Double-broadband substrate integrated waveguide cavity-backed slot antenna

Abstract

The double-broadband substrate integrated waveguide back cavity slot antenna comprises a circular dielectric substrate, and the upper layer and the lower layer of the dielectric substrate are covered with a first metal layer and a second metal layer respectively; the outer ring of the antenna unit is provided with a plurality of metalized through holes, so that the antenna unit forms a substrate integrated waveguide structure; the center of the first metal layer and the center of the second metal layer are respectively provided with a feed hole, and a feed probe penetrates through the feed hole. A plurality of metalized short-circuit through holes are formed in the circumference of the first metal layer by taking the feed hole as a circle center; the first metal layer is provided with a plurality of gaps in different shapes, and the metalized short-circuit through holes are located among the gaps. According to the invention, the bandwidth of the antenna is obviously improved by fusing a plurality of resonant modes of the substrate integrated waveguide, and the antenna gain can be improved while the broadband performance is obtained by optimally designing the structure of the radiation slot of the substrate integrated waveguide back cavity slot antenna.

Description

Technical Field

[0001] The invention belongs to the technical field of waveguide antennas, and in particular relates to a dual-broadband substrate integrated waveguide cavity-backed slot antenna applied to C band and Ku band. Background Art

[0002] With the continuous growth of global marine resource development and offshore activities, offshore platforms are playing an increasingly important role in energy extraction, environmental monitoring and other fields. The communication environment of offshore platforms is complex, requiring both long-distance two-way communication with land base stations or satellites and high-bandwidth local data transmission within and around the platform.

[0003] At the same time, in terms of antenna design, antenna systems that can adapt to a variety of application scenarios have become an important direction of communication research today. Therefore, for offshore platforms, designing dual broadband antennas that combine the long-distance transmission advantages of the C band and the high-bandwidth transmission requirements of the Ku band can reduce the complexity of multi-band antenna systems and improve the efficiency and flexibility of offshore platform communication systems.

[0004] At present, substrate-integrated waveguide antennas have become an ideal choice to meet this demand due to their compact structure, low loss and high integration. By limiting the propagation of electromagnetic waves within the substrate, substrate-integrated waveguide antennas ensure the effective transmission of energy and are particularly suitable for remote communication systems. However, due to the single resonant mode and high Q value of traditional standing wave type substrate-integrated waveguide slot antennas, their bandwidth is often narrow, which limits the working efficiency of the antenna in multiple frequency bands. Summary of the invention

[0005] The present invention aims to solve one of the technical problems existing in the related art at least to a certain extent.

[0006] One object of the present invention is to provide a dual broadband substrate integrated waveguide back cavity slot antenna applied to C band and Ku band, by fusing multiple resonant modes of the substrate integrated waveguide so that the bandwidth of the antenna is significantly improved, and by optimizing the structure of the radiation slot of the substrate integrated waveguide back cavity slot antenna, the antenna gain can be improved while obtaining broadband performance.

[0007] In order to achieve the above-mentioned object, the present invention provides a dual broadband substrate integrated waveguide back cavity slot antenna, comprising a circular dielectric substrate, wherein the upper layer and the lower layer of the dielectric substrate are respectively covered with a first metal layer and a second metal layer, and the first metal layer, the second metal layer and the dielectric substrate together constitute an antenna unit;

[0008] The outer ring of the antenna unit is provided with a plurality of metallized through holes, so that the antenna unit forms a substrate integrated waveguide structure;

[0009] A feeding hole for inserting a feeding probe is provided at the center of the first metal layer and the second metal layer; a plurality of metallized short-circuit through holes are provided on the first metal layer with the feeding hole as the center and the circumference thereof;

[0010] The first metal layer is provided with a plurality of gaps of different shapes, and the metallized short-circuit through holes are located between the gaps.

[0011] A further preferred technical solution of the present invention is that an octagonal annular groove and a circular annular groove are provided on the first metal layer as antenna gaps;

[0012] The annular groove is located in the inner circle of the octagonal annular groove.

