A broadband high-gain omnidirectional antenna based on dipole linear array

Abstract

A broadband high-gain omnidirectional antenna based on a dipole linear array comprises a bottom plate and four side plate antenna units fixed in a cross shape through the bottom plate, the four side plate antenna units have the same structure, the side plate antenna units all comprise a substrate and an antenna vibrator printed on the substrate, the substrates of adjacent side plate antenna units are orthogonally arranged, the antenna vibrator comprises a first vibrator structure located on the upper surface of the substrate and a second vibrator structure located on the lower surface of the substrate, the first vibrator structure and the second vibrator structure are both composed of a plurality of vibrator units connected in sequence, the vibrator unit of the first vibrator structure comprises a first feeding strip line and a first L-shaped radiating arm vertically connected to the first feeding strip line, the vibrator unit of the second vibrator structure comprises a second feeding strip line and a second L-shaped radiating arm vertically connected to the second feeding strip line, the first feeding strip line and the second feeding strip line of the four side plate antenna units are connected to a power divider for feeding. The present invention has good omnidirectional radiation characteristics.

Description

Technical Field

[0001] The invention belongs to the technical field of communications, and in particular relates to a broadband high-gain omnidirectional antenna based on a dipole linear array. Background Art

[0002] Antennas are key components for transmitting signals in communication equipment. Their performance often depends on the communication environment in which they are located. Different wireless communication environments have different design requirements for antennas. Antennas can be classified into directional antennas and omnidirectional antennas according to the uniformity of the radiated energy, that is, the directivity. Directional antennas are often used in environments where a single point is connected to a limited number of fixed points, such as communications on roads or offshore areas. These areas require directional antennas to generate one or more main beams in a known specific azimuth, and form nulls in other directions to weaken the radiation (or reception) capability in this direction. Since directional antennas can radiate all energy in a specific azimuth, they are characterized by high gain, long communication distance, and are not easy to be monitored. In communications from a single point to any uncertain multiple points, omnidirectional antennas are often selected because omnidirectional antennas can radiate electromagnetic waves evenly in the azimuth plane, thereby achieving all-round coverage of the signal. An omnidirectional antenna is an antenna that achieves 360° uniform radiation in the horizontal plane and has a certain beam width in the vertical plane. The signal transmitted by an omnidirectional antenna can be received by the receiving end at any azimuth in the horizontal plane, and can also receive signals in all directions in the horizontal plane. Omnidirectional antennas are generally used in communication systems for wide coverage and point-to-multipoint communication systems, such as radio and television. Omnidirectional antennas are characterized by low gain, short communication distance, but large coverage, and can be used in special communication environments. For example, in scenarios such as radio, television, and mobile communication base stations that require large-scale coverage of electromagnetic wave signals, omnidirectional antennas are more suitable than directional antennas. In short-range communications without specific targets, such as indoor WLAN, walkie-talkie systems and other communication equipment, omnidirectional antennas have the advantage of being more reliable. In addition, omnidirectional antennas are also widely used in projects such as roadbed navigation, radio frequency identification, radar sensor networks, and channel detection. Compared with mechanical scanning antennas and phased array antennas, omnidirectional antennas can naturally achieve 360° omnidirectional coverage, and have a simple structure and low manufacturing cost.

[0003] With the development of the times, science and technology are changing with each passing day. The development of wireless communication technology has profoundly changed people's work and life, giving rise to people's persistent pursuit of higher performance, faster mobile communication, interconnection and information acquisition technology. For example, the amount of information in the fourth generation of mobile communications has increased dramatically. In addition to the need to meet the data transmission of language and text, it also requires the transmission of high-quality pictures, audio and video. The fifth generation requires a large number of terminals to access at the same time, ultra-fast network connection, stable and uninterrupted communication, and timely and high-quality multimedia experience. To achieve this goal, it requires a very large improvement in information transmission rate, signal spectrum utilization and network capacity. This forces wireless communication systems to develop towards the goal of broadband and comprehensive intelligence. In the military, based on the needs of confidential communication, frequency hopping spread spectrum technology is widely used. At the same time, it is also necessary to ensure that large-scale digital communication data can achieve rapid wireless transmission of information under high-precision requirements, which inevitably requires the bandwidth of the antenna in the system to be rapidly improved. In addition, in order to meet the needs of electromagnetic compatibility of various devices in complex electromagnetic environments, it is required to reduce the mutual coupling and interference between antennas in multiple systems on radio equipment. Using a broadband or ultra-wideband antenna to adapt to a variety of different working environments and cover all communication frequency bands is a feasible method. This can greatly reduce the number of antennas in the working environment, reduce interference between systems, and achieve the purpose of reducing costs and optimizing system performance. Therefore, whether in civil or military use, the research and development of broadband omnidirectional antennas is a research topic worthy of attention in modern wireless communication systems. Summary of the invention

[0004] The purpose of the present invention is to provide a broadband high-gain omnidirectional antenna based on a dipole linear array in order to solve the above problems in the prior art. The antenna has good omnidirectional radiation characteristics and can cover a wide frequency band while maintaining good working characteristics.

