TWI525901B - Dipole antenna structure and antenna device - Google Patents

Description

Dipole antenna structure and antenna device

The present invention relates to an antenna structure and an antenna device, and more particularly to a circularly polarized dipole antenna structure and an antenna device having a dipole antenna structure mounted therein.

With the maturity of satellite broadcasting technology, traditional radio stations, analog TVs and multimedia services are no longer available. As satellite broadcasting systems have driven high-volume, high-quality audio and video streaming services, they have received attention from all walks of life. The satellite system has gradually increased from the early fixed device application to the mobile audio and video multimedia service, and how to completely receive the satellite broadcast signal, the antenna plays a very important role in this.

Due to many applications today, antennas often need to be placed on the surface of highly conductive objects or have a metal environment. The antenna is susceptible to the effect of metal shielding and the overall radiation characteristics change to exhibit irregular field variations. For European and American countries where satellite broadcasting systems are more popular, a satellite usually needs to cover a wide area, so the satellite broadcasting system will standardize a certain antenna gain value within a certain elevation angle. Antennas on highly conductive objects have difficulty in design, especially in the low elevation range close to the conductive object. If the antenna is not specially designed, the gain value will drop rapidly and the specification of the satellite broadcasting system cannot be achieved.

However, since the structure of the antenna (for example, a microstrip antenna) used in the prior art is not ideal, for example, the conventional antenna is disposed on a highly conductive object, which easily affects the original antenna radiation characteristics, so that the radiation field type is not easy to achieve the uniformity. Furthermore, the radiation pattern of a conventional circularly polarized dipole antenna cannot be characterized by a high gain and wide beam circular polarization field without special design (average-like Radiation field type). In addition, the radiation field type of the conventional four-arm helical antenna has the characteristics of wide beam circular polarization, but this type of architecture has the disadvantages of high limitation and less structural change, and thus is less flexible in design. Therefore, how to improve the characteristics of an antenna such as a large-scale high-conductivity object by the design of the structure has become an important issue that the business person wants to solve.

Embodiments of the present invention provide a dipole antenna structure and an antenna device capable of effectively considering the influence of a metal on an antenna field characteristic based on a design above a large high-conductivity object, and by using a highly conductive object The structure of the cylindrical metal reflecting surface is placed to achieve an average gain value for adjusting the radiation pattern of each elevation angle.

One embodiment of the present invention provides a dipole antenna structure disposed on a conductive body, including a reflective body, a transmission line, and an antenna body. The reflective body has a reflective surface. The transmission line passes through and is disposed on the reflective body. The transmission line includes a center conductor, an insulator covering the center conductor, and an outer ground conductor covering the insulator. The two ends of the center conductor respectively have a feeding end and a first connecting end, and the outer grounding conductor has The second connection end. The antenna body includes a first radiating unit and a second radiating unit. The first radiating unit is electrically connected to the first connecting end of the center conductor, and the second radiating unit is electrically connected to the second connecting end of the outer grounding conductor.

Another embodiment of the present invention provides an antenna device including a reflective body, a transmission line, an antenna body, and an antenna housing. The reflective body has a reflective surface. The transmission line passes through and is disposed on the reflective body. The transmission line includes a center conductor, an insulator covering the center conductor, and an outer ground conductor covering the insulator. The two ends of the center conductor respectively have a feeding end and a first connecting end. The outer ground conductor has a second connection end. The antenna body includes a first radiating unit and a second radiating unit. The first radiating unit is electrically connected to the first connecting end of the center conductor, and the second radiating unit is electrically connected to the second connecting end of the outer grounding conductor. In addition, the reflective body, the transmission line, and the antenna body are disposed within the antenna housing.

In summary, the dipole antenna structure and the antenna device provided by the embodiments of the present invention can transmit the first connecting end and the second end of the first radiating element electrically connected to the center conductor through the “reflecting body having a reflecting surface” and the “first radiating unit” The radiation unit is electrically connected to the second connection end of the outer ground conductor" so that the dipole antenna structure and the antenna device of the present invention can be disposed above the large high-conductivity object to improve the average gain of the antenna low-elevation radiation pattern Value, and reduce the cost of manufacturing.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the accompanying drawings.

