CN103117450A - Circularly-polarized helical antenna with square boundary metal net - Google Patents

Abstract

The invention relates to a circularly polarized helical antenna loaded with a square boundary metal mesh, which relates to a circularly polarized helical antenna, in particular to a circularly polarized helical antenna loaded with a square boundary metal mesh. The invention aims to solve the problem that when the coil number of the existing helical antenna is too large, the effect of gain improvement is not obvious, and the manufacture of the antenna will become very complicated. The square boundary metal mesh of the present invention is arranged above the top of the helix, and the distance between the lower surface of the square boundary metal mesh and the upper end face of the helix is 16mm, and the upper end of the outer conductor of the coaxial feeder and the lower surface of the circular metal floor Connection, the lower end of the helix passes through the upper surface of the circular metal floor and connects with the inner conductor in the upper end surface of the coaxial feeder, the lower surface of the square boundary metal mesh is parallel to the upper surface of the circular metal floor, the central axis of the helix Perpendicular to the upper surface of the circular metal floor. The invention is used in the radio field.

Description

Circularly Polarized Helical Antenna Loaded with Square Boundary Metal Mesh

technical field

The invention relates to a circularly polarized helical antenna, in particular to a circularly polarized helical antenna loaded with a square boundary metal mesh.

Background technique

The helical antenna is a kind of antenna with a helical metal wire as the radiator. Due to the different shapes of the helical wire winding, it can be divided into cylindrical helix, elliptical cylindrical helix, conical helix and spherical helix, etc. The axial mode is the helical antenna. An important working mode, this mode mainly produces radiation along the helical axis, and the radiated electromagnetic wave is a circularly polarized wave, so it is widely used in satellite communication. Recently, with the development of mobile communication, in order to obtain a large range For stable WLAN coverage, axial mode helical antennas are also used as base station antennas. The input impedance of the helical antenna working in the axial mode is approximately a constant in a wide frequency band (the theoretical value is close to the frequency range of 2:1), which is about 140Ω, so it has broadband impedance characteristics. Generally, the gain of a helical antenna is determined by the number of helical turns. When the pitch is constant, the longer the helix, the higher the gain of the antenna. will become very complicated. In order to obtain high gain, three methods can be adopted: 1. Forming an array: the disadvantage is that it will introduce a complex feed network, which limits the application of the array; Detector: Compared with ordinary helical antennas under the same axial length and number of turns, the gain can be increased by about 1dB in a certain frequency range, but the production of the antenna is very complicated; 3. Using a large reflector: using this method The antenna has a high gain and a simple structure, but the size of the antenna is very large. In addition, the impedance of the existing feed port is generally 50Ω. If the 140Ω helical antenna is fed directly, 22.5% of the energy reflection loss will be generated, so the impedance matching problem must be considered.

Contents of the invention

In order to solve the problem that the effect of increasing the gain is not obvious when the number of coils of the existing helical antenna is too large, and the manufacture of the antenna will become very complicated, the invention further proposes a circularly polarized helical antenna with a square boundary metal mesh loading.

The technical scheme adopted by the present invention to solve the above-mentioned problems is: the present invention comprises a square boundary metal mesh, a spiral wire, a circular metal floor and a coaxial feeder, the square boundary metal mesh is arranged above the upper end of the spiral line, and the square boundary metal mesh The distance between the lower surface of the coil and the upper end of the helix is 16mm, the upper end of the outer conductor of the coaxial feeder is connected to the lower surface of the circular metal floor, and the lower end of the helix passes through the upper surface of the circular metal floor and the coaxial feeder The inner conductor in the upper end surface is connected, the lower surface of the square boundary metal mesh is parallel to the upper surface of the circular metal floor, and the central axis of the spiral line is perpendicular to the upper surface of the circular metal floor.

The beneficial effects of the present invention are: after the present invention introduces a square boundary metal net to load, under the situation that other performances are less affected, the gain is increased from 10dB to 11dB, which is significantly improved; the present invention does not add special impedance The converter is adjusted only by using the distance change between the helix and the metal floor, so that the working frequency band of the antenna is 2GHz-2.6GHz, and the relative bandwidth reaches a maximum value of 26%; the present invention has simple structure, small size, and Compared with ordinary helical antennas for loading, the gain value per unit axial length is higher.

Description of drawings

Fig. 1 is a front view of the present invention, Fig. 2 is a top view of a square boundary metal mesh, Fig. 3 is a simulation result of an antenna standing wave coefficient, and Fig. 4 is a simulation result of a circular polarization gain pattern of an antenna at 2.4GHz.

