Band elimination filter based on printing ridge gap waveguide

Abstract

The invention discloses a band elimination filter based on a printed ridge gap waveguide. The band elimination filter comprises a bottom dielectric substrate; a periodic mushroom unit; a metal top plate; the microstrip line transmission line is placed on the upper surface of the bottom dielectric substrate; the periodic mushroom units are uniformly arranged on the two sides of the feed network, M columns and N rows are respectively arranged on the left and right sides in the wide edge direction of the dielectric substrate, M and N are integers, M is greater than or equal to 2, and N is greater than or equal to 5. The energy in the band elimination filter is transmitted in the air gap, so that the dielectric loss can be effectively reduced, the transmission efficiency is improved, especially in a millimeter wave frequency band, the structure is simple, the processing difficulty is low, and the miniaturization and high-efficiency design of a millimeter wave system can be realized.

Description

Technical Field

[0001] The invention relates to the field of radio frequency microwave technology, and in particular to a band-stop filter based on a printed ridge gap waveguide. Background Art

[0002] As an important electronic device or circuit, filters play a key role in electronic signal processing and communication systems. During signal transmission, signals are often affected by various noises and interferences, which can seriously reduce the quality and accuracy of signals. Filters improve the quality of signals by selectively filtering out these noises and interference signals. For example, in radio communication systems, filters can filter out interference signals in different frequency bands, thereby improving communication quality and reliability. In radar and radio systems, filters are used to suppress stray signals, filter out interference, and other tasks, which helps to improve the resolution and reliability of signals and ensure the normal operation of the system.

[0003] In the related art, the microstrip gap waveguide used in the transmission process will produce a certain amount of electromagnetic energy loss due to the influence of structural characteristics and dielectric materials. This loss will not only reduce the transmission efficiency of the signal, but also may affect the overall performance of the system. Or the gap waveguide with a metal structure is relatively heavy because it uses all metal or metal as the main component material, which is not conducive to high-density integration and miniaturization design. Therefore, a band-stop filter that can solve the loss, can be miniaturized, and is easy to integrate is needed to be better applied in various fields. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the first object of the present invention is to provide a band-stop filter based on a printed ridge gap waveguide.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention proposes a band-stop filter based on a printed ridge gap waveguide, comprising: a substrate; a metal bottom plate, the metal bottom plate is attached to the lower surface of the substrate; a plurality of pads, the plurality of pads are attached to the upper surface of the substrate; a metal column, the metal column connects the plurality of pads and the metal bottom plate; a metal top plate, the metal top plate is arranged in parallel at a preset distance directly above the plurality of pads; a feeding part, the feeding part adopts printed ridge gap waveguide feeding, the feeding part is a metal microstrip line, the metal microstrip line divides the plurality of pads into two parts on average, the plurality of pads are arranged in M ​​columns on the left and right along the wide side direction of the substrate, and in N rows along the long side direction of the substrate, and are arranged on both sides of the metal microstrip line with a preset period, the metal microstrip line is connected to the metal bottom plate through the metal column, wherein M and N are integers, and M≥2, N≥5.

[0006] According to the band-stop filter based on the printed ridge gap waveguide of the embodiment of the present invention, the substrate, the metal bottom plate, the pad, and the metal column are periodically combined to form an equivalent ideal magnetic conductor, and the metal top plate is an ideal electrical conductor. The two conductors are placed in parallel and do not touch each other, and an electromagnetic band gap structure is formed at this time. The electromagnetic wave is confined to the area of ​​the electrical conductor and the magnetic conductor and can only propagate along the metal ridge, that is, the electromagnetic wave propagates in the air gap between the metal top plate and the metal microstrip line. As a result, the band-stop filter can transmit energy or electromagnetic waves in the air gap between the PEC (Perfect Electrical Conductor) and the PMC (Perfect Magnetic Conductor). This propagation mode can reduce dielectric loss and improve transmission efficiency. The effect is more significant in the millimeter wave and even terahertz frequency bands, and the structure is simple and the processing difficulty is low, which is conducive to the miniaturization and high-density integration of the system.