[First Embodiment]

First, please refer to FIG. 1A to FIG. 1D at the same time. As can be seen from the above figures, the first embodiment of the present invention provides a dipole antenna structure 1 disposed on a conductive body W. In practice, the conductive body W may be the roof of an automobile as a reference ground plane of the antenna, but the invention is not limited thereto.

As shown in FIGS. 1A and 1D, the dipole antenna structure 1 includes a reflective body 11, a transmission line 12, and an antenna body 13. The reflective body 11 has a reflective surface 110. Furthermore, the reflective body 11 can be disposed above the conductive body W to form a stepped ground plane structure. For example It is said that the reflective body 11 can adopt a cylindrical symmetrical structure. In other words, since the cylindrical symmetrical structure is planar and uniform, the reflected wave does not cause irregularities in the radiation pattern due to the influence of the discontinuous surface. Thereby, the present invention can improve the uniformity of the radiation pattern and improve the overall average gain by adjusting the size, height or shape of the reflective body 11. In practice, the shape of the reflective body 11 may be a cylindrical shape, and the material of the reflective body 11 may be a metal material such as bare copper. It should be noted that the shape of the reflective body 11 may be changed according to actual needs. For example, the reflective body 11 may be a symmetrical structure such as a trapezoidal structure or a double-layered cylindrical structure.

As shown in FIGS. 1B and 1C, the transmission line 12 is passed through and disposed on the reflective body 11, and further, the transmission line 12 is disposed at a center point of the reflective body 11. The transmission line 12 includes a central conductor 121, an insulator 122 covering the central conductor 121, and an outer ground conductor 123 covering the insulator 122. The two ends of the central conductor 121 have a feeding end 1210 and a first connecting end 1211, respectively, and the outer grounding conductor 123 has The second connection end 1231. In practice, the transmission line 12 can be a semi-rigid coaxial cable.

As shown in FIG. 1B, the antenna unit 13 includes a first radiating unit 131 and a second radiating unit 132. The first radiating unit 131 is electrically connected to the first connecting end 1211 of the center conductor 121, and the second radiating unit 132 is electrically connected to The second connection end 1231 of the outer layer ground conductor 123. Furthermore, since the antenna body 13 is a crossed dipole antenna structure having circular polarization characteristics, the present invention can make the two dipole antennas (the first radiating unit 131 and the second radiating unit 132) through appropriate design. Current characteristics with the same amplitude and phase difference of 90 degrees to achieve circular polarization characteristic. For example, the first radiating unit 131 includes a first L-type radiating portion 1311 and a second L-shaped radiating portion 1312, and the first end 1311b of the first L-shaped radiating portion 1311 and the first portion of the second L-shaped radiating portion 1312 The first end 1312a is electrically connected to the first connecting end 1211 of the center conductor 121, and the second radiating unit 132 includes a third L-shaped radiating portion 1323 and a fourth L-shaped radiating portion 1324, and the second L-shaped radiating portion 1323 is second. The second end 1324a of the tail end 1323b and the fourth L-type radiating portion 1324 is electrically connected to the second connecting end 1231 of the outer layer grounding conductor 123, respectively.

As shown in FIG. 1B, and at the same time according to the coordinate direction defined in FIG. 1B. The first L-type radiating portion 1311 includes a first radiating section 1311 extending from the first trailing end 1311b toward the first predetermined direction (the opposite direction of the x-axis) and the end of the first radiating section 1311 toward the second predetermined direction (z-axis) a second radiant section 1312 extending at a first predetermined angle θ ₁ from the first predetermined direction, and further, the first radiant section 13111 is parallel to the reflective body 11 and the second radiant section 13112 is perpendicular to Reflecting body 11 (as shown in Figure 1D). The angle between the first radiating section 13111 and the second radiating section 13112 is a first predetermined angle θ ₁ , and may be, for example, 90 degrees. It should be noted that the above first predetermined angle θ ₁ can be adjusted according to actual needs.

