Antenna structure

Abstract

The present invention provides an antenna structure, comprising: a substrate, having a first surface and a second surface that are opposite to each other; a first sheet body, provided on the first surface and comprising: a first bottom edge corresponding to a top edge of the substrate, and a second bottom edge spaced apart from the first bottom edge; a metal wire, provided on the first surface; and a second sheet body, provided on the second surface and corresponding to the metal wire.

Description

Antenna structure Technical Field

[0001] The present 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 power supply quality and reliability. Partial discharge (PD) within high-voltage switchgear indicates defects in the equipment's insulation and can affect the dielectric. If PD continues to occur under long-term operating voltage, its cumulative effect can gradually degrade the insulation's dielectric properties and rapidly reduce its strength, ultimately leading to insulation breakdown and damage to the high-voltage switchgear. Therefore, monitoring PD in high-voltage switchgear is an effective means of maintaining, repairing, or replacing it. However, existing PD detection equipment remains expensive and susceptible to interference from metal and magnetic materials.

[0003] Summary of the Invention

[0004] The present invention mainly provides an antenna structure that can be used for partial discharge sensing of high-voltage switchgear. The antenna structure can be easily installed on an iron plate of the high-voltage switchgear, and the antenna structure of the present invention is not affected by the iron plate or even by magnetic interference.

[0005] 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 disposed 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 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 corresponding to the bottom edge of the substrate; and a second sheet disposed on the second surface and corresponding to the metal wire.

[0006] 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.

[0007] 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.

[0008] As in the aforementioned antenna structure, the first sheet is an isosceles trapezoidal metal sheet.

[0009] 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.

[0010] 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 have a triangular shape.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] As in the aforementioned antenna structure, the second sheet is a rectangular metal sheet.

[0015] 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.

[0016] As in the aforementioned antenna structure, the second sheet is grounded.

[0017] In summary, the antenna structure design of the present invention can achieve 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

[0018] FIG1 is a front view of an antenna structure according to an embodiment of the present invention.

[0019] FIG. 2 is a side view of an antenna structure according to an embodiment of the present invention.

[0020] FIG. 3 is a rear view of an embodiment of the antenna structure of the present invention.

[0021] FIG4 is a front view of another embodiment of the antenna structure of the present invention.

[0022] FIG5 is a frequency response diagram of the return loss of the antenna structure of the present invention.

[0023] FIG6 is a frequency response diagram of the standing wave ratio of the antenna structure of the present invention.

[0024] FIG7 is a Smith chart of the antenna structure of the present invention.

[0025] FIG8 is a schematic diagram of the radiation efficiency values ​​of the antenna structure of the present invention at various frequencies.

[0026] FIG. 9 is a schematic diagram showing gain values ​​at various frequencies of the antenna structure of the present invention.

[0027] Key Component Symbols 1 Antenna structure 2 Substrate 21 First surface 22 Second surface 23 Top edge 24 Bottom edge 3 First sheet 31 First bottom edge 32 Second bottom edge 33 Waist edge 4 Second sheet 5 Metal wire DETAILED DESCRIPTION

[0028] The following describes the implementation of the present invention through specific embodiments. People familiar with this technology 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 it through other different embodiments.

[0029] Referring to Figures 1, 2, and 3, the antenna structure 1 of the present invention includes a substrate 2, a first plate 3, a second plate 4, and metal conductors 5. The substrate 2 has corresponding first and second surfaces 21, 22, and corresponding top and bottom edges 23, 24. In this embodiment, the substrate 2 may be a flame-retardant FR4 substrate with a dielectric constant between 4.2 and 4.7, but this is not limiting.

[0030] The first plate 3 is disposed on the first surface 21 of the substrate 2 and includes a first base 31, a second base 32, and two side edges 33. The first base 31 and the second base 32 are parallel and spaced apart from each other, with the two side edges 33 connecting the first base 31 and the second base 32, respectively. In this embodiment, the length of the first base 31 is greater than the length of the second base 32, thereby forming a roughly trapezoidal shape for the first plate 3, but this is not limiting. In a preferred embodiment, the length of the second base 32 is between 1 / 2 and 3 / 4 of the length of the first base 31. The distances between the opposite ends of the second base 32 and the opposite sides of the substrate 2 can be equal or unequal, but this is not limiting. In another preferred embodiment, the two side edges 33 are equal in length, forming the first plate 3 into an isosceles trapezoidal metal sheet. In this case, the opposite ends of the second base 32 are equal in distance from the opposite sides of the substrate 2.

