Base station antenna based on microstrip and integrated waveguide feed

Abstract

This application provides a base station antenna based on microstrip and integrated waveguide feeding, belonging to the field of microwave antenna technology. The base station antenna based on microstrip and integrated waveguide feeding includes a first dielectric substrate and a second dielectric substrate. The patch radiating element includes a microstrip patch disposed on the first dielectric substrate and a first metal via array, the first metal via array and the microstrip patch together forming a half-mode microstrip patch resonator. The waveguide radiating element includes a metal layer disposed on the second dielectric substrate and a second metal via array. A ground plane is disposed on the side of the second dielectric substrate opposite to the first dielectric substrate. The ground plane, the second metal via array, and the metal layer together form a half-mode substrate integrated waveguide resonant cavity. A coupling slot is used to electromagnetically couple the radiated energy of the waveguide radiating element to the patch radiating element. The base station antenna based on microstrip and integrated waveguide feeding provided by this application is beneficial for expanding the antenna's operating bandwidth and achieving structural miniaturization.

Description

Technical Field

[0001] This application relates to microwave antenna technology, and more particularly to a base station antenna based on microstrip and integrated waveguide feeding. Background Technology

[0002] As wireless communication systems demand higher data transmission rates and capacities, the performance requirements for base station antennas, such as operating bandwidth and gain, are also increasing. Microstrip patch antennas are widely used in base station antennas due to their advantages such as low profile, light weight, and ease of integration; however, their inherent narrow bandwidth limitation restricts their application in broadband systems.

[0003] In related technologies, to extend the bandwidth of microstrip patch antennas, microstrip patches are generally combined with substrate integrated waveguide resonators. However, the use of planar side-by-side or cascaded layouts for microstrip patches and integrated waveguide resonators results in a large overall size, low energy coupling efficiency between different resonators, high losses, and poor performance improvement. Summary of the Invention

[0004] This application provides a base station antenna based on microstrip and integrated waveguide feeding to solve the problems of large size and low energy coupling efficiency of base station antennas in related technologies.

[0005] The base station antenna based on microstrip and integrated waveguide feeding provided in this application includes:

[0006] A first dielectric substrate and a second dielectric substrate are stacked together;

[0007] The patch radiating unit includes a microstrip patch disposed on the first dielectric substrate and a first metal via array extending along one edge of the microstrip patch. The first metal via array and the microstrip patch together form a half-mode microstrip patch resonator.

[0008] A waveguide radiating unit, the waveguide radiating unit comprising a metal layer and a second metal via array disposed on the second dielectric substrate, the second metal via array being disposed around the edge of the metal layer;

[0009] A ground plane is disposed on the side of the second dielectric substrate opposite to the first dielectric substrate. The ground plane, the second metal via array, and the metal layer together form a half-mode substrate integrated waveguide resonant cavity.

[0010] A coupling gap is disposed on a metal layer on the second dielectric substrate, and the coupling gap is used to electromagnetically couple the radiated energy of the waveguide radiating unit to the patch radiating unit.

[0011] In some possible implementations, the microstrip patch has an electric wall boundary, and the microstrip patch is capable of axisymmetric mapping along the electric wall boundary;

[0012] The first array of metal vias is arranged along the extension direction of the electric wall boundary to form the equivalent electric wall of the microstrip patch.

[0013] In some possible implementations, the microstrip patch is a semi-circular patch or a semi-elliptical patch;

[0014] The electric wall boundary is the straight edge of the semi-circular patch or the semi-elliptical patch.

[0015] In some possible implementations, the metal layer has at least one open radiating side, and the second metal via array is disposed around the edge of the metal layer to form a semi-enclosed half-mode substrate integrated waveguide resonant cavity together with the ground plane.

[0016] The half-mode substrate integrated waveguide resonant cavity radiates energy outward through the open radiation side.

[0017] In some possible implementations, the metal layer is a rectangular layer;

[0018] The second metal via array is arranged along the long side and the two adjacent short sides of the metal layer to enclose and form the half-mode substrate integrated waveguide resonant cavity.