The third L-type radiating portion 1323 includes a fifth radiating portion 13235 extending from the second trailing end 1323b in an opposite direction to the first predetermined direction and an opposite direction from the end of the fifth radiating portion 13235 toward the second predetermined direction (z-axis) The sixth radiant section 13236 extends in the opposite direction. Furthermore, the angle θ ₃ between the fifth radiating section 13235 and the sixth radiating section 13236 may be 90 degrees. The fifth radiating section 13235 is inversely symmetric with respect to the first radiating section 1311, and the sixth radiating section 13236 is inversely symmetric with respect to the second radiating section 13112. In other words, since the first L-type radiating portion 1311 and the third L-type radiating portion 1323 are of an inverse symmetrical structure, it is possible to avoid the occurrence of current cancellation in the above-described radiant section, thereby maintaining the magnitude of the antenna radiation field strength.

The second L-type radiating portion 1312 includes a third radiating portion 13123 extending from the first head end 1312a toward the third predetermined direction (opposite direction of the y-axis) and at a second predetermined angle θ ₂ with the first predetermined direction, and by the third The end of the radiating section 13123 faces the fourth radiating section 13124 extending in the opposite direction of the first predetermined direction (the direction of the x-axis). Furthermore, the third radiant section 13123 and the fourth radiant section 13124 are both parallel to the reflective body 11 (as shown in FIG. 1D). The angle between the third radiating section 13123 and the first radiating section 13111 is a second predetermined angle θ ₂ , which may be, for example, 90 degrees, and the angle between the third radiating section 13123 and the fourth radiating section 13124 may be 90 degrees. It should be noted that the above second predetermined angle θ ₂ can be adjusted according to actual needs.

The fourth L-type radiating portion 1324 includes a seventh radiating section 13247 extending from the second head end 1324a toward the opposite direction of the third predetermined direction (the direction of the y-axis) and extending from the end of the seventh radiating section 13247 toward the first predetermined direction The eighth radiating section 13248. Furthermore, the angle θ ₄ of the angle between the seventh radiating section 13247 and the eighth radiating section 13248 may be 90 degrees. The seventh radiating section 13247 is inversely symmetric with respect to the third radiating section 13123, and the eighth radiating section 13248 is inversely symmetric with respect to the fourth radiating section 13124. In other words, since the second L-type radiating portion 1312 and the fourth L-shaped radiating portion 1324 are of an inverse symmetrical structure, it is possible to avoid the occurrence of current cancellation in the above-described radiant section, thereby maintaining the magnitude of the antenna radiation field strength. In addition, since the first radiating element 131 and the second radiating element 132 form a U-shaped antenna structure, the distribution of the circularly polarized current in the low elevation direction can be improved, thereby increasing the average gain value of the low elevation angle.

In addition, since the antenna body 13 is directly connected to the transmission line 12, a leakage current is generated, and the transmission line 12 is also a part of the radiator. Therefore, the antenna body 13 needs to have a design that suppresses current generation. As shown in FIG. 1B and FIG. 1C, for example, the antenna body 13 includes a matching conversion unit 133, and one end of the outer ground conductor 123 contacts the matching conversion unit 133, and the remaining portion of the matching conversion unit 133 surrounds the outer ground conductor 123 and is spaced apart from the outer layer. The ground conductor 123 is a predetermined distance. More specifically, the present invention short-circuits the outer ground conductor 123 of the transmission line 12 by matching the end of the matching conversion unit 133 with the characteristics of the quarter-wavelength, and exhibits an infinite impedance of the open circuit impedance at the top end of the matching conversion unit 133. The high frequency current is prevented from flowing to the outer ground conductor 123 of the transmission line 12. Thereby, the present invention can achieve the suppression of leakage current through the design of the matching conversion unit 133 to maintain the original radiation characteristics of the antenna. In practice, the matching conversion unit 133 may be a sleeve balun converter, but the invention is not limited thereto.

As shown in FIG. 2A and FIG. 2B, the dipole antenna structure 1 provided by the first embodiment of the present invention can measure the reflection loss and the antenna axis ratio between the operating frequency of 2170 MHz and 2200 MHz to satisfy the satellite broadcasting system. The demand for the S-band (for example, the reflection loss specified by the ONDAS satellite broadcasting system is -10 dB or less and the antenna axis ratio is 3 dB or less).

