Inner slotted ring patch antenna for insulator core rod defect detection

Abstract

The utility model belongs to the technical field of insulator core rod defect detection, and discloses an inner slotted ring patch antenna for insulator core rod defect detection, which comprises a dielectric substrate, a coplanar waveguide feed ground conductor is etched on the upper surface of the dielectric substrate, the coplanar waveguide feed ground conductor comprises an inner slotted ring patch arranged on the upper surface of the dielectric substrate, and the inner slotted ring patch is arranged on the lower surface of the dielectric substrate. The inner side edge of each inner slotted annular patch is provided with a slot, the coplanar waveguide feed ground conductor comprises a central conductor arranged on the upper surface of the dielectric substrate and rectangular ground conductors symmetrically distributed on the two sides of the central conductor, and the two rectangular ground conductors are connected with the outer edges of the two inner slotted annular patches respectively. According to the utility model, the arc-shaped coupling section extends into the inner side of the slotted ring, so that high-efficiency electromagnetic coupling is realized, and the working frequency band is widened; the rectangular ground conductor is connected with the outer edge of the inner slotted annular patch, the symmetry is improved, the radiation loss is reduced, the arrangement of the slots concentrates the surface current distribution, and the radiation stability is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model relates to insulator core rod defect detection technical field especially relates to a kind of inner split ring patch antennas for insulator core rod defect detection. BACKGROUND

[0002] Composite insulator is composed of composite core rod, composite shell umbrella skirt and metal end. The core rod and the metal end at both ends mainly bear the mechanical performance of the insulator, and the external silicone rubber umbrella skirt is mainly responsible for its electrical characteristics. The main component material of the core rod inside the composite insulator is epoxy resin and glass fiber, and the insulation performance of these two materials is their outstanding advantage. In 1967, composite insulator with room temperature vulcanized silicone rubber as umbrella sleeve material was developed by German Rosenthal Company, and it was found that the material had excellent hydrophobicity, and since then the material has been widely used in outdoor running insulators.

[0003] At present, microwave transmission method is adopted, and microwave transmission method is considered as an ideal solution because of its non-contact, high penetration and sensitivity to medium changes. However, its practical application is limited by the performance of the antenna: the existing patch antenna has a narrow working frequency band and cannot cover the defect characteristic frequency band of the composite insulator; traditional coplanar waveguide feed structure is easy to produce impedance mismatch, which leads to signal reflection and reduces the defect signal-to-noise ratio. UTILITY MODEL CONTENT

[0004] In order to overcome the technical defects existing in the prior art, the utility model provides an inner split ring patch antenna for insulator core rod defect detection.

[0005] The technical solution adopted by the utility model is as follows: an inner split ring patch antenna for insulator core rod defect detection, comprising a dielectric substrate, a coplanar waveguide feed ground conductor is etched on the upper surface of the dielectric substrate, the coplanar waveguide feed ground conductor comprises an inner split ring patch provided on the upper surface of the dielectric substrate, a split is formed in the inner side edge of the inner split ring patch, the coplanar waveguide feed ground conductor comprises a center conductor provided on the upper surface of the dielectric substrate and two rectangular ground conductors symmetrically distributed on both sides of the center conductor, and the two rectangular ground conductors are connected with the outer edges of the two inner split ring patches respectively; the center conductor is integrally formed by a rectangular matching section at the input end and an arc-shaped coupling section at the end, and the arc-shaped coupling section extends into the inner side of the inner split ring patch.

[0006] Preferably, the dielectric substrate adopts FR-4 dielectric substrate, and the dielectric constant of the dielectric substrate is 4.3.

[0007] Preferably, the size of the dielectric substrate is 20mm×20mm×0.8mm.

[0008] Preferably, the distance between the arc-shaped coupling section and the inner side of the inner split ring patch is 1.5mm.

[0009] Preferably, the gap width between the rectangular matching section and the two side rectangular ground conductors is 1mm.

[0010] Preferably, the inner slotted ring patch antenna has a working frequency band of 5.5-22GHz, and a return loss in free space ≤-10dB.

[0011] The beneficial effects of the present application are: the arc-shaped coupling section extends into the inner side of the slotted ring, realizing efficient electromagnetic coupling and widening the working frequency band; the rectangular ground conductor connects the outer edge of the inner slotted ring patch, improving the symmetry, reducing the radiation loss, the slotted setting concentrates the surface current distribution, and enhances the radiation stability. BRIEF DESCRIPTION OF DRAWINGS

[0012] One or more embodiments are illustrated by way of example in the figures that form a part of this patent document, these example are not intended to limit the embodiments, elements having the same reference numbers in the figures indicate like elements, unless otherwise specifically noted, the figures in the drawings do not constitute a proportional limitation.

