Silicon-based MEMS filters

Abstract

The present invention provides a silicon-based MEMS filter, comprising: an N-order filter, a first U-shaped coupling line, a second U-shaped coupling line, an input feeder, and an output feeder are provided in a first region on the upper surface of a first silicon substrate; one end of the N-order filter is connected to one side of the first U-shaped coupling line, and the other side of the first U-shaped coupling line is connected to the input feeder; the other end of the N-order filter is connected to one side of the second U-shaped coupling line, and the other side of the second U-shaped coupling line is connected to the output feeder; a first and second resonance suppression rods are provided in a second region on the upper surface of a second silicon substrate, wherein the first resonance suppression rod is vertically positioned directly above the first U-shaped coupling line, and the second resonance suppression rod is vertically positioned directly above the second U-shaped coupling line, and the opening directions of the first and second U-shaped coupling lines are respectively the length directions of the first and second resonance suppression rods. The silicon-based MEMS filter provided by the present invention has a high rectangular coefficient.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a silicon-based MEMS filter. Background Art

[0002] With the rapid development of wireless communication systems, spectrum and system space resources have become extremely tight. As an indispensable and important frequency-selective device in microwave systems, filters have higher requirements on the squareness coefficient and size of filters.

[0003] Filters allow electrical signals of a certain frequency range to pass through while blocking signals of other frequencies. Improving the filter's rectangular coefficient and reducing its size are key design challenges. MEMS technology is a micromachining process that creates three-dimensional structures such as metal patterns and through-holes on high-resistance silicon, achieving processing precision at the micro-nanometer level. Silicon-based filters manufactured using MEMS technology offer numerous advantages, including small size, light weight, high consistency, and ease of integration. Products based on MEMS filters will play a vital role in future communication systems.

[0004] At present, the product suppression degree is usually improved by increasing the filter order, but this will increase the volume of the filter and increase the rectangular coefficient. How to improve the rectangular coefficient based on miniaturized products has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The embodiment of the present invention provides a silicon-based MEMS filter to solve the problem of low rectangular coefficient of current miniaturized filters.

[0006] In a first aspect, an embodiment of the present invention provides a silicon-based MEMS filter, comprising:

[0007] A first silicon substrate is provided, wherein an N-order filter, a first U-shaped coupling line, a second U-shaped coupling line, an input feeder, and an output feeder are provided in a first region on an upper surface of the first silicon substrate; one end of the N-order filter is connected to one side of the first U-shaped coupling line, and the other side of the first U-shaped coupling line is connected to the input feeder; the other end of the N-order filter is connected to one side of the second U-shaped coupling line, and the other side of the second U-shaped coupling line is connected to the output feeder; a first metal layer is provided on the upper surface of the first silicon substrate, and the first metal layer avoids the first region; one end of each resonant rod in the N-order filter is connected to the first metal layer.

[0008] A second silicon substrate is located on the upper surface of the first silicon substrate, and a first suppressed resonance rod and a second suppressed resonance rod are provided in the second area on the upper surface of the second silicon substrate, and the first suppressed resonance rod is vertically located directly above the first U-shaped coupling line, and the second suppressed resonance rod is vertically located directly above the second U-shaped coupling line, and the opening directions of the first U-shaped coupling line and the second U-shaped coupling line are respectively the length directions of the first suppressed resonance rod and the second suppressed resonance rod; a second metal layer is provided on the upper surface of the second silicon substrate, and the second metal layer avoids the second area; one end of the first suppressed resonance rod and the second suppressed resonance rod are both connected to the second metal layer.

[0009] In one possible implementation, the width of the first resonance suppression rod is equal to the sum of the width of the first U-shaped coupling line and the interval between the first U-shaped coupling lines; the width of the second resonance suppression rod is equal to the sum of the width of the second U-shaped coupling line and the interval between the second U-shaped coupling lines.

[0010] In a possible implementation, an N-order filter includes N resonant rods, and the N resonant rods are connected by coupling lines;

[0011] The N-order filter also includes a first coupling line. The first resonant rod or the last resonant rod in the N-order filter is connected to one end of the first coupling line, and the other end of the first coupling line is connected to the first U-shaped coupling line or the second U-shaped coupling line. The first coupling line and the resonant rod connected thereto form an inductive coupling.

