Multi-band mining double-open sleeve antenna

Abstract

The invention relates to a multi-band mining double-open sleeve antenna, and belongs to the technical field of wireless communication. The antenna structure comprises a monopole structure, a first open sleeve structure and a second open sleeve structure, wherein the first open sleeve structure and the second open sleeve structure are respectively fixed at two ends of the monopole structure. The first open sleeve structure comprises a metal cylinder connected with the monopole structure and four metal cylinders fixed on the surface of the metal cylinder and distributed around the monopole structure; the second open sleeve structure comprises a metal cylinder connected with the monopole structure and four metal cylinders fixed on the surface of the metal cylinder and distributed around the monopole structure. Wherein the first open sleeve structure can increase the resonance path of the antenna through the four metal cylinders, and the second open sleeve structure can improve the impedance matching performance of the antenna through the four metal cylinders, thereby widening the working frequency band of the antenna. Besides, a lumped resistor is loaded in the monopole structure, so that the current flowing through the antenna is distributed in a traveling wave manner, and the working frequency band of the antenna is expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communications and relates to a multi-band mining double-open sleeve antenna. Background Art

[0002] The radio communication distance in the underground tunnel of coal mines is highly correlated with the frequency selection. The underground disaster relief wireless broadband communication system needs to use wireless channels of different frequency bands at different tunnel locations to achieve the best balance between the network length and the final bandwidth. Therefore, underground disaster relief wireless communication equipment needs to be compatible with multiple communication frequency bands at the same time. Generally, in order to meet the various communication needs in the coal mine environment, it is necessary to select five frequency bands with different functions, and cover the five frequency bands through the design and optimization of the antenna to realize the underground wireless communication function. These five frequency bands are: 566MHz~678MHz, 806MHz~826MHz, which are usually used in the field of public safety and emergency communications; 1427.9MHz~1447.9MHz for LTE band11, which is a 4G communication frequency band; 2401.5MHz~2481.5MHz, 5150MHz~5850MHz for WLAN / WiMAX frequency bands.

[0003] As the end of the wireless communication system, the antenna is responsible for receiving and transmitting electromagnetic waves and is a key component that determines the performance of the communication system. However, general antennas only support 1 to 2 frequency bands. Different coal mines are selective in their working frequency bands and need to frequently replace antennas, which brings great inconvenience to practical applications. Although the frequency band reconfigurable antenna can cover multiple frequency bands with one antenna, it still requires a switch to switch the working frequency band, which is still not the best choice. Therefore, it is necessary to study multi-frequency shared antennas to achieve the use of a single antenna to cover the radio transmission and reception of underground wireless equipment in multiple frequency bands. Multi-frequency antennas directly determine the working flexibility of underground wireless communication equipment, and indirectly promote the improvement of underground wireless transmission distance and the stability of wireless communication systems.

[0004] The monopole antenna itself has a simple structure and is easy to process. Its compact size makes it a more practical choice, but its lack of multi-frequency performance is one of the main factors limiting its promotion. The sleeve structure has the possibility of achieving broadband and multi-frequency, and is an effective solution to expand the frequency band of the monopole antenna. Applying the sleeve structure to the monopole antenna is an important method to realize the multi-band antenna solution for mining. At the same time, the open sleeve structure can significantly reduce the size of the antenna, and at the same time has multi-frequency and broadband characteristics. It is a better solution for designing compact antennas, which makes it widely used in mobile devices. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a multi-band double open sleeve antenna for mining, which utilizes the multi-frequency and broadband performance of the sleeve structure, transforms the traditional sleeve into an open sleeve structure that can correspond to multiple resonant frequencies, and uses lumped resistance loading and top loading to achieve coverage of five target frequency bands with a monopole antenna, and includes both low and high frequency bands, so that underground wireless communication equipment can switch operating frequencies without replacing the antenna.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A multi-band double open sleeve antenna for mining comprises a monopole structure, and a first open sleeve structure and a second open sleeve structure respectively fixed at two ends of the monopole structure.

