A miniaturized substrate integrated ridge waveguide filter

Abstract

The application discloses a miniaturized substrate integrated ridge waveguide filter, comprising: a dielectric substrate for providing a signal transmission medium environment; upper surface metal and lower surface metal for covering the upper surface and the lower surface respectively arranged outside the dielectric substrate; a plurality of through holes, each through hole penetrating the dielectric substrate, the upper surface metal and the lower surface metal, and a plurality of the through holes are periodically arranged according to a preset path to enclose at least one resonant cavity; wherein at least one resonant cavity is provided with a plurality of blind holes, each blind hole penetrating the upper surface metal and the part of the dielectric substrate close to the upper surface metal, or penetrating the lower surface metal and the part of the dielectric substrate close to the lower surface metal. The application can significantly reduce the volume of the filter while ensuring the high frequency response, power bearing and batch consistency of the filter.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a miniaturized substrate-integrated ridge waveguide filter. Background Technology

[0002] With the rapid popularization of 5G / 6G, IoT, wearable devices, automotive radar, and satellite communications, radio frequency (RF) systems are being designed with high frequency, multiple frequency bands, high integration, low power consumption, and extreme miniaturization. As the core of signal transmission and reception, the RF front-end must complete multi-channel signal filtering, interference suppression, and noise reduction within a limited space. Traditional discrete filters, due to their large size, significant parasitic parameters, and low integration, cannot meet the requirements of compact system layout and high performance.

[0003] Miniaturized filters have become key fundamental components supporting high-density interconnects, multi-antenna arrays, and low-power terminals, and are the core technological support for achieving high performance and miniaturization in modern wireless communication and intelligent electronic systems. To overcome the bottlenecks in size and performance, rapid iterations have been made around technologies such as MEMS filters, LTCC multilayer ceramic filters, and substrate-integrated waveguide filters. Relying on high-precision photolithography, thin-film deposition, three-dimensional stacking, and wafer-level packaging, this invention significantly reduces volume while ensuring high-frequency response, power handling, and batch consistency.

[0004] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art. Summary of the Invention

[0005] Based on the aforementioned technical problems of large size and low integration of traditional filters, the purpose of this invention is to achieve miniaturization of filters while ensuring high-frequency response, power handling and batch consistency.

[0006] To achieve the above objectives, the present invention provides a miniaturized substrate-integrated ridge waveguide filter, comprising: a dielectric substrate for providing a signal transmission medium environment; an upper surface metal and a lower surface metal, respectively covering the upper and lower surfaces disposed on the outer side of the dielectric substrate; a plurality of through holes, each through hole penetrating the dielectric substrate, the upper surface metal, and the lower surface metal, the plurality of through holes being periodically arranged according to a preset path to enclose at least one resonant cavity; wherein, at least one resonant cavity is provided with a plurality of blind holes, each blind hole penetrating the upper surface metal and a portion of the dielectric substrate near the upper surface metal, or penetrating the lower surface metal and a portion of the dielectric substrate near the lower surface metal.

[0007] The blind holes are covered with metal and arranged at periodic intervals to form at least one row of ridge-shaped structures.

[0008] The ridge structure formed by the periodic intervals of the blind holes is parallel or perpendicular to the signal transmission direction; when the ridge structure is parallel to the signal transmission direction, the ridge structure is located on the central axis of the resonant cavity or is symmetrically distributed with respect to the central axis of the resonant cavity.

[0009] Wherein, at least one row of ridge structures formed by the periodic interval arrangement of the blind holes is disposed only on the upper surface metal or only on the lower surface metal, forming a unilateral ridge structure, so that the resonant cavity constitutes a single-ridge waveguide resonant cavity; Alternatively, at least one row of ridge structures formed by the periodic spacing of the blind holes can be simultaneously disposed on the upper and lower metal surfaces to form a double-sided ridge structure, thereby making the resonant cavity a double-ridge waveguide resonant cavity.

[0010] The diameter of the blind aperture varies between 0.05 mm and 0.5 mm, and the diameter of the blind aperture must be less than λ / 20; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1 mm to 300 mm.

[0011] The horizontal spacing between adjacent blind holes varies between 0.1 mm and 1 mm, and the horizontal spacing must be less than λ / 10; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1 mm to 300 mm.

[0012] When blind vias form multiple ridge structures on a surface metal, the vertical spacing between adjacent rows must be less than λ / 10; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1mm to 300mm.