As shown in FIG. 2C and FIG. 2D, the dipole antenna structure 1 provided by the first embodiment of the present invention is measured at an operating frequency of 2185 MHz and between an elevation angle (EA) of 30 degrees and 90 degrees. The radiation field type has a type-like radiation field type. Furthermore, the elevation angle is measured between 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees. The average gain value can meet the requirements of the S-band of the satellite broadcasting system (for example, the ONDAS satellite broadcasting system has an elevation angle of 30 degrees or more of 3 dB, an elevation angle of 45 degrees to 75 degrees of 5 dB or more, and an elevation angle of 90 degrees of 4 dB or more). In other words, since the dipole antenna structure 1 has an isotropic radiation field type, a stable satellite signal receiving function can be achieved, thereby meeting the requirements of the satellite broadcasting system. It should be noted that the dipole antenna structure of the present invention is not limited to a satellite broadcasting system, and the operating frequency can be adjusted according to actual data requirements to be applied to systems of different frequency bands.

[Second embodiment]

First, please refer to Figure 3B. It can be seen from the comparison between FIG. 3B and FIG. 1B that the second embodiment of the present invention differs from the first embodiment in that, in the second embodiment, the first radiating unit 131 includes a first L-shaped radiating portion 1311, and the first L-shaped The first turning point 1311c of the radiating portion 1311 is electrically connected to the first connecting end 1211 of the center conductor 121, the second radiating unit 132 includes the second L-shaped radiating portion 1322, and the second turning portion of the second L-shaped radiating portion 1322 The 1322c is electrically connected to the second connection end 1231 of the outer ground conductor 123.

Further, as shown in FIG. 3B, and at the same time according to the coordinate direction defined in FIG. 3B. The first L-shaped radiating portion 1311 includes a first radiating portion 13111 extending from the first turning portion 1311c toward the first predetermined direction (the opposite direction of the x-axis) and a second predetermined portion (the opposite of the y-axis by the first turning portion 1311c) a second radiant section 1312 extending in a first predetermined angle θ ₁ with respect to the first predetermined direction, the second L-shaped radiating portion 1322 including an opposite direction (x-axis) from the second turning point 1322c toward the first predetermined direction The third radiant section 13223 extending in the direction and the fourth radiant section 13224 extending from the second turning point 1322c in the opposite direction to the second predetermined direction (the direction of the y-axis). In other words, the first L-type radiating portion 1311 and the second L-shaped radiating portion 1322 are of an inverse symmetrical structure. Thereby, the present invention can transmit the design of the first L-type radiating portion 1311 and the second L-type radiating portion 1322 so that the dipole antenna structure 1 of the present invention can provide a radiation-like pattern of the homogeneity.

[Third embodiment]

First, please refer to Figure 4B. 4B and FIG. 1B, the third embodiment of the present invention differs from the first embodiment in that, in the third embodiment, the first radiating unit 131 includes the first L-shaped radiating portion 1311 and the first straight type. The first end 1311a of the first L-shaped radiating portion 1311 and the first end 1315a of the first straight radiating portion 1315 are electrically connected to the first connecting end 1211 of the center conductor 121, and the second radiating unit is respectively connected to the radiating portion 1315. 132 includes a second L-shaped radiating portion 1322 and a second straight-type radiating portion 1325. The second head end 1322a of the second L-shaped radiating portion 1322 and a second head end 1325a of the second straight-type radiating portion 1325 are electrically connected. The second connection end 1231 of the outer ground conductor 123. In other words, the first L-type radiating portion 1311 and the second L-shaped radiating portion 1322 are of an inverse symmetrical structure, and the first straight radiating portion 1315 and the second straight radiating portion 1325 are of an inverse symmetrical structure.

