This invention takes a regular hexagonal structure composed of 6 sets of half-wave dipoles as an example, and aims to improve the non-circularity of the antenna by arranging the upper and lower layers of arrays with a 30-degree misalignment.

[0061] Note: Rotating one layer horizontally by 30 degrees relative to another can improve the non-circularity of the antenna pattern, but the maximum gain will decrease slightly. The six sets of guides are misaligned by 30 degrees. If N sets of guides are used, the misalignment rotation angle will be 180 / N degrees. The 180 / N degree misalignment between the upper and lower layers is not mandatory. If there is no misalignment, the maximum gain will be relatively higher, but the non-circularity will be worse. In actual engineering applications, a compromise should be made based on the specific situation. Both methods are objects that need to be protected by this patent, as shown in Table 13.

[0062] Table 13 Gain Table for Horizontal Lead-Up and Upper / Lower Layer Arrays

[0063] Table 14 Comparison of the present invention and the half-wave dipole linear array antenna

[0064] As shown in Table 14, the horizontal antenna has a gain of 5.5 dBi after being arrayed in two layers, and a length of 127 mm. If a conventional omnidirectional antenna is used with the same gain, the length would be 217 mm. The antenna of this invention with a gain of 5.4 dBi is only 58.5% of the length of a conventional omnidirectional antenna, which is nearly half the length.

[0065] In this optional embodiment, the two adjacent layers of the first-level horizontal guiding structure are offset and rotated 180 / N degrees in the horizontal direction to further improve the antenna gain.

[0066] Specifically, 4.2, Horizontal Four-Layer Array: To further improve antenna gain, a four-layer array can be used. The four stimulated elements 1 are fed with equal amplitude and in-phase power. The array is rotated horizontally by 30 degrees between layers, such as rotating layers 1 and 3 or layers 2 and 4, to achieve better non-circularity. The structure is as follows: Figures 27-29 As shown.

[0067] Table 15 Gain Table for Horizontal Induction Four-Layer Array

[0068] Table 16 Comparison of the present invention and the half-wave dipole linear array antenna

[0069] After being arrayed in four layers, the gain can reach 8dBi and the length is 379mm. When using a conventional omnidirectional antenna with the same gain, the length would be 462mm. The length of this invention's antenna is only 82% of that of a conventional omnidirectional antenna.

[0070] If more layers of array are used, the gain can be further increased, but these will not be listed here.

[0071] In this alternative embodiment, the distance between the director 2 and the stimulated unit 1 is approximately one-third of the operating wavelength.

[0072] In this alternative embodiment, the length of the director 2 is approximately 0.45 times the operating wavelength.

[0073] Specifically, in this invention, an omnidirectional antenna vibrator is used as the stimulated element 1, and a ring of directors is placed around the stimulated element 1. Figure 2 As shown, the distance between the director 2 and the stimulated unit 1 is about one-third of the wavelength, and the length of the director 2 is about 0.45 times the wavelength. By reasonably optimizing the distance between the director 2 and the stimulated unit 1 and the length of the director 2, the optimal gain improvement can be obtained.

[0074] The present invention adds 6, 8, or 12 directors 2 in three forms. As long as other numbers of directors 2 are evenly arranged around the excited unit 1, the same effect can be achieved. The diameter of the directors 2 and the excited unit 1 is 3.2 mm. The present invention is not limited to this diameter, and other diameters can also be achieved.

[0075] Table 17 English-Chinese Glossary of Radiation Pattern and Gain Parameters

[0076] Figure 2 An embodiment of an omnidirectional antenna according to the present invention is shown.

[0077] In this optional embodiment, the omnidirectional antenna includes: An omnidirectional antenna element serves as the stimulated element 1. Several directors 2 are evenly distributed around the stimulated unit 1 in the circumferential direction, and there is no physical connection between the directors 2 and the stimulated unit 1. An insulating support structure 3 is used to fix the stimulated unit 1 and the director 2.

[0078] To facilitate understanding of the above technical solutions of the present invention, the following further explains the above technical solutions of the present invention from the perspective of architecture and principle, as follows: The design of Director 2 is inspired by the Yagi antenna. This structure utilizes the spatial coupling and phase superposition of electromagnetic waves to achieve beam convergence and improve antenna gain. The specific principle is as follows: Figure 30 As shown.

[0079] The Yagi antenna mainly consists of three parts: stimulated element 1, director 2, and reflector 8. The stimulated element 1 is an active dipole, and a half-wave dipole is used as an example here. The reflector 8 and director 2 are passive dipoles and are not connected to the feed 4. The approximate optimal dimensions of each part are as follows: the reflector 8 is half a wavelength long and is one-quarter a wavelength away from the stimulated element 1; the director is about 0.45 wavelengths long and is one-third a wavelength away from the stimulated element 1. In actual design, the dimensions marked above need to be optimized to obtain the best performance.