[0013] Preferably, the inner circle of the annular groove is further provided with four rectangular grooves, which are evenly distributed radially with the feeding hole on the first metal layer as the center, and a short side away from the feeding hole coincides with the annular groove.

[0014] Preferably, there are four metallized short-circuit through holes, which are respectively located between two adjacent rectangular grooves.

[0015] Preferably, the octagonal annular groove is an annular structure formed by coaxially overlapping two octagons of different areas and cutting off the overlapping portion;

[0016] The annular groove is an annular structure formed by coaxially overlapping two circles of different areas and cutting off the overlapping portion.

[0017] Preferably, the metallized through hole penetrates the first metal layer, the dielectric substrate and the second metal layer to form a side wall of the substrate integrated waveguide structure.

[0018] Preferably, the metallized through holes are symmetrically distributed around the center of the antenna, the radius of the metallized through holes is 0.5 mm, and the angle between adjacent metallized through holes and the center of the antenna unit is 5°.

[0019] Preferably, the dielectric substrate is made of high-frequency plate material with a relative dielectric constant of 2.2 and a loss tangent of 0.0009.

[0020] Preferably, the first metal layer and the second metal layer are both made of copper.

[0021] Preferably, the antenna is manufactured by a printed circuit board process.

[0022] Beneficial effects: (1) The present invention adopts substrate integrated waveguide technology to construct a circular substrate integrated waveguide antenna that solves the problem of narrow bandwidth of traditional cavity-backed slot antennas and greatly expands the bandwidth of the antenna while maintaining high gain.

[0023] (2) The antenna of the present invention can simultaneously realize the long-distance transmission advantages of the C band (6.76-8.22 GHz, 19.49% relative impedance bandwidth) and the high-bandwidth transmission requirements of the Ku band (14.14-18.09 GHz, 24.51% relative impedance bandwidth), achieving dual broadband coverage.

[0024] (3) The present invention improves the matching performance of the antenna by introducing four rectangular slots that are symmetrical about the center of the antenna.

[0025] In summary, the present invention accurately controls the electromagnetic field distribution by loading short-circuit vias in the circular substrate integrated waveguide cavity. The loading of the short-circuit vias makes the TM of the circular substrate integrated waveguide cavity 01 The mode moves up and with the circular patch TM 02 Mode fusion generates low-frequency broadband; high-frequency broadband is mainly generated by the mutual coupling effect of the two annular slots. This design solves the mutual interference problem between multiple modes while ensuring bandwidth expansion, ensuring stable resonance and efficient communication performance of the antenna in dual frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the three-dimensional structure of the antenna in an embodiment of the present invention.

[0027] Figure 2 Graph showing simulation results of |S11| of the antenna in an embodiment of the present invention.

[0028] Figure 3 Graph showing the gain simulation results of the antenna in an embodiment of the present invention.

[0029] Figure 4 : is the radiation pattern of the antenna at 7 GHz in the embodiment of the present invention.

[0030] Figure 5 : is the radiation pattern of the antenna at 8 GHz in the embodiment of the present invention.

[0031] Figure 6 : is the radiation pattern of the antenna at 15.1 GHz in the embodiment of the present invention.

[0032] Figure 7 : is the radiation pattern of the antenna at 17.8 GHz in the embodiment of the present invention.

[0033] Among them, 1-octagonal annular groove, 2-circular annular groove, 3-first metal layer, 4-dielectric substrate, 5-second metal layer, 6-metallized through hole, 7-rectangular groove, 8-metallized short-circuit through hole, 9-coaxial feeding probe. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, and they should not be understood as limitations on the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be understood that the terms used are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0035] Combine the following Figure 1-Figure 7 The invention describes a dual broadband substrate integrated waveguide cavity-backed slot antenna applied to C band and Ku band.

[0036] In view of the problems existing in traditional substrate integrated waveguide antennas, after a large number of experimental studies, it was found that the bandwidth of the antenna can be significantly improved by integrating multiple resonant modes of the substrate integrated waveguide, and by optimizing the structure of the radiation slot of the substrate integrated waveguide back cavity slot antenna, the antenna gain can be improved while obtaining broadband performance. Therefore, the present invention proposes the following specific embodiments.

