High-performance filtering antenna based on slot-loaded substrate integrated cavity

Abstract

The invention discloses a high-performance filtering antenna based on a slot-loaded substrate integrated cavity. The antenna comprises a dielectric substrate, a metal layer arranged on the upper surface of the dielectric substrate, a metal layer arranged on the lower surface of the dielectric substrate, a central metal through hole and a peripheral metal through hole array. The novel filtering antenna provided by the invention has the advantages of simple structure, low profile, small size and high frequency selectivity, and can be well applied to the field of 5G wireless communication systems.

Description

Technical Field

[0001] The present invention belongs to the technical field of 5G wireless mobile communications, and in particular relates to a high-performance filtering antenna based on a slot-loaded substrate integrated cavity. Background Art

[0002] With the rapid development of wireless communication technology, RF front-end systems are developing towards high performance, high integration and miniaturization. Traditionally, passive components of RF front-ends such as filters, antennas and duplexers are designed separately and work in cascade. This inevitably leads to large physical size and complex circuits, as well as high insertion loss and signal distortion, especially at the passband edge. As key components of RF front-end systems, filters and antennas can be integrated to achieve miniaturization and significantly improve system performance such as frequency selectivity, in-band gain and out-of-band suppression. The present invention proposes a high-performance filtering antenna based on a slot-loaded substrate integrated cavity. The proposed new filtering antenna has the advantages of simple structure, low profile, small size and high frequency selectivity, which is in line with actual engineering needs and has important theoretical and practical significance. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to design a high-performance filtering antenna based on a slot-loaded substrate integrated cavity. The design of the present invention innovatively constructs a ground patch radiating unit and a circular patch radiating unit through circular slot loading, which significantly reduces the size and widens the bandwidth; the exposed ground patch is encapsulated in a substrate integrated cavity that is closed around it using a metal through-hole array, forming a packaging feature.

[0004] Technical solution: In order to achieve the above-mentioned purpose, the present invention proposes a high-performance filtering antenna based on a slot-loaded substrate integrated cavity, the filtering antenna comprising a first metal layer (100), a dielectric substrate (200), and a second metal layer (300); the first metal layer (100) is arranged on the upper surface of the dielectric substrate (200); the second metal layer (300) is arranged on the lower surface of the dielectric substrate (200), and the first metal layer (100), the dielectric substrate (200), and the second metal layer (300) together constitute a substrate integrated cavity.

[0005] Furthermore, the first metal layer (100) is provided with two trapezoidal grooves and one annular groove (105), wherein the horizontal ends of the two trapezoidal grooves are parallel, and the vertical ends are respectively connected to the upper and lower ends of the annular groove (105), and the two trapezoidal grooves and the annular groove (105) are symmetrical about the center of the first metal layer (100); the annular groove (105) divides the first metal layer (100) into a symmetrical first ground patch (103) and a second ground patch (104); a notch is provided on the side of the first ground patch (103) away from the annular groove, and a microstrip feed line (101) is symmetrically provided in the notch to form an input port; the other end of the microstrip feed line (101) is connected to the dielectric substrate (200), and the two sides of the microstrip feed line (101) do not contact the notch, and the microstrip feed line (101) located in the notch forms a coplanar waveguide structure (102).

[0006] Furthermore, a metal through hole array (201) is provided on the dielectric substrate (200) directly below the edge of the first metal layer (100), and except for a portion directly below the coplanar waveguide (102) without a first metal through hole (201), the remaining portions are provided with first metal through holes (201) arranged in a rectangular shape; a central metal through hole (202) is provided at the center of the dielectric substrate (200), and the center of the central metal through hole (202) coincides with the center of the first metal layer (100).

[0007] Furthermore, the material of the dielectric substrate (200) is Rogers 5880, with a relative dielectric constant of 2.2 and a thickness of 1.575 mm.

[0008] Furthermore, the second metal layer (300) constitutes a ground plane of the filtering antenna.

[0009] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0010] (1) The present invention provides a high-performance filtering antenna design based on a slot-loaded substrate integrated cavity, which realizes multifunctionality and miniaturization. It has both the good radiation performance of a directional radiation linear polarization antenna and the frequency selection performance of the filter device itself. It uses one device instead of the cascade of multiple devices, avoiding the problems of high loss and large size, and realizing multifunctional integration; it also has the advantages of simple structure, low profile, compact size, high frequency selectivity, and wide stopband range.

[0011] (2) The present invention utilizes gap-coupled ground patches and circular patches, and the proposed filtering antenna has three resonance points within the desired frequency range. Two of the resonance points are provided by gap-coupled patch resonators, and the third is achieved by a circular patch resonator loaded by a center via. Since both ground patches have a radiation effect, a radiation zero point is generated on the right side of the passband. Because of the cross-coupling between the three resonators, a radiation zero point is generated on the left side of the passband. Ultimately, the filtering antenna obtains good frequency selection characteristics and a wider passband range. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods, so as to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, and the advantages and implementation methods of the present invention will be more obvious. The contents of the accompanying drawings are only used to illustrate and explain the present invention, but will not constitute any limitation to the present invention in any sense. In the accompanying drawings:

[0013] Figure 1 It is a three-dimensional structural schematic diagram of a high-performance filtering antenna based on a slot-loaded substrate integrated cavity of the present invention.

[0014] Figure 2 It is a schematic diagram of the planar dimensions of a high-performance filtering antenna based on a slot-loaded substrate integrated cavity of the present invention.

[0015] Figure 3 The invention discloses a reflection coefficient and gain curve of a high-performance filtering antenna based on a slot-loaded substrate integrated cavity.

[0016] Figure 4 The radiation pattern of a high-performance filtering antenna based on a slot-loaded substrate integrated cavity at a center frequency point of the present invention: (a) E plane, (b) H plane. DETAILED DESCRIPTION

[0017] The embodiments of the present invention will be described below in conjunction with the accompanying drawings. The implementation modes shown in the accompanying drawings are only exemplary and are intended to explain the principles of the present invention, but are not intended to limit the scope of the present invention.

[0018] like Figure 1 As shown, the present invention provides a high-performance filtering antenna based on a slot-loaded substrate integrated cavity, the filtering antenna comprising a first metal layer (100), a dielectric substrate (200), and a second metal layer (300); the first metal layer (100) is arranged on the upper surface of the dielectric substrate (200); the second metal layer (300) is arranged on the lower surface of the dielectric substrate (200), and the first metal layer (100), the dielectric substrate (200), and the second metal layer (300) together constitute a substrate integrated cavity.

[0019] Furthermore, the first metal layer (100) is provided with two trapezoidal grooves and one annular groove (105), wherein the horizontal ends of the two trapezoidal grooves are parallel, and the vertical ends are respectively connected to the upper and lower ends of the annular groove (105), and the two trapezoidal grooves and the annular groove (105) are symmetrical about the center of the first metal layer (100); the annular groove (105) divides the first metal layer (100) into a symmetrical first ground patch (103) and a second ground patch (104); a notch is provided on the side of the first ground patch (103) away from the annular groove, and a microstrip feed line (101) is symmetrically provided in the notch to form an input port; the other end of the microstrip feed line (101) is connected to the dielectric substrate (200), and the two sides of the microstrip feed line (101) do not contact the notch, and the microstrip feed line (101) located in the notch forms a coplanar waveguide structure (102).

[0020] Furthermore, a metal through hole array (201) is provided on the dielectric substrate (200) directly below the edge of the first metal layer (100), and except for a portion directly below the coplanar waveguide (102) without a first metal through hole (201), the remaining portions are provided with first metal through holes (201) arranged in a rectangular shape; a central metal through hole (202) is provided at the center of the dielectric substrate (200), and the center of the central metal through hole (202) coincides with the center of the first metal layer (100).

[0021] Furthermore, the material of the dielectric substrate (200) is Rogers 5880, with a relative dielectric constant of 2.2 and a thickness of 1.575 mm.

[0022] Furthermore, the second metal layer (300) constitutes a ground plane of the filtering antenna.

[0023] In this design example, two ground patches and one circular patch (106) are obtained by etching the annular groove (105), thereby achieving miniaturization and a wider frequency band. In addition, due to the presence of multiple radiation units and the cross-coupling between different resonators, two radiation zero points are provided on both sides of the passband, and finally the filtering antenna obtains good frequency selection characteristics and a wider passband range. This design example achieves multifunctionality and miniaturization, and the final size is 0.61λg×0.61λg×0.027λg, as shown in FIG. Figure 2 As shown, the specific dimensions are shown in Table 1 (unit: mm):

[0024] Table 1

[0025] parameter value parameter value W 35 sw 1.34 L 35 dw 4.5 wl 1.97 sl 32.5 g 8.62 r 0.8 ds 16.95 Ra 7 dr 17.67 R 9

[0026] Figure 3is the reflection coefficient and achievable gain simulated by the present invention. In the simulation results of the present invention, the -10dB impedance bandwidth reaches 7.76%, the maximum actual gain is 6.22dBi, the in-band efficiency exceeds 80%, and the efficiency at the center frequency reaches 98.5%. Two radiation zeros can be observed at 3.36GHz and 3.74GHz, indicating the high selectivity of the design. Figure 4 (a) and (b) are the radiation patterns of the E-plane and H-plane of the filtering antenna at the center frequency of 3.54 GHz, respectively, showing stable radiation characteristics and a cross-polarization suppression level of more than 36 dB in the main radiation direction, with good radiation performance.

[0027] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, chip, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, chip, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, chip, article or device including the elements.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A high-performance filtering antenna based on a slot-loaded substrate integrated cavity, characterized in that: The filtering antenna comprises a first metal layer (100), a dielectric substrate (200), and a second metal layer (300); the first metal layer (100) is arranged on the upper surface of the dielectric substrate (200); the second metal layer (300) is arranged on the lower surface of the dielectric substrate (200); the first metal layer (100), the dielectric substrate (200), and the second metal layer (300) together constitute a substrate integrated cavity.

2. A high performance filtering antenna based on a slot loaded substrate integrated cavity according to claim 1, characterized in that: The first metal layer (100) is provided with two trapezoidal grooves and one annular groove (105), wherein the horizontal ends of the two trapezoidal grooves are parallel, and the vertical ends are respectively connected to the upper and lower ends of the annular groove (105), and the two trapezoidal grooves and one annular groove (105) are symmetrical about the center of the first metal layer (100); the annular groove (105) divides the first metal layer (100) into a symmetrical first ground patch (103) and a second ground patch (104); a notch is provided on the side of the first ground patch (103) away from the annular groove, and a microstrip feed line (101) is symmetrically provided in the notch to form an input port; the other end of the microstrip feed line (101) is connected to a dielectric substrate (200), and the two sides of the microstrip feed line (101) do not contact the notch, and the microstrip feed line (101) located in the notch forms a coplanar waveguide structure (102).

3. A high performance filtering antenna based on slot loaded substrate integrated cavity according to claim 2, characterized in that: A metal through hole array (201) is provided on the dielectric substrate (200) directly below the edge of the first metal layer (100), and except for a portion directly below the coplanar waveguide (102) without the first metal through hole (201), the remaining portions are provided with the first metal through holes (201) and are arranged in a rectangular shape; a central metal through hole (202) is provided at the center of the dielectric substrate (200), and the center of the central metal through hole (202) coincides with the center of the first metal layer (100).

4. A high performance filtering antenna based on slot loaded substrate integrated cavity according to claim 1, characterized in that: The material of the dielectric substrate (200) is Rogers 5880, with a relative dielectric constant of 2.2 and a thickness of 1.575 mm.

5. The high performance filtering antenna based on slot loaded substrate integrated cavity according to claim 1, characterized in that: The second metal layer (300) constitutes a ground plane of the filtering antenna.

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