[0005] In order to achieve the above object, the present invention has the following technical solutions:

[0006] A broadband high-gain omnidirectional antenna based on a dipole linear array comprises a bottom plate and four side plate antenna units fixed in a cross shape through the bottom plate, the four side plate antenna units have the same structure, the side plate antenna units all comprise a substrate and an antenna vibrator printed on the substrate, the substrates of adjacent side plate antenna units are orthogonally arranged, the antenna vibrator comprises a first vibrator structure located on the upper surface of the substrate and a second vibrator structure located on the lower surface of the substrate, the first vibrator structure and the second vibrator structure are both composed of a plurality of vibrator units connected in sequence, the vibrator unit of the first vibrator structure comprises a first feeding strip line and a first L-shaped radiating arm vertically connected to the first feeding strip line, the vibrator unit of the second vibrator structure comprises a second feeding strip line and a second L-shaped radiating arm vertically connected to the second feeding strip line, and the first feeding strip lines and the second feeding strip lines of the four side plate antenna units are connected to a power divider for feeding.

[0007] As a preferred solution of the present invention, the bottom plate is circular, and four slots are provided in a cross shape on the bottom plate. The substrates of the four side panel antenna units are inserted and installed in the slots of the bottom plate to achieve cross-shaped fixation.

[0008] As a preferred solution of the present invention, the substrate is rectangular, and a plurality of bottom plates are arranged at intervals along the long side of the substrate for support.

[0009] As a preferred solution of the present invention, the number of vibrator units in the first vibrator structure and the second vibrator structure is equal.

[0010] As a preferred solution of the present invention, the vibrator units of the first vibrator structure and the second vibrator structure are arranged in pairs on the upper and lower surfaces of the substrate, and each pair of first L-shaped radiation arms and second L-shaped radiation arms are oriented in opposite directions.

[0011] As a preferred solution of the present invention, the distance between two adjacent first L-shaped radiation arms or between two adjacent second L-shaped radiation arms is 33 mm.

[0012] As a preferred solution of the present invention, the width of the second feeding strip line is greater than the width of the first feeding strip line.

[0013] As a preferred solution of the present invention, the power divider is arranged at the same side end of the substrate of the four side panel antenna units, and the power divider is a one-to-four power divider, and the four side panel antenna units are fed by a one-to-four power divider at the same time.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: the four side panel antenna units are fixed in a cross shape, the substrates of the four side panel antenna units are arranged orthogonally in pairs to form a final broadband omnidirectional high-gain array, the antenna vibrator includes a first vibrator structure located on the upper surface of the substrate and a second vibrator structure located on the lower surface of the substrate, the first vibrator structure and the second vibrator structure are both composed of a number of vibrator units connected in sequence, the vibrator unit of the first vibrator structure includes a first feeding strip line and a first L-shaped radiating arm vertically connected to the first feeding strip line, the vibrator unit of the second vibrator structure includes a second feeding strip line and a second L-shaped radiating arm vertically connected to the second feeding strip line, the vibrator unit array has good gain in the entire vertical plane, the antenna of the present invention has good omnidirectional radiation characteristics, and the frequency band that can be covered by maintaining good working characteristics is relatively wide, and the bandwidth reaches 2GHz. The antenna of the present invention has a simple structure, excellent performance, and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a vibrator unit of a first vibrator structure according to an embodiment of the present invention;

[0016] Figure 2 A schematic structural diagram of a vibrator unit of a second vibrator structure according to an embodiment of the present invention;

[0017] Figure 3 The S11 reflection coefficient diagram of the omnidirectional antenna element unit according to the embodiment of the present invention;

[0018] Figure 4 A two-dimensional directional pattern of the omnidirectional antenna element unit in the first direction according to an embodiment of the present invention;

[0019] Figure 5 A two-dimensional directional pattern of the second direction of the omnidirectional antenna element unit of an embodiment of the present invention;

[0020] Figure 6 A schematic diagram of a first vibrator structure on the upper surface of a substrate according to an embodiment of the present invention;

[0021] Figure 7 A schematic diagram of the second vibrator structure on the lower surface of the substrate according to an embodiment of the present invention;

[0022] Figure 8 The S11 reflection coefficient diagram of the side panel antenna unit according to the embodiment of the present invention;

