Substrate integrated cavity based beam scanning array antenna

Abstract

This invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate, a middle substrate, and a lower substrate arranged sequentially from top to bottom. A slot array is disposed on the upper surface of the upper substrate, and an upper substrate integrated cavity is disposed within the upper substrate, surrounding the slot array. A feed probe is disposed on the upper surface of the middle substrate, and a middle substrate integrated cavity is disposed within the middle substrate, surrounding the feed probe. The upper substrate integrated cavity is connected to the middle substrate integrated cavity. A feed structure and a signal transmission structure are disposed on the upper surface of the lower substrate. The cavity structures of the upper and middle substrate integrated cavities of this invention can effectively suppress surface wave propagation along the substrate. Furthermore, the cavity structure surrounding the feed probe can effectively reduce feed coupling, thereby improving antenna performance.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a beam scanning array antenna based on a substrate integrated cavity. Background Technology

[0002] With the rapid development of wireless communication technology, the millimeter-wave band has attracted much attention and research due to its abundant spectrum resources. Antennas, as crucial components in wireless communication systems, are also evolving towards miniaturization, multi-polarization, and high gain. However, as the frequency increases, antenna performance becomes increasingly susceptible to the influence of material properties and process limitations. Low-Temperature Co-fired Ceramic (LTCC) technology has garnered widespread attention due to its flexible stacking process. However, the high dielectric constant of LTCC materials easily leads to surface wave excitation. These waves propagate on the material surface, increasing coupling between elements and consequently degrading antenna performance. Summary of the Invention

[0003] To address the technical problems existing in the prior art, this invention provides a beam scanning array antenna based on a substrate integrated cavity. The cavity structure of the upper and middle substrate integrated cavities can effectively suppress the propagation of surface waves along the substrate. In addition, the cavity structure formed around the feed probe can effectively reduce feed coupling, thereby improving the antenna performance.

[0004] This invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate, a middle substrate, and a lower substrate arranged sequentially from top to bottom. A slot array is disposed on the upper surface of the upper substrate, and an upper substrate integrated cavity is disposed within the upper substrate, surrounding the slot array. A feed probe is disposed on the upper surface of the middle substrate, and a middle substrate integrated cavity is disposed within the middle substrate, surrounding the feed probe. The upper substrate integrated cavity is connected to the middle substrate integrated cavity for suppressing surface... Wave propagation along the substrate; the upper surface of the lower substrate is provided with a power supply structure and a signal transmission structure. The input end of the power supply structure is connected to an external chip, the output end of the power supply structure is connected to the input end of the signal transmission structure, and the output end of the signal transmission structure is connected to the input end of the power supply probe; the power supply structure is used to transmit the signal from the external chip to the power supply probe through the signal transmission structure; the power supply probe is used to transmit the received signal to the slot array; the slot array is used to convert the received signal and radiate it to form an electromagnetic wave for beam scanning.

[0005] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the slot array is a one-drive four-slot array, the one-drive four-slot array comprising four slot elements, each slot element being rectangular in shape; the feeding mode of the one-drive four-slot array is TE. 220 mold.

[0006] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the upper substrate integrated cavity is a rectangular cavity surrounded by a plurality of first vias, and the middle substrate integrated cavity is a rectangular cavity surrounded by a plurality of second vias; the first vias and the corresponding second vias penetrate each other.

[0007] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the thickness of the middle substrate is greater than the thickness of the upper substrate, and the thickness of the upper substrate is greater than the thickness of the lower substrate.

[0008] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the signal transmission structure is a columnar coaxial structure; the coaxial structure is embedded in the middle substrate and located in the middle substrate integrated cavity; the bottom of the coaxial structure serves as the input end of the signal transmission structure, and the top of the coaxial structure serves as the output end of the signal transmission structure.

[0009] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the quasi-coaxial structure includes a plurality of third vias, and the plurality of third vias uniformly surround to form an inner coaxial structure.

