Antenna structure

Abstract

The invention provides an antenna structure, comprising a substrate having a first surface and a second surface corresponding to each other; the first sheet body is arranged on the first surface and comprises a first bottom edge which is correspondingly positioned on the top edge of the substrate; the second bottom edge is spaced from the first bottom edge; the metal wire is arranged on the first surface; and the second sheet body is arranged on the second surface and corresponds to the metal wire.

Description

Technical Field

[0001] The invention relates to an antenna structure, in particular to a microstrip antenna structure with ultra-high frequency and ultra-wideband. Background Art

[0002] High-voltage switchgear is widely used in power systems and is directly related to the quality and reliability of power supply. Partial discharge (PD) generated in high-voltage switchgear means that there are defects in the insulation of the equipment and will affect the insulating medium. If partial discharge continues to occur under long-term operating voltage, the partial discharge will have a cumulative effect, causing the dielectric properties of the insulation to gradually crack and the insulation strength to drop rapidly, eventually leading to insulation breakdown and damage to the high-voltage switchgear. Therefore, monitoring the occurrence of partial discharge in high-voltage switchgear is obviously one of the effective means of maintaining, repairing or replacing high-voltage switchgear. However, existing partial discharge detection equipment still has the problem of being expensive and also being interfered by metal and magnetism. Summary of the invention

[0003] The present invention mainly provides an antenna structure that can be used for partial discharge sensing of a high-voltage switchgear, which can be easily installed on an iron plate of the high-voltage switchgear, and the antenna structure of the present invention is not interfered by the iron plate or even by magnetism.

[0004] The present invention provides an antenna structure, comprising: a substrate having a first surface and a second surface corresponding to each other; a first sheet body arranged on the first surface and comprising: a first bottom edge corresponding to the top edge of the substrate; and a second bottom edge spaced apart from the first bottom edge; a metal wire arranged on the first surface, one end of which is connected to the second bottom edge of the first sheet body and the other end of which is corresponding to the bottom edge of the substrate; and a second sheet body arranged on the second surface and corresponding to the metal wire.

[0005] As in the aforementioned antenna structure, the length of the first bottom side is greater than the length of the second bottom side, and the first bottom side and the second bottom side are parallel to each other.

[0006] As in the aforementioned antenna structure, the length of the second bottom side is between 1 / 2 and 3 / 4 of the length of the first bottom side.

[0007] As in the aforementioned antenna structure, the first sheet is an isosceles trapezoidal metal sheet.

[0008] As in the aforementioned antenna structure, the length of the first bottom side is equal to the length of the top side of the substrate.

[0009] As in the aforementioned antenna structure, the length of the second bottom side is equal to the width of the metal wire, thereby making the first sheet body triangular.

[0010] As in the aforementioned antenna structure, the length of the first bottom side is smaller than the length of the top side of the substrate.

[0011] As in the aforementioned antenna structure, the length of the metal wire is equal to the vertical distance between the first bottom side and the second bottom side.

[0012] As in the aforementioned antenna structure, a long side of the second sheet is located corresponding to the bottom side of the substrate, and the height of the second sheet is equal to the length of the metal wire.

[0013] As in the aforementioned antenna structure, the second sheet is a rectangular metal sheet.

[0014] As in the aforementioned antenna structure, one end of the metal wire is located at the midpoint of the long side of the second sheet, and the other end is connected to the midpoint of the second bottom side.

[0015] As in the aforementioned antenna structure, the second sheet is grounded.

[0016] In summary, the antenna structure design of the present invention can provide better broadband impedance matching and radiation efficiency, achieve anti-magnetic and anti-metal interference effects, and can be applied to partial discharge sensing of high-voltage switchgear. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. 4 is a front view of an antenna structure according to an embodiment of the present invention.

[0018] Figure 2 FIG. 4 is a side view of an antenna structure according to an embodiment of the present invention.

[0019] Figure 3 FIG. 4 is a rear view of an antenna structure according to an embodiment of the present invention.

[0020] Figure 4 FIG. 4 is a front view of another embodiment of the antenna structure of the present invention.

[0021] Figure 5 FIG. 4 is a frequency response diagram of the return loss of the antenna structure of the present invention.

[0022] Figure 6 It is the frequency response diagram of the standing wave ratio of the antenna structure of the present invention.

[0023] Figure 7 It is the Smith chart of the antenna structure of the present invention.

[0024] Figure 8 FIG. 4 is a schematic diagram of the radiation efficiency values ​​of the antenna structure of the present invention at various frequencies.

[0025] Fig. 9 Schematic diagram of the gain values ​​of the antenna structure at various frequencies of the present invention.