[0037] Embodiment: This embodiment provides a dual broadband substrate integrated waveguide back cavity slot antenna, such as Figure 1 As shown, it includes a circular dielectric substrate 4, which is made of Rogers RT / Duroid 5880 high-frequency plate, with a relative dielectric constant of 2.2, a loss tangent of 0.0009, and a dielectric substrate thickness of 1.575 mm. The upper and lower layers of the dielectric substrate 4 are respectively provided with a first metal layer 3 and a second metal layer 5.

[0038] The first metal layer 3 and the second metal layer 5 are both made of copper. The first metal layer 3 is placed on the upper layer of the dielectric substrate 4 and has a thickness of 0.035 mm; the second metal layer 5 is placed on the lower layer of the dielectric substrate 4 and has a thickness of 0.035 mm.

[0039] The first metal layer 3, the second metal layer 5 and the dielectric substrate 4 together form an antenna unit. The outer ring of the antenna unit is provided with a number of metallized through holes 6, so that the antenna unit forms a substrate integrated waveguide structure. Substrate Integrated Waveguide (SIW) technology is a new waveguide structure with low insertion loss, low radiation, high power capacity and other characteristics that can be integrated into a dielectric substrate proposed in recent years. It is realized by using a metallized through hole array on a low-loss dielectric substrate with metal layers on the upper and lower bottom surfaces. Its purpose is to realize the function of a traditional metal waveguide on a dielectric substrate. It can effectively realize passive and active integration, miniaturize the microwave millimeter wave system, and even make the entire microwave millimeter wave system in one package.

[0040] The metallized through holes 6 are symmetrically distributed around the center of the antenna unit to form the side wall of the substrate integrated waveguide structure. The radius of the metallized through hole 6 is 0.5 mm, the height is 1.575 mm, the distance from the center of the antenna unit is 18.395 mm, and the angle between adjacent metallized through holes 6 and the center of the antenna unit is 5°.

[0041] Feeding holes for penetrating the feeding probe 9 are provided at the centers of the first metal layer 3 and the second metal layer 5 .

[0042] The first metal layer 3 is provided with a plurality of metallized short-circuit through holes 8 with the feed hole as the center and the circumference. The metallized short-circuit through hole 8 runs through the entire antenna unit, has a radius of 0.348 mm, a height of 1.575 mm, a distance of 6.71 mm from the center of the antenna, and an angle of 90° between adjacent metallized short-circuit through holes 8 and the center of the antenna. The metallized short-circuit through holes 8 enhance the circular substrate integrated waveguide cavity TM by adjusting the electric field distribution in the cavity. 01 The electric field strength of the mode in the low frequency band, thus producing a low-frequency resonance point.

[0043] The first metal layer 3 is provided with a plurality of slots of different shapes, including an octagonal annular slot 1, a circular annular slot 2, and four rectangular slots 7, which are used as antenna slots. The circular annular slot 2 is located in the inner circle of the octagonal annular slot 1, and the rectangular slot 7 is located in the inner circle of the circular annular slot 2.

[0044] The octagonal annular groove 1 is a ring structure formed by coaxially overlapping two octagons of different areas and cutting off the overlapping part. The octagon is obtained by rotating two squares around the center by 45 degrees. The outer octagon is composed of two squares with a side length of 21.85 mm, and the inner octagon is composed of two squares with a side length of 19.65 mm.

[0045] The annular groove 2 is an annular structure formed by coaxially overlapping two circles of different areas and cutting off the overlapping portion. The radius of the outer circle is 9.645 mm, and the radius of the inner circle is 8.025 mm.

[0046] The four rectangular slots 7 are evenly distributed radially with the feeding hole on the first metal layer 3 as the center, and a short side away from the feeding hole coincides with the annular slot 2. The rectangular slot 7 is 6 mm long and 1.47 mm wide, and the angle between adjacent rectangular slots and the center of the antenna is 90°.