[0010] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the coaxial structure, the upper substrate integrated cavity, and the middle substrate integrated cavity together form a periodic unit.

[0011] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity further includes a notch suppression via; the notch suppression via is embedded in the middle layer substrate and located in the middle layer substrate integrated cavity, and is used to suppress notches.

[0012] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity is provided, wherein the number of notch suppression vias is two, and the two notch suppression vias are symmetrically arranged on both sides of the coaxial structure.

[0013] According to the present invention, a beam scanning array antenna based on a substrate integrated cavity, for beam scanning at a frequency of 94 GHz with phi=90, the beam coverage range of the antenna is as follows: .

[0014] This invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate, a middle substrate, and a lower substrate arranged sequentially from top to bottom. A slot array is disposed on the upper surface of the upper substrate, and an upper substrate integrated cavity is disposed within the upper substrate, surrounding the slot array. A feed probe is disposed on the upper surface of the middle substrate, and a middle substrate integrated cavity is disposed within the middle substrate, surrounding the feed probe. The upper substrate integrated cavity is connected to the middle substrate integrated cavity. A feed structure and a signal transmission structure are disposed on the upper surface of the lower substrate. The cavity structures of the upper and middle substrate integrated cavities of this invention can effectively suppress surface wave propagation along the substrate. Furthermore, the cavity structure surrounding the feed probe can effectively reduce feed coupling, thereby improving antenna performance. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the beam scanning array antenna based on a substrate integrated cavity provided by the present invention.

[0017] Figure 2 It is a comparison of the standing wave characteristic curves with and without a coaxial structure.

[0018] Figure 3 It compares the gain curves with and without coaxial curves.

[0019] Figure 4 It is an array beam scanning curve.

[0020] Figure label:

[0021] 1: Upper substrate; 2: Middle substrate; 3: Lower substrate; 4: Slot array; 5: Upper substrate integrated cavity; 6: Feed probe; 7: Middle substrate integrated cavity; 8: Feed structure; 9: Signal transmission structure; 10: Notch suppression via. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] With the continuous development of communication technology, spectrum resources in the traditional microwave band are becoming increasingly scarce. To alleviate this problem, attention has gradually shifted to the higher-frequency millimeter-wave band. Millimeter waves have attracted widespread attention due to their short wavelength, wide bandwidth, and high transmission rate. In wireless communication systems, both signal transmission and reception rely on antennas. As a key component in millimeter-wave communication systems, millimeter-wave antennas have a crucial impact on the final performance of the system. In the millimeter-wave band, as the frequency increases, antenna performance is easily affected by material properties and manufacturing limitations. Because millimeter waves experience significant attenuation when propagating through air, millimeter-wave antennas require higher gain to be suitable for long-distance millimeter-wave wireless communication. Low-Temperature Co-fired Ceramic (LTCC) technology, due to its unique stacking process, enables more diverse antenna structure designs, allowing antenna layouts to expand from two-dimensional planar space to three-dimensional space, resulting in more compact antenna structures and providing the necessary conditions for the design of miniaturized millimeter-wave antennas. LTCC technology can achieve integrated three-dimensional integration of antennas and feed networks, facilitating the realization of high-gain millimeter-wave antennas. LTCC technology can also integrate antennas with other active and passive millimeter-wave devices on the same LTCC substrate, achieving system integration and modularization. In addition, LTCC technology is a parallel processing technology, allowing each layer of the substrate to be processed in parallel, resulting in high processing efficiency. Furthermore, the LTCC process facilitates automated mass production, reducing antenna product costs. However, in the millimeter-wave band, the relatively high dielectric constant of LTCC will lead to increased surface wave loss, thereby reducing antenna gain. Surface waves propagating along the antenna substrate will increase mutual coupling between antenna elements, deteriorate standing wave characteristics, narrow the antenna bandwidth, and worsen cross-polarization characteristics, limiting the improvement of antenna gain.

[0024] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the beam scanning array antenna based on a substrate integrated cavity provided by the present invention.