[0080] When the stimulated unit 1 radiates electromagnetic waves outward, it will induce an alternating current on the surrounding director 2. By optimizing the length and position of the director 2, the electromagnetic waves radiated by the director 2 in the second phase are kept in phase with the electromagnetic waves directly emitted by the stimulated unit 1.

[0081] In-phase electromagnetic waves are enhanced by spatial superposition, ultimately achieving beam convergence and effectively improving antenna gain. Traditional Yagi antennas rely on the coupling of director 2 to generate secondary radiation, which is superimposed with the emitted phase of stimulated element 1 to contract the beam to a single direction, forming directional radiation. This significantly reduces the horizontal and vertical bandwidth of the antenna pattern compared to when stimulated element 1 is used alone, resulting in a significant increase in maximum gain.

[0082] Table 18 Comparison Summary of Methods 1-4

[0083] As shown in Table 18, the comparison above shows that the antenna length is significantly shortened at the same gain compared to the traditional method after adopting the directing method. The shorter the gain, the greater the shortening ratio, especially the horizontal directing method, which has a more obvious effect.

[0084] In summary, placing a ring of directors 2 evenly around the radiating element of an omnidirectional antenna, and rationally designing the length and position of the directors 2, can improve the gain of the omnidirectional antenna. Directional technology is typically used in directional antenna applications. In conventional designs, adding a metal structure around the omnidirectional antenna often blocks electromagnetic radiation and degrades antenna performance. This invention, by rationally designing the size and position of the directors 2, not only avoids radiation blocking problems but also improves antenna gain.

[0085] This invention is not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

Claims

1. A method for shortening the length of an omnidirectional antenna using a director, characterized in that, include: An omnidirectional antenna vibrator is used as the stimulated element; Several directors are evenly arranged circumferentially around the stimulated unit; wherein the directors are placed vertically or horizontally relative to the stimulated unit. By optimizing the length of the director and the distance between it and the stimulated unit, the secondary radiated electromagnetic wave generated by the director through spatial electromagnetic coupling is superimposed with the direct electromagnetic wave of the stimulated unit. This improves the antenna gain while maintaining the omnidirectional radiation characteristics in the horizontal plane, thereby shortening the omnidirectional antenna length required to achieve the target gain.

2. The method for shortening the length of an omnidirectional antenna using a director according to claim 1, characterized in that, The placement of the director and the stimulated unit in a vertical configuration includes: The stimulated element is a vertically polarized half-wave dipole antenna; The director is arranged around the stimulated unit in the same horizontal plane, and the axis of the director is parallel to the axis of the stimulated unit, forming a vertically directed single-layer antenna structure.

3. The method for shortening the length of an omnidirectional antenna using a director according to claim 2, characterized in that, Several groups of vertically directed single-layer antenna structures are arrayed vertically, with each layer of stimulated elements using equal-amplitude and in-phase feeding, forming a vertically directed multi-layer array structure to improve antenna gain.

4. The method for shortening the length of an omnidirectional antenna using a director according to claim 1, characterized in that, The placement of the director and the stimulated unit in a horizontal manner includes: N sets of half-wave dipole antennas are placed horizontally and arranged at equal intervals around the same center to form an N-sided structure of stimulated unit. N sets of directors are arranged circumferentially around the excitation unit of the N-sided structure. The axis of the horizontal director is parallel to the axis of the half-wave dipole antenna, forming a first-level horizontal director structure.

5. A method for shortening the length of an omnidirectional antenna using a director according to claim 4, characterized in that, N sets of directors are sequentially added along the radial direction outside the first-level horizontal guiding structure to form a second-level horizontal guiding structure, thereby improving the antenna gain.

6. A method for shortening the length of an omnidirectional antenna using a director according to claim 4, characterized in that, The n-layer first-level horizontally directed structure is arrayed vertically, with each layer of stimulated elements using equal-amplitude and in-phase feeding, forming a horizontally directed multi-layer array structure to improve antenna gain.

7. A method for shortening the length of an omnidirectional antenna using a director according to claim 6, characterized in that, The two adjacent first-level horizontal guiding structures are offset and rotated 180 / N degrees in the horizontal direction to improve antenna gain.

8. A method for shortening the length of an omnidirectional antenna using a director according to claim 1, characterized in that, The distance between the director and the stimulated unit is approximately one-third of the operating wavelength.

9. A method for shortening the length of an omnidirectional antenna using a director according to claim 1, characterized in that, The length of the director is approximately 0.45 times the operating wavelength.

10. An omnidirectional antenna, arranged using the method described in any one of claims 1-9, which shortens the length of the omnidirectional antenna by employing a director, characterized in that... include: An omnidirectional antenna element serves as the stimulated unit. Several directors are evenly distributed around the excited unit in the circumferential direction; An insulating support structure is provided for securing the stimulated unit and the director.

Images