[0023] Fig. 9 A two-dimensional directional pattern of a side panel antenna unit in a first direction according to an embodiment of the present invention;

[0024] Fig.10 A two-dimensional directional pattern of the side panel antenna unit in the second direction according to an embodiment of the present invention;

[0025] Fig.11 A schematic diagram of the structure of a 3D model of an omnidirectional antenna in a coordinate system according to an embodiment of the present invention;

[0026] Fig.12 A schematic diagram of the structure of a one-to-four power distributor in a coordinate system according to an embodiment of the present invention;

[0027] Fig.13 A simulated two-dimensional radiation pattern of the first direction of the omnidirectional antenna according to an embodiment of the present invention;

[0028] Fig.14 A simulated two-dimensional radiation pattern of the second direction of the omnidirectional antenna according to an embodiment of the present invention;

[0029] Fig.15 Simulated S11 reflection coefficient diagram of the omnidirectional antenna according to the embodiment of the present invention;

[0030] Fig.16 Schematic diagram of the dipole principle. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0032] The broadband high-gain omnidirectional antenna based on the dipole linear array of the present invention comprises a bottom plate and four side plate antenna units 2 fixed in a cross shape through the bottom plate. The four side plate antenna units 2 have the same structure, and the side plate antenna units 2 all comprise a substrate 21 and an antenna vibrator 22 printed on the substrate 21. The bottom plate is circular, and four slots are provided in a cross shape on the bottom plate. The substrates 21 of the four side plate antenna units 2 are inserted and installed in the slots of the bottom plate to realize cross-shaped fixation. The substrate 21 is rectangular, and a plurality of bottom plates are arranged at intervals along the long side of the substrate 21 for support.

[0033] The substrates 21 of the adjacent side panel antenna units 2 are arranged orthogonally, and the antenna vibrator 22 includes a first vibrator structure located on the upper surface of the substrate 21 and a second vibrator structure located on the lower surface of the substrate 21. The first vibrator structure and the second vibrator structure are both composed of a plurality of vibrator units connected in sequence, see Figure 1 The oscillator unit of the first oscillator structure includes a first feeding strip line 221 and a first L-shaped radiation arm 222 vertically connected to the first feeding strip line 221, see Figure 2 The oscillator unit of the second oscillator structure includes a second feeding strip line 223 and a second L-shaped radiation arm 224 vertically connected to the second feeding strip line 223. Figure 1 and Figure 2 In this embodiment, the width of the second feeding strip line 223 is greater than the width of the first feeding strip line 221 .

[0034] Figure 3 The S11 reflection coefficient of the omnidirectional antenna element unit of the embodiment of the present invention is shown. Figure 4 and Figure 5 Two two-dimensional directional diagrams of the omnidirectional antenna element unit according to the embodiment of the present invention are respectively shown;

[0035] See also Figure 6 and Figure 7 In this embodiment, the number of the first oscillator structure and the number of the oscillator units of the second oscillator structure are equal. The oscillator units of the first oscillator structure and the second oscillator structure are arranged in pairs on the upper and lower surfaces of the substrate 21, and each pair of the first L-shaped radiation arm 222 and the second L-shaped radiation arm 224 are oriented in opposite directions. Figure 1 and Figure 2 The distance between two adjacent first L-shaped radiation arms 222 or between two adjacent second L-shaped radiation arms 224 is 33 mm.

[0036] Figure 8 The S11 reflection coefficient of the side panel antenna unit in the embodiment of the present invention is shown. Fig. 9 and Fig.10Two two-dimensional directional diagrams of the side panel antenna unit 2 of the embodiment of the present invention are respectively shown. Four such side panel antenna units 2 are arranged orthogonally in pairs to form a final broadband omnidirectional high-gain array.

[0037] Fig.11 The 3D simulation model of the omnidirectional antenna according to the embodiment of the present invention in HFSS is shown.

[0038] In this embodiment, the first feeding strip lines 221 and the second feeding strip lines 223 of the four side panel antenna units 2 are connected to the power divider 1 for feeding. The four side panel antenna units 2 are vertically inserted on the bottom plate, and the power divider 1 is arranged at the same side end of the substrate 21 of the four side panel antenna units 2. The power divider 1 is a one-to-four power divider, and the four side panel antenna units 2 are fed by one one-to-four power divider at the same time. The structure of the one-to-four power divider is as follows: Fig.12 shown.