[0025] This invention provides a beam scanning array antenna based on a substrate integrated cavity, comprising an upper substrate 1, a middle substrate 2, and a lower substrate 3 arranged sequentially from top to bottom; a slot array 4 is disposed on the upper surface of the upper substrate 1, and an upper substrate integrated cavity 5 is disposed within the upper substrate 1, arranged around the slot array 4; a feed probe 6 is disposed on the upper surface of the middle substrate 2, and a middle substrate integrated cavity 7 is disposed within the middle substrate 2, arranged around the feed probe 6; the upper substrate integrated cavity 5 is connected to the middle substrate integrated cavity 7 for... Suppressing surface wave propagation along the substrate; the upper surface of the lower substrate 3 is provided with a power supply structure 8 and a signal transmission structure 9. The input end of the power supply structure 8 is connected to an external chip, the output end of the power supply structure 8 is connected to the input end of the signal transmission structure 9, and the output end of the signal transmission structure 9 is connected to the input end of the power supply probe 6; the power supply structure 8 is used to transmit the signal from the external chip to the power supply probe 6 through the signal transmission structure 9; the power supply probe 6 is used to transmit the received signal to the slot array 4; the slot array 4 is used to convert the received signal and radiate it to form electromagnetic waves for beam scanning.

[0026] In order to solve the technical problems existing in the prior art, the present invention provides a beam scanning array antenna based on a substrate integrated cavity, including an upper substrate 1, a middle substrate 2 and a lower substrate 3.

[0027] The upper surface of the upper substrate 1 is provided with a slot array 4. The upper substrate integrated cavity 5 is designed as a rectangle and arranged around the slot array 4. Due to its built-in cavity structure, it can effectively suppress surface waves propagating along the substrate, thereby improving the antenna performance. The resonant frequency of the upper substrate integrated cavity 5 can be obtained by formula... Calculation, where c It's the speed of light. It is the relative permittivity of the medium.

[0028] A feed probe 6 is provided on the upper surface of the middle substrate 2. The feed probe 6 has a low surface roughness to minimize signal transmission losses. The middle substrate integrated cavity 7 is arranged around the feed probe 6, and its structure and function are similar to those of the upper substrate integrated cavity 5. Due to the cavity structure surrounding the feed probe 6, the coupling of feeds between units can be effectively reduced, and the quality factor of the feed network can be improved.

[0029] The upper surface of the lower substrate 3 is provided with a power supply structure 8 and a signal transmission structure 9. The power supply structure 8 is connected to the output terminal of an external chip (such as a signal generator or RF power amplifier). The signal transmission structure 9 can adopt a coaxial design.

[0030] To achieve beam scanning, the input terminal of the feed probe 6 is connected to the output terminal of the signal transmission structure 9. By controlling the phase and amplitude of the signal generated by the external chip, the direction of the electromagnetic waves radiated by the slot array 4 can be controlled. For example, by changing the signal phase at the feed probe 6, the beam can be deflected in the horizontal plane.

[0031] In a preferred embodiment, the slot array 4 is a one-drive four-slot array, which includes four slot elements, each of which is rectangular in shape; the power supply mode of the one-drive four-slot array is TE. 220 mold.

[0032] To improve the antenna array gain and reduce overall feed loss, in this embodiment, the slot array 4 can be implemented as a one-drive four-slot array as a unit structure using aperture coupling, and based on the cavity TE 220 The module supplies power to four slotted cells, replacing the traditional power divider and reducing feeder losses caused by power combining. Each slotted cell is rectangular in shape. TE 220 This is a type of cavity resonant mode, where TE represents the transverse electric mode, and 220 indicates that the mode has two nodes in two dimensions. This mode has a specific field distribution, and the electric field distribution at the gap is particularly suitable for exciting gap radiation. By adjusting the size and material of the cavity, the resonant frequency can be precisely controlled.