[0012] In a possible implementation, an N-order filter includes N resonant rods, and the N resonant rods are connected by coupling lines;

[0013] The N-order filter also includes a second coupling line. The first resonant rod or the last resonant rod in the N-order filter is spaced apart from one end of the second coupling line. The other end of the second coupling line is connected to the first U-shaped coupling line or the second U-shaped coupling line. The second coupling line and the resonant rod spaced apart from it form a capacitive coupling.

[0014] In a possible implementation, an N-order filter includes N resonant rods, and the N resonant rods are connected by coupling lines;

[0015] The N-order filter also includes a first coupling line and a second coupling line. The first resonant rod in the N-order filter is connected to the first coupling line, the first coupling line is connected to the first U-shaped coupling line, and the first coupling line and the first resonant rod connected thereto form an inductive coupling; the last resonant rod in the N-order filter is spaced apart from one end of the second coupling line, the other end of the second coupling line is connected to the second U-shaped coupling line, and the second coupling line and the last resonant rod spaced apart from it form a capacitive coupling.

[0016] In a possible implementation, the first coupling line is a Z-shaped coupling line;

[0017] The second coupling line is composed of multiple coupling line segments, wherein the second coupling line includes at least one coupling line segment parallel to the resonant rod.

[0018] In a possible implementation, each resonant rod in the N-th order filter is a 1 / 4 wavelength resonator with a single-end short circuit.

[0019] In a possible implementation, the first suppression resonance rod and the second suppression resonance rod are both single-ended short-circuited 1 / 4 wavelength resonators.

[0020] In a possible implementation, metallized through holes are distributed on the metal layer of the first silicon substrate and the metal layer of the second silicon substrate, and metal is distributed on all areas of the lower surface of the first silicon substrate.

[0021] In a possible implementation, the thickness of the first silicon substrate is smaller than the thickness of the second silicon substrate, and both the first silicon substrate and the second silicon substrate are high-resistance silicon substrates.

[0022] An embodiment of the present invention provides a silicon-based MEMS filter, which uses a MEMS process to prepare a filter with a non-resonant node structure on a double-layer silicon substrate. That is, a first U-shaped coupling line and a second U-shaped coupling line are arranged on a first silicon substrate, and a first suppressed resonance rod and a second suppressed resonance rod corresponding to the first U-shaped coupling line and the second U-shaped coupling line are prepared at corresponding positions on the second silicon substrate. As a result, the first U-shaped coupling line and the first suppressed resonance rod, the second U-shaped coupling line and the second suppressed resonance rod form two transmission zeros outside the passband of the N-order filter, thereby improving the rectangular coefficient of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 1 is a schematic diagram of the overall structure of a silicon-based MEMS filter provided by an embodiment of the present invention;

[0025] Figure 2 The embodiment of the present invention provides Figure 1 A schematic structural diagram of the upper surface of the first silicon substrate;

[0026] Figure 3 The embodiment of the present invention provides Figure 1 A schematic structural diagram of the lower surface of the first silicon substrate;

[0027] Figure 4 The embodiment of the present invention provides Figure 1 Schematic diagram of the structure of the upper surface of the second silicon substrate. DETAILED DESCRIPTION

[0028] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0030] Currently, the main approach to improving rejection is increasing the filter order, but this increases the filter size and losses. Introducing a transmission zero can achieve higher rejection while maintaining a smaller filter size. While cross-coupling structures can also be used to introduce transmission zeros into filters, they offer limited design flexibility and are more complex.

[0031] In order to solve the problems in the prior art, an embodiment of the present invention provides a silicon-based MEMS filter. The silicon-based MEMS filter provided by the embodiment of the present invention is introduced below.

[0032] A silicon-based MEMS filter comprises a first silicon substrate and a second silicon substrate stacked together. An N-order filter, a first U-shaped coupling line, a second U-shaped coupling line, an input feeder, and an output feeder are provided in a first region on the upper surface of the first silicon substrate. One end of the N-order filter is connected to one side of the first U-shaped coupling line, and the other side of the first U-shaped coupling line is connected to the input feeder. The other end of the N-order filter is connected to one side of the second U-shaped coupling line, and the other side of the second U-shaped coupling line is connected to the output feeder. A first metal layer is provided on the upper surface of the first silicon substrate, and the first metal layer avoids the first region; one end of each resonant rod in the N-order filter is connected to the first metal layer.