As shown in Figure 4B, and in accordance with the coordinate direction defined in Figure 4B. The first L-type radiating portion 1311 includes a first radiating section 1311 extending from the first head end 1311a toward the first predetermined direction (the opposite direction of the y-axis) and extending from the end of the first radiating section 1311 toward the second predetermined direction (x) The second radiant section 1312 of the direction of the axis and at a first predetermined angle θ ₁ with the first predetermined direction. The second L-type radiating portion 1322 includes a fourth radiating portion 13224 extending from the second head end 1322a toward the opposite direction of the first predetermined direction (the direction of the y-axis) and the end of the fourth radiating portion 13224 toward the second predetermined direction A fifth radiant section 13225 extending in the opposite direction (the opposite direction of the x-axis). In other words, the first radiant section 13111 is parallel to the reflective body 11, and the angle between the first radiant section 13111 and the second radiant section 13112 is a first predetermined angle θ ₁ , which may be, for example, 90 degrees. It should be noted that the above first predetermined angle θ ₁ can be adjusted according to actual needs.

The first straight type radiating portion 1315 includes a third radiating portion 13153 extending from the first head end 1315a toward the opposite direction of the second predetermined direction (opposite direction of the x-axis) and at a second predetermined angle θ ₂ with the first predetermined direction. In other words, the angle between the third radiant section 13153 and the first radiant section 13111 is a second predetermined angle θ ₂ , which may be, for example, 90 degrees. It should be noted that the above second predetermined angle θ ₂ can be adjusted according to actual needs. Further, the third radiant section 13153 may be slightly inclined upward at an angle of, for example, 15 degrees (not shown) with respect to the first radiant section 13111. In other words, the third radiant section 13153 is not parallel to the reflective body 11.

The second straight radiating portion 1325 includes a sixth radiating portion 13256 that extends from the second head end 1325a toward the second predetermined direction. In other words, the sixth radiant section 13256 can be a slightly downwardly inclined angle, such as 15 degrees (not shown), relative to the fourth radiant section 13224. Furthermore, although the sixth radiating section 13256 is closer to the conductive body W (reference ground plane) than the other radiating sections, it still maintains a considerable distance, so that the radiation field can be reduced by reference. The impact of the ground. Thereby, the dipole antenna structure 1 of the present invention can improve the symmetry of the radiation pattern and improve the overall average gain value.

[Fourth embodiment]

First, please refer to Figure 5. As can be seen from the above figures, the fourth embodiment of the present invention An antenna device 2 is provided, including a reflective body 11, a transmission line 12, an antenna body 13, and an antenna housing 21. For example, the antenna device 2 can be disposed on the roof of the automobile as a reference ground plane of the antenna, but the invention is not limited thereto.

As shown in FIG. 5, the reflective body 11 has a reflective surface 110. The transmission line 12 passes through and is disposed on the reflective body 11. The transmission line 12 includes a center conductor 121, an insulator 122 covering the center conductor 121, and an outer ground conductor 123 covering the insulator 122. The two ends of the center conductor 121 respectively have a feeding end 1210. And the first connection end 1211, the outer ground conductor 123 has a second connection end 1231. The antenna body 13 includes a first radiating unit 131 and a second radiating unit 132. The first radiating unit 131 is electrically connected to the first connecting end 1211 of the center conductor 121, and the second radiating unit 132 is electrically connected to the outer grounding conductor 123. Two connection ends 1231. For example, the reflective body 11, the transmission line 12, and the antenna body 13 may be disposed in the antenna housing 21. In other words, the reflective body 11, the transmission line 12, and the antenna body 13 are both covered inside the antenna housing 21. Thereby, the antenna device 2 of the present invention can maintain the integrity and aesthetics of the overall appearance of the product.

[Possible effects of the examples]

In summary, the dipole antenna structure and the antenna device provided by the embodiments of the present invention can transmit the first connecting end and the second end of the first radiating element electrically connected to the center conductor through the “reflecting body having a reflecting surface” and the “first radiating unit” The radiation unit is electrically connected to the second connection end of the outer ground conductor" so that the dipole antenna structure and the antenna device of the present invention can be disposed above the large high-conductivity object to improve the average gain of the antenna low-elevation radiation pattern Value, and reduce the cost of manufacturing.