[0007] In addition, the band-stop filter based on the printed ridge gap waveguide according to the above embodiment of the present invention may also have the following additional technical features:

[0008] According to an embodiment of the present invention, the substrate is rectangular and has a thickness of 0.8-1.2 mm.

[0009] According to an embodiment of the present invention, the material of the substrate is a ceramic-filled reinforced material, and the relative dielectric constant of the ceramic-filled reinforced material is 3 and the relative magnetic permeability is 1.

[0010] According to one embodiment of the present invention, the length and width of the metal bottom plate and the metal top plate are the same as those of the substrate, the height of the metal column is the same as the thickness of the substrate, and the length of the metal microstrip line is the same as the length of the substrate.

[0011] According to an embodiment of the present invention, the metal bottom plate, the metal top plate, the pad, the metal column and the metal microstrip line are all made of copper, silver or gold of a printed circuit.

[0012] According to one embodiment of the present invention, the shape of the pad is a rectangle with equal length and width, the length and width of the pad are smaller than the preset period, and the horizontal and vertical distances between adjacent pads are the difference between the preset period and the length or width of the pad.

[0013] According to an embodiment of the present invention, the band-stop filter further includes a resonance unit, the resonance unit replaces at least one of the plurality of pads, the resonance unit is a circular pad, and a diameter of the resonance unit is smaller than a length of the pad.

[0014] According to an embodiment of the present invention, the resonance unit is adjacent to the metal microstrip line, and when there are multiple resonance units, the multiple resonance units are arranged on the same side of the metal microstrip line.

[0015] According to one embodiment of the present invention, the equivalent inductance between the resonant unit and the metal base plate and the metal column is determined according to the following formula:

[0016]

[0017] Wherein, L is the equivalent inductance, u0 is the vacuum magnetic permeability, h1 is the distance between the resonant unit and the metal base plate, p is the period of the pad, d is the diameter of the metal column, and a is the radius of the metal column.

[0018] According to one embodiment of the present invention, the equivalent capacitance between the resonant unit and the metal top plate is determined according to the following formula:

[0019] C=kC0

[0020]

[0021] Among them, C is the equivalent capacitance after considering the edge effect, C0 is the ideal parallel plate capacitance, ε0 is the vacuum dielectric constant, hair is the distance between the resonant unit and the metal top plate, S is the area of ​​the resonant unit, r is the radius of the resonant unit, and b is the aspect ratio, which is the ratio of the distance hair between the resonant unit and the metal top plate to the radius r of the resonant unit.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] The widely used microstrip gap waveguide structure or metal structure at this stage has high loss or low integration. The present invention adopts a printed ridge gap waveguide structure. The printed ridge gap waveguide is completely shielded by metal, which reduces the radiation leakage of electromagnetic waves. No electrical contact is required between the two layers of parallel plates, so it has lower transmission loss and reduces the possibility of internal interference. The printed ridge gap waveguide has a simpler structure and low processing difficulty. It can be well integrated with other planar circuit structures (such as microstrip lines, substrate integrated waveguides, etc.), which is conducive to miniaturization and high-density integration of the system. The present invention adjusts the shape and size of the pad on the upper surface of the substrate while keeping the rest of the structure unchanged, introduces a resonant cavity to form a defect resonance, and thus achieves filtering. Each pad corresponds to a resonance point, thereby increasing the filtering band. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a band-stop filter based on a printed ridge gap waveguide according to an embodiment of the present invention;

[0025] Figure 2 is a schematic structural diagram of a basic unit according to an embodiment of the present invention;

[0026] Figure 3 is a schematic top view of a band-stop filter without a metal top plate according to an embodiment of the present invention;

[0027] Figure 4 for Figure 3 The corresponding S parameter diagram of the band-stop filter;

[0028] Figure 5 A schematic top view of a band-stop filter having a resonant unit and a metal-free top plate according to an embodiment of the present invention;

[0029] Figure 6 for Figure 5 The corresponding S parameter diagram of the band-stop filter;

[0030] Figure 7 A schematic top view of a band-stop filter having two resonant units and a metal-free top plate according to an embodiment of the present invention;

[0031] Figure 8 for Figure 7 The corresponding S-parameter diagram of the band-stop filter.