[0008] The first open sleeve structure includes a first metal cylinder connected to the monopole structure, and second to fifth metal cylinders fixed on the surface of the first metal cylinder and symmetrically distributed around the monopole structure. In addition, the first open sleeve structure also includes a coaxial line and a rectangular metal plate, wherein the inner conductor of the coaxial line passes through the first metal cylinder and is connected to the monopole structure, the rectangular metal plate is arranged on the surface of the first metal cylinder away from the monopole structure, and screws for fixing the second to fifth metal cylinders are respectively arranged at the four corners of the rectangular metal plate. The first open sleeve structure feeds energy through the coaxial line, and increases the resonance path of the antenna through the second to fifth metal cylinders. Among them, the second to fifth metal cylinders have different lengths, and the lengths of the second to fifth metal cylinders correspond to the wavelengths of different resonant frequencies. By changing the length of the corresponding frequency point, the resonant frequency point of the antenna can be flexibly adjusted.

[0009] The second open sleeve structure includes a seventh metal cylinder connected to the monopole structure, and four metal cylinders fixed on the surface of the seventh metal cylinder and symmetrically distributed around the monopole structure, wherein two metal cylinders have the same first length, and the other two metal cylinders have the same second length, and the first length and the second length are not equal. The second open sleeve structure can improve the impedance matching performance of the antenna through the four metal cylinders, so that the antenna has the ability to cover a wider frequency band, thereby widening the working frequency band of the antenna.

[0010] Optionally, the monopole structure includes a sixth metal cylinder, a first plastic cylinder, a second plastic cylinder and a lumped resistor. One end of the sixth metal cylinder is fixed to the first metal cylinder through the first plastic cylinder, and the other end is fixed to the seventh metal cylinder; the lumped resistor is set in the middle of the sixth metal cylinder, and the sixth metal cylinder is cut off, and then the lumped resistor is fixed and connected to the sixth metal cylinder through the second plastic cylinder. By setting the resistance value of the lumped resistor, the current from the coaxial line of the antenna to the second open sleeve structure can be distributed in a traveling wave, thereby widening the multiple frequency bands of the antenna.

[0011] The beneficial effects of the present invention are as follows: the present invention proposes a dual open sleeve antenna, which combines a monopole antenna with two open sleeve structures, increases the antenna current resonance path through one of the open sleeve structures, introduces a new resonance frequency, thereby achieving the multi-frequency goal of the antenna, and expands the working frequency band of the antenna through the other open sleeve structure, so that the antenna can be applied to a communication environment with a complex environment that requires more and wider communication frequency bands. In addition, the present invention also loads a lumped resistor in the middle of the monopole antenna, so that the current from the feed structure (i.e., the coaxial line) to the second open sleeve structure is distributed in a traveling wave, which optimizes the multiple bandwidth performance of the antenna and expands the working frequency band of the antenna.

[0012] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0014] Figure 1 The overall structure of a multi-band mining double open sleeve antenna provided by an embodiment of the present invention;

[0015] Figure 2 The top view of the antenna's screw structure;

[0016] Figure 3 and Figure 4 It is a side view of the double open sleeve antenna structure;

[0017] Figure 5 is the standing wave ratio of the double open sleeve antenna of the present invention;

[0018] Figure 6 The H-plane radiation pattern of the double open sleeve antenna of the present invention at 0.62 GHz;

[0019] Figure 7 The H-plane radiation pattern of the double open sleeve antenna of the present invention at 0.82 GHz;

[0020] Figure 8 The H-plane radiation pattern of the double open sleeve antenna of the present invention at 1.44 GHz;

[0021] Fig. 9 H-plane radiation pattern of the double open sleeve antenna of the present invention at 2.44 GHz;

[0022] Fig.10 H-plane radiation pattern of the double open sleeve antenna of the present invention at 5.50 GHz;

[0023] Fig.11 This is the peak gain diagram of the double open sleeve antenna of the present invention.

[0024] Figure markings: 1-coaxial line; 2-screw; 3-rectangular metal plate; 401-metal cylinder I; 402-metal cylinder II; 403-metal cylinder III; 404-metal cylinder IV; 405-metal cylinder V; 501-metal cylinder VI; 502-plastic cylinder I; 503-plastic cylinder II; 504-lumped resistor; 601-metal cylinder VII; 602-metal cylinder VIII; 603-metal cylinder IX. DETAILED DESCRIPTION

[0025] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0027] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] Aiming at the special communication environment in the underground tunnels of coal mines, the present invention utilizes the multi-frequency and broadband performance of the sleeve structure. By transforming the traditional sleeve into an open sleeve structure that can correspond to multiple resonant frequency points, and loading through lumped resistance and top loading, a small-sized and easy-to-process monopole antenna is used to achieve coverage of five target frequency bands, including both low-frequency bands and high-frequency bands, so that the underground wireless communication equipment can switch the operating frequency without changing the antenna.