[0047] The coaxial feeding probe 9 is located at the center of the antenna unit, with a radius of 0.23 mm and a height of 1.575 mm. The feeding port is arranged on the second metal layer 5. The antenna is made of printed circuit board technology.

[0048] The performance of the antenna of the embodiment is described in detail below with reference to the accompanying drawings.

[0049] like Figure 2 , which is the reflection coefficient |S of the dual broadband substrate integrated waveguide cavity-backed slot antenna applied to C-band and Ku-band of the embodiment. 11 |Simulation result diagram, the impedance bandwidth range is 6.76-8.22GHz (relative bandwidth 19.49%), 14.14-18.09GHz (relative bandwidth 24.51%), achieving dual broadband coverage.

[0050] like Figure 3 As shown, it is a gain simulation result diagram of the dual broadband substrate integrated waveguide back cavity slot antenna applied to C band and Ku band of the embodiment, the low frequency gain range is 4.08-7.09dBi, and the high frequency gain range is 5.54-9.5dBi.

[0051] like Figure 4-7 As shown, the radiation patterns of the dual broadband substrate integrated waveguide back-cavity slot antenna applied to C-band and Ku-band of the embodiment respectively operate at 7 GHz, 8 GHz, 15.1 GHz, and 17.8 GHz. It can be seen that the antenna pattern is stable, and the difference between the main polarization and the cross polarization is greater than 20 dB.

[0052] In the present embodiment, the description of "upper" and "lower" is only used to describe the present invention and simplify the description, and cannot be understood as indicating or implying that a device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to describe the appearance, and cannot be understood as indicating or implying relative importance.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual broadband substrate integrated waveguide back cavity slot antenna, comprising a circular dielectric substrate, wherein the upper layer and the lower layer of the dielectric substrate are respectively covered with a first metal layer and a second metal layer, wherein the first metal layer, the second metal layer and the dielectric substrate together constitute an antenna unit; characterized in that: The outer ring of the antenna unit is provided with a plurality of metallized through holes, so that the antenna unit forms a substrate integrated waveguide structure; A feeding hole for inserting a feeding probe is provided at the center of the first metal layer and the second metal layer; a plurality of metallized short-circuit through holes are provided on the first metal layer with the feeding hole as the center and the circumference thereof; The first metal layer is provided with a plurality of gaps of different shapes, and the metallized short-circuit through holes are located between the gaps.

2. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 1, characterized in that: The first metal layer is provided with an octagonal annular groove and a circular annular groove as antenna gaps; The annular groove is located in the inner circle of the octagonal annular groove.

3. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 2, characterized in that: The inner circle of the annular groove is further provided with four rectangular grooves, which are evenly distributed radially with the feeding hole on the first metal layer as the center, and a short side away from the feeding hole coincides with the annular groove.

4. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 3, characterized in that: There are four metallized short-circuit through holes, which are respectively located between two adjacent rectangular grooves.

5. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 2, characterized in that: The octagonal annular groove is an annular structure formed by coaxially overlapping two octagons of different areas and cutting off the overlapping portion; The annular groove is an annular structure formed by coaxially overlapping two circles of different areas and cutting off the overlapping portion.

6. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 1, characterized in that: The metallized through hole penetrates the first metal layer, the dielectric substrate and the second metal layer to form a side wall of the substrate integrated waveguide structure.

7. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to claim 6, characterized in that: The metallized through holes are symmetrically distributed around the center of the antenna, the radius of the metallized through holes is 0.5 mm, and the angle between adjacent metallized through holes and the center of the antenna unit is 5°.

8. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to any one of claims 1 to 7, characterized in that: The dielectric substrate is made of a high-frequency plate material, has a relative dielectric constant of 2.2, and a loss tangent of 0.0009.

9. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to any one of claims 1 to 7, characterized in that: The first metal layer and the second metal layer are both made of copper material.

10. The dual broadband substrate integrated waveguide cavity-backed slot antenna according to any one of claims 1 to 7, characterized in that: The antenna is manufactured by a printed circuit board process.

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