[0033] In order to achieve TE 220 For modal feeding, the feed probe 6 is designed to be aligned with the center of the slot array 4 to ensure uniform energy distribution to each slot element. The feed probe 6 is connected to the mid-layer substrate integrated cavity 7 via a precisely designed coupling aperture, the position and size of which are optimized for efficient mode switching and minimal loss. During beam scanning operation, the phase difference of the electromagnetic waves radiated by the slot array 4 can be controlled by adjusting the phase of the feed probe 6, thereby achieving directional beam scanning. By precisely controlling the feed phase of each slot element, precise beam scanning in the desired direction can be achieved.

[0034] In a preferred embodiment, the upper substrate integrated cavity 5 is a rectangular cavity surrounded by a plurality of first vias, and the middle substrate integrated cavity 7 is a rectangular cavity surrounded by a plurality of second vias; the first vias and the corresponding second vias penetrate each other.

[0035] In this embodiment, the substrate integrated cavity of the antenna is designed as a rectangle to optimize the cavity's resonance characteristics and radiation modes. The cavity structure can effectively suppress the transmission of surface waves, thereby reducing the mutual coupling between units. Both the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 are surrounded by multiple vias, which play a crucial role in the construction of the cavity.

[0036] The upper substrate integrated cavity 5 is located within the upper substrate 1 and is arranged directly around the slot array 4. The cavity is surrounded by 52 first vias, each of which ensures the integrity and rigidity of the cavity.

[0037] The intermediate substrate integrated cavity 7 is located within the intermediate substrate 2 and is arranged around the feed probe 6. This cavity is surrounded by 52 second vias. The layout of the second vias is designed to maximize the resonant frequency of the cavity and minimize interference to the feed probe 6.

[0038] The design of the first and second vias considers not only the structural integrity of the cavity but also the transmission efficiency of electromagnetic waves. The vias have high conductivity, thus introducing minimal loss during RF signal transmission. Furthermore, the vias contribute to good electromagnetic shielding, thereby reducing mutual interference between different antenna elements.

[0039] To achieve efficient signal transmission, the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7 are connected through corresponding vias. This connection method allows signals to be smoothly transmitted from the feed structure 8 of the lower substrate 3 to the feed probe 6 of the middle substrate 2, and finally to the slot array 4 of the upper substrate 1. By controlling the resonant frequencies of the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7, precise control of the beam scanning direction can be achieved.

[0040] Furthermore, the resonant characteristics and radiation modes of the cavity can be further optimized by adjusting the number and layout of vias. For example, increasing the number of vias can increase the resonant frequency of the cavity, while decreasing the number of vias can decrease the resonant frequency.

[0041] In a preferred embodiment, the thickness of the middle substrate 2 is greater than the thickness of the upper substrate 1, and the thickness of the upper substrate 1 is greater than the thickness of the lower substrate 3.

[0042] In this embodiment, antenna performance is optimized through a designed substrate thickness gradient. This thickness design facilitates beamforming and control, while also improving the antenna's structural stability and mechanical strength.

[0043] The lower substrate 3 carries the feed structure 8 and the signal transmission structure 9. Its thickness is designed to be the thinnest to reduce the overall weight of the antenna while providing sufficient rigidity to support the upper structure. The upper substrate 1 is thicker than the lower substrate 3 to accommodate the placement of the slot array 4 and the integration of the upper substrate integrated cavity 5. The middle substrate 2 is the thickest of the three substrates. The middle substrate 2 not only carries the feed probe 6 and the middle substrate integrated cavity 7, but its thickness also helps to provide additional isolation, reducing crosstalk and electromagnetic interference between different layers.

[0044] The increased thickness also means that the path of the signal propagation inside the substrate is longer, which helps to adjust the phase of the signal, thereby enabling beam scanning.

[0045] In a preferred embodiment, the signal transmission structure 9 is a columnar coaxial structure; the coaxial structure is embedded in the middle substrate 2 and located in the middle substrate integrated cavity 7; the bottom of the coaxial structure serves as the input end of the signal transmission structure 9, and the top of the coaxial structure serves as the output end of the signal transmission structure 9.

