A silicon-based ultra-wideband / dual-band tunable microwave filter

Abstract

The application discloses a silicon-based ultra-wide passband / dual-passband adjustable microwave filter, which comprises a silicon-based composite dielectric layer, a first metal layer and a second metal layer; the first metal layer is stacked on the upper surface of the silicon-based composite dielectric layer, and the second metal layer is stacked on the lower surface of the silicon-based composite dielectric layer; the first metal layer is provided with a first window, the first window is provided with a first metal pattern, the second metal layer is provided with a second window, and the second window is provided with a second metal pattern; the silicon-based composite dielectric layer is provided with a plurality of through holes, each through hole is provided with a metal column surrounded by silicon dioxide, and the first metal layer and the second metal layer are electrically connected through the metal column, so that a three-dimensional spiral inductance is formed in the silicon-based ultra-wide passband / dual-passband adjustable microwave filter by the first metal pattern and the second metal pattern. The application reduces the filter area and is more conducive to the integration of the filter and other silicon-based devices.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit manufacturing and packaging technology, specifically relating to a silicon-based ultrawide passband / dual passband adjustable microwave filter. Background Technology

[0002] The slowdown in Moore's Law and the diversification of integrated circuit applications are two key characteristics of the current integrated circuit industry. With the rise of products in fields such as smartphones, the Internet of Things (IoT), automotive electronics, high-performance computing, 5G, and artificial intelligence, especially the high-speed, high-frequency, and heterogeneous integration requirements of 5G bands, there is a need for continuous innovation and development in advanced packaging technologies. Specifically, 5G bands include: 28-60GHz (5G millimeter wave coverage), 6GHz (5G Sub coverage), and 1GHz (5G IoT Sub coverage).

[0003] Substrate integrated waveguide (SIW) technology, due to its ability to transmit signals on planar dielectric substrates like metallic waveguides, ensuring low-loss signal transmission, has been able to replace rectangular waveguides and planar transmission line structures to continue driving the development of microwave circuit systems. With continuous advancements in manufacturing processes, SIW can be integrated with most communication system components on a single substrate without requiring additional fabrication of specific devices, thereby reducing signal transmission losses and suppressing parasitic phenomena.

[0004] However, filters manufactured using SIW technology inevitably employ planar spiral inductors, resulting in a large overall filter structure area, which is not conducive to the integration of the filter with other devices. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a silicon-based ultrawide passband / dual passband tunable microwave filter.

[0006] The technical problem to be solved by this invention is achieved through the following technical solution:

[0007] A silicon-based ultrawide passband / dual passband tunable microwave filter includes: a silicon-based composite dielectric layer, a first metal layer, and a second metal layer;

[0008] The first metal layer is superimposed on the upper surface of the silicon-based composite dielectric layer, and the second metal layer is superimposed on the lower surface of the silicon-based composite dielectric layer; the first metal layer has a first window with a first metal pattern, and the second metal layer has a second window with a second metal pattern.

[0009] The silicon-based composite dielectric layer has multiple through holes, each of which contains a metal pillar surrounded by silicon dioxide. The first metal layer and the second metal layer are electrically connected through the metal pillars, so as to form a three-dimensional spiral inductor in the silicon-based ultrawide passband / dual passband tunable microwave filter using the first metal pattern and the second metal pattern.

[0010] In one embodiment, the first metal layer includes: a first rectangular metal sheet; two first windows are symmetrically opened in the middle of the first rectangular metal sheet, the two first windows being spaced apart from each other; and the first metal pattern is provided in each of the two first windows.

[0011] The second metal layer includes: a second rectangular metal sheet; two second windows are symmetrically opened in the middle of the second rectangular metal sheet, the opening positions of the two second windows and the two first windows are vertically corresponding, and the second metal pattern is provided in each of the two second windows;

[0012] The plurality of through holes includes: a plurality of first through holes and a plurality of second through holes;

[0013] The plurality of first through holes are arranged at intervals along a symmetry axis of the silicon-based composite dielectric layer within the specified distance; the metal pillars in the plurality of second through holes are used to electrically connect the upper and lower corresponding first metal patterns and second metal patterns.