[0026] Main component symbols

[0027] 1 Antenna structure

[0028] 2 substrate

[0029] 21 First Surface

[0030] 22 Second Surface

[0031] 23 Top edge

[0032] 24 bottom edge

[0033] 3 The first piece

[0034] 31 First bottom edge

[0035] 32 Second bottom edge

[0036] 33 Waist

[0037] 4 Second piece

[0038] 5 Metal wire. DETAILED DESCRIPTION

[0039] The following describes the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and technical effects of the present invention from the contents disclosed in this specification, and can also implement or apply the present invention by means of other different embodiments.

[0040] Please also see Figure 1 , Figure 2 and Figure 3 The antenna structure 1 of the present invention includes a substrate 2, a first sheet 3, a second sheet 4 and a metal wire 5. The substrate 2 has a corresponding first surface 21 and a second surface 22 and a corresponding top edge 23 and a bottom edge 24. In this embodiment, the substrate 2 can be a FR4 flame retardant grade substrate, and its dielectric constant is between 4.2 and 4.7, but it is not limited thereto.

[0041] The first sheet 3 is disposed on the first surface 21 of the substrate 2, and includes a first bottom edge 31, a second bottom edge 32 and two waist edges 33. The first bottom edge 31 and the second bottom edge 32 are parallel to each other and spaced apart, and the two waist edges 33 are connected to the first bottom edge 31 and the second bottom edge 32 respectively. In this embodiment, the length of the first bottom edge 31 is greater than the length of the second bottom edge 32, so that the first sheet 3 is roughly trapezoidal, but it is not limited to this. In a preferred embodiment, the length of the second bottom edge 32 is between 1 / 2 and 3 / 4 of the length of the first bottom edge 31, and the distances between the opposite ends of the second bottom edge 32 and the opposite two sides of the substrate 2 can be equal or unequal, but it is not limited to this. In another preferred embodiment, the two waist edges 33 are equal in length, so that the first sheet 3 forms an isosceles trapezoid, that is, the first sheet 3 is an isosceles trapezoid metal sheet, and at this time, the distances between the opposite ends of the second bottom edge 32 and the opposite two sides of the substrate 2 are equal.

[0042] In one embodiment, the length of the first bottom edge 31 is equal to the length of the top edge 23 of the substrate 2, but the invention is not limited thereto, and the length of the first bottom edge 31 may also be smaller than the length of the top edge 23 of the substrate 2. In addition, the first bottom edge 31 is located corresponding to the top edge 23 of the substrate 2, for example, the first bottom edge 31 overlaps with the top edge 23 of the substrate 2, or is adjacent to the top edge 23 of the substrate 2.

[0043] The second sheet 4 is disposed on the second surface 22 for grounding. In this embodiment, the second sheet 4 is a rectangular metal sheet, one long side of which corresponds to the bottom edge 24 of the substrate 2, for example, overlaps with the bottom edge 24 of the substrate 2, or is adjacent to the bottom edge 24 of the substrate 2.

[0044] The metal wire 5 is disposed on the first surface 21, one end of which is connected to the second bottom edge 32 of the first sheet 3, and the other end is located at the bottom edge 24 of the substrate 2, and the metal wire 5 as a whole corresponds to the second sheet 4. In this embodiment, the length of the metal wire 5 can be equal to the vertical distance between the first bottom edge 31 and the second bottom edge 32 and the height of the second sheet 4, but it is not limited thereto. In one embodiment, one end of the metal wire 5 is located at the midpoint of the long side of the second sheet 4, and the other end is connected to the midpoint of the second bottom edge 32, but it is not limited thereto.

[0045] In other embodiments, the first sheet 3 in the antenna structure 1 of the present invention may be in the shape of an isosceles trapezoid or a triangle, such as Figure 4 The following is only a description of Figure 4 and Figure 1 The differences between the two and the same technical features are not repeated here. Figure 4 In the embodiment, the length of the second bottom side 32 is equal to the width of the metal wire 5, so that the first sheet 3 is triangular. In addition, the length of the first bottom side 31 is less than the length of the top side 23 of the substrate 2, but it is not limited thereto.

[0046] The size design of the antenna structure 1 of the present invention can be performed using the following formula:

[0047]

[0048]

[0049] Wherein, W is the first bottom edge 31 or the second bottom edge 32 of the first sheet 3, L is the vertical distance between the first bottom edge 31 and the second bottom edge 32 of the first sheet 3, C is the speed of light, ∈ is the dielectric parameter of the antenna structure 1 as a whole, and f is the frequency of the electromagnetic wave.