[0033] The second silicon substrate is located on the upper surface of the first silicon substrate. A first resonance suppression rod and a second resonance suppression rod are provided in the second region on the upper surface of the second silicon substrate, and the first resonance suppression rod is vertically located directly above the first U-shaped coupling line, and the second resonance suppression rod is vertically located directly above the second U-shaped coupling line. The opening directions of the first U-shaped coupling line and the second U-shaped coupling line are respectively the length directions of the first resonance suppression rod and the second resonance suppression rod. A second metal layer is provided on the upper surface of the second silicon substrate, and the second metal layer avoids the second region. One end of the first resonance suppression rod and the second resonance suppression rod are both connected to the second metal layer.

[0034] Among them, the N-order filter is prepared on a double-layer high-resistance silicon using MEMS technology.

[0035] By adding non-resonant nodes to an N-order filter, consisting of a first U-shaped coupling line and a first resonant suppression rod, and a second U-shaped coupling line and a second resonant suppression rod, the non-resonant nodes are cascaded to generate transmission zeros, improving the filter's suppression performance and rectangularity factor. Silicon-based MEMS filters with non-resonant nodes can flexibly implement zero location and multi-zero characteristics, effectively improving the filter's suppression. This further enhances filter performance based on miniaturized filters, meeting the higher requirements for filters in future communications.

[0036] In some embodiments, a better suppression effect can be achieved by adjusting the widths of the first U-shaped coupling line and the first suppression resonance rod, the second U-shaped coupling line and the second suppression resonance rod.

[0037] In this embodiment, the width of the first resonance suppression rod can be equal to the sum of the width of the first U-shaped coupling line and the interval between the first U-shaped coupling line. The width of the second resonance suppression rod can be equal to the sum of the width of the second U-shaped coupling line and the interval between the second U-shaped coupling line.

[0038] For example, the line width of any side of the first U-shaped coupling line can be set to 1 / 3 of the width of the first resonant suppression rod, and the spacing between the first U-shaped coupling lines is also 1 / 3 of the width of the first resonant suppression rod, so that the width of the first resonant suppression rod is equal to the sum of the width of the first U-shaped coupling line and the spacing between the first U-shaped coupling lines. Correspondingly, the line width of any side of the second U-shaped coupling line can be set to 1 / 3 of the width of the second resonant suppression rod, and the spacing between the second U-shaped coupling lines is also 1 / 3 of the width of the second resonant suppression rod, so that the width of the second resonant suppression rod is equal to the sum of the width of the second U-shaped coupling line and the spacing between the second U-shaped coupling lines.

[0039] In this embodiment, in order to facilitate the adjustment of the zero point suppression degree, the length and position of the first U-shaped coupling line and the second U-shaped coupling line are tuned independently, and the zero point suppression degree is adjusted by controlling the coupling strength with the first suppression resonance rod and the second suppression resonance rod.

[0040] In some embodiments, in order to achieve different feeding strengths and phases, make the filter have good in-band standing waves, obtain good loss and suppression, and further reduce the volume of the filter, an inductive coupling structure can be added to the N-order filter.

[0041] In this embodiment, an N-order filter may include N resonant rods, each of which is connected by a coupling line. To improve suppression and reduce the size of the filter, the first or last resonant rod of the N-order filter is connected to one end of a first coupling line to form an inductive coupling. The other end of the first coupling line is connected to a first U-shaped coupling line or a second U-shaped coupling line.

[0042] Exemplarily, the first coupling line may be configured as a Z-shaped coupling line.

[0043] In some embodiments, in order to achieve different feeding strengths and phases, make the filter have good in-band standing waves, obtain good loss and suppression, and further reduce the volume of the filter, a capacitive coupling structure can be added to the N-order filter.

[0044] In this embodiment, an N-order filter may include N resonant rods, each of which is connected by a coupling line. To improve suppression and reduce the size of the filter, the first or last resonant rod of the N-order filter is spaced apart from one end of a second coupling line, the other end of the second coupling line is connected to the first or second U-shaped coupling line, and the second coupling line forms a capacitive coupling with the resonant rod spaced apart from it.