[0029] like Figure 1 As shown, a multi-band mining dual open sleeve antenna with lumped resistance loading provided by an embodiment of the present invention includes three parts: an open sleeve structure, a monopole structure and a top loading structure connected in sequence.

[0030] The open sleeve structure includes a feeding structure, a connection structure and a sleeve structure. The sleeve structure is a coaxial line 1, which serves as the energy feeding point of the antenna. The connection structure includes a screw 2 and a rounded rectangular metal plate 3 with smooth edges and corners. Figure 2 As shown, four screws 2 are distributed at the four rounded corners of the rectangular metal plate 3, and the sleeve structure and the rectangular metal plate 3 are fixed together by these four screws. The sleeve structure is composed of a thick and short metal cylinder I 401 and slender metal cylinders II to V. The four slender metal cylinders are of different lengths, among which the slender metal cylinder IV 404 and the metal cylinder V 405 are of equal length and symmetrically distributed. The slender metal cylinders II to V are all connected to the thick and short metal cylinder I 401 and fixed by screws, so as to be combined with the rectangular metal plate 3 into a whole.

[0031] The monopole structure consists of three parts: a metal cylindrical structure, a lumped resistor structure and a plastic cylindrical structure. Among them, the metal cylindrical structure is the metal cylinder VI 501, which is connected to the inner conductor of the coaxial line 1 and is part of the antenna radiation structure. The lumped resistor structure is a lumped resistor 504 loaded in the middle of the metal cylinder VI 501, which is an important structure for the antenna to achieve frequency band expansion. The plastic cylindrical structure is a hollow structure used to achieve a fixing function, and its interior fits the metal cylinder VI 501. Among them, the plastic cylinder I 502 is set at the connection between the metal cylinder VI 501 and the thick and short metal cylinder I 401, so that the metal cylinder VI and the metal cylinder I are fixed, and the plastic cylinder II 503 is used to fix the lumped resistor 504 and the metal cylinder VI 501 separated by the lumped resistor 504.

[0032] The top loading structure is composed of metal cylinders of different diameters and heights. Specifically, the thick and short metal cylinder VII601 is located at the top of the metal cylinder VI501 and is a loading structure of a monopole structure. Four slender metal cylinders are arranged on the thick and short metal cylinder VII601, and these four metal cylinders are distributed around the metal cylinder VI501. Among them, the two slender metal cylinders IX603 are equal in length and symmetrically distributed, and the two slender metal cylinders VIII602 are equal in length and symmetrically distributed, but are longer than the length of the metal cylinder IX603.

[0033] In the above-mentioned multi-band mining double open sleeve antenna, the slender metal structures II to V increase the resonant path of the antenna current, help the antenna generate more resonant frequencies, and achieve the multi-frequency performance of the antenna. Among them, the length of the slender metal cylinders II to V corresponds to the wavelength of different resonant frequencies. By changing the length of the corresponding frequency point, the resonant frequency of the antenna can be flexibly adjusted. The stubby metal cylinder I and the slender metal structures II to V together constitute the open sleeve structure of the antenna, which reduces the size of the antenna and is a key measure to make the antenna compact and miniaturized.

[0034] In the above-mentioned multi-band mining double open sleeve antenna, the plastic cylinder I 502 fixes the monopole structure on the thick metal cylinder I 401 without causing a significant impact on the impedance performance and radiation performance of the antenna. The plastic cylinder II 503 fixes the metal cylinder VI 501 separated by the lumped resistor 504 together, so that the antenna maintains continuity in the vertical direction. Among them, the lumped resistor 504 has a resistance of 910Ω, so that the current from the feed structure to the top loading structure is distributed in a traveling wave, thereby widening the multiple frequency bands of the antenna.

[0035] In the above-mentioned multi-band mining double open sleeve antenna, by loading the slender metal cylindrical structures VIII and IX at the top, more modes of the antenna are stimulated, and the impedance matching performance of the antenna is improved, so that the antenna has the ability to cover a wider frequency band. The stubby metal cylinder VII601 and the slender metal cylinders VIII and IX together constitute the second open sleeve structure of the antenna, expanding the working frequency band of the antenna, so that the antenna can be used in a complex environment that requires more and wider communication frequency bands.