[0046] In this embodiment, the signal transmission structure 9 adopts a columnar coaxial structure, the height of which matches the thickness of the intermediate substrate 2. The coaxial structure is embedded within the intermediate substrate 2 and precisely located within the intermediate substrate integrated cavity 7. This design helps protect the signal transmission path and reduces the impact of external electromagnetic interference on signal integrity. The bottom of the coaxial structure is connected to the feed structure 8 of the lower substrate 3, serving as the input terminal of the signal transmission structure 9. The top is connected to the feed probe 6 of the intermediate substrate 2, serving as the output terminal of the signal transmission structure 9.

[0047] The signal is transmitted from the external chip to the feed structure 8 of the lower substrate 3, and then through a coaxial structure to the feed probe 6 of the middle substrate 2. Energy is then transferred to the four slot antenna elements at the top via aperture coupling feeding. This transmission method utilizes the low-loss characteristics of the coaxial structure to ensure minimal signal loss during transmission. The coaxial structure design also helps suppress mode conversion and the generation of higher-order modes during signal transmission, thereby maintaining signal quality and phase consistency.

[0048] As a preferred embodiment, the coaxial-like structure includes a plurality of third vias, which are uniformly arranged around to form an inner coaxial structure.

[0049] In this embodiment, eight third vias are uniformly integrated around the mid-layer substrate 2 in a coaxial-like structure. These third vias have the same height as the mid-layer substrate 2. These third vias form an inner coaxial structure, which helps to provide a more uniform electromagnetic field distribution, thereby reducing signal loss during transmission and improving impedance matching.

[0050] In a preferred embodiment, the coaxial structure, the upper substrate integrated cavity 5, and the middle substrate integrated cavity 7 together form a periodic unit.

[0051] To achieve beam scanning of the SIC (Substrate Integrated Cavity) antenna array, the chip needs to be connected to the SIC unit via a coaxial structure. Since the coaxial structure has a ring of third vias around its perimeter, in this embodiment, the coaxial structure, together with the upper substrate integrated cavity 5 and the middle substrate integrated cavity 7, forms a single periodic unit structure to eliminate the influence of the ring of third vias on the SIC unit.

[0052] As a preferred embodiment, it also includes a notch suppression via 10; the notch suppression via 10 is embedded in the middle layer substrate 2 and located in the middle layer substrate integrated cavity 7, and is used to suppress notch waves.

[0053] Since the coaxial structure within the intermediate substrate integrated cavity 7 may cause self-resonance and degrade the gain curve, in this embodiment, the notch suppression via 10 is not only embedded within the intermediate substrate 2 but also precisely positioned within the intermediate substrate integrated cavity 7. This design helps suppress notch waves that may be caused by materials, structure, or operating frequency without affecting the cavity's resonant characteristics. The number of vias is determined based on the cavity size and the desired notch suppression effect; assumed to be four, evenly distributed within the cavity.

[0054] In a preferred embodiment, there are two notch suppression vias 10, which are symmetrically arranged on both sides of the coaxial structure.

[0055] In this embodiment, the notch suppression via 10 can be symmetrically arranged on both sides of the coaxial structure to eliminate the self-resonance that the coaxial structure may cause in the cavity, thereby eliminating the notch in the band, and thus improving the antenna gain flatness and antenna performance.

[0056] Notch waves are typically caused by electromagnetic waves encountering structural discontinuities or changes in medium properties during propagation. The notch suppression via 10 suppresses notches by providing a continuous path, reducing discontinuous signal reflections within the cavity. The introduction of the via also helps to homogenize the electromagnetic field distribution and reduce the standing wave ratio (VSWR) inside the cavity.

[0057] Please refer to Figure 2 , Figure 2 To compare the standing wave characteristics curves with and without a coaxial structure.

[0058] Please refer to Figure 3 , Figure 3 To compare the gain curves with and without coaxial curves.