[0045] Exemplarily, the second coupling line is composed of multiple coupling line segments, wherein the second coupling line includes at least one coupling line segment parallel to the resonant rod.

[0046] In some embodiments, in order to achieve different feeding strengths and phases, make the filter have good in-band standing waves, obtain good loss and suppression, and further reduce the volume of the filter, inductive coupling and capacitive coupling can be added simultaneously in the N-order filter.

[0047] In this embodiment, an N-order filter may include N resonant rods, each of which is connected by a coupling line. To improve suppression and reduce the size of the filter, an inductive coupling is provided at one end of the N-order filter and a capacitive coupling is provided at the other end of the N-order filter.

[0048] Exemplarily, the first resonant rod in an N-order filter is connected to a first coupling line, which is connected to a first U-shaped coupling line. The first coupling line and the first resonant rod connected thereto form an inductive coupling. The last resonant rod in the N-order filter is spaced apart from one end of a second coupling line. The other end of the second coupling line is connected to a second U-shaped coupling line. The second coupling line and the last resonant rod spaced apart from it form a capacitive coupling.

[0049] In some embodiments, in order to obtain good loss and suppression, the coupling between resonators can be adjusted by adjusting the position of the coupling line connecting the N resonant rods.

[0050] In this embodiment, each resonant rod in the N-th order filter is a 1 / 4 wavelength resonator with a single-ended short circuit.

[0051] In order to facilitate the adjustment of the passband frequency of the N-order filter, the length of each resonant rod in the N-order filter is independent of each other, and the passband frequency of the N-order filter can be adjusted by adjusting the length of each resonant rod.

[0052] In some embodiments, the first suppressed resonant rod and the second suppressed resonant rod are both single-ended short-circuited 1 / 4 wavelength resonators, and the position of the transmission zero point can be flexibly adjusted by adjusting their lengths.

[0053] Exemplarily, the length of the first resonance suppression rod may be greater than the length of the second resonance suppression rod.

[0054] In some embodiments, to ensure good shielding properties, grounding metal is provided throughout the lower surface of the first silicon substrate. Metallized through-holes are provided on both the metal layer of the first silicon substrate and the metal layer of the second silicon substrate. The metallized through-holes on the metal layer of the first silicon substrate extend through the upper and lower surfaces of the first silicon substrate, while the metallized through-holes on the metal layer of the second silicon substrate extend through the upper and lower surfaces of the second silicon substrate. The locations of the metallized through-holes on the upper and lower surfaces of the two silicon substrates are not limited.

[0055] In some embodiments, in order to increase the capacitance of the filter and further reduce the volume of the filter, the thickness of the first silicon substrate may be smaller than the thickness of the second silicon substrate, and both the first silicon substrate and the second silicon substrate are high-resistance silicon substrates.

[0056] In some embodiments, to facilitate input and output, grooves may be provided on the second silicon substrate at positions corresponding to the input feeder and the output feeder to expose the input feeder and the output feeder.

[0057] The silicon-based MEMS filter provided by the present invention adopts a MEMS process to prepare a filter with a non-resonant node structure on a double-layer high-resistance silicon substrate. That is, a first U-shaped coupling line and a second U-shaped coupling line are arranged on a first silicon substrate, and a first suppression resonance rod and a second suppression resonance rod corresponding to the first U-shaped coupling line and the second U-shaped coupling line are prepared on corresponding positions of the second silicon substrate. As a result, the first U-shaped coupling line and the first suppression resonance rod, the second U-shaped coupling line and the second suppression resonance rod form two transmission zeros outside the passband of the N-order filter, thereby improving the rectangular coefficient of the filter.

[0058] Please refer to Figures 1-4 , provides a schematic structural diagram of a silicon-based MEMS filter. The silicon-based MEMS filter includes a first silicon substrate 10 and a second silicon substrate 20. The thickness of the first silicon substrate 10 is 0.12 mm, and the thickness of the second silicon substrate 20 is 0.25 mm.

[0059] like Figure 2 As shown, a second-order filter, a first U-shaped coupling line 111 , a second U-shaped coupling line 112 , an input feed line 113 and an output feed line 114 are provided in the first region 110 of the first silicon substrate 10 .