[0014] In one embodiment, the first metal pattern includes: a pair of first strip-shaped metal pieces and a pair of second strip-shaped metal pieces; wherein the pair of first strip-shaped metal pieces are symmetrical about the central origin of the first window and connected to the first rectangular metal piece; the pair of second strip-shaped metal pieces are symmetrical about the central origin of the first window;

[0015] The second metal pattern includes three third strip-shaped metal sub-pieces, which are arranged in parallel.

[0016] The first metal pattern and the second metal pattern are electrically connected through a matrix of 3×2 second through holes.

[0017] In one embodiment, the first metal pattern includes: a fourth strip-shaped metal piece, a pair of fifth strip-shaped metal pieces, and a pair of sixth strip-shaped metal pieces; wherein the line connecting the midpoints of the long sides of the fourth strip-shaped metal piece coincides with the axis of symmetry; the pair of fifth strip-shaped metal pieces are parallel to the fourth strip-shaped metal piece and connected to the first rectangular metal piece, the pair of fifth strip-shaped metal pieces are respectively located on both sides of the fourth strip-shaped metal piece and are symmetrical about the axis of symmetry; the pair of sixth strip-shaped metal pieces are parallel to the fourth strip-shaped metal piece and are symmetrical about the axis of symmetry.

[0018] The second metal pattern includes four seventh strip-shaped metal sub-pieces, which are arranged in parallel.

[0019] The first metal pattern and the second metal pattern are electrically connected through a matrix of 4×2 second through holes.

[0020] In one embodiment, the first metal layer further includes: an input stub and an output stub;

[0021] The input branch and the output branch are respectively connected to the two sides of the first rectangular metal sheet, and the two sides are symmetrical about the axis of symmetry.

[0022] In one embodiment, both sides have notches; the input branch and the output branch are both located within the notches when connecting the two sides.

[0023] In one embodiment, when the length W1 of the first rectangular metal sheet is less than the target length, the silicon-based ultra-wide passband / dual passband tunable microwave filter is a dual passband filter; when the length W1 of the first rectangular metal sheet is greater than the target length, the silicon-based ultra-wide passband / dual passband tunable microwave filter is a wide passband filter; the target length is obtained through simulation.

[0024] In one embodiment, the silicon-based composite dielectric layer comprises: a silicon dielectric layer, a first SiO2 dielectric layer, and a second SiO2 dielectric layer;

[0025] The first SiO2 dielectric layer is stacked on the upper surface of the silicon dielectric layer, and the second SiO2 dielectric layer is stacked on the lower surface of the silicon dielectric layer;

[0026] The first metal layer is superimposed on the upper surface of the first SiO2 dielectric layer, and the second metal layer is superimposed on the lower surface of the second SiO2 dielectric layer.

[0027] In one embodiment, both the first metal layer and the second metal layer are made of copper.

[0028] In the silicon-based ultrawide passband / dual passband tunable microwave filter provided by this invention, both the upper and lower surfaces of the silicon-based composite dielectric layer have metal layers, and both metal layers contain metal patterns. Thus, the metal patterns of the upper and lower layers together form a three-dimensional spiral inductor in the silicon-based ultrawide passband / dual passband tunable microwave filter, thereby avoiding the use of planar spiral inductors in the filter, reducing the area of ​​the filter, and making it more conducive to the integration of the filter with other devices.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a silicon-based ultrawide passband / dual passband tunable microwave filter provided in an embodiment of the present invention;

[0031] Figure 2 This is a top view of the first metal layer in a silicon-based ultrawide passband microwave filter provided in an embodiment of the present invention;

[0032] Figure 3 This is a top view of the second metal layer in a silicon-based ultrawide passband microwave filter provided in an embodiment of the present invention;

[0033] Figure 4 This is a top view of the first metal layer in a silicon-based dual-passband microwave filter provided in an embodiment of the present invention;

