Open-type compact wideband antenna based on substrate-integrated waveguide

Abstract

The present invention relates to a compact, wideband antenna based on a secondary open-circuit integrated waveguide, which is related to the microwave antenna technology. It comprises a base dielectric substrate and an upper dielectric substrate. A first metal layer is provided on the lower surface of the base dielectric substrate, and a second metal layer is provided on the upper surface of the base dielectric substrate. The second metal layer has a split, strip-shaped open-circuit slit and functions as a radiating surface for the first metal layer, the second metal layer, and the base dielectric substrate. A plurality of metal cylinders penetrate the base dielectric substrate, and their upper and lower ends are connected to the first metal layer and the second metal layer, respectively. The second metal layer is connected to a microstrip line feed on the side away from the strip-shaped open-circuit slit. The upper dielectric substrate is attached to the upper surface of the second metal layer and also to the split, strip-shaped open-circuit slit in the second metal layer. The compact, wideband antenna of the present invention covers the X frequency band, and the impedance and bandwidth can be improved by optimizing the number and position of the open-circuit slits and metal through-holes.

Description

[Technical Field]

[0001] The present invention relates to the technical field of microwave antennas, and more particularly to an open-type compact wideband antenna based on an integrated waveguide (or an open-type compact wideband antenna using an integrated waveguide). [Background technology]

[0002] Antennas are wireless communication devices used to transmit and receive radio signals, and their performance affects the quality of the entire communication system. With the development of communication systems, there is an ever-increasing demand for smaller and broader antennas. Conventional antennas suffer from problems such as large size, narrow bandwidth, and low efficiency. While miniaturized antennas can meet more device integration requirements, they suffer from a narrow frequency range and are unable to be applied to broadband networks. Therefore, how to design and manufacture compact, broadband antennas has become an important research topic in the field of antenna technology.

[0003] Substrate-integrated waveguide antennas significantly outperform traditional microstrip and waveguide antennas due to their compact structure, efficient performance, and ease of fabrication. However, they have a narrow frequency bandwidth due to their high Q factor. Under certain conditions, the Q factor of an electrically small antenna is inversely proportional to its bandwidth. Therefore, the antenna bandwidth can be improved by partially opening the closed cavity to reduce energy accumulation in the SIW cavity and lower the antenna Q factor.

[0004] Although there have been many studies on compact broadband antennas using substrate-integrated waveguides, there have been no designs that take into account both the operating bandwidth and gain. Therefore, the development of antennas with good operating bandwidth and gain performance is very important. Summary of the Invention [Problem to be solved by the invention]

[0005] To solve the above technical problems, the present invention provides an open-type small-sized wideband antenna based on a substrate-integrated waveguide, which realizes a wideband antenna with a slit structure in an open-type SIW and eliminates some metal pillars, thereby improving the narrowband antenna into a wideband antenna structure with a simple design and structure and improving performance effects. [Means for solving the problem]

[0006] To achieve the above objectives, the present invention proposes the following technical solutions:

[0007] The present invention provides an open-type small wideband antenna using a substrate-integrated waveguide, the open-type small wideband antenna covering the X-band and comprising a base layer dielectric substrate and an upper layer dielectric substrate. A first metal layer is provided on the lower surface of the base layer dielectric substrate, and a second metal layer is provided on the upper surface of the base layer dielectric substrate, the second metal layer having a strip-shaped slit (slit structure) cleaved to form an open circuit, and functioning as a radiation surface for the first metal layer, the second metal layer and the base layer dielectric substrate. A plurality of metal cylinders penetrate the base layer dielectric substrate, and the upper and lower ends of the plurality of metal cylinders are connected to the first metal layer and the second metal layer, respectively, and the front Note There is no metal column near the lit (11), thereby forming a partially open SIW structure. The second metal layer is strip-shaped. No. The side away from the slit is connected to a microstrip line feed, thereby forming a SIW feed structure. The upper dielectric substrate is attached to the upper surface of the second metal layer, and the cleaved strip shape of the second metal layer is No. The upper surface of the upper dielectric substrate is the third metal layer.