[0019] In some possible implementations, the metal layer is a circular layer or an elliptical layer;

[0020] The second metal via array is arranged along the arc segment of the circular layer or the elliptical layer.

[0021] In some possible implementations, the first metal via array is arranged symmetrically about the midline of the microstrip patch; the second metal via array is arranged symmetrically about the midline of the metal layer.

[0022] In some possible implementations, the coupling gaps have at least two spaced apart on the metal layer, and the at least two coupling gaps are symmetrically arranged along the midline of the metal layer.

[0023] In some possible implementations, a feed probe is also included, which passes through the second dielectric substrate and is connected to the metal layer to feed the half-mode substrate integrated waveguide resonant cavity.

[0024] In some possible implementations, the feed probe and the feed point of the metal layer are located on the midline of the metal layer, and there is a gap between the feed point and the second metal via array.

[0025] The base station antenna based on microstrip and integrated waveguide feeding provided in this application embodiment reduces the overall height of the antenna by using a first dielectric substrate and a second dielectric substrate stacked together. The patch radiating element forms a half-mode patch radiating resonant mode, and the waveguide radiating element forms a half-mode substrate integrated waveguide resonant mode. The two half-mode modes can further reduce the overall lateral size of the antenna, which is beneficial to realizing the compact and miniaturized design of the antenna.

[0026] Furthermore, the radiated energy of the waveguide radiating element is electromagnetically coupled to the patch radiating element through the coupling slot. The waveguide radiating element and the patch radiating element can excite two half-mode microstrip patch resonators. By design, the frequencies of the two half-mode microstrip patch resonators can be merged to form a wider composite impedance bandwidth, which is beneficial to expanding the overall operating bandwidth of the antenna. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 This is a schematic diagram of the structure of a base station antenna based on microstrip and integrated waveguide feeding in an embodiment of this application;

[0029] Figure 2 The simulated reflection coefficient diagram of the base station antenna based on microstrip and integrated waveguide feeding in the embodiments of this application is shown.

[0030] Figure 3 This is the radiation pattern of the first resonant point of the base station antenna based on microstrip and integrated waveguide feeding in the embodiments of this application;

[0031] Figure 4 This is the radiation pattern of the second resonant point of the base station antenna based on microstrip and integrated waveguide feeding in the embodiments of this application;

[0032] Figure 5 This is a radiation gain curve of a base station antenna based on microstrip and integrated waveguide feeding in the main radiation direction according to an embodiment of this application.

[0033] Explanation of reference numerals in the attached figures

[0034] 100 - First dielectric substrate;

[0035] 200 - Second dielectric substrate;

[0036] 300 - Patch radiating element; 310 - Microstrip patch; 311 - Electric wall boundary; 320 - First metal via array;

[0037] 400 - Waveguide radiating element; 410 - Metal layer; 411 - Long side; 412 - Short side; 420 - Second metal via array;

[0038] 500 - Flooring;

[0039] 600 - Coupling gap; 700 - Feed probe; 710 - Feed point.

[0040] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application.

[0042] As mentioned in the background section, in related technologies, the physical size of traditional multimode antennas based on conventional resonators, whether microstrip patches or substrate integrated waveguide resonators, is usually limited by the operating wavelength. Furthermore, while using half-mode substrate integrated waveguides (HMSIWs) reduces the size, their bandwidth is limited, significantly restricting their application.

[0043] Existing designs that combine microstrip patches with substrate integrated waveguide resonators can extend the bandwidth of HMSIWs to some extent. However, these hybrid designs often employ a side-by-side or cascaded planar layout, which occupies a large lateral area and is not conducive to the miniaturization requirements of base station antenna systems.

[0044] Based on the above description, one or more embodiments of this application provide a base station antenna based on microstrip and integrated waveguide feeding. This base station antenna utilizes a stacked first dielectric substrate and a second dielectric substrate to reduce the overall height of the antenna. The patch radiating element forms a half-mode patch radiating resonant mode, and the waveguide radiating element forms a half-mode substrate integrated waveguide resonant mode. These two half-mode modes further reduce the overall lateral size of the antenna, facilitating compact and miniaturized design. Furthermore, the radiated energy of the waveguide radiating element is electromagnetically coupled to the patch radiating element through a coupling slot. The waveguide and patch radiating elements can excite two half-mode microstrip patch resonators. Through design, the frequencies of the two half-mode microstrip patch resonators can be merged to form a wider composite impedance bandwidth, which is beneficial for extending the overall operating bandwidth of the antenna.