[0039] Fig.13 and Fig.14 The two-dimensional directional pattern of the omnidirectional antenna in two directions of the embodiment of the present invention is simulated. It can be seen that the omnidirectional antenna has good gain in the entire vertical plane. Fig.15 The simulated S11 reflection coefficient of the omnidirectional antenna of the embodiment of the present invention is shown. It can be seen from the figure that the array has good working characteristics in the frequency band of 5.07 GHz to 7 GHz, that is, the bandwidth reaches 2 GHz. At the frequency of 6.5 GHz, the S11 performance of the omnidirectional antenna of the embodiment of the present invention is the best, reaching -42dB.

[0040] See also Fig.16 The symmetrical oscillator is also called a dipole. It is evolved from an open structure transmission line. It consists of two wires of equal length and thickness. It has a simple structure and is the most widely used.

[0041] The study of the current distribution on the vibrator surface can deduce its radiation direction characteristics from a theoretical perspective. Generally speaking, the current distribution on the vibrator arm can be regarded as an approximate sine distribution. If the symmetrical vibrator is placed on the Z axis, the current distribution above can be obtained as:

[0042] I=I m sinβ(L-|z|) 0 <z<L (1)

[0043] In the formula, I m is the antinode current, β is the propagation constant, and L is the length of one arm of the oscillator. After feeding, high-frequency currents will be excited in both arms, and the high-frequency currents will excite radiation fields in all directions in space. Therefore, its radiation field distribution in space is:

[0044]

[0045] The normalized direction function is:

[0046]

[0047] It can be seen that the above formula and the spherical coordinate components Regardless of , the electric field changes with the pitch angle θ.

[0048] when hour, is a constant, and the oscillator radiates omnidirectionally in the horizontal plane.

[0049] However, in actual situations, the coaxial line feeding structure causes the current imbalance, which will cause the current on the two arms of the dipole to be unbalanced, greatly affecting the performance of the antenna and deteriorating the omnidirectional radiation characteristics.

[0050] In view of this problem, the present invention proposes a broadband high-gain omnidirectional antenna based on a dipole linear array, which not only has the advantages of a simple structure, but also has good omnidirectional radiation characteristics, and can cover a wide frequency band while maintaining good working characteristics, with a bandwidth of up to 2 GHz. The antenna of the present invention has excellent performance and therefore has a good application prospect.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A broadband high-gain omnidirectional antenna based on a dipole linear array, characterized in that: The invention comprises a bottom plate and four side plate antenna units (2) fixed in a cross shape by the bottom plate. The four side plate antenna units (2) have the same structure. The side plate antenna units (2) all comprise a substrate (21) and an antenna vibrator (22) printed on the substrate (21). The substrates (21) of adjacent side plate antenna units (2) are arranged orthogonally. The antenna vibrator (22) comprises a first vibrator structure located on the upper surface of the substrate (21) and a second vibrator structure located on the lower surface of the substrate (21). The first vibrator structure and the second vibrator structure are both connected in sequence. The antenna is composed of a plurality of dipole units connected to each other, the dipole unit of the first dipole structure comprising a first feeding strip line (221) and a first L-shaped radiating arm (222) vertically connected to the first feeding strip line (221), the dipole unit of the second dipole structure comprising a second feeding strip line (223) and a second L-shaped radiating arm (224) vertically connected to the second feeding strip line (223), and the first feeding strip lines (221) and the second feeding strip lines (223) of the four side panel antenna units (2) are connected to a power divider (1) for feeding; The first vibrator structure and the second vibrator structure have an equal number of vibrator units; The vibrator units of the first vibrator structure and the second vibrator structure are arranged in pairs on the upper and lower surfaces of the substrate (21), and each pair of the first L-shaped radiation arm (222) and the second L-shaped radiation arm (224) are oriented in opposite directions; The width of the second feeding strip line (223) is greater than the width of the first feeding strip line (221).

2. The broadband high-gain omnidirectional antenna based on a dipole linear array according to claim 1, characterized in that: The bottom plate is circular and has four slots formed in a cross shape on it. The base plates (21) of the four side plate antenna units (2) are inserted and installed in the slots of the bottom plate to achieve cross-shaped fixation.

3. The broadband high-gain omnidirectional antenna based on dipole linear array according to claim 2, characterized in that: The substrate (21) is rectangular, and a plurality of bottom plates are arranged at intervals along the long side of the substrate (21) for support.

4. The broadband high-gain omnidirectional antenna based on a dipole linear array according to claim 1, characterized in that: The distance between two adjacent first L-shaped radiation arms (222) or between two adjacent second L-shaped radiation arms (224) is 33 mm.

5. The broadband high-gain omnidirectional antenna based on a dipole linear array according to claim 1, characterized in that: The power distributor (1) is arranged at the same side end of the substrate (21) of the four side panel antenna units (2); the power distributor (1) is a one-to-four power distributor, and the one-to-four power distributor simultaneously feeds the four side panel antenna units (2).

Images