[0008] Further improvements of the present invention are as follows: the third metal layer is composed of two T-shaped metal patches spaced apart by the width of the slit, the upper dielectric substrate is provided with four metal shorting through holes, and the four metal shorting through holes penetrate the upper dielectric substrate, and the size of the upper dielectric substrate is 1 / 4.5 of the size of the underlying dielectric substrate.

[0009] Further improvements of the present invention are: Strip shape No. The width of the ribs is the same as that of the slits, and is 1.55 mm to 1.75 mm in both cases.

[0010] Further improvements of the present invention are as follows: The underlayer dielectric substrate on the same side as the microstrip line feed is opened to have no metal cylinders to form an open structure, and the underlayer dielectric substrate on the same side as the microstrip line feed is opened to have a strip-shaped of In order to form an open structure in the slit, the metal cylinder is not provided, and the underlayer dielectric substrate on the side opposite to the microstrip line feed is formed in a strip shape. of Three metal cylinders are provided on each side of the symmetrical axis at the center of the slit (a straight line that runs perpendicular to the longitudinal direction of the slit and passes through the center of the slit in the longitudinal direction).

[0011] Further improvements of the present invention include: Microstrip line feed of The impedance at the end is 50 ohms.

[0012] The working principle of the present invention is as follows: A plurality of metal rods penetrate the dielectric substrate of the intermediate layer, and both ends are connected to the first metal layer and the second metal layer, respectively, to form a SIW feeding structure, thereby achieving the goal of a low profile. ,vinegarThe metal pillars for SIW waveguiding near the slit are not provided, and the SIW structure is opened to form a wideband SIW power supply structure. In addition, the SIW structure is supplied with power by the microstrip line structure of the second metal layer, and the second metal layer of The slits are excited to radiate electromagnetic waves to the outside. Furthermore, by electrically coupling the slits to four metal shorting through-holes on the upper surface of the second-layer dielectric substrate, the shape and position of the patches in the third metal layer can be optimized to form a compact, open-circuit broadband antenna. The antenna exhibits good radiation performance, with relatively low cross-polarization levels in the E and H planes, a flat gain curve within the operating frequency range, a maximum gain of 7.14 dBi, and a relative bandwidth of 25.86% within the operating frequency range. Compared with other types of SIW broadband antennas, the present invention exhibits good performance in terms of relative operating bandwidth and radiation gain within the operating frequency range. [Effects of the Invention]

[0013] The advantageous effects of the present invention are as follows:

[0014] (1) The present invention can reduce the Q value of the SIW cavity and increase the energy radiation of the sidewall by removing some of the metal pillars. ,vinegar By providing a slit, the antenna bandwidth can be widened.

[0015] (2) By introducing a second layer of a completely open (open, aperture-type) antenna structure, the present invention can relatively reduce the cross-polarization level of the antenna while broadening the antenna bandwidth.

[0016] (3) This invention proposes a new design for realizing an open-type SIW compact broadband antenna. Due to the independence of the parasitic patch, the antenna of this invention has a simpler structure than other SIW and other array broadband antennas. The impedance bandwidth can be increased by simply removing some metal pillars without adding complex network matching or special structures.

[0017] (4) The present invention finally enables an open-type SIW miniature broadband antenna to have a simpler and easier to fabricate antenna structure while maintaining good radiation performance. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of the present invention. [Figure 2] FIG. 1 is a plan view of the present invention. [Figure 3] FIG. 2 is a plan view of a localized portion of the present invention. [Figure 4] FIG. 10 is a diagram showing a simulation result of S parameters in the embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating a simulation result of a gain in an embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing simulation results of main polarization and cross polarization E-plane antenna patterns of an embodiment of the present invention at 9.7 GHz. [Figure 7] FIG. 10 is a diagram showing simulation results of main polarization and cross polarization H-plane antenna patterns of an embodiment of the present invention at 9.7 GHz. [Figure 8] FIG. 10 is a diagram showing simulation results of main polarization and cross polarization E-plane antenna patterns of an embodiment of the present invention at 10.6 GHz. [Figure 9] FIG. 10 is a diagram showing simulation results of main polarization and cross polarization H-plane antenna patterns of an embodiment of the present invention at 10.6 GHz. [Figure 10]FIG. 10 is a diagram showing simulation results of main polarization and cross polarization E-plane antenna patterns of an embodiment of the present invention at 11.75 GHz. [Figure 11] FIG. 10 is a diagram showing simulation results of main polarization and cross polarization H-plane antenna patterns of an embodiment of the present invention at 11.75 GHz. [Explanation of symbols]