[0045] The following description, in conjunction with the accompanying drawings, illustrates the solutions of the embodiments of this application.

[0046] like Figure 1 As shown, the base station antenna based on microstrip and integrated waveguide feeding in this application embodiment includes a first dielectric substrate 100 and a second dielectric substrate 200, a patch radiating element 300, a waveguide radiating element 400, a ground plane 500 and a coupling slot 600 stacked together.

[0047] The patch radiating unit 300 includes a microstrip patch 310 disposed on the first dielectric substrate 100, and a first metal via array 320 extending along one edge of the microstrip patch 310. The first metal via array 320 and the microstrip patch 310 together form a half-mode microstrip patch resonator. The waveguide radiating unit 400 includes a metal layer 410 and a second metal via array 420 disposed on the second dielectric substrate 200. The second metal via array 420 is semi-closed around the edge of the metal layer 410. A ground plane 500 is disposed on the side of the second dielectric substrate 200 away from the first dielectric substrate 100. The ground plane 500, the second metal via array 420 and the metal layer 410 together form a half-mode substrate integrated waveguide resonator cavity. A coupling gap 600 is disposed on the metal layer 410. The coupling gap 600 is used to electromagnetically couple the radiated energy of the waveguide radiating unit 400 to the patch radiating unit 300.

[0048] As can be seen from the above description, the base station antenna based on microstrip and integrated waveguide feeding in this application embodiment uses a first metal via array 320 and a microstrip patch 310 to form a half-mode patch resonant mode, and uses a second metal via array 420 to semi-enclose a metal layer 410, a ground plane 500, the second metal via array 420 and the metal layer 410 to form a half-mode substrate integrated waveguide resonant cavity. The base station antenna can form two half-mode microstrip patch resonators. When the frequencies of the two half-mode microstrip patch resonators are similar and merge, a wider composite impedance bandwidth than a single resonator can be formed, which is beneficial to expanding the operating bandwidth of the base station antenna.

[0049] It should be noted that, in the embodiments of this application, the directional terms such as "up" and "down" are used with reference to... Figure 1 The layout is explained. Figure 1 In the middle, the first dielectric substrate 100, the second dielectric substrate 200 and the ground plane 500 are arranged sequentially from top to bottom.

[0050] In this embodiment, the first dielectric substrate 100 and the second dielectric substrate 200 can be made of microwave dielectric materials with the same dielectric constant and thickness, such as FR-4 (glass fiber reinforced epoxy resin substrate), Rogers RO4350B, polytetrafluoroethylene composite material, or ceramic material. The first dielectric substrate 100 and the second dielectric substrate 200 are stacked in parallel and tightly bonded together, and a complete ground plane 500 is provided under the second dielectric substrate 200. As an alternative implementation, the first dielectric substrate 100 and the second dielectric substrate 200 can also be dielectric substrates with different dielectric constants or thicknesses to adapt to different impedance bandwidth tuning requirements.

[0051] Here, the ground plane 500 covers the lower surface of the second dielectric substrate 200. The ground plane 500, the second metal via array 420, and the metal layer 410 together constitute the bottom closed metal wall of the half-mode substrate integrated waveguide resonant cavity. At the same time, the ground plane 500 also provides electromagnetic shielding for the upper structure.

[0052] like Figure 1 As shown, in some embodiments, the patch radiating unit 300 has an electric wall boundary 311, and the microstrip patch 310 can be axisymmetrically mapped along the electric wall boundary 311; the first metal via array 320 is arranged in an array along the extension direction of the electric wall boundary 311 to form the equivalent electric wall of the patch radiating unit 300.