[0060] Among them, the second-order filter includes two single-ended short-circuited 1 / 4 wavelength resonators. Figure 2 115 and 116 are two single-ended short-circuited quarter-wavelength resonators, the other ends of which are connected to the first metal layer of the first silicon substrate 10. The first metal layer is arranged on the top surface of the first silicon substrate 10 and is uniformly distributed in all areas except the first area 110, facilitating effective shielding. A coupling line 117 is connected between the two single-ended short-circuited quarter-wavelength resonators. Adjusting the position of coupling line 117 adjusts the coupling between the resonators.

[0061] To improve filter performance and reduce filter size, a Z-type coupling line 118 may be connected to the resonator 115. The resonator 115 and the Z-type coupling line 118 form an inductive coupling, and the coupling strength can be adjusted by adjusting the contact point between the resonator 115 and the Z-type coupling line 118.

[0062] Furthermore, resonator 116 and second coupling line 119 form a capacitive impedance. The length of second coupling line 119 and the gap between resonator 116 and second coupling line 119 can adjust the coupling strength. Second coupling line 119 is composed of four zigzag lines, and the zigzag line that forms the capacitive impedance with resonator 116 is parallel to resonator 116.

[0063] The input feed line 113 and the output feed line 114 are both 50-ohm transmission lines.

[0064] The first metal layer on the upper surface of the first silicon substrate 10 is further provided with metallized through holes penetrating the upper and lower surfaces. Figure 2 Not shown, please refer to Figure 1 . Figure 2 The blank area within the first region 110 is a high-resistance silicon substrate. The second-order filter, first U-shaped coupling line 111, second U-shaped coupling line 112, input feed line 113, and output feed line 114 within the first region 110 are fabricated on the high-resistance silicon within the first region 110. The area outside the first region 110 is a first metal layer.

[0065] like Figure 3 As shown, the lower surface of the first silicon substrate 10 is uniformly provided with grounding metal, ensuring good shielding properties.

[0066] like Figure 4 As shown, a first resonance suppression rod 210 and a second resonance suppression rod 211 are provided in a second region 213 on the upper surface of the second silicon substrate 20. Two grooves 212 are provided on the second silicon substrate 20 at positions corresponding to the input feeder 113 and the output feeder 114. These grooves 212 allow the input feeder 113 and the output feeder 114 on the first silicon substrate 10 to be exposed on the outer surface for easy connection.

[0067] The first suppressed resonance rod 210 and the second suppressed resonance rod 211 are respectively located vertically above the first U-shaped coupling line 111 and the second U-shaped coupling line 112. The opening directions of the first U-shaped coupling line 111 and the second U-shaped coupling line 112 are respectively the length directions of the first suppressed resonance rod and the second suppressed resonance rod. The first suppressed resonance rod 210 and the second suppressed resonance rod 211 are both single-ended short-circuited 1 / 4 wavelength resonators. The position of the transmission zero point can be flexibly adjusted by adjusting their lengths. The line width on either side of the first U-shaped coupling line 111 is set to 1 / 3 of the width of the first suppressed resonance rod 210, and the spacing of the first U-shaped coupling line 111 is also 1 / 3 of the width of the first suppressed resonance rod 210, so that the width of the first suppressed resonance rod 210 is equal to the sum of the width of the first U-shaped coupling line 111 and the spacing of the first U-shaped coupling line 111. Accordingly, the line width of either side of the second U-shaped coupling line 112 is set to 1 / 3 of the width of the second resonance suppression rod 211, and the spacing between the second U-shaped coupling lines 112 is also 1 / 3 of the width of the second resonance suppression rod 211, so that the width of the second resonance suppression rod 211 is equal to the sum of the width of the second U-shaped coupling line 112 and the spacing between the second U-shaped coupling lines 112. The length of the first resonance suppression rod 210 can be greater than the length of the second resonance suppression rod 211.

[0068] The first resonance suppression rod 210 and the first U-shaped coupling line 111 , the second resonance suppression rod 211 and the second U-shaped coupling line 112 form two groups of non-resonance nodes.