[0013] Wherein, the thickness h of the dielectric substrate must be less than λ / 4, and the depth h1 of the blind via must be less than the thickness h of the dielectric substrate. The resonant frequency of the resonant cavity is adjusted by changing the depth h1 of the blind via. Wherein, λ is the operating wavelength in the dielectric substrate, and its value ranges from 1mm to 300mm.

[0014] The preset paths of the multiple through holes are configured as rectangular paths, L-shaped paths, or closed paths with one side open, so as to form 1 / 2 mode resonant cavities, 1 / 4 mode resonant cavities, or full mode resonant cavities respectively.

[0015] The blind aperture is disposed within the 1 / 2 mode resonant cavity or the 1 / 4 mode resonant cavity; the 1 / 2 mode resonant cavity or the 1 / 4 mode resonant cavity with the blind aperture is combined with the full mode resonant cavity without the blind aperture to form a cross-coupled filter.

[0016] Compared with the prior art, the present invention has the following advantages: 1. Significant Miniaturization Effect. This invention creates a ridge structure by incorporating multiple blind holes within the resonant cavity. This drastically reduces the distance between the ridge and the opposite cavity wall, concentrating the electric field within the narrow gap and significantly increasing the equivalent capacitance, thereby effectively lowering the resonant frequency of the cavity. Under the same resonant frequency requirements, the physical size of the cavity can be greatly reduced, achieving filter miniaturization. Furthermore, the blind hole technology can be combined with 1 / 2-mode or 1 / 4-mode resonant cavity technology to achieve dual or even multiple miniaturization, further reducing the overall filter size.

[0017] 2. High design flexibility. The arrangement of blind holes is flexible and varied, and can form a single-sided ridge structure or a double-sided ridge structure. By adjusting the depth, diameter, spacing and arrangement of blind holes, the resonant frequency and operating frequency band of the cavity can be flexibly changed to adapt to the design requirements of different frequency bands and different performance indicators.

[0018] 3. Stable and reliable performance. The filter's size constraints ensure that the blind aperture array can be equivalent to a continuous metal conductive sidewall, making it almost impossible for electromagnetic waves to penetrate and leak through the gaps in the blind apertures. At the same time, it effectively controls parasitic scattering and mode distortion. The dielectric substrate thickness constraint ensures that the electric field in the thickness direction cannot form a half-wavelength standing wave distribution, strictly maintaining pure TE10 single-mode transmission and avoiding problems such as resonance peaks, difference loss jumps, and isolation degradation caused by higher-order mode coupling.

[0019] 4. Good process compatibility, suitable for mass production. The invention has a simple structure, mature processing technology, and is compatible with both blind hole and through hole processes. It does not require the introduction of additional complex processes or expensive auxiliary components, making it easy to achieve stable and repeatable mass production. It is low in cost and has good engineering application value and promotion prospects. Attached Figure Description

[0020] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings in the following description are two embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the filter model structure of the first preferred embodiment of the present invention; Figure 2 This is a three-dimensional perspective view of the filter model of the first preferred embodiment of the present invention; Figure 3 This is a graph of the S-parameters of the filter in the first preferred embodiment of the present invention. Figure 4 The frequency response curves of the filter with different parameters in the first preferred embodiment of the present invention are shown. Figure 5This is a schematic diagram of the filter model structure of the second preferred embodiment of the present invention; Figure 6 This is a three-dimensional perspective view of the filter model of the second preferred embodiment of the present invention; Figure 7 This is a graph of the S-parameters of the filter according to the second preferred embodiment of the present invention. Detailed Implementation

[0021] The following is in conjunction with the appendix Figures 1-7 The present invention provides a miniaturized substrate-integrated ridge waveguide filter with specific embodiments. The advantages and features of the invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clarify the illustration of the embodiments of the invention. Please refer to the accompanying drawings for a clearer understanding of the objectives, features, and advantages of the invention. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes and to aid those skilled in the art, and are not intended to limit the implementation conditions of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives of the invention, should still fall within the scope of the technical content disclosed in the invention.

[0022] This invention discloses a miniaturized substrate-integrated ridge waveguide filter, comprising: a dielectric substrate for providing a signal transmission medium environment; an upper surface metal and a lower surface metal, respectively covering the upper and lower surfaces disposed on the outer side of the dielectric substrate; and a plurality of through holes, each through hole penetrating the dielectric substrate and the upper and lower surface metals, wherein the plurality of through holes are periodically arranged according to a preset path to form at least one resonant cavity. At least one resonant cavity contains a plurality of blind holes, each blind hole penetrating the upper surface metal and a portion of the dielectric substrate near the upper surface metal, or penetrating the lower surface metal and a portion of the dielectric substrate near the lower surface metal.