The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the invention, and the equivalents of the invention are included in the scope of the invention.

1‧‧‧ Dipole antenna structure

11‧‧‧Reflecting ontology

110‧‧‧Reflective surface

12‧‧‧ transmission line

121‧‧‧Center conductor

1210‧‧‧Feeding end

1211‧‧‧First connection

122‧‧‧Insulator

123‧‧‧ outer grounding conductor

1231‧‧‧second connection

13‧‧‧Antenna body

131‧‧‧First Radiation Unit

1311‧‧‧First L-type Radiation Department

1311a‧‧‧ first head

1311b‧‧‧First end

1311c‧‧‧First Turning Place

13111‧‧‧First radiant section

13112‧‧‧second radiant section

1312‧‧‧Second L-type radiation department

1312a‧‧‧ first head

13123‧‧‧The third radiant section

13124‧‧‧fourth radiant section

1315‧‧‧The first straight radiation department

1315a‧‧‧ first head

13153‧‧‧The third radiant section

132‧‧‧second radiation unit

1322‧‧‧Second L-type radiation department

1322a‧‧‧second head

1322c‧‧‧second turning point

13223‧‧‧third radiant section

13224‧‧‧fourth radiant section

13225‧‧‧The fifth radiant section

1323‧‧‧ Third L-type Radiation Department

1323b‧‧‧second end

13235‧‧‧The fifth radiant section

13236‧‧‧Sixth radiant section

1324‧‧‧Fourth L-type Radiation Department

1324a‧‧‧second head

13247‧‧‧ seventh radiant section

13248‧‧‧8th radiant section

1325‧‧‧Second straight radiation department

1325a‧‧‧second head

13256‧‧‧Sixth radiant section

133‧‧‧match conversion unit

2‧‧‧Antenna device

21‧‧‧Antenna housing

θ ₁ ‧‧‧first predetermined angle

θ ₂ ‧‧‧second predetermined angle

θ ₃ , θ ₄ ‧‧‧ angle

W‧‧‧Electrical ontology

1A is a perspective view of a first embodiment of the present invention.

Fig. 1B is an enlarged schematic view of a portion A of Fig. 1A.

1C is a perspective view of another perspective of the first embodiment of the present invention.

Figure 1D is a side elevational view of a first embodiment of the present invention.

2A is a graph showing the reflection loss measured at different frequencies according to the first embodiment of the present invention.

2B is a graph showing an antenna shaft ratio measured at different frequencies according to the first embodiment of the present invention.

2C is a graph showing the radiation pattern measured at different elevation angles according to the first embodiment of the present invention.

2D is a graph showing the right-handed circular polarization average gain measured at different elevation angles according to the first embodiment of the present invention.

3A is a perspective view of a perspective view of a second embodiment of the present invention.

Fig. 3B is an enlarged schematic view of a portion A of Fig. 3A.

4A is a perspective view of a perspective view of a third embodiment of the present invention.

4B is a perspective view of another perspective of the third embodiment of the present invention.

Figure 5 is a perspective view of a fourth embodiment of the present invention.

1‧‧‧ Dipole antenna structure

11‧‧‧Reflecting ontology

110‧‧‧Reflective surface

12‧‧‧ transmission line

13‧‧‧Antenna body

W‧‧‧Electrical ontology

Claims (9)