[0069] The microwave input signal is fed in through the input feeder 113, passes through the first U-shaped coupling line 111, and reaches the Z-shaped coupling line 118, resonator 115, resonator 116, and second coupling line 119. Resonators 115 and 116 form a second-order filter, providing transmission characteristics for signals within the passband frequency and attenuation characteristics within the stopband. The signal then passes through the second U-shaped coupling line 112 and is finally transmitted out through the output feeder 114. The first suppressed resonant rod 210 and the second suppressed resonant rod 211 are respectively located in the vertical direction of the first U-shaped coupling line 111 and the second U-shaped coupling line 112, generating a transmission zero point outside the band, thereby improving the rectangular coefficient.

[0070] The multi-zero silicon-based MEMS filter provided by the present invention, which contains a non-resonant node (NRN) structure, utilizes a MEMS process to implement a filter with non-resonant nodes on a double layer of high-resistance silicon. The main transmission circuit is located between a first silicon substrate 10 and a second silicon substrate 20, exhibiting excellent shielding properties and ease of integration. The bottom first silicon substrate 10 is made of thin silicon, which can increase capacitance and further reduce size. The resonant suppression rods on the second silicon substrate 20 add two transmission zeros outside the passband, thereby increasing the filter's rectangular coefficient. This allows the filter to be compact, have a high rectangular coefficient, exhibit excellent shielding properties, and be easily integrated.

[0071] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A silicon-based MEMS filter, characterized in that: include: A first silicon substrate, wherein an N-order filter, a first U-shaped coupling line, a second U-shaped coupling line, an input feeder, and an output feeder are provided in a first region on an upper surface of the first silicon substrate; the N-order filter includes N resonant rods, and the N resonant rods are all connected by coupling lines; the N-order filter also includes a first coupling line and a second coupling line, wherein a first resonant rod in the N-order filter is connected to the first coupling line, the first coupling line is connected to the first U-shaped coupling line, the first coupling line and the first resonant rod connected thereto form an inductive coupling, and the other side of the first U-shaped coupling line is connected to the input feeder; a last resonant rod in the N-order filter is spaced apart from one end of the second coupling line, the other end of the second coupling line is connected to the second U-shaped coupling line, the second coupling line and the last resonant rod spaced apart from it form a capacitive coupling, and the other side of the second U-shaped coupling line is connected to the output feeder; a first metal layer is provided on the upper surface of the first silicon substrate, and the first metal layer avoids the first region; one end of each resonant rod in the N-order filter is connected to the first metal layer; A second silicon substrate is located on the upper surface of the first silicon substrate, and a first suppression resonance rod and a second suppression resonance rod are provided in the second area on the upper surface of the second silicon substrate, and the first suppression resonance rod is vertically located directly above the first U-shaped coupling line, and the second suppression resonance rod is vertically located directly above the second U-shaped coupling line, and the opening directions of the first U-shaped coupling line and the second U-shaped coupling line are the length directions of the first suppression resonance rod and the second suppression resonance rod, respectively; a second metal layer is provided on the upper surface of the second silicon substrate, and the second metal layer avoids the second area; one end of the first suppression resonance rod and the second suppression resonance rod are both connected to the second metal layer.

2. The silicon-based MEMS filter according to claim 1, wherein: The width of the first resonance suppression rod is equal to the sum of the width of the first U-shaped coupling line and the interval between the first U-shaped coupling lines; the width of the second resonance suppression rod is equal to the sum of the width of the second U-shaped coupling line and the interval between the second U-shaped coupling lines.

3. The silicon-based MEMS filter according to claim 1, wherein: The first coupling line is a Z-shaped coupling line; The second coupling line is composed of multiple coupling line segments, wherein the second coupling line includes at least one coupling line segment parallel to the resonant rod.

4. The silicon-based MEMS filter according to claim 2, wherein: Each resonant rod in the N-order filter is a 1 / 4 wavelength resonator with a single end short circuit.

5. The silicon-based MEMS filter according to claim 4, wherein: The first suppression resonance rod and the second suppression resonance rod are both single-ended short-circuited 1 / 4 wavelength resonators.

6. The silicon-based MEMS filter according to claim 1, wherein: Metallized through holes are distributed on the metal layer of the first silicon substrate and the metal layer of the second silicon substrate, and metal is distributed on all areas of the lower surface of the first silicon substrate.

7. The silicon-based MEMS filter according to claim 1, wherein: The thickness of the first silicon substrate is smaller than that of the second silicon substrate, and both the first silicon substrate and the second silicon substrate are high-resistance silicon substrates.

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