[0053] In this embodiment, the microstrip patch 310 is an electrical conductor pattern disposed on the upper surface of the first dielectric substrate 100. The electric wall boundary 311 refers to a straight edge boundary of the microstrip patch 310. The electric wall boundary 311 is electromagnetically equivalent to an ideal electric wall. An equivalent electric wall is formed on the electric wall boundary 311 through the first metal via array 320. The outline shape of the microstrip patch 310 is mirror-symmetrical about the straight line where the electric wall boundary 311 is located. That is, the microstrip patch 310 is a patch symmetrically cut from the original complete patch. The complete patch is cut at the location of the first metal via array 320, so that the microstrip patch 310 forms a half-mode microstrip patch resonator.

[0054] Specifically, the first metal via array 320 consists of multiple metallized cylindrical holes penetrating the first dielectric substrate 100. The first metal via array 320 is arranged closely at intervals along the path where the electric wall boundary 311 is located. By adjusting the via diameter and the spacing between the vias of the first metal via array 320, the first metal via array 320 is ensured to block electromagnetic field leakage, forming a continuous ideal metal wall, i.e., an equivalent electric wall.

[0055] The first metal via array 320 forms an equivalent electric wall, causing the microstrip patch 310 to generate a radiation field on the side away from the electric wall boundary 311, forming a half-mode microstrip patch resonator. As a result, the size of the patch radiation unit 300 is reduced by half compared to the full-mode microstrip patch 310, realizing the miniaturization of the patch radiation unit 300.

[0056] Furthermore, in some embodiments, the microstrip patch 310 is a semi-circular patch or a semi-elliptical patch; the electric wall boundary 311 is the straight edge of the semi-circular patch or the semi-elliptical patch.

[0057] Here, a semi-circular patch refers to a half-pattern that is retained after a complete circular patch is cut along its diameter. The electric wall boundary 311 of the semi-circular patch is the straight edge where the cutting diameter is located. The first metal through-hole array 320 is arranged along the straight path where the cutting diameter is located to form the equivalent electric wall of the semi-circular patch. The semi-circular arc edge opposite the straight edge of the semi-circular patch constitutes an open radiating edge.

[0058] Similarly, a semi-elliptical patch is a half-patch retained after cutting a complete elliptical patch along its major or minor axis. The electric wall boundary 311 of the semi-elliptical patch is also the straight edge where the major or minor axis is cut. The first metal through-hole array 320 is arranged along the straight path where the major or minor axis is cut to form the equivalent electric wall of the semi-elliptical patch. The semi-circular arc edge opposite the straight edge of the semi-elliptical patch constitutes an open radiating edge.

[0059] The selection principle of the microstrip patch 310 is that the outline shape of the microstrip patch 310 can be symmetrical about the straight line axis where the electric wall boundary 311 is located, and the first metal through-hole array 320 is arranged along the axis of symmetry, thereby converting the full-mode patch resonator into a half-mode resonator with half the size.

[0060] This also shows that, since the overall size of the microstrip patch 310 is reduced by half, the lateral dimension of the microstrip patch 310 in the base station antenna is smaller, which is conducive to the miniaturization and compactness of the base station antenna.

[0061] like Figure 1As shown, in some embodiments, the metal layer 410 has at least one open radiation side, and the second metal via array 420 is arranged around the edge of the metal layer 410 to form a semi-closed half-mode substrate integrated waveguide resonant cavity together with the ground plane 500; wherein the half-mode substrate integrated waveguide resonant cavity radiates energy outward through the open radiation side.

[0062] Here, the metal layer 410 is a conductor layer disposed on the upper surface of the second dielectric substrate 200, and the open radiation side refers to the edge side of the metal layer 410 where the second metal via array 420 is not disposed. The open radiation side allows the electromagnetic energy of the half-mode substrate integrated waveguide resonant cavity to leak and radiate into the outer space.

[0063] The second metal via array 420 consists of multiple metallized cylindrical holes penetrating the second dielectric substrate 200. The second metal via array 420 is arranged along the edge sides of the metal layer 410 except for the open radiation side, thereby forming the simulated electric wall boundary of the half-mode substrate integrated waveguide resonant cavity. Here, the via diameter and the spacing between the vias of the second metal via array 420 can be set according to the relevant parameters of the dielectric substrate, and are not absolutely limited in this embodiment.