[0019] 1: First metal layer, 2: Second metal layer, 3: Third metal layer, 4: Underlayer dielectric substrate, 6: Upper layer dielectric substrate, 7: Microstrip line feed, 8: Slit, 9: T-shaped metal patch, 10: Metal short-circuit through-hole, 11: Strip shape of slit DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For clarity, the following description will explain details for implementing the invention. However, it should be understood that these details do not limit the present invention. That is, the details described in some embodiments of the present invention are not essential configurations for the configuration of the present invention. Furthermore, to simplify the drawings, some commonly used structures and components are shown in schematic form.

[0021] This invention provides an open-type SIW (Substrate Integrated Waveguide) compact wideband antenna. By removing the metal pillars on the sidewalls, the energy accumulation in the SIW cavity is reduced, lowering the antenna's Q value and widening the bandwidth (making it possible to achieve broadband). In addition, by introducing a second-layer substrate structure through coupling with slits and short-circuit through-holes, the antenna's cross-polarization can be reduced, further improving and expanding the bandwidth.

[0022] 1 to 3 show an open-type small wideband antenna based on a substrate-integrated waveguide of the present invention. The open-type small wideband antenna covers the X-band. The open-type small wideband antenna of the present invention comprises a base layer dielectric substrate 4 and an upper layer dielectric substrate 6. The size of the upper layer dielectric substrate 6 is 1 / 4.5 of the size of the base layer dielectric substrate 4. A first metal layer 1 is provided on the lower surface of the base layer dielectric substrate 4. A second metal layer 2 is provided on the upper surface of the base layer dielectric substrate 4. The second metal layer 2 is in the form of strips that are cleaved (separated from each other). of The metal cylinders are provided with slits 11 and function as radiation surfaces of the first metal layer 1, the second metal layer 2, and the underlying dielectric substrate 4. The metal cylinders penetrate the underlying dielectric substrate 4, and the upper and lower ends of the metal cylinders are connected to the first metal layer 1 and the second metal layer 2. ,of The second metal layer 2 has a strip shape, and the metal pillars for SIW waveguiding are not provided near the slit, forming a partially open SIW structure. of The side away from the slit 11 is connected to the microstrip line feed 7, finally forming a wideband SIW feed structure. of The impedance of both ends is 50 ohms. An upper dielectric substrate 6 is attached to the upper surface of the second metal layer 2, and the second metal layer 2 is split into strips. of The upper surface of the upper dielectric substrate 6 is the third metal layer 3. of The width of the slit 11 is the same as that of the slit 8, and both are 1.55 mm to 1.75 mm, preferably 1.65 mm. SThe slits couple energy from the lower layer to the upper layer (energy is transmitted and reflected from the lower layer to the upper layer), reducing energy leakage from the open lower layer. The third metal layer 3 is composed of two T-shaped metal patches 9 spaced apart by the width of the slit 8. Four metal shorting through holes 10 are provided in the upper dielectric substrate 6, and the four metal shorting through holes 10 penetrate the upper dielectric substrate 6 and are open on the lower dielectric substrate 4 on the same side as the microstrip line feed 7 (opening the conventional closed form, i.e., forming in a state where no metal cylinder is provided). On the lower dielectric substrate 4 on the same side as the microstrip line feed 7, the strip-shaped of The slit 11 is also provided so as to be open (i.e., formed so that no metal cylinder is provided), while the underlayer dielectric substrate 4 on the side opposite to the microstrip line feed 7 is formed so as to have the strip shape of The center of the slit 11 is the axis of symmetry (strip shape) of Three metal cylinders are provided on both sides of the slit 11 (the axis of symmetry is a line defined to pass through the center of the slit 11 in the longitudinal direction and be perpendicular to the longitudinal direction).