[0059] Figure 2 The standing wave curves of three types of SIC elements were compared: traditional non-coaxial structure, only with coaxial structure, and with coaxial structure and notch suppression via 10. Figure 3 The gain curves for the three cases were compared. Figure 2 and 3 As can be seen, by adding the coaxial structure necessary for connecting the chip to the traditional SiC unit, it can be found that there is a significant notch in the gain passband at 95.6 and 97 GHz. Therefore, this invention proposes that the notch in the passband can be effectively eliminated by adding and adjusting the position of the vias on both sides of the coaxial structure.

[0060] As a preferred embodiment, for a 94GHz frequency with phi=90 beam scanning, the antenna's beam coverage is: .

[0061] Please refer to Figure 4 , Figure 4 This is the array beam scanning curve.

[0062] In this embodiment, the chip is connected to the SiC unit via a coaxial cable. Beam scanning can be achieved by controlling the output phase of the chip. However, to increase the overall antenna gain, the beam scanning range is sacrificed. Figure 4 The beam scanning configuration at 94 GHz with phi=90 is given, and the beam coverage range can reach [missing information]. The case where Pi=0 is similar and will not be elaborated further.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A beam scanning array antenna based on a substrate integrated cavity, characterized in that, It includes an upper substrate, a middle substrate, and a lower substrate arranged from top to bottom; The upper substrate has a slot array on its upper surface and an upper substrate integrated cavity arranged around the slot array. The middle substrate has a feed probe on its upper surface and a middle substrate integrated cavity arranged around the feed probe. The upper substrate integrated cavity is connected to the middle substrate integrated cavity to suppress surface wave propagation along the substrate. The lower substrate has a feed structure and a signal transmission structure on its upper surface. The input end of the feed structure is connected to an external chip, the output end of the feed structure is connected to the input end of the signal transmission structure, and the output end of the signal transmission structure is connected to the input end of the feed probe. The power supply structure is used to transmit the signal from the external chip to the power supply probe through the signal transmission structure. The feed probe is used to transmit the received signal to the slot array; the slot array is used to convert the received signal and radiate it into electromagnetic waves for beam scanning. The thickness of the middle substrate is greater than the thickness of the upper substrate, and the thickness of the upper substrate is greater than the thickness of the lower substrate. The signal transmission structure is a columnar coaxial structure; the coaxial structure is embedded in the middle layer substrate and located in the integrated cavity of the middle layer substrate; the bottom of the coaxial structure serves as the input end of the signal transmission structure, and the top of the coaxial structure serves as the output end of the signal transmission structure. It also includes notch suppression vias; the notch suppression vias are embedded in the middle layer substrate and located in the integrated cavity of the middle layer substrate, and are used to suppress notches.

2. The beam scanning array antenna based on a substrate integrated cavity according to claim 1, characterized in that, The slot array is a one-drive four-slot array, which includes four slot elements, each of which is rectangular in shape; the power supply mode of the one-drive four-slot array is TE. 220 mold.

3. The beam scanning array antenna based on a substrate integrated cavity according to claim 1, characterized in that, The upper substrate integrated cavity is a rectangular cavity surrounded by a number of first vias, and the middle substrate integrated cavity is a rectangular cavity surrounded by a number of second vias; the first vias and the corresponding second vias penetrate each other.

4. The beam scanning array antenna based on a substrate integrated cavity according to claim 1, characterized in that, The coaxial-like structure includes several third vias, which are uniformly arranged to form an inner coaxial structure.

5. The beam scanning array antenna based on a substrate integrated cavity according to claim 1, characterized in that, The coaxial structure, the upper substrate integrated cavity, and the middle substrate integrated cavity together form a periodic unit.

6. The beam scanning array antenna based on a substrate integrated cavity according to claim 1, characterized in that, The number of notch suppression vias is two, and the two notch suppression vias are symmetrically arranged on both sides of the coaxial structure.

7. The beam scanning array antenna based on a substrate integrated cavity according to any one of claims 1 to 6, characterized in that, For a 94GHz frequency beam scan at phi=90, the beam coverage of the antenna is: .

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