[0036] In this embodiment, the overall size of the proposed multi-band mining double open sleeve antenna is 248.25mm×18mm, the main radiation structure is made of metal copper, and the fixed structure is made of plastic. For the specific size of the antenna, see Figure 3-4 And Table 1.

[0037] Table 1

[0038]

[0039] like Figure 5 As shown in the figure, it is the standing wave ratio of the double open sleeve antenna for mining proposed in this embodiment. Figure 5 It can be seen that the standing wave ratio of the antenna at center frequencies of 0.62 GHz, 0.82 GHz, 1.44 GHz, 2.44 GHz, and 5.50 GHz are 1.07, 1.30, 1.31, 1.40, and 1.41, respectively. That is, the standing wave ratio of the antenna is less than 2 in the frequency bands of 0.55-0.70 GHz, 0.70-0.87 GHz, 1.38-1.49 GHz, 2.23-2.50 GHz, and 4.46-6.00 GHz.

[0040] like Figure 6 to Figure 10 The H-plane radiation pattern simulations of the mining double open sleeve antenna proposed in this embodiment at 0.62 GHz, 0.82 GHz, 1.44 GHz, 2.44 GHz, and 5.50 GHz respectively show that the H-plane radiation pattern of the antenna has a small non-circularity and omnidirectional radiation at the five frequency points.

[0041] like Fig.11 The figure shows the gain simulation of the double open sleeve antenna for mining provided in this embodiment. Fig.11 It can be seen that the gains of the antenna at resonant frequencies of 0.62 GHz, 0.82 GHz, 1.44 GHz, 2.44 GHz, and 5.50 GHz are 0.39 dBi, 3.07 dBi, 5.37 dBi, 4.61 dBi, and 6.34 dBi, respectively.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A multi-band mining double open sleeve antenna, characterized in that: It includes a monopole structure, and a first open sleeve structure and a second open sleeve structure respectively fixed at two ends of the monopole structure; The first open sleeve structure includes a first metal cylinder connected to the monopole structure, and second to fifth metal cylinders fixed on the surface of the first metal cylinder and distributed around the monopole structure, the first open sleeve structure is used to feed energy, and increase the resonance path of the antenna through the second to fifth metal cylinders; the second to fifth metal cylinders have different lengths; The second open sleeve structure includes a seventh metal cylinder connected to the monopole structure, and four metal cylinders fixed on the surface of the seventh metal cylinder and distributed around the monopole structure. The second open sleeve structure improves the impedance matching performance of the antenna through the four metal cylinders and broadens the working frequency band of the antenna.

2. The multi-band mining double open sleeve antenna according to claim 1, characterized in that: The first open sleeve structure also includes a coaxial line and a rectangular metal plate; the coaxial line serves as the energy feeding point of the antenna, and the inner conductor of the coaxial line passes through the first metal cylinder and is connected to the monopole structure; the rectangular metal plate is arranged on the surface of the first metal cylinder away from the monopole structure at one end, and screws for fixing the second to fifth metal cylinders are respectively arranged at the four corners of the rectangular metal plate.

3. The multi-band mining double open sleeve antenna according to claim 1, characterized in that: The monopole structure includes a sixth metal cylinder, a first plastic cylinder, a second plastic cylinder and a lumped resistor; one end of the sixth metal cylinder is fixed to the first metal cylinder through the first plastic cylinder, and the other end is fixed to the seventh metal cylinder; the lumped resistor is arranged in the middle of the sixth metal cylinder, and is fixed to the fifth metal cylinder through the second plastic cylinder.

4. The multi-band mining double open sleeve antenna according to claim 3, characterized in that: The lumped resistor divides the sixth metal cylinder into two parts, and the sixth metal cylinder and the lumped resistor are connected via the second plastic cylinder.

5. The multi-band mining double open sleeve antenna according to claim 1, characterized in that: Among the four metal cylinders on the surface of the seventh metal cylinder, two of the metal cylinders have the same first length and are symmetrically distributed, and the other two metal cylinders have the same second length and are symmetrically distributed, and the first length and the second length are not equal.

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