[0023] The open-type SIW compact broadband antenna of the present invention is an improved open-type structure based on a closed-substrate integrated waveguide cavity structure, which achieves both compactness and broadband performance without the need for complex network feeds or additional design structures, and is easy to integrate into planar circuits for practical use.

[0024] The technical solutions of the present invention are described below using specific embodiments.

[0025] As shown in FIG. 1, the open-type SIW compact wideband antenna of this embodiment includes a two-layer dielectric substrate, which is made of Rogers 5880, has a dielectric constant of 2.2, a loss tangent of 0.0009, and a thickness of 1.575 mm and 0.787 mm, respectively. The upper surface of the base dielectric substrate is covered with a third metal layer, and the lower layer is covered with a second metal layer. Metal through-holes are evenly arranged on the base dielectric substrate. Metal cylinders pass through the metal through-holes and penetrate the upper dielectric substrate, and are attached to the upper surface of the upper dielectric substrate. ,vinegar Two T-shaped metal patches are provided, spaced apart by the width of the slit. The bottom surface is the surface of the upper metal layer of the underlying dielectric substrate, and the dielectric substrate is provided with four metal shorting through-holes. The closed-type rectangular cavity SIW slit antenna has a frequency range of 10.74 GHz to 10.87 GHz where S11 ≤ -10 dB, a relative bandwidth of 1.2%, and a maximum gain of 3.26 dBi within the operating frequency range. However, when modified to an open-type, the frequency range of S11 ≤ -10 dB is realized to be 9.46 GHz to 12.27 GHz, and three resonant frequency bins at 9.7 GHz, 10.6 GHz, and 11.75 GHz can be generated, with good impedance matching and a relative bandwidth of 25.86%. This results in a flat gain curve within the operating frequency range, a maximum gain of 7.14 dBi, and good radiation characteristics.

[0026] Figure 2 shows the first layer structure of the antenna structure body of the present invention. The structure is fed by a 50 Ω microstrip line. A number of metal cylinders penetrate the middle layer dielectric substrate, and their ends are connected to the first metal layer and the second metal layer, respectively, to form a SIW transmission structure. A strip-shaped metal cylinder is formed on the second metal layer. of Etched slits and strip shapes of By removing some of the metal pillars around the slit, the closed cavity (SIW structure) is partially opened.

[0027] Figure 3 shows the second diagram of the antenna structure body of the present invention, which is composed of a dielectric substrate, two metal T-patches arranged on the upper surface, and four metal short-circuiting through-holes (metal through-holes).

[0028] Figure 4 shows the S-parameter simulation results of the open-type SIW compact broadband antenna. The operating frequency range is 9.46 GHz to 12.27 GHz, with three resonant frequency bins at 9.7 GHz, 10.6 GHz, and 11.75 GHz. The impedance matching is good, and the relative bandwidth reaches 25.86%.

[0029] Figure 5 shows the simulation results of the gain of the open-type SIW compact wideband antenna.

[0030] FIG. 6 shows the simulation results of the main polarization and cross polarization E-plane antenna patterns of the present invention at 9.7 GHz.

[0031] FIG. 7 shows the simulation results of main polarization and cross polarization H-plane antenna patterns of the present invention at 9.7 GHz.

[0032] FIG. 8 shows the simulation results of the main polarization and cross polarization E-plane antenna patterns of the present invention at 10.6 GHz.

[0033] FIG. 9 is a diagram showing the simulation results of the main polarization and cross polarization H-plane antenna patterns of the present invention at 10.6 GHz.

[0034] FIG. 10 shows the simulation results of the main polarization and cross polarization E-plane antenna patterns of the present invention at 11.75 GHz.

[0035] FIG. 11 is a diagram showing the simulation results of main polarization and cross polarization H-plane antenna patterns of the present invention at 11.75 GHz.