[0050] The antenna structure 1 of the present invention can meet the antenna specifications of Ultra High Hrequency (UHF)-Ultra-Wide Band (UWB), and can be used in the frequency range between 900MHz and 4GHz. The antenna structure 1 of the present invention is installed in a shell made of ABS resin. Magnets can be installed around the antenna structure 1 in the shell so that the shell can be magnetically adsorbed on the iron plate. In this case, the antenna structure 1 of the present invention is tested using a network analyzer, and the measurement results are as follows:

[0051] 1. As Figure 5 As shown, in the measurement of the return loss (S11) of the antenna structure 1 of the present invention between 150 MHz and 4 GHz, it can be clearly seen that the return loss between 900 MHz and 4 GHz is less than -10 dB.

[0052] 2. If Figure 6 As shown, when the antenna structure 1 of the present invention is subjected to the Standing Wave Ratio (SWR) measurement between 150 MHz and 4 GHz, it is clearly seen that the SWR between 900 MHz and 4 GHz is less than 2.

[0053] 3. Such as Figure 7 As shown, when the antenna structure 1 of the present invention is measured on a Smith Chart between 150 MHz and 4 GHz, it is clearly seen that the characteristic impedance of the antenna structure 1 of the present invention is distributed in a concentrated trend of 50 ohms (Ω) at the center.

[0054] 4. Such as Figure 8 As shown, the radiation efficiency of the antenna structure 1 of the present invention can reach 30%; Fig. 9 As shown, the maximum gain value of the antenna structure of the present invention can reach 4dBi.

[0055] In addition, the comparison data between the antenna structure 1 of the present invention and the prior art are provided as follows. According to the above formula, the range of the first bottom side and the second bottom side is between 119 mm and 11.9 mm, and when the first bottom side is larger than the second bottom side, Figure 1 For Experimental Example 1, Figure 4 This is Experimental Example 2, and the antenna structure in which the first sheet is a rectangle is used as a comparative example. The comparison table of return loss less than -10dB is as follows:

[0056] Experimental Example 1 Experimental Example 2 Comparative Example Frequency range 900MHz to 4GHz 800MHz to 4GHz 1GHz to 4GHz

[0057] The comparison table for standing wave ratio less than 2 is:

[0058] Experimental Example 1 Experimental Example 2 Comparative Example Frequency range 460MHz to 4GHz 652MHz to 4GHz 772MHz to 4GHz

[0059] It can be seen that the antenna structure 1 of the present invention (Experimental Example 1 and Experimental Example 2) is better than the comparative example, and the sensitivity of Experimental Example 1 is the best.

[0060] In summary, the antenna structure design of the present invention can provide better broadband impedance matching and radiation efficiency, achieve anti-magnetic and anti-metal interference effects, and can be applied to partial discharge sensing of high-voltage switchgear.

[0061] The above embodiments are only used to illustrate the technical principles, features and technical effects of the present invention, and are not intended to limit the scope of the present invention. Any person skilled in the art may modify and change the above embodiments without violating the concept and scope of the present invention. However, any equivalent modifications and changes made by using the content of the present invention should still be covered by the claims. The scope of protection of the present invention should be as listed in the claims.

Claims

1. An antenna structure, comprising: A substrate having a first surface and a second surface corresponding to each other; The first sheet is disposed on the first surface and comprises: A first bottom edge, corresponding to the top edge of the substrate; and a second bottom edge, spaced apart from the first bottom edge; A metal wire is disposed on the first surface, one end of which is connected to the second bottom edge of the first sheet, and the other end of which is located corresponding to the bottom edge of the substrate; as well as The second sheet is disposed on the second surface and corresponds to the metal wire.

2. The antenna structure according to claim 1, wherein: The length of the first bottom side is greater than the length of the second bottom side, and the first bottom side and the second bottom side are parallel to each other.

3. The antenna structure according to claim 2, wherein: The length of the second bottom side is between 1 / 2 and 3 / 4 of the length of the first bottom side.

4. The antenna structure according to claim 2, wherein: The first sheet is an isosceles trapezoidal metal sheet.

5. The antenna structure according to claim 4, wherein: The length of the first bottom side is equal to the length of the top side of the substrate.

6. The antenna structure according to claim 2, wherein: The length of the second bottom side is equal to the width of the metal wire, thereby making the first sheet body triangular.

7. The antenna structure according to claim 6, wherein: The length of the first bottom side is smaller than the length of the top side of the substrate.

8. The antenna structure according to claim 1, wherein: The length of the metal wire is equal to the vertical distance between the first bottom side and the second bottom side.

9. The antenna structure according to claim 1, wherein: A long side of the second sheet body is located corresponding to the bottom side of the substrate, and the height of the second sheet body is equal to the length of the metal wire.

10. The antenna structure according to claim 9, wherein: The second sheet is a rectangular metal sheet.

11. The antenna structure according to claim 9, wherein: One end of the metal wire is located at the middle point of the long side of the second sheet body, and the other end is connected to the middle point of the second bottom side.

12. The antenna structure according to claim 1, wherein: The second sheet is grounded.

Images