[0013] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0014] Figure 2 It is a schematic diagram of the inner slotted ring patch antenna structure of the present application;

[0015] Figure 3 It is a diagram of the inner slotted ring patch antenna in free space of the present application;

[0016] Figure 4 It is a schematic diagram of different placement methods of the inner slotted ring patch antenna of the present application;

[0017] Figure 5 It is a distance scanning simulation result diagram of the rectangular ground conductor and the rectangular matching section of the present application;

[0018] Figure 6 It is a distance scanning simulation result diagram between the arc-shaped coupling section and the rectangular ground conductor of the present application;

[0019] Figure 7 It is a comparison diagram before and after the antenna optimization of the present application;

[0020] Figure 8 It is a simulation result diagram under different placement methods of the antenna of the present application;

[0021] Figure 9 It is a measured result diagram under different placement methods of the antenna of the present application.

[0022] Explanation of reference signs: In the figure: 1, medium substrate; 2, coplanar waveguide feed ground conductor; 201, inner split ring-shaped patch; 202, split; 203, center conductor; 2031, rectangular matching section; 2032, arc-shaped coupling section; 204, rectangular ground conductor. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the utility model clearer, the various embodiments of the utility model will be described in detail below in combination with the drawings. However, those skilled in the art can understand that, in the various embodiments of the utility model, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the claims of the present application can be implemented.

[0024] As shown in Figure 1 The present embodiment provides an inner split ring patch antenna for insulator core rod defect detection, comprising a medium substrate 1, the upper surface of the medium substrate 1 is etched with a coplanar waveguide feed ground conductor 2, the coplanar waveguide feed ground conductor 2 comprises an inner split ring-shaped patch 201 arranged on the upper surface of the medium substrate 1, the inner side edge of the inner split ring-shaped patch 201 is provided with a split 202, the coplanar waveguide feed ground conductor 2 comprises a center conductor 203 arranged on the upper surface of the medium substrate 1 and a rectangular ground conductor 204 symmetrically arranged on both sides of the center conductor 203, the two rectangular ground conductors 204 are respectively connected with the outer edges of the two inner split ring-shaped patches 201; the center conductor 201 is integrally composed of a rectangular matching section 2031 at the input end and an arc-shaped coupling section 2032 at the end, the arc-shaped coupling section 2032 extends into the inner side of the inner split ring-shaped patch 201, the arrangement of the inner split ring-shaped patch 201 and the arc-shaped coupling section 2032 realizes efficient electromagnetic coupling by the arc-shaped coupling section 2032 extending into the inner side of the split 202, and widens the working frequency band; the rectangular ground conductor 204 is connected with the outer edge of the inner split ring-shaped patch 201, which improves the symmetry and reduces the radiation loss; the arrangement of the split 202 concentrates the surface current distribution and enhances the radiation stability.

[0025] The medium substrate 1 adopts an FR-4 medium substrate, the dielectric constant of the medium substrate 1 is 4.3, the cost is low and the process is mature, and the high-frequency performance and mechanical strength are considered.

[0026] The size of the medium substrate 1 is 20mm*20mm*0.8mm, the miniaturized design facilitates integration into the end of a composite insulator core rod, and is suitable for actual detection scenarios.

[0027] The distance between the arc-shaped coupling section 2032 and the inner side of the inner split ring-shaped patch 201 is 1.5mm, which optimizes the electromagnetic coupling efficiency and avoids energy loss caused by signal reflection.

[0028] The gap width between the rectangular matching section 2031 and the two side rectangular ground conductors 204 is set to 1 mm, balancing impedance matching and probe welding process requirements, and reducing processing difficulty.

[0029] The working frequency band of the inner slot ring patch antenna is 5.5-22 GHz, and the return loss in free space is ≤-10 dB, covering the defect characteristic frequency band of the composite insulator, ensuring signal penetration depth and signal-to-noise ratio.

[0030] Meanwhile, the contents not described in detail in the specification all belong to the prior art known to those skilled in the art.