[0036] As shown in Figures 6, 8, and 10, the antenna of the present invention has a ratio of main polarization to cross polarization in the E plane of about 20 dB. As shown in Figures 7, 9, and 11, the antenna of the present invention has a ratio of main polarization to cross polarization in the H plane of about 40 dB.

[0037] This invention ultimately provides a compact, wideband antenna covering the X frequency band (X-band), with a relative bandwidth of 25.86%, a flat gain curve within the frequency band, and a maximum gain of 7.14 dBi, achieving excellent radiation performance. Starting with a rectangular, substrate-integrated waveguide antenna with a simple structure, the bandwidth expansion performance of an open-type substrate-integrated waveguide antenna was verified. Furthermore, the impedance bandwidth can be increased by simply removing some metal pillars, without adding a complex matching network or special structures. This is simple and low-cost to manufacture, providing further possibilities for future wideband antenna designs.

[0038] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Those skilled in the art can make various changes and modifications to the present invention. All modifications, equivalent replacements, improvements, etc. made within the spirit and scope of the present invention are intended to be included in the scope of the claims of the present invention.

Claims

1. An open-type small wideband antenna using a substrate-integrated waveguide, comprising a base layer dielectric substrate (4) and an upper layer dielectric substrate (6), a first metal layer (1) provided on the lower surface of the base layer dielectric substrate (4), and a second metal layer (2) provided on the upper surface of the base layer dielectric substrate (4); The second metal layer (2) has a strip-shaped slit (11) that is split to form an open circuit, and the slit (11) functions as a radiation surface for the first metal layer (1), the second metal layer (2), and the underlying dielectric substrate (4). A plurality of metal cylinders penetrate the underlying dielectric substrate (4), and the upper and lower ends of the plurality of metal cylinders are connected to the first metal layer (1) and the second metal layer (2), respectively. No metal cylinders for SIW waveguiding are provided near the slit (11), thereby opening up the SIW structure. the second metal layer (2) is connected to a microstrip line feed (7) at the side away from the strip-shaped slit (11) to form a wideband SIW feed structure, an upper dielectric substrate (6) is attached to the upper surface of the second metal layer (2) and to the cleaved strip-shaped slit (11) of the second metal layer (2), and the upper surface of the upper dielectric substrate (6) is a third metal layer (3).

2. The open-type small wideband antenna using a substrate-integrated waveguide as described in claim 1, characterized in that the third metal layer (3) is composed of two T-shaped metal patches (9) arranged at an interval equal to the width of the slit (8), and four metal shorting through holes (10) are provided in the upper dielectric substrate (6), and the four metal shorting through holes (10) penetrate the upper dielectric substrate (6) and are connected at their upper and lower ends to the first metal layer (1) and the second metal layer (2), respectively.

3. 3. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 2, wherein the width of the strip-shaped slit (11) is the same as the width of the slit (8).

4. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 3, characterized in that the widths of the strip-shaped slit (11) and the slit (8) are both 1.55 mm to 1.75 mm.

5. 2. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 1, wherein the underlayer dielectric substrate (4) on the same side as the microstrip line feed (7) is not provided with a metal cylinder so as to form an open structure, the underlayer dielectric substrate (4) on the side opposite to the microstrip line feed (7) is not provided with a metal cylinder in the strip-shaped slit (11) so as to form an open structure, and the underlayer dielectric substrate (4) on the side opposite to the microstrip line feed (7) is provided with three metal cylinders on each side of a symmetry axis that passes through the longitudinal center of the strip-shaped slit (11) and is perpendicular to the longitudinal direction.

6. 2. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 1, wherein the size of the upper layer dielectric substrate (6) is 1 / 4.5 of the size of the underlying layer dielectric substrate (4).

7. 2. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 1, wherein the impedance of each of the ends of the microstrip line feeder (7) is 50 ohms.

8. 8. The open-type small wideband antenna using a substrate-integrated waveguide according to claim 1, wherein the open-type small wideband antenna covers the X band.

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