[0032] Reference numerals:

[0033] Substrate 1; metal bottom plate 2; pad 3; metal column 4; metal microstrip line 5; metal top plate 6; resonant unit 7. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0035] Gap waveguide technology is a technology that uses electromagnetic bandgap structures to achieve electromagnetic wave transmission. It introduces a specific periodic structure (such as a metal column array) into the waveguide structure to form a bandgap for electromagnetic waves in a specific frequency band, thereby achieving effective control of electromagnetic wave propagation.

[0036] The commonly used microstrip gap waveguide structure will produce a certain amount of electromagnetic energy loss during the transmission process due to the influence of structural characteristics and dielectric materials. This loss will not only reduce the transmission efficiency of the signal, but may also affect the overall performance of the system. Once the structure of the microstrip gap waveguide is determined and processed, its electrical properties (such as resonant frequency, bandwidth, etc.) are difficult to fine-tune, which limits its use in application scenarios that require high precision and flexible tuning. For excellent metal gap waveguide structures, high processing accuracy is required, especially in high-frequency applications, there are strict requirements on the smoothness, parallelism and uniformity of the metal surface. This increases the difficulty and complexity of processing. At the same time, due to the limitations of its volume and weight, as well as compatibility issues with other circuit structures, the metal structure gap waveguide may face certain difficulties in system integration, which reduces the overall integration and design flexibility of the system.

[0037] In order to solve the above technical problems, the band-stop filter based on the printed ridge gap waveguide of the embodiment of the present invention adopts a printed ridge gap waveguide structure, which is completely shielded by metal, reducing the radiation leakage of electromagnetic waves, and thus has a lower transmission loss, making the energy transmission efficiency high. Compared with the traditional pin-type slot gap waveguide, the ridge gap waveguide has a simpler structure, lower processing difficulty, and its assembly process is relatively convenient, which is conducive to reducing production costs and improving production efficiency, and realizing miniaturization and high-density integration of the system.

[0038] The following describes a band-stop filter based on a printed ridge gap waveguide according to an embodiment of the present invention with reference to the accompanying drawings.

[0039] like Figure 1 As shown, the band-stop filter based on printed ridge gap waveguide according to an embodiment of the present invention comprises: a substrate 1, a metal bottom plate 2, a plurality of pads 3, a metal column 4, a metal top plate 6 and a feeding part.

[0040] The substrate 1 is a bottom dielectric substrate, the metal bottom plate 2 is attached to the lower surface of the substrate 1, a plurality of pads 3 are attached to the upper surface of the substrate 1, and the metal pillars 4 connect the plurality of pads 3 and the metal bottom plate 2. The metal top plate 6 is arranged in parallel and directly above the plurality of pads 3 at a preset distance, wherein the preset distance is set according to the wavelength of the electromagnetic wave, for example, the preset distance may range from 0.22 to 0.42 mm, and the medium between the plurality of pads 3 and the metal top plate 6 is air.

[0041] The feeding part adopts printed ridge gap waveguide feeding, and the feeding part is a metal microstrip line 5. The metal microstrip line 5 divides the multiple pads 3 into two parts evenly. The multiple pads 3 have M columns on the left and right along the wide side direction of the substrate 1, and N rows along the long side direction of the substrate 1. They are arranged on both sides of the metal microstrip line 5 with a preset period. The metal microstrip line 5 is connected to the metal base plate 2 through a metal column 4, where M and N are integers, and M≥2, N≥5. The preset period can be calibrated according to the actual situation, and M and N can be set according to the size of the band-stop filter. For example, in Figure 3 In the band-stop filter shown, M is 3 and N is 11.