[0034] Figure 5 This is a top view of the second metal layer in a silicon-based dual-passband microwave filter provided in an embodiment of the present invention;

[0035] Figure 6 This is a passband frequency response diagram of a silicon-based ultrawide passband microwave filter provided in an embodiment of the present invention;

[0036] Figure 7 This is a passband frequency response diagram of a silicon-based dual-passband microwave filter provided in an embodiment of the present invention. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0038] To facilitate the integration of the filter with other devices, this invention provides a silicon-based ultrawide passband / dual passband tunable microwave filter. This filter does not require the use of planar spiral inductors, has a small area, and can be well integrated with other devices. Figure 1 A front view of the silicon-based ultrawide passband / dual passband tunable microwave filter provided in an embodiment of the present invention is shown, as follows. Figure 1 As shown, the silicon-based ultrawide / dual-passband tunable microwave filter provided in this embodiment of the invention includes: a silicon-based composite dielectric layer, a first metal layer 1, and a second metal layer 5. The silicon-based composite dielectric layer may include: a silicon dielectric layer 3, a first SiO2 dielectric layer 2, and a second SiO2 dielectric layer 4; the first SiO2 dielectric layer 2 is stacked on the upper surface of the silicon dielectric layer 3, and the second SiO2 dielectric layer 4 is stacked on the lower surface of the silicon dielectric layer 3; the first metal layer 1 is stacked on the upper surface of the first SiO2 dielectric layer 2, and the second metal layer 5 is stacked on the lower surface of the second SiO2 dielectric layer 4. The first metal layer 1 and the second metal layer 5 are preferably made of copper, but are not limited to this.

[0039] A first metal layer 1 is superimposed on the upper surface of a silicon-based composite dielectric layer, and a second metal layer 5 is superimposed on the lower surface of the silicon-based composite dielectric layer. The first metal layer 1 has a first window 11 with a first metal pattern inside, and the second metal layer 5 has a second window 13 with a second metal pattern inside. The silicon-based composite dielectric layer has multiple through holes, and each through hole has a metal pillar 6 surrounded by silicon dioxide. The first metal layer 1 and the second metal layer 5 are electrically connected through the metal pillars 6, so as to form a three-dimensional spiral inductor in the silicon-based ultra-wideband / dual-band adjustable microwave filter using the first metal pattern and the second metal pattern, thereby achieving electromagnetic coupling while introducing zero suppression at out-of-band high frequencies.

[0040] In the silicon-based ultrawide passband / dual passband tunable microwave filter provided in this embodiment of the invention, both the upper and lower surfaces of the silicon-based composite dielectric layer have metal layers, and both metal layers contain metal patterns. Thus, the metal patterns of the upper and lower layers together form a three-dimensional spiral inductor in the silicon-based ultrawide passband / dual passband tunable microwave filter, thereby avoiding the use of planar spiral inductors in the filter, reducing the area of ​​the filter, and making it more conducive to the integration of the filter with other devices.

[0041] In one embodiment, the first metal layer 1 may include: a first rectangular metal sheet 10; two first windows 11 are symmetrically formed in the middle of the first rectangular metal sheet 10, and the two first windows 11 are spaced apart from each other; each of the two first windows 11 is provided with a first metal pattern. Figure 2 The diagram shows a top view of the first metal layer 1; the second metal layer 5 may include: a second rectangular metal sheet 20; two second windows 13 are symmetrically opened in the center of the second rectangular metal sheet 20, the opening positions of the two second windows 13 and the two first windows 11 are vertically corresponding, and each of the two second windows 13 is provided with a second metal pattern. Figure 3 A top view of the second metal layer 5 is shown; the multiple vias provided in the silicon-based composite dielectric layer include multiple first vias and multiple second vias; the multiple first vias are arranged at intervals along a symmetry axis X of the silicon-based composite dielectric layer within a distance between the two first windows 11; the metal pillars 6 in the multiple second vias are used to electrically connect the corresponding upper and lower first metal patterns and second metal patterns.