A dipole antenna structure is disposed on a conductive body, the dipole antenna structure includes: a reflective body having a reflective surface; a transmission line passing through and disposed on the reflective body, the transmission line including a a central conductor, an insulator covering the central conductor, and an outer grounding conductor covering the insulator, the two ends of the central conductor respectively have a feeding end and a first connecting end, and the outer grounding conductor has a second connection And an antenna body including a first radiating unit and a second radiating unit, the first radiating unit is electrically connected to the first connecting end of the center conductor, and the second radiating unit is electrically connected to the first radiating unit The second connection end of the outer ground conductor. The dipole antenna structure of claim 1, wherein the antenna body comprises a matching conversion portion, an end of the outer ground conductor contacts the matching conversion portion, and the remaining portion of the matching conversion portion surrounds the outer ground conductor And a predetermined distance from the outer ground conductor. The dipole antenna structure of claim 2, wherein the first radiating unit comprises a first L-type radiating portion and a second L-shaped radiating portion, and a first tail of the first L-shaped radiating portion The first end of the second L-shaped radiating portion is electrically connected to the first connecting end of the center conductor, and the second radiating unit comprises a third L-shaped radiating portion and a fourth L-shaped radiation a second tail end of the third L-shaped radiating portion and a second end end of the fourth L-shaped radiating portion are electrically connected to the second connecting end of the outer grounding conductor, respectively. The dipole antenna structure as described in claim 3, wherein the An L-shaped radiating portion includes a first radiating section extending from the first trailing end toward a first predetermined direction and a second extending direction from the end of the first radiating section and forming a first predetermined direction a second radiant section of a predetermined angle, the second L-shaped radiating section including a third radiant section extending from the first head end toward a third predetermined direction and at a second predetermined angle to the first predetermined direction a fourth radiating section extending from an end of the third radiating section toward an opposite direction of the first predetermined direction, the third L-shaped radiating section including a second end extending from the second end toward the first predetermined direction a fifth radiant section and a sixth radiant section extending from an end of the fifth radiant section toward the second predetermined direction, the fourth L-shaped radiating section including a second head end facing the third predetermined a seventh radiating section extending in opposite directions of the direction and an eighth radiating section extending from the end of the seventh radiating section toward the first predetermined direction. The dipole antenna structure of claim 2, wherein the first radiating unit comprises a first L-shaped radiating portion, and a first turning portion of the first L-shaped radiating portion is electrically connected to the central conductor The second connecting unit includes a second L-shaped radiating portion, and a second turning portion of the second L-shaped radiating portion is electrically connected to the second connecting end of the outer grounding conductor. The dipole antenna structure of claim 5, wherein the first L-type radiating portion comprises a first radiating portion extending from the first turning portion toward a first predetermined direction and a first turning portion a second radiating section extending toward a second predetermined direction and at a first predetermined angle to the first predetermined direction, the second L-shaped radiating portion including an extension of the second inflection direction opposite to the first predetermined direction a third radiant section and a fourth radii extending from the second turn toward the second predetermined direction Shooting segment. The dipole antenna structure of claim 2, wherein the first radiating unit comprises a first L-shaped radiating portion and a first straight radiating portion, and a first head of the first L-shaped radiating portion The first end of the first straight type radiating portion is electrically connected to the first connecting end of the center conductor, and the second radiating unit comprises a second L-shaped radiating portion and a second straight type The second end of the second L-shaped radiating portion and the second end of the second straight radiating portion are electrically connected to the second connecting end of the outer grounding conductor, respectively. The dipole antenna structure of claim 7, wherein the first L-type radiating portion comprises a first radiating portion extending from the first head end toward a first predetermined direction and a first radiating portion a second radiant section extending toward a second predetermined direction and at a first predetermined angle to the first predetermined direction, the first straight radiating portion including a reverse direction from the first head end toward the second predetermined direction a third radiant section extending in a direction and at a second predetermined angle to the first predetermined direction, the second L-shaped radiating portion including a fourth radiation extending from the second head end in an opposite direction to the first predetermined direction a fifth radiant section extending from an end of the fourth radiant section toward an opposite direction of the second predetermined direction, the second straight radiating portion including a second tip end extending toward the second predetermined direction The sixth radiant section. An antenna device includes: a reflective body having a reflective surface; a transmission line passing through and disposed on the reflective body, the transmission line including a center conductor, an insulator covering the center conductor, and a covering An outer layer grounding conductor of the insulator, the two ends of the center conductor respectively having The first grounding conductor has a second connecting end, and the antenna body includes a first radiating unit and a second radiating unit. The first radiating unit is electrically connected to the antenna. The first connecting end of the center conductor, the second radiating unit is electrically connected to the second connecting end of the outer grounding conductor; and an antenna housing, wherein the reflecting body, the transmission line and the antenna body are disposed on the antenna Inside the housing.