[0042] Specifically, the printed ridge gap waveguide technology is based on parallel plate waveguides, one of which is an ideal electrical conductor and the other is designed as a textured periodic surface that behaves as an ideal magnetic conductor. Therefore, it is possible to achieve no conductive contact between the two surfaces, i.e., a cost-effective manufacturing process and a completely open structure. In addition, because the signal is transmitted in the air gap between the ideal electrical conductor and the guiding structure that introduces the ideal magnetic conductor, the dielectric loss is negligible. That is, when the distance between the two plates is equal to or less than a quarter wavelength, the space between the parallel plates behaves as a high impedance region, which can suppress the propagation of parallel plate waves within the desired frequency range. The waveguide structure in the gap waveguide technology is realized by introducing ridges, grooves or microstrip lines in an ideal magnetic conductor, in this way, the propagating wave is confined to the air gap between the PEC and the introduced guiding element.

[0043] Specifically, Figure 2 As shown, the mushroom-shaped structural unit consists of a metal bottom plate 2, a pad 3, and a metal column 4. The mushroom-shaped structural unit is embedded in the substrate. The mushroom-shaped structural unit can form an equivalent ideal magnetic conductor through periodic combination. The metal top plate 6 is an ideal electric conductor. The two conductors are placed in parallel and do not touch each other. At this time, an electromagnetic band gap structure is formed. The electromagnetic wave is confined to the area of ​​the electric conductor and the magnetic conductor and can only propagate along the metal ridge, that is, the electromagnetic wave propagates in the air gap between the metal top plate 6 and the metal microstrip line 5. This non-contact propagation mode reduces dielectric loss and improves transmission efficiency. It can be applied to various fields such as microwave, millimeter wave or 5G.

[0044] According to one embodiment of the present invention, the substrate 1 is rectangular, and the thickness of the substrate 1 is 0.8-1.2 mm. Preferably, the thickness of the substrate 1 can be 1 mm. The length and width of the substrate 1 can be set according to the size of the device, for example, the length L of the substrate 1 can be 16.5 mm, and the width W of the substrate 1 can be 10.5 mm.

[0045] According to an embodiment of the present invention, the material of the substrate 1 is a ceramic-filled reinforced material, and the ceramic-filled reinforced material has a relative dielectric constant of 3 and a relative magnetic permeability of 1.

[0046] According to one embodiment of the present invention, the length and width of the metal bottom plate 2 and the metal top plate 6 are the same as those of the substrate 1 , the height of the metal column 4 is the same as the thickness of the substrate 1 , and the length of the metal microstrip line 5 is the same as that of the substrate 1 .

[0047] For example, if Figure 3 In the band-stop filter shown, the thickness h1 of the substrate 1 is 1 mm, the length L of the substrate 1 is 16.5 mm, and the width W of the substrate 1 is 10.5 mm. Then, the length of the metal bottom plate 2 and the metal top plate 6 is 16.5 mm, the width is 10.5 mm, the height of the metal column 4 is 1 mm, the diameter of the metal column 4 is 0.25 mm, the length of the metal microstrip line 5 is 16.5 mm, and the width W1 of the metal microstrip line 5 is 1.18 mm.

[0048] According to an embodiment of the present invention, the metal bottom plate 2 , the metal top plate 6 , the pad 3 , the metal column 4 and the metal microstrip line 5 are all made of copper, silver or gold of a printed circuit.

[0049] For cost considerations, the material of the metal bottom plate 2, the metal top plate 6, the pad 3, the metal column 4 and the metal microstrip line 5 is preferably the copper foil of the printed circuit, and the thickness of the copper foil is usually 0.035 mm. In other words, the thickness of the metal bottom plate 2, the metal top plate 6, the pad 3 and the metal microstrip line 5 is 0.035 mm.

[0050] According to one embodiment of the present invention, the shape of the pad 3 is a rectangle with equal length and width, the length and width of the pad 3 are smaller than the preset period, and the horizontal and vertical distances between adjacent pads 3 are the difference between the preset period and the length or width of the pad 3.

[0051] For example, if Figure 3 As shown, the length W of pad 3 pad The width W of pad 3 is 1.26 mm. pad The period P of the pads 3 is 1.26 mm, and the period P of the pads 3 is 1.5 mm, so the horizontal and vertical distances between adjacent pads 3 are 0.24 mm. There are periodically arranged pads 3 and metal pillars 4 on the substrate 1, with 3 columns on the left and right along the wide side of the substrate 1 and 11 rows along the long side, with a period P of 1.5 mm on both sides of the metal microstrip line 5. Figure 3 The S parameter diagram of the band-stop filter based on printed ridge gap waveguide is shown in Figure 4 As shown, the adopted electromagnetic bandgap structure has good pass rate and extremely low loss, and the electromagnetic wave passes through the band-stop filter with extremely low loss.

[0052] According to one embodiment of the present invention, Figure 5 and Figure 7As shown, the band-stop filter further includes a resonance unit 7 , which replaces at least one of the plurality of pads 3 . The resonance unit 7 is a circular pad, and a diameter of the resonance unit 7 is smaller than a length of the pad 3 .

[0053] For example, when the number of the resonance unit 7 is 1, Figure 5 As shown, a rectangular pad 3 is replaced by a resonant unit 7. The resonant unit 7 is a circular pad. The diameter d1 of the resonant unit 7 is 0.65 mm, which is smaller than the length W of the pad 3. pad It is 1.26mm. At this time, the structure destroys the original periodic structure and forms a resonant cavity. When the electromagnetic wave passes through, the wave at the corresponding frequency point will be confined to the defect resonance and cannot pass through, thus forming a filtering characteristic. Figure 5 The S parameter diagram of the band-stop filter based on printed ridge gap waveguide is shown in Figure 6 As shown, when the electromagnetic wave passes through the structure, a resonance point is formed at 26.5 GHz. When the electromagnetic wave passes through, the wave at 26.5 GHz will be confined to the defect resonance and cannot pass through, achieving a good filtering effect. It should be understood that the filtering frequency can be changed by adjusting the size of the resonance unit 7, and a corresponding filter can be designed.

[0054] When the number of the resonant units 7 is 2, as Figure 7 As shown, the two rectangular pads 3 are replaced by the resonance unit 7, and the diameter d2 is 0.6mm. Similarly, the original periodic structure changes at this time, and the central resonance frequency is 27.27GHz. When two resonators of the same frequency are close to each other, mutual coupling will occur, and they will split into two resonance points, thereby expanding the stopband width, so that a resonance band can be formed to filter a section of electromagnetic wave frequency. Figure 7 The S parameter diagram of the band-stop filter based on printed ridge gap waveguide is shown in Figure 8 As shown, by introducing two defect resonances, good filtering is formed near 27.27 GHz. The stopband is widened by using two resonance units 7 to split the resonance points, forming a resonance band, and forming good filtering characteristics for electromagnetic waves in the frequency range of 27.1 GHz to 27.3 GHz. It should be understood that the spacing between the two pads 3 can be adjusted to change the range of the stopband, and a high-order filter can also be formed for the resonance unit 7 by adjusting multiple pads 3.

[0055] It should be noted that the resonance unit 7 is a reduced-size pad 3, and a circular structure will have better performance at high frequencies. For the straight-through structure, it is equivalent to use the resonance unit 7 at any position, but in order to avoid the influence of the port on the resonance frequency, the resonance unit 7 is generally placed in the middle.

[0056] It is important to understand that S parameters, or Scatter parameters, are parameters used to describe the characteristics of RF circuit networks and are widely used in microwave and RF fields. S parameters can provide information about signal reflection and transmission in the context of band-stop filters. Figure 4 , Figure 6 and Figure 8 The meaning of the S parameters is as follows:

[0057] S1,1 (input reflection coefficient): indicates the reflection coefficient of port 1 when port 2 is matched; a low S1,1 value means that the signal reflected at port 1 is small and the signal transmission efficiency is high.

[0058] S2,1 (forward transmission coefficient): indicates the forward transmission coefficient from port 1 to port 2 when port 2 is matched. This parameter describes the efficiency of signal transmission from port 1 to port 2. The larger the value of S2,1, the better. Ideally, it is 0dB, indicating lossless transmission.

[0059] According to an embodiment of the present invention, the resonance unit 7 is adjacent to the metal microstrip line 5 , and in the case that there are multiple resonance units 7 , the multiple resonance units 7 are arranged on the same side of the metal microstrip line 5 .

[0060] Specifically, the closer the resonant unit 7 is to the metal microstrip line 5, the better the transmission effect of the electromagnetic wave, so the resonant unit 7 is arranged in a row adjacent to the metal microstrip line 5. In addition, when there are multiple resonant units 7, they need to be placed on the same side of the microstrip line to adjust the resonant band and expand the stopband range. If they are placed on both sides of the transmission line, the resonant band cannot be formed.

[0061] Below Figure 5 The relevant parameters of the corresponding band-stop filter explain in detail the calculation process of the center frequency of the resonance unit 7.

[0062] According to one embodiment of the present invention, the equivalent inductance between the resonant unit 7 and the metal base plate 2 and the metal column 4 is determined according to the following formula:

[0063]

[0064] Wherein, L is the equivalent inductance, u0 is the vacuum magnetic permeability, h1 is the distance between the resonant unit 7 and the metal base plate 2, p is the period of the pad 3, d is the diameter of the metal column 4, and a is the radius of the metal column 4.

[0065] According to one embodiment of the present invention, the equivalent capacitance between the resonant unit 7 and the metal top plate 6 is determined according to the following formula:

[0066]

[0067] Among them, C is the equivalent capacitance after considering the edge effect, C0 is the ideal parallel plate capacitance, ε0 is the vacuum dielectric constant, hair is the distance between the resonance unit 7 and the metal top plate 6, S is the area of ​​the resonance unit 7, d1 is the diameter of the resonance unit 7, r is the radius of the resonance unit 7, and b is the aspect ratio, which is the ratio of the distance hair between the resonance unit 7 and the metal top plate 6 to the radius r of the resonance unit 7.

[0068] Specifically, the calculation formula of the center frequency f of the resonance unit 7 is as follows:

[0069]

[0070] The charged ions between the resonant unit 7 and the metal bottom plate 2 will flow along the metal pillar 4 and the metal bottom plate 2, and this effect can be equivalent to the inductance L. The resonant unit 7 and the metal top plate 6 can be equivalent to a parallel plate capacitor. Figure 5 The relevant parameters of the corresponding band-stop filter: the distance h1 between the resonance unit 7 and the metal bottom plate 2 is 1mm, the period p of the pad 3 is 1.5mm, the diameter d of the metal column 4 is 0.25mm, the distance hair between the resonance unit 7 and the metal top plate 6 is 0.32mm, and the diameter d1 of the resonance unit 7 is 0.65mm are substituted into the above formulas (1) and (2) respectively to obtain the equivalent inductance L and the equivalent capacitance C. Then, the equivalent inductance L and the equivalent capacitance C are substituted into the above formula (3) to obtain the center frequency f of the resonance unit 7.

[0071] In summary, the present invention analyzes and designs a band-stop filter based on a printed ridge gap waveguide, and simulates an S-parameter curve, and obtains that the structure can change the filtering characteristics of electromagnetic waves of different frequencies when the pad size is changed. The band-stop filter structure of the present invention can be equivalent to an ideal electric conductor and an ideal magnetic conductor. The magnetic conductor can be formed by a periodic electromagnetic structure, and then the electromagnetic wave is propagated through the air gap, which has the characteristics of low loss and low cost.

[0072] In summary, according to the band-stop filter based on the printed ridge gap waveguide of the embodiment of the present invention, the substrate, the metal bottom plate, the pad, and the metal column are periodically combined to form an equivalent ideal magnetic conductor, and the metal top plate is an ideal electric conductor. The two conductors are placed in parallel and do not touch each other, and an electromagnetic band gap structure is formed at this time. The electromagnetic wave is confined to the area of ​​the electric conductor and the magnetic conductor and can only propagate along the metal ridge, that is, the electromagnetic wave propagates in the air gap between the metal top plate and the metal microstrip line. As a result, the band-stop filter can enable energy or electromagnetic waves to be transmitted in the air gap between the PEC and the PMC. This propagation mode can reduce dielectric loss and improve transmission efficiency. The effect is more significant in the millimeter wave and even terahertz frequency bands, and the structure is simple and the processing difficulty is low, which is conducive to the miniaturization and high-density integration of the system.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A band-stop filter based on printed ridge gap waveguide, It is characterized in that include: substrate; A metal bottom plate, the metal bottom plate being attached to the lower surface of the substrate; A plurality of pads, wherein the plurality of pads are attached to the upper surface of the substrate; A metal column, wherein the metal column connects the plurality of pads and the metal base plate; A metal top plate, the metal top plate is arranged in parallel and directly above the plurality of pads at a preset distance; A feeding part, wherein the feeding part adopts a printed ridge gap waveguide for feeding, and the feeding part is a metal microstrip line, and the metal microstrip line divides the plurality of pads into two parts on average, and the plurality of pads have M columns on the left and right sides along the wide side direction of the substrate, and N rows along the long side direction of the substrate, and are arranged on both sides of the metal microstrip line with a preset period, and the metal microstrip line is connected to the metal base plate through the metal column, wherein M and N are integers, and M≥2, N≥5.

2. The band-stop filter based on printed ridge gap waveguide according to claim 1, It is characterized in that The substrate is rectangular and has a thickness of 0.8-1.2 mm.

3. The band-stop filter based on printed ridge gap waveguide according to claim 2, It is characterized in that The material of the substrate is a ceramic filling and reinforcement material, and the relative dielectric constant of the ceramic filling and reinforcement material is 3 and the relative magnetic permeability is 1.

4. The band-stop filter based on printed ridge gap waveguide according to claim 1, It is characterized in that The length and width of the metal bottom plate and the metal top plate are the same as those of the substrate, the height of the metal column is the same as the thickness of the substrate, and the length of the metal microstrip line is the same as that of the substrate.

5. The printed ridge gap waveguide based band-stop filter according to claim 1, It is characterized in that The metal bottom plate, the metal top plate, the pad, the metal column and the metal microstrip line are all made of copper, silver or gold of a printed circuit.

6. The printed ridge gap waveguide based band-stop filter according to claim 1, It is characterized in that The shape of the pad is a rectangle with equal length and width. The length and width of the pad are smaller than the preset period. The horizontal and vertical distances between adjacent pads are the difference between the preset period and the length or width of the pad.

7. The band-stop filter based on printed ridge gap waveguide according to claim 6, It is characterized in that The band-stop filter further includes a resonance unit, wherein the resonance unit replaces at least one of the plurality of pads, the resonance unit is a circular pad, and a diameter of the resonance unit is smaller than a length of the pad.

8. The printed ridge gap waveguide based band-stop filter according to claim 7, It is characterized in that The resonance unit is adjacent to the metal microstrip line, and when there are multiple resonance units, the multiple resonance units are arranged on the same side of the metal microstrip line.

9. The printed ridge gap waveguide based band-stop filter according to claim 8, It is characterized in that The equivalent inductance between the resonant unit and the metal base plate and the metal column is determined according to the following formula: Where, L is the equivalent inductance, u 0 is the vacuum permeability, h 1 is the distance between the resonance unit and the metal base plate, p is the period of the pad, d is the diameter of the metal column, and a is the radius of the metal column.

10. The printed ridge gap waveguide based band stop filter according to claim 8, It is characterized in that The equivalent capacitance between the resonant unit and the metal top plate is determined according to the following formula: C=kC 0 Where C is the equivalent capacitance after considering the edge effect, C 0 is an ideal parallel plate capacitor, ε 0 is the dielectric constant of vacuum, hair is the distance between the resonance unit and the metal top plate, S is the area of ​​the resonance unit, r is the radius of the resonance unit, and b is the aspect ratio, which is the ratio of the distance hair between the resonance unit and the metal top plate to the radius r of the resonance unit.

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