[0042] Understandably, a row of first vias in the silicon-based composite dielectric layer divides the filter's resonant cavity into two. Each second via electrically connects the first metal pattern in the upper first window 11 to the second metal pattern in the lower second window 13. Thus, the filter's interior is divided into two resonant cavities, R1 and R2. Electromagnetic hybrid coupling between the two resonant cavities R1 and R2 is achieved through coupling windows formed by openings in the upper and lower metal layers. By adjusting the dimensions of resonant cavities R1 and R2, the filter can be controlled to operate in quasi-TEM mode and TE201 mode, achieving dual-passband and wide-passband switching.

[0043] For details, see Figure 2 and Figure 4 As shown, with the half-width L1 of the fixed resonant cavity remaining constant, the length W1 of the resonant cavity is continuously adjusted. Through simulation, a critical value for W1 can be found. Below this critical value, the silicon-based ultra-wideband / dual-passband tunable microwave filter is a dual-passband filter; above this critical value, it is an ultra-wideband filter. In practical applications, the length W1 of the resonant cavity is the length of the first rectangular metal sheet 10. Taking the aforementioned critical value as a target length for the first rectangular metal sheet 10, when the length W1 of the first rectangular metal sheet 10 is lower than this target length, the silicon-based ultra-wideband / dual-passband tunable microwave filter is a dual-passband filter; when the length W1 of the first rectangular metal sheet 10 is higher than this target length, it is a wideband filter.

[0044] In one embodiment, see Figure 2 and Figure 3 As shown, the first metal pattern may include: a pair of first strip-shaped metal pieces 15 and a pair of second strip-shaped metal pieces 16; wherein, the pair of first strip-shaped metal pieces 15 are symmetrical about the central origin of the first window 11 and connected to the first rectangular metal piece 10; the pair of second strip-shaped metal pieces 16 are symmetrical about the central origin of the first window 11; the second strip-shaped metal pieces 16 are not connected to the first rectangular metal piece 10; correspondingly, the second metal pattern may include three third strip-shaped metal pieces 23, which are arranged in parallel; thus, as in Figure 3 As shown, the first and second metal patterns can be electrically connected through 3×2 second through holes arranged in a matrix.

[0045] In one embodiment, such as Figure 4 and Figure 5As shown, the first metal pattern may include: a fourth strip metal piece 45, a pair of fifth strip metal pieces 43, and a pair of sixth strip metal pieces 44; wherein, the line connecting the midpoints of the long sides of the fourth strip metal piece 45 coincides with the aforementioned axis of symmetry, which is the axis of symmetry along which the plurality of first through holes are arranged at intervals; the aforementioned pair of fifth strip metal pieces 43 are parallel to the fourth strip metal piece 45 and connected to the first rectangular metal piece 10, and the pair of fifth strip metal pieces 43 are respectively located on both sides of the fourth strip metal piece 45 and are symmetrical about the aforementioned axis of symmetry; the aforementioned pair of sixth strip metal pieces 44 are parallel to the fourth strip metal piece 45 and are symmetrical about the aforementioned axis of symmetry; correspondingly, the second metal pattern may include four seventh strip metal pieces 53, which are arranged in parallel; thus, as in Figure 5 As shown, the first and second metal patterns can be electrically connected through a matrix of 4×2 second through holes.

[0046] It is understood that there are many combinations of upper and lower metal patterns that can form a three-dimensional spiral inductor in practice. Therefore, the two combinations of upper and lower metal patterns given above are only preferred examples and do not constitute a limitation on the embodiments of the present invention. In practice, other three-dimensional spiral inductors can be designed based on the idea of ​​forming a three-dimensional spiral inductor by combining upper and lower metal patterns in the embodiments of the present invention.