[0064] In this embodiment, the half-mode substrate integrated waveguide resonator is a three-dimensional cavity structure. The half-mode substrate integrated waveguide resonator is formed by a top metal layer 410, an equivalent metal sidewall composed of a second metal via array 420 on the sides, and a bottom ground plane 500. Since the second metal via array 420 is only arranged around a portion of the edge of the metal layer 410, the half-mode substrate integrated waveguide resonator is not closed in the direction of the open radiation side, thus enabling the formation of a half-mode microstrip patch resonator.

[0065] The lateral dimension of the half-mode substrate-integrated waveguide resonator is half that of the full-mode cavity, which is beneficial for the miniaturization and compactness of the waveguide radiating element 400. In addition, the substrate-integrated waveguide resonator has a higher Q value and lower radiation loss compared to pure microstrip lines in related technologies, which can produce a more stable resonant response and improve antenna radiation efficiency.

[0066] Furthermore, in some embodiments, the metal layer 410 is a rectangular layer; the second metal via array 420 is arranged along the long side 411 and the two adjacent short side 412 of the metal layer 410 to enclose and form a half-mode substrate integrated waveguide resonant cavity.

[0067] Here, the second metal via array 420 is arranged along one long side 411 and two short sides 412 adjacent to the long side 411 of the rectangular metal layer 410. The second metal via array 420 surrounds the three continuous edge sides of the metal layer 410, thereby forming a "U" shaped boundary. The other long side 411 not surrounded by the second metal via array 420 is the radiation side corresponding to the half-mode substrate integrated waveguide resonator. The half-mode substrate integrated waveguide resonator is rectangular in cross-section.

[0068] When the externally fed waveguide resonant unit is excited, the electromagnetic wave is confined in the semi-closed substrate integrated waveguide resonant cavity and resonates. Since one side of the half-mode substrate integrated waveguide resonant cavity is open, the field distribution of the main mode of the substrate integrated waveguide is in the open side stage. The electric field lines are strongest in the open side and are perpendicular to the second dielectric substrate 200. The electric field lines are continuously radiated into a spatial radiation field by the displacement current at this point, achieving efficient radiation.

[0069] It should be noted that the resonant frequency, quality factor (Q value) and radiation impedance of the half-mode substrate integrated waveguide resonant cavity can be controlled by precisely designing the geometry of the metal layer 410, the dielectric constant and thickness of the second substrate, and the length of the open radiation side. This application does not impose absolute limitations on these aspects.

[0070] As an alternative implementation, the metal layer 410 is a circular layer or an elliptical layer; the second metal via array 420 is arranged along the arc segment of the circular layer or elliptical layer.

[0071] Here, the second vias do not completely cover the outer contour of the metal layer 410, and the continuous arc-shaped boundary not covered by the second via array is the open radiation side of the half-mode substrate integrated waveguide resonator. This also shows that the half-mode substrate integrated waveguide resonator can be a rectangular cavity or a cylindrical cavity, which can be flexibly selected according to different design requirements.

[0072] like Figure 1 As shown, in some embodiments, the first metal via array 320 is symmetrically arranged about the midline of the microstrip patch 310; the second metal via array 420 is symmetrically arranged about the midline of the metal layer 410.

[0073] exist Figure 1 In the diagram, line A is the midline of the microstrip patch 310. The midline of the microstrip patch 310 and the midline of the metal layer 410 coincide in the height direction. The projection of the first metal via array 320 onto the ground plane 500 falls into the projection of the second metal via array 420 onto the ground plane 500. The straight edge of the microstrip patch 310 coincides with the long edge of the metal layer 410 in the height direction.

[0074] The symmetrical arrangement of the first metal via array 320 and the second metal via array 420 ensures that the main mode field distribution of the microstrip patch 310 and the half-mode substrate integrated waveguide resonant cavity is highly symmetrical, avoiding the parasitic modes or mode distortion caused by structural asymmetry. This helps to make the resonant frequency, input impedance and other parameters of the base station antenna based on microstrip and integrated waveguide feeding more stable, thereby improving the consistency of antenna performance.