[0031] In operation, the microwave signal excites the surface current of the inner slot ring patch 201 through the coplanar waveguide feed ground conductor 2, generates a radiated electromagnetic field, and the current is concentratedly distributed on the outer edge of the inner slot ring patch 201, so that the antenna has stable radiation performance in the frequency band of 5.5-22 GHz (as shown in Figure 3

[0032] When detecting the defects of the composite insulator core rod, the inner slot ring patch antenna is placed parallel to the axial direction of the composite insulator core rod at both ends of the composite insulator core rod (as shown in Figure 4 Figure 8 and Figure 9 The inner slot ring patch antenna can be used in combination with the current microwave transmission method to detect the defects of the composite insulator core rod. When the composite insulator core rod has cracks or debonding, the electromagnetic wave amplitude / phase changes abnormally, the receiving antenna captures the change and outputs the S11 parameter (return loss), and the defect is located by the amplitude peak value shift (as shown in Figure 7

[0033] According to the above idea, the transceiver antennas and the core rod are modeled, simulated and optimized in the CST microwave studio; Figure 2 The distance (dwj) between the inner slot ring patch 201 and the rectangular ground conductor 204 and the distance (dwb) between the rectangular ground conductor 204 and the rectangular matching section 2031 are two parameters for optimizing the antenna in the model. The antenna is fixed parallel to the axial direction of the core rod at both ends of the core rod, and is fed by a probe. The two optimization parameters are scanned and analyzed respectively, and the simulation frequency range is 0-10 GHz; Figure 5 The scanning simulation result of the distance between the rectangular ground conductor 204 and the rectangular matching section 2031 is that, in the frequency band of 6-10 GHz, the greater the distance between the rectangular ground conductor 204 and the rectangular matching section 2031, ​​​The greater the distance between the inner slit annular patch 201 and the rectangular ground conductor 204, the greater the amplitude of the reflection coefficient, but the maximum distance between the feed probe pins used in the actual measurement process is 4.7mm, considering the probe welding problem in actual detection, the distance between the rectangular ground conductor 204 and the rectangular matching section 2031 is finally selected as 1mm; Figure 6 is the scanning simulation result of the distance between the inner slit annular patch 201 and the rectangular ground conductor 204, in the frequency band of 2-6GHz and 9-10GHz, the greater the distance between the inner slit annular patch 201 and the rectangular ground conductor 204, the greater the amplitude, so the distance between the inner slit annular patch 201 and the rectangular ground conductor 204 is finally selected as 1.5mm; Fig. 7 is the simulation results of the two antennas before and after the optimization of the above two antenna parameters By comparison, it can be found that after optimization, the amplitude is significantly increased, and the peak value can reach near-10dB;

[0034] Through Fig. 8 and Figure 9 The simulation and actual measurement results of different antenna placement methods show that the different antenna placement methods have little effect on the overall amplitude during simulation, but in actual measurement, it is found that the overall amplitude of the detection device when the antenna is placed away from the core rod is slightly larger than that when the antenna is placed close to the core rod in the 3-6GHz frequency band, so the method of placing the antenna away from the core rod is adopted during simulation and actual detection.

[0035] Those skilled in the art can understand that the above embodiments are specific examples for implementing the present application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the present application.

Claims

1. An inner split-ring patch antenna for insulator core rod defect detection, characterized in that: The application relates to a microstrip-fed antenna, which comprises a medium substrate (1), the upper surface of the medium substrate (1) is etched with a coplanar waveguide feed ground conductor (2), the coplanar waveguide feed ground conductor (2) comprises inner split ring patches (201) arranged on the upper surface of the medium substrate (1), the inner side edges of the inner split ring patches (201) are provided with splits (202), the coplanar waveguide feed ground conductor (2) comprises a center conductor (203) arranged on the upper surface of the medium substrate (1) and rectangular ground conductors (204) symmetrically arranged on both sides of the center conductor (203), and the two rectangular ground conductors (204) are respectively connected with the outer edges of the two inner split ring patches (201). The center conductor (203) is integrally formed by a rectangular matching section (2031) at an input end and an arc-shaped coupling section (2032) at a tail end, and the arc-shaped coupling section (2032) extends into the inner side of the inner split ring patch (201).

2. An inner split-ring patch antenna for detecting defects of a core rod of an insulator according to claim 1, characterized in that: The medium substrate (1) is an FR-4 medium substrate, and the dielectric constant of the medium substrate (1) is 4.

3.

3. An inner split-ring patch antenna for defect detection of a core rod of an insulator according to claim 1, characterized in that: The size of the medium substrate (1) is 20mm*20mm*0.8mm.

4. An inner split-ring patch antenna for defect detection of a core rod of an insulator according to claim 1, characterized in that: The spacing between the arc-shaped coupling section (2032) and the inner side of the inner split ring patch (201) is 1.5mm.

5. An inner split-ring patch antenna for defect detection of a core rod of an insulator according to claim 1, characterized in that: The gap width between the rectangular matching section (2031) and the two rectangular ground conductors (204) is 1mm.

6. An inner split-ring patch antenna for defect detection of a core rod of an insulator according to claim 1, characterized in that: The working frequency band of the inner split ring patch antenna is 5.5-22GHz, and the return loss in free space is less than or equal to -10dB.

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