[0023] The blind aperture is covered with metal and arranged at periodic intervals to form at least one row of ridge-shaped structures, i.e., ridge waveguides.

[0024] The blind aperture may be disposed only on the upper metal surface or only on the lower metal surface, forming a unilateral ridge structure, thereby making the resonant cavity a single-ridge waveguide resonant cavity. In a preferred embodiment, the blind aperture may be formed as a single row of ridge structures on either the upper or lower metal surface; or multiple rows of ridge structures may be formed on either the upper or lower metal surface.

[0025] The blind vias can also be simultaneously disposed on both the upper and lower metal surfaces, forming a double-sided ridge structure, thus making the resonant cavity a double-ridge waveguide resonant cavity. In a preferred embodiment, the blind vias can form one or more rows of ridge structures on the upper metal surface, and simultaneously, the blind vias can form one or more rows of ridge structures on the lower metal surface.

[0026] The ridge structure formed by the periodic intervals of the blind holes can be parallel to the signal transmission direction and can be located on the central axis of the resonant cavity or symmetrically distributed with respect to the central axis of the resonant cavity.

[0027] The ridge structure formed by the periodic intervals of the blind holes can also be perpendicular to the signal transmission direction.

[0028] The preset paths of the multiple through holes can be configured as rectangular paths, L-shaped paths, or closed paths with one side open, to form 1 / 2 mode resonant cavities, 1 / 4 mode resonant cavities, or full mode resonant cavities, respectively.

[0029] Depending on the processing technology and the operating frequency of the device, when λ is the operating wavelength in the dielectric substrate, the value of the operating wavelength λ ranges from 1 mm to 300 mm. Furthermore, the diameter of the blind aperture varies between 0.05 mm and 0.5 mm, and the diameter of the blind aperture must be less than λ / 20. This constraint effectively prevents electromagnetic waves from scattering, thereby distorting the electromagnetic field distribution on the sidewalls, leading to problems such as effective width distortion and deterioration of return loss.

[0030] Furthermore, the horizontal spacing between adjacent blind holes varies between 0.1 mm and 1 mm, and the horizontal spacing must be less than λ / 10. When blind holes form multiple rows of ridge-shaped structures on a surface metal, the vertical spacing between two adjacent rows must also be less than λ / 10.

[0031] By optimizing the design of the blind aperture diameter and spacing, the blind aperture is ensured to be equivalent to a solid metal waveguide sidewall, which can effectively suppress electromagnetic leakage of the sidewall, ensure the validity of the substrate integrated ridge waveguide filter model, and suppress parasitic scattering and mode distortion.

[0032] Furthermore, such as Figure 2 As shown, the thickness h of the dielectric substrate needs to be less than λ / 4, and the blind via depth h1 needs to be less than the thickness h of the dielectric substrate. Simultaneously, the resonant frequency of the resonant cavity can be adjusted by changing the blind via depth h1, thereby altering the filter response and achieving adjustment of the filter frequency and bandwidth.

[0033] The constraint on the thickness of the dielectric substrate ensures that the electromagnetic field size in the thickness direction is less than half a wavelength, and the electromagnetic field is approximately uniform along the thickness direction, strictly maintaining pure TE10 single-mode transmission. If the dielectric substrate is too thick, high-order mode coupling will form inside the substrate-integrated ridge waveguide, leading to multimode transmission effects, resulting in resonance peaks, difference loss jumps, and deterioration of isolation. If the depth of the blind via is greater than the thickness of the dielectric substrate, the blind via becomes a through via, which will greatly change the transmission mode of the substrate-integrated ridge waveguide filter, causing the filter to fail.

[0034] Furthermore, the blind aperture can be combined with 1 / 2-mode and 1 / 4-mode resonant cavities formed by multiple through apertures to further miniaturize the filter. The 1 / 2-mode and 1 / 4-mode resonant cavities with blind apertures can be combined with full-mode resonant cavities without blind apertures to form a cross-coupled filter. The cross-coupling method can make the two transmission paths of the signal have equal amplitude and a phase difference of 180° at a certain out-of-band frequency, thereby causing complete wave destructive interference, forming a transmission zero, and improving the rectangular coefficient of the filter.

[0035] The dielectric substrate can be fabricated using processes such as glass vertical interconnect vias (TGV), high-frequency microwave circuit boards, low-temperature co-fired multilayer ceramics (LTCC), high-temperature co-fired multilayer ceramics (HTCC), and microelectromechanical systems (MEMS).

[0036] The above structure can be used to flexibly change the resonant frequency of the resonant cavity. By fabricating blind vias on the dielectric substrate of the filter to form a ridge structure, the distance between the cavity walls is drastically reduced, and the electric field is compressed into the narrow gaps, significantly increasing the equivalent capacitance. This is equivalent to applying a capacitive boundary load at the point of strongest electric field. Under the same external dimensions, the effective electric wall length is significantly increased, and the resonant frequency is effectively reduced. The depth of the blind via is the size of the equivalent capacitance. By adjusting the depth of the blind via, the resonant frequency can be adjusted. The deeper the via, the lower the resonant frequency, ultimately achieving miniaturization of passive devices such as filters.

[0037] The first preferred embodiment of the present invention, as follows: Figure 1As shown, a miniaturized filter based on glass-based TGV technology is disclosed, comprising a glass-based dielectric substrate 1, the upper and lower surfaces of which are respectively covered with an upper surface metal 2 and a lower surface metal 3; multiple through holes 4, each through hole 4 penetrating the glass-based dielectric substrate 1 and the upper and lower surface metals 2 and 3, forming a resonant cavity through periodic arrangement; an upper row of blind vias 5, which are disposed within the resonant cavity and located on the upper surface metal 2, i.e., the upper row of blind vias 5 penetrates the upper surface metal 2 and part of the dielectric substrate 1; and a lower row of blind vias 6, which are disposed within the resonant cavity and located on the lower surface metal 3, i.e., the lower row of blind vias 6 penetrates the lower surface metal 3 and part of the dielectric substrate 1; the two ridge structures formed by the arrangement of the upper row of blind vias 5 and the lower row of blind vias 6 are parallel to the signal transmission direction and symmetrically distributed about the central axis of the cavity; finally, due to the arrangement of the upper row of blind vias 5 and the lower row of blind vias 6, the resonant cavity constitutes a double-ridge waveguide resonant cavity 7. The glass-based dielectric substrate 1 is fabricated using glass TGV technology.

[0038] like Figure 2 and Figure 3 As shown, the center frequency of operation in this embodiment 1 is 90GHz. The dielectric constant of the substrate is approximately 4. The operating wavelength λ in the substrate is 1.67mm. The diameter of the blind via is 0.08mm. The horizontal spacing d between adjacent blind vias is 0.15mm, which meets the requirements that the horizontal spacing is less than λ / 10 and the diameter of the blind via is less than λ / 20. The thickness h of the substrate is 0.4mm, which meets the requirement that it is less than λ / 4. The depth h1 of the blind via is 0.1mm, which meets the requirement that it is less than the substrate thickness h.

[0039] like Figure 4 As shown, in the first preferred embodiment of the present invention, by changing the blind aperture depth h1 to vary it between 0.001 mm and 0.2 mm, the operating center frequency of the filter can be adjusted from 76.7 GHz to 91 GHz, thereby achieving the purpose of changing the filter response.

[0040] The second preferred embodiment of the present invention, as follows: Figure 5As shown, a miniaturized cross-coupled filter based on glass-based TGV technology is disclosed, including a glass-based dielectric substrate 1, the upper and lower surfaces of which are respectively covered with an upper surface metal 2 and a lower surface metal 3; multiple through holes 4, each through hole 4 penetrating the glass-based dielectric substrate 1 and the upper and lower surface metals 2 and 3, forming a full-mode resonant cavity and a half-mode resonant cavity through periodic arrangement; an upper row of blind vias 5, which are disposed in the half-mode resonant cavity and located on the upper surface metal 2, that is, the upper row of blind vias 5 penetrates the upper surface metal 2 and part of the dielectric substrate 1; the upper row of blind vias 5 are arranged to form a double-row ridge structure, and each row of ridge structure is parallel to the signal transmission direction, ultimately forming a single-ridge waveguide; due to the arrangement of the upper row of blind vias 5, the half-mode resonant cavity and the single-ridge waveguide together constitute a hybrid resonant cavity 6 and a hybrid resonant cavity 7; a normal resonant cavity 8, which is the full-mode resonant cavity without the single-ridge waveguide. The glass-based dielectric substrate 1 is implemented using glass TGV technology.

[0041] like Figure 6 and Figure 7 As shown, the center frequency of operation in this embodiment 2 is 63GHz. The dielectric constant of the substrate is approximately 4. The operating wavelength λ in the substrate is 2.38mm. The diameter of the blind via is 0.09mm. The horizontal spacing d between adjacent blind vias is 0.2mm. The vertical spacing d1 between two adjacent rows of ridge structures is 0.2mm, which satisfies the requirements that both the horizontal and vertical spacings are less than λ / 10 and the diameter of the blind via is less than λ / 20. The thickness h of the substrate is 0.4mm, which satisfies the requirement that it is less than λ / 4. The depth h1 of the blind via is 0.1mm, which satisfies the requirement that it is less than the substrate thickness h.

[0042] The dimensions of the hybrid resonators 6 and 7, constructed from a 1 / 2-mode resonator and a single-ridge waveguide, are both 1.38 mm * 1.38 mm, while the dimensions of the ordinary resonator 8 are 2.76 mm * 1.26 mm. The area of ​​a single hybrid resonator is 55% of the area of ​​an ordinary resonator, significantly reducing the size of the resonator.

[0043] The above description is only a specific embodiment of the present invention. For dimensions and structures not described in detail, it should be understood that they are implemented using common equipment and methods already available in the art.

[0044] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0046] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A miniaturized substrate-integrated ridge waveguide filter, characterized in that, include: Dielectric substrate, used to provide a signal transmission medium environment; The upper surface metal and the lower surface metal respectively cover the upper surface and the lower surface disposed on the outer side of the dielectric substrate; Multiple through holes, each penetrating the dielectric substrate, the upper surface metal, and the lower surface metal, are arranged periodically according to a preset path to form at least one resonant cavity; In this embodiment, at least one of the resonant cavities is provided with a plurality of blind holes, each of which penetrates the upper surface metal and a portion of the dielectric substrate near the upper surface metal, or penetrates the lower surface metal and a portion of the dielectric substrate near the lower surface metal.

2. The miniaturized substrate-integrated ridge waveguide filter according to claim 1, characterized in that, The blind holes are lined with metal and arranged at periodic intervals to form at least one row of ridge-shaped structures.

3. The miniaturized substrate-integrated ridge waveguide filter according to claim 2, characterized in that, The ridge-shaped structure formed by the periodic intervals of the blind holes is parallel or perpendicular to the signal transmission direction; When the ridge structure is parallel to the signal transmission direction, the ridge structure is located on the central axis of the resonant cavity or is symmetrically distributed with respect to the central axis of the resonant cavity.

4. The miniaturized substrate-integrated ridge waveguide filter according to claim 3, characterized in that, The blind holes are periodically arranged to form at least one row of ridge structures, which are disposed only on the upper surface metal or only on the lower surface metal, forming a unilateral ridge structure, so that the resonant cavity constitutes a single-ridge waveguide resonant cavity. Alternatively, at least one row of ridge structures formed by the periodic spacing of the blind holes can be simultaneously disposed on the upper and lower metal surfaces to form a double-sided ridge structure, thereby making the resonant cavity a double-ridge waveguide resonant cavity.

5. The miniaturized substrate-integrated ridge waveguide filter according to claim 4, characterized in that, The diameter of the blind aperture varies between 0.05 mm and 0.5 mm, and the diameter of the blind aperture must be less than λ / 20; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1 mm to 300 mm.

6. The miniaturized substrate-integrated ridge waveguide filter according to claim 4, characterized in that, The horizontal spacing between adjacent blind holes varies between 0.1 mm and 1 mm, and the horizontal spacing must be less than λ / 10; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1 mm to 300 mm.

7. The miniaturized substrate-integrated ridge waveguide filter according to claim 4, characterized in that, When blind vias form multiple rows of ridge structures on a surface metal, the vertical spacing between two adjacent rows must be less than λ / 10; where λ is the operating wavelength in the dielectric substrate, and its value ranges from 1 mm to 300 mm.

8. The miniaturized substrate-integrated ridge waveguide filter according to claim 4, characterized in that, The thickness h of the dielectric substrate must be less than λ / 4, and the depth h1 of the blind via must be less than the thickness h of the dielectric substrate. The resonant frequency of the resonant cavity is adjusted by changing the depth h1 of the blind via. Wherein, λ is the operating wavelength in the dielectric substrate, and its value ranges from 1mm to 300mm.

9. The miniaturized substrate-integrated ridge waveguide filter according to claim 1, characterized in that, The preset paths of the multiple through holes are configured as rectangular paths, L-shaped paths, or closed paths with one side open, so as to form 1 / 2 mode resonant cavities, 1 / 4 mode resonant cavities, or full mode resonant cavities respectively.

10. The miniaturized substrate-integrated ridge waveguide filter according to claim 9, characterized in that, The blind aperture is disposed within the 1 / 2 mode resonant cavity or the 1 / 4 mode resonant cavity; the 1 / 2 mode resonant cavity or the 1 / 4 mode resonant cavity with the blind aperture is combined with the full mode resonant cavity without the blind aperture to form a cross-coupled filter.

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