[0031] 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 present invention is not limited thereto. The length of the first bottom edge 31 may also be less 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.

[0032] The second plate 4 is disposed on the second surface 22 for grounding. In this embodiment, the second plate 4 is a rectangular metal plate, one long side of which corresponds to the bottom edge 24 of the substrate 2, for example, coincides with the bottom edge 24 of the substrate 2, or is adjacent to the bottom edge 24 of the substrate 2.

[0033] A metal wire 5 is disposed on the first surface 21, with one end connected to the second bottom edge 32 of the first sheet 3 and the other end corresponding to the bottom edge 24 of the substrate 2. The metal wire 5 is also entirely aligned with 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 this is not limiting. In one embodiment, one end of the metal wire 5 corresponds to 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 this is not limiting.

[0034] In other embodiments, the first plate 3 of the antenna structure 1 of the present invention can be triangular in addition to an isosceles trapezoid, as shown in Figure 4 . The following only describes the differences between Figure 4 and Figure 1 ; identical technical features are not further described. In Figure 4 , the length of the second base 32 is equal to the width of the metal conductor 5 , thereby giving the first plate 3 a triangular shape. Furthermore, the length of the first base 31 is less than the length of the top edge 23 of the substrate 2 , but this is not a limitation.

[0035] The dimensions of the antenna structure 1 of the present invention can be designed using the following formula:

[0036] 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 entire antenna structure 1, and f is the frequency of the electromagnetic wave.

[0037] The antenna structure 1 of the present invention complies with ultra-high frequency (UHF) and ultra-wideband (UWB) antenna specifications and is capable of operating in the frequency range of 900 MHz to 4 GHz. The antenna structure 1 of the present invention was installed in a housing made of ABS resin. Magnets were installed around the antenna structure 1 within the housing, allowing the housing to be magnetically attached to a metal plate. In this case, the antenna structure 1 of the present invention was tested using a network analyzer. The measurement results are as follows:

[0038] 1. As shown in FIG5 , when the return loss (S11) of the antenna structure 1 of the present invention is measured between 150 MHz and 4 GHz, it is clearly seen that the return loss between 900 MHz and 4 GHz is less than -10 dB.

[0039] 2. As shown in FIG6 , 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.

[0040] 3. As shown in FIG. 7 , when the Smith Chart measurement of the antenna structure 1 of the present invention is performed between 150 MHz and 4 GHz, it is clearly seen that the characteristic impedance of the antenna structure 1 of the present invention is concentrated at the center of 50 ohms (Ω).

[0041] 4. As shown in FIG8 , the radiation efficiency of the antenna structure 1 of the present invention can reach 30%; as shown in FIG9 , the maximum gain value of the antenna structure of the present invention can reach 4 dBi.

[0042] In addition, comparative data between the antenna structure 1 of the present invention and the prior art is provided below. Based on the above formula, the range of the first and second bases is between 119 mm and 11.9 mm, and with the first base being larger than the second base, Figure 1 represents Experimental Example 1, Figure 4 represents Experimental Example 2, and an antenna structure with a rectangular first element serves as a comparative example. The comparison table for antenna structures with return losses less than -10 dB is as follows:

[0043] The comparison table for standing wave ratio less than 2 is:

[0044] It can be seen that the antenna structure 1 of the present invention (Experimental Example 1 and Experimental Example 2) is superior to the comparative example, and the sensitivity of Experimental Example 1 is the best.

[0045] 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.

[0046] The above embodiments are merely illustrative of the technical principles, features, and effects of the present invention and are not intended to limit the scope of the present invention. Any skilled artisan may modify or alter the above embodiments without departing from the spirit and scope of the present invention. However, any equivalent modifications or alterations resulting from the teachings of the present invention are encompassed by the claims. The scope of protection of the present invention is as set forth 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.

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