[0075] Furthermore, the symmetrically arranged first metal via array 320 and second metal via array 420 make the electromagnetic field distribution of the half-mode microstrip patch resonator of the patch radiating unit 300 and waveguide radiating unit 400 symmetrical. The symmetrical distribution of the electromagnetic field makes the antenna beam more regular in the main radiation direction and the sidelobe level lower, which is beneficial to improving the radiation characteristics of the antenna and enhancing the coupling efficiency and stability of the patch radiating unit 300 and waveguide radiating unit 400.

[0076] In some embodiments, the coupling gaps 600 have at least two spaced apart on the metal layer 410, and the at least two coupling gaps 600 are symmetrically arranged along the midline of the metal layer 410.

[0077] For example, the coupling slot 600 described above is a rectangular slot etched on the metal layer 410. Of course, the coupling slot 600 can also be other shapes, such as dumbbell, H-shaped or circular. The size and shape of the coupling slot 600 affect the coupling strength and frequency characteristics, and can be flexibly designed according to the application scenarios and required parameters of the base station antenna based on microstrip and integrated waveguide feeding.

[0078] Figure 1 The system has two coupling slots 600, which are located on both sides of the center line and are equidistant from the center line. When the lower half-mode substrate integrated waveguide resonant cavity is excited, a high-frequency current distribution and a corresponding electromagnetic field will be formed on the upper surface of the metal layer 410. The symmetrically arranged coupling slots 600 cut off the surface current at this point and generate dense displacement current and edge electric field at the coupling slots 600, thereby leaking the electromagnetic energy in the resonant cavity to the upper layer. The leaked energy radiates upward through the coupling slots 600 and excites the upper microstrip patch 310 to resonate in the form of electromagnetic coupling. The symmetrically arranged coupling slots 600 help to excite the pure resonant mode of the microstrip patch 310.

[0079] It should be noted that, in some embodiments, by adjusting the coupling gap 600 parameter, the coupling coefficient and resonant frequency spacing between the half-mode substrate integrated waveguide resonant cavity and the microstrip patch 310 can be adjusted accordingly. After adjustment, the resonant peaks corresponding to the two radiating elements are merged into a wider impedance bandwidth, which is beneficial to expanding the bandwidth of the base station antenna based on microstrip and integrated waveguide feeding.

[0080] like Figure 1 As shown, in some embodiments, the base station antenna based on microstrip and integrated waveguide feeding further includes a feed probe 700, which passes through the second dielectric substrate 200 and is connected to the metal layer 410 to feed the half-mode substrate integrated waveguide resonant cavity.

[0081] Specifically, the feed probe 700 and the feed point 710 of the metal layer 410 are located on the midline of the metal layer 410, and there is a gap between the feed point 710 and the second metal via array 420.

[0082] The feed probe 700 acts as a conductor of the transmission line, introducing external radio frequency signals into the antenna. One end of the feed probe 700 is connected to the inner core of the coaxial connector, and the other end passes through the second dielectric substrate 200 and is electrically connected to the metal layer 410. Here, the connection point between the feed probe 700 and the metal layer 410 is the corresponding feed point 710. The feed point 710 is located on the center line of the metal layer 410. The feed probe 700 is at a better excitation position in the half-mode substrate integrated waveguide resonator, which can more efficiently excite the half-mode substrate integrated waveguide resonator.

[0083] In the above embodiments, the interval between the feed point 710 and the second metal via array 420 refers to the interval between the feed point 710 and the nearest array of the second metal via array 420. By adjusting the interval between the feed point 710 and the second metal via array 420, the relative position of the feed probe 700 and the equivalent electric wall of the half-mode substrate integrated waveguide resonator can be changed accordingly, thereby adjusting the input impedance of the base station antenna so that the external radio frequency signal and the base station antenna based on microstrip and integrated waveguide feeding form a good impedance match, and the external radio frequency signal can enter the half-mode substrate integrated waveguide resonator more efficiently.

[0084] The base station antenna based on microstrip and integrated waveguide feeding in this embodiment of the application uses an external radio frequency signal input via a coaxial connector through a feeding probe 700. This signal first excites the operating mode of the half-mode substrate integrated waveguide resonant cavity. The energy from the half-mode substrate integrated waveguide resonant cavity, through coupling gaps 600 etched on the metal layer 410, electromagnetically couples to the microstrip patch 310 on the first dielectric substrate 100, causing it to generate a corresponding resonant mode. By precisely designing the position and size of the patch radiating element 300, the waveguide radiating element 400, and the coupling gap 600, the frequencies of the two resonant modes can be brought close together and merged, thus forming a continuous and wide impedance bandwidth. Within the operating frequency band, the radiation fields of the two radiating elements are spatially superimposed, improving the antenna gain. Outside the operating frequency band, the mutual cancellation of the radiation fields of the two radiating elements generates a radiation null outside the high-frequency band, improving the frequency selectivity of the antenna.

[0085] Based on the antenna structure and operating principle, the size of the waveguide radiating element 400 primarily determines the low-frequency resonant frequency of the antenna's operating band, while the size of the patch radiating element 300 primarily determines the high-frequency resonant frequency. The size and position of the coupling slot 600 are used to adjust the coupling strength between the waveguide radiating element 400 and the patch radiating element 300, controlling the resonant frequencies of the two radiating elements to approach and merge. For example, to lower the low-frequency resonant point, the lateral dimension of the waveguide radiating element 400 can be increased; to raise the high-frequency resonant point, the size of the patch radiating element 300 can be decreased; if the two resonant points are too far apart, the coupling can be enhanced by increasing the length or width of the coupling slot, bringing them closer together until they merge.

[0086] An exemplary size design for the base station antenna based on microstrip and integrated waveguide feeding in this application embodiment is as follows:

[0087] The center frequency of the base station antenna based on microstrip and integrated waveguide feeding is 3.5GHz. When using a semi-circular microstrip patch 310, the diameter of the microstrip patch 310 is 29mm. When using a rectangular metal layer 410, the length of the half-mode rectangular substrate integrated waveguide resonant cavity is 60mm and the width is 14.5mm. The diameters of the first metal via array 320 and the second metal via array 420 are both 0.6mm. The center-to-center distance between two adjacent metal vias is 0.9mm. The length of the coupling slot 600 is 3mm and the width is 0.5mm. The center-to-center distance between two coupling slots 600 is 4mm. The distance between the coupling slot 600 and the nearest metal via is 1mm. The distance between the feed point 710 and the nearest metal via is 7mm.

[0088] Figure 2 The simulated reflection coefficient diagram of the base station antenna based on microstrip and integrated waveguide feeding is given in the figure. Figure 3 The radiation pattern is shown at the first resonant point of the antenna (3.41 GHz). Figure 4 The radiation pattern is shown at the second resonant point (3.64 GHz) of the antenna. Figure 5 This is a graph showing the radiation gain of the antenna in the main radiation direction.

[0089] in, Figure 3 In the diagram, A and B represent the realized gain of the Phi(φ) component of the antenna at 3.41 GHz with azimuth angles of 0° and 90°, respectively; C and D represent the realized gain of the Theta(θ) component of the antenna at 3.41 GHz with azimuth angles of 0° and 90°, respectively.

[0090] Figure 4In this context, E and F represent the realized gain of the Phi(φ) component of the antenna at 3.64 GHz with azimuth angles of 0° and 90°, respectively; G and H represent the realized gain of the Theta(θ) component of the antenna at 3.64 GHz with azimuth angles of 0° and 90°, respectively.

[0091] Depend on Figures 2 to 5 It can be seen that the antenna passband is 3.33-3.67GHz, and there are two resonant points within the passband, namely 3.41GHz and 3.64GHz. The radiation patterns at the two resonant points are similar, the maximum gain reaches 6.85dBi, and a radiation null point is presented at 3.75GHz.

[0092] The radiation fields of the two types of radiating elements cancel each other out of the high-frequency band due to their opposite phase, presenting a radiation null at 3.75 GHz. This eliminates the need for specially designed filtering circuits, resulting in a simpler and more compact structure. It effectively improves the frequency selectivity of the antenna, suppresses out-of-band interference, and enhances the anti-interference capability of the base station antenna system.

[0093] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0094] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A base station antenna based on microstrip and integrated waveguide feeding, characterized in that, include: A first dielectric substrate (100) and a second dielectric substrate (200) are stacked together. The patch radiating unit (300) includes a microstrip patch (310) disposed on the first dielectric substrate (100) and a first metal via array (320) extending along one edge of the microstrip patch (310). The first metal via array (320) and the microstrip patch (310) together form a half-mode microstrip patch resonator. A waveguide radiating unit (400) includes a metal layer (410) and a second metal via array (420) disposed on the second dielectric substrate (200), the second metal via array (420) being disposed around the edge of the metal layer (410); Ground plane (500) is disposed on the side of the second dielectric substrate (200) away from the first dielectric substrate (100). The ground plane (500), the second metal via array (420) and the metal layer (410) together form a half-mode substrate integrated waveguide resonant cavity. A coupling gap (600) is provided on a metal layer (410) on the second dielectric substrate (200). The coupling gap (600) is used to electromagnetically couple the radiation energy of the waveguide radiation unit (400) to the patch radiation unit (300).

2. The base station antenna based on microstrip and integrated waveguide feeding according to claim 1, characterized in that, The microstrip patch (310) has an electric wall boundary (311) and the microstrip patch (310) is capable of axisymmetric mapping along the electric wall boundary (311); The first metal via array (320) is arranged in an array along the extension direction of the electric wall boundary (311) to form the equivalent electric wall of the microstrip patch (310).

3. The base station antenna based on microstrip and integrated waveguide feeding according to claim 2, characterized in that, The microstrip patch (310) is a semi-circular patch or a semi-elliptical patch; The electric wall boundary (311) is the straight edge of the semi-circular patch or the semi-elliptical patch.

4. The base station antenna based on microstrip and integrated waveguide feeding according to any one of claims 1 to 3, characterized in that, The metal layer (410) has at least one open radiation side, and the second metal via array (420) is arranged around the edge of the metal layer (410) to form a semi-closed half-mode substrate integrated waveguide resonant cavity together with the ground plane (500). The half-mode substrate integrated waveguide resonant cavity radiates energy outward through the open radiation side.

5. The base station antenna based on microstrip and integrated waveguide feeding according to claim 4, characterized in that, The metal layer (410) is a rectangular layer; The second metal via array (420) is arranged along the long side (411) and the two adjacent short sides (412) of the metal layer (410) to enclose and form the half-mode substrate integrated waveguide resonant cavity.

6. The base station antenna based on microstrip and integrated waveguide feeding according to claim 4, characterized in that, The metal layer (410) is a circular layer or an elliptical layer; The second metal via array (420) is arranged along the arc segment of the circular layer or the elliptical layer.

7. The base station antenna based on microstrip and integrated waveguide feeding according to claim 4, characterized in that, The first metal via array (320) is symmetrically arranged about the midline of the microstrip patch (310); the second metal via array (420) is symmetrically arranged about the midline of the metal layer (410).

8. The base station antenna based on microstrip and integrated waveguide feeding according to any one of claims 1 to 3, characterized in that, The coupling gaps (600) have at least two spaced apart on the metal layer (410), and the at least two coupling gaps (600) are symmetrically arranged along the midline of the metal layer (410).

9. The base station antenna based on microstrip and integrated waveguide feeding according to any one of claims 1 to 3, characterized in that, It also includes a feed probe (700) that passes through the second dielectric substrate (200) and is connected to the metal layer (410) to feed the half-mode substrate integrated waveguide resonant cavity.

10. The base station antenna based on microstrip and integrated waveguide feeding according to claim 9, characterized in that, The feed probe (700) and the feed point (710) of the metal layer (410) are located on the midline of the metal layer (410), and there is a gap between the feed point (710) and the second metal via array (420).

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