Detailed ways

Specific Embodiment 1: This embodiment is described with reference to FIGS. 1 to 4. The circularly polarized helical antenna loaded with a square boundary metal mesh in this embodiment includes a square boundary metal mesh 1, a helix 2, and a circular metal floor 3. and the coaxial feeder 4, the square boundary metal mesh 1 is arranged above the upper end of the helix 2, and the distance h1 between the lower surface of the square boundary metal mesh 1 and the upper end face of the helix 2 is 16mm, and the outer surface of the coaxial feeder 4 The upper end of the conductor is connected to the lower surface of the circular metal floor 3, the lower end of the spiral wire 2 passes through the upper surface of the circular metal floor 3 and is connected to the inner conductor in the upper end surface of the coaxial feeder 4, and the lower surface of the square boundary metal mesh 1 Parallel to the upper surface of the circular metal floor 3 , the central axis of the helix 2 is perpendicular to the upper surface of the circular metal floor 3 .

Specific Embodiment 2: This embodiment is described in conjunction with FIG. 2. The square boundary metal mesh 1 of the circularly polarized helical antenna loaded with a square boundary metal mesh in this embodiment consists of a square frame 1-1 and a plurality of horizontal lines 1. -2 and a plurality of vertical lines 1-3, a plurality of horizontal lines 1-2 and a plurality of vertical lines 1-3 are interlaced in a square frame 1-1, and a plurality of horizontal lines 1-2 and a plurality of vertical lines The wires 1-3 form a plurality of square meshes 1-4 in the square frame body 1-1, and the plurality of square meshes 1-4 are arranged in a matrix.

The technical effect of this embodiment is that the introduced square border metal mesh reduces the weight of loaded components, and the structure is easy to realize.

Other components and connections are the same as those in the first embodiment.

Specific Embodiment Three: This embodiment is described in conjunction with FIG. 2 . The square frame body 1-1 of the circularly polarized helical antenna with a square boundary metal mesh loading described in this embodiment has a side length of 41 mm to 43 mm, and the square frame body 1 The width W1 of each frame side of -1 is 2 mm to 2.5 mm, the width W2 of each horizontal line 1-2 is 2 mm to 2.5 mm, and the width W3 of each vertical line 1-3 is 2 mm to 2.5 mm, each The side length of the square meshes 1-4 is 8mm-9mm. Other components and connections are the same as those in the second embodiment.

Embodiment 4: This embodiment is described in conjunction with FIG. 2 . The square frame body 1-1 of the circularly polarized helical antenna with a square border metal mesh loading described in this embodiment has a side length of 42mm, and the square frame body 1-1 The width W1 of each frame side is 2mm, the width W2 of each horizontal line 1-2 is 2mm, the width W3 of each vertical line 1-3 is 2mm, and the side length of each square mesh 1-4 is 8mm .

The technical effect of this embodiment is: not only the strength of the loaded square metal mesh is ensured, but also the weight of the loading element can be effectively reduced, and the gain of the antenna can be improved, while other parameters change little.

Other components and connections are the same as those in the third embodiment.

Specific embodiment five: this embodiment is described in conjunction with Fig. 1, the diameter D of the helix 2 of the circularly polarized helical antenna with the square boundary metal mesh loading described in this embodiment is 31mm～33mm, and the pitch S of the helix 2 is 23mm-25mm, the number of turns of the helix 2 is 5 turns. Other components and connections are the same as those in the first embodiment.

Embodiment 6: This embodiment is described with reference to FIG. 1 . The diameter D of the helix 2 of the circularly polarized helical antenna loaded with a square boundary metal mesh in this embodiment is 32 mm, and the pitch S of the helix 2 is 24 mm.

The technical effect of this embodiment is that the impedance matching of the antenna in a wider frequency band can be realized only by setting parameters such as the pitch and diameter of the helix without introducing a special impedance converter.

Other compositions and connections are the same as those in Embodiment 5.

Embodiment 7: This embodiment is described in conjunction with FIG. 1. The diameter of the circular metal floor 3 of the circularly polarized helical antenna loaded with a square boundary metal mesh in this embodiment is 95 mm to 105 mm, and the diameter of the circular metal floor 3 is The thickness is 2mm to 5mm. Other components and connections are the same as those in the first embodiment.

Embodiment 8: This embodiment is described in conjunction with FIG. 1. The diameter of the circular metal floor 3 of the circularly polarized helical antenna loaded with a square boundary metal mesh described in this embodiment is 100 mm, and the thickness of the circular metal floor 3 is 100 mm. 2mm.

The technical effect of this embodiment is that the circular metal floor combined with the size of the helix can make the antenna achieve impedance matching in a wider frequency band.

Other compositions and connections are the same as those in Embodiment 7.

Specific Embodiment Nine: This embodiment is described in conjunction with FIG. 1. The coaxial feeder 4 of the circularly polarized helical antenna with a square boundary metal mesh loading described in this embodiment is made of a 50Ω coaxial cable with a diameter of 5 mm to 9 mm. Coaxial feeder 4. Other components and connections are the same as those in the first embodiment.

Embodiment 10: This embodiment is described in conjunction with FIG. 1. The coaxial feeder 4 of the circularly polarized helical antenna with a square boundary metal mesh loading described in this embodiment is a coaxial cable made of a 50Ω coaxial cable with a diameter of 9mm. Feed line 4.

The technical effect of this embodiment is that the power capacity of the antenna can be improved by using a cable with a larger diameter, which is suitable for base stations and other occasions.

Other compositions and connections are the same as those in Embodiment 9.

Claims (10)

1. the circularly polarized helical antenna with square border metal mesh loading is characterized in that: the circular polarized helical antenna with square border metal mesh loading comprises square border metal mesh (1), helix (2), The circular metal floor (3) and the coaxial feeder (4), the square boundary metal mesh (1) is arranged above the upper end of the helix (2), and the lower surface of the square boundary metal mesh (1) is in contact with the helix (2) ) is 16mm, the upper end of the outer conductor of the coaxial feeder (4) is connected to the lower surface of the circular metal floor (3), and the lower end of the helix (2) passes through the circular metal floor ( The upper surface of 3) is connected to the inner conductor in the upper end face of the coaxial feeder (4), the lower surface of the square boundary metal mesh (1) is parallel to the upper surface of the circular metal floor (3), and the helix (2) The central axis is perpendicular to the upper surface of the circular metal floor (3). 2. The circularly polarized helical antenna with square border metal mesh loading according to claim 1, is characterized in that: the square border metal mesh (1) consists of a square frame (1-1), a plurality of horizontal lines (1- 2) and a plurality of vertical lines (1-3), a plurality of horizontal lines (1-2) and a plurality of vertical lines (1-3) are arranged in a square frame (1-1), and a plurality of horizontal lines The line (1-2) and the plurality of longitudinal lines (1-3) constitute a plurality of square meshes (1-4) in the square frame body (1-1), and the plurality of square meshes (1-4) are arranged in a matrix. 3. The circularly polarized helical antenna loaded with a square boundary metal mesh according to claim 2, characterized in that: the side length of the square frame (1-1) is 41mm～43mm, and the square frame (1-1) The width (W1) of each frame edge is 2mm~2.5mm, the width (W2) of each horizontal line (1-2) is 2mm~2.5mm, and the width (W3) of each vertical line (1-3) 2mm-2.5mm, and the side length of each square mesh (1-4) is 8mm-9mm. 4. according to claim 3, there is the circularly polarized helical antenna loaded with square border metal mesh, it is characterized in that: the side length of square frame body (1-1) is 42mm, each of square frame body (1-1) The width (W1) of each frame side is 2mm, the width (W2) of each horizontal line (1-2) is 2mm, the width (W3) of each vertical line (1-3) is 2mm, and each square mesh (1-4) has a side length of 8 mm. 5. The circularly polarized helical antenna with square border metal mesh loading according to claim 1, characterized in that: the diameter (D) of the helix (2) is 31mm～33mm, and the pitch (S) of the helix (2) ) is 23mm-25mm, and the number of turns of the helix (2) is 5 turns. 6. The circularly polarized helical antenna with square border metal mesh loading according to claim 5 is characterized in that: the diameter (D) of the helix (2) is 32mm, and the pitch (S) of the helix (2) is 24mm. 7. The circularly polarized helical antenna with square boundary metal mesh loading according to claim 1, characterized in that: the diameter of the circular metal floor (3) is 95mm～105mm, and the thickness of the circular metal floor (3) is 2mm ~ 5mm. 8. The circularly polarized helical antenna loaded with square boundary metal mesh according to claim 7, characterized in that: the diameter of the circular metal floor (3) is 100mm, and the thickness of the circular metal floor (3) is 2mm. 9. The circularly polarized helical antenna with a square border metal mesh loading according to claim 1, characterized in that: the coaxial feeder (4) is a coaxial feeder made of a 50 Ω coaxial cable with a diameter of 5 mm to 9 mm (4). 10. according to claim 9, there is the circularly polarized helical antenna loaded with square boundary metal mesh, it is characterized in that: coaxial feeder (4) is the coaxial feeder (4) that the 50Ω coaxial cable that diameter is 9mm makes ).

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