[0047] In practical applications, the first metal layer 1 also includes an input stub 8 and an output stub 9 to facilitate connection between the filter and integrated pre- and post-stage devices. The input stub 8 forms the input port of the filter, and the output stub 9 forms the output port. The input stub 8 and output stub 9 are respectively connected to two sides of the first rectangular metal sheet 10. These two sides are symmetrical about an axis of symmetry of the silicon-based composite dielectric layer. This axis of symmetry is also the axis of symmetry along which the plurality of first vias in the silicon-based composite dielectric layer are arranged at intervals. (See [reference needed] for details.) Figure 2 and Figure 4 As shown.

[0048] For example, as in Figure 2 and Figure 4 As shown, both the input stub 8 and the output stub 9 can be L-shaped stubs, with the short side of the L-shaped stub connected to the side of the first rectangular metal sheet 10 and the long side parallel to the side of the first rectangular metal sheet 10.

[0049] In one embodiment, such as in Figure 2 and Figure 4As shown, notches 7 can be formed on both sides of the first rectangular metal sheet 10; the positions where the input stub 8 and the output stub 9 connect to the two sides of the first rectangular metal sheet 10 are both located in the notches 7, which can reduce the in-band insertion loss of the silicon-based ultrawide passband / dual passband adjustable microwave filter.

[0050] based on Figure 2 or Figure 4 The working process of the silicon-based microblogging filter provided in this embodiment of the invention is explained below using the filter structure shown:

[0051] First, electromagnetic waves are input from the filter's input port to the resonant cavity R1, simultaneously exciting electromagnetic waves in both the quasi-TEM mode and the TE201 mode. Then, the waves are coupled through the coupling window to the resonant cavity R2, and finally output from the filter's output port. Since the frequency of the quasi-TEM mode depends only on the length of the resonant cavity, while the frequency of the TE201 mode is determined by both the length and width of the resonant cavity, a wide-passband filter can be achieved by fixing the width of the resonant cavity and adjusting its length to be higher than the target length of the first rectangular metal plate 10, making the frequency of the TE201 mode similar to that of the quasi-TEM mode; or, by adjusting the length of the resonant cavity to be lower than the target length of the first rectangular metal plate 10, separating the frequencies of the TE201 mode from those of the quasi-TEM mode.

[0052] In one specific embodiment, this invention provides a silicon-based ultrawideband microwave filter with quasi-TEM and TE201 electromagnetic resonant modes, the structure of which is described below. Figure 2 and Figure 3 As shown, its specific structural parameters are shown in Table 1:

[0053] Table 1

[0054]

[0055]

[0056]

[0057] Figure 6 The above-mentioned silicon-based ultrawide passband microwave filter is shown in its passband frequency response diagram. Figure 6 As can be seen, the filter achieves a relative bandwidth of 63.6%.

[0058] In another specific embodiment, this invention provides a silicon-based dual-passband microwave filter with quasi-TEM and TE201 electromagnetic resonant modes, the structure of which is described below. Figure 4 and Figure 5 As shown, its specific structural parameters are shown in Table 2:

[0059] Table 2

[0060]

[0061]

[0062] Figure 7 The above-mentioned silicon-based dual-passband microwave filter is shown in its passband frequency response diagram. Figure 7 As can be seen, the filter has two passbands with center frequencies of 13.89 GHz and 21.21 GHz.

[0063] In summary, the silicon-based ultrawide / dual-passband tunable microwave filter provided in this embodiment of the invention is a three-dimensional passive device fabricated using a silicon substrate. This reduces the filter area, making it more convenient for integration with other devices. Furthermore, by controlling the size of the filter's resonant cavity, the conversion between a dual-passband filter and an ultrawide-passband filter can be achieved.

[0064] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A silicon-based ultrawide passband / dual passband tunable microwave filter, characterized in that, include: A silicon-based composite dielectric layer, a first metal layer (1), and a second metal layer (5); The first metal layer (1) is superimposed on the upper surface of the silicon-based composite dielectric layer, and the second metal layer (5) is superimposed on the lower surface of the silicon-based composite dielectric layer; the first metal layer (1) is provided with a first window (11), and a first metal pattern is provided in the first window (11); the second metal layer (5) is provided with a second window (13), and a second metal pattern is provided in the second window (13). The silicon-based composite dielectric layer has multiple through-holes, each containing a metal pillar (6) surrounded by silicon dioxide. The first metal layer (1) and the second metal layer (5) are electrically connected through the metal pillars (6), thereby forming a three-dimensional spiral inductor in the silicon-based ultra-wideband / dual-band tunable microwave filter using the first and second metal patterns. The first metal layer (1) includes: a first rectangular metal sheet (10); two first windows (11) are symmetrically opened in the middle of the first rectangular metal sheet (10), and the two first windows (11) are spaced apart from each other; the first metal pattern is provided in each of the two first windows (11); The second metal layer (5) includes: a second rectangular metal sheet (20); two second windows (13) are symmetrically opened in the middle of the second rectangular metal sheet (20), the opening positions of the two second windows (13) and the two first windows (11) are vertically corresponding, and the two second windows (13) are provided with the second metal pattern. The plurality of through holes includes: a plurality of first through holes and a plurality of second through holes; The plurality of first through holes are arranged at intervals along a symmetry axis of the silicon-based composite dielectric layer within the specified distance; the metal pillars (6) in the plurality of second through holes are used to electrically connect the corresponding first metal patterns and second metal patterns above and below.

2. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, The first metal pattern includes: a pair of first strip metal pieces (15) and a pair of second strip metal pieces (16); wherein, the pair of first strip metal pieces (15) are symmetrical about the center origin of the first window (11) and connected to the first rectangular metal piece (10); the pair of second strip metal pieces (16) are symmetrical about the center origin of the first window (11); The second metal pattern includes three third strip-shaped metal sub-pieces (23), which are arranged in parallel. The first metal pattern and the second metal pattern are electrically connected through a matrix of 3×2 second through holes.

3. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, The first metal pattern includes: a fourth strip-shaped metal piece (45), a pair of fifth strip-shaped metal pieces (43), and a pair of sixth strip-shaped metal pieces (44); wherein, the line connecting the midpoints of the long side of the fourth strip-shaped metal piece (45) coincides with the axis of symmetry; the pair of fifth strip-shaped metal pieces (43) are parallel to the fourth strip-shaped metal piece (45) and connected to the first rectangular metal piece (10), the pair of fifth strip-shaped metal pieces (43) are located on both sides of the fourth strip-shaped metal piece (45) and are symmetrical about the axis of symmetry; the pair of sixth strip-shaped metal pieces (44) are parallel to the fourth strip-shaped metal piece (45) and are symmetrical about the axis of symmetry; The second metal pattern includes four seventh strip metal sub-pieces (53), which are arranged in parallel. The first metal pattern and the second metal pattern are electrically connected through a matrix of 4×2 second through holes.

4. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, The first metal layer (1) further includes: an input stub (8) and an output stub (9); The input branch (8) and the output branch (9) are respectively connected to the two sides of the first rectangular metal sheet (10), and the two sides are symmetrical about the axis of symmetry.

5. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 4, characterized in that, Both sides have notches (7); the input branch (8) and the output branch (9) are located in the notches (7) where they connect to the two sides.

6. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, When the length W1 of the first rectangular metal sheet (10) is lower than the target length, the silicon-based ultra-wide passband / dual passband adjustable microwave filter is a dual passband filter; when the length W1 of the first rectangular metal sheet (10) is higher than the target length, the silicon-based ultra-wide passband / dual passband adjustable microwave filter is a wide passband filter; the target length is obtained through simulation.

7. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, The silicon-based composite dielectric layer includes: a silicon dielectric layer (3), a first SiO2 dielectric layer (2), and a second SiO2 dielectric layer (4); The first SiO2 dielectric layer (2) is superimposed on the upper surface of the silicon dielectric layer (3), and the second SiO2 dielectric layer (4) is superimposed on the lower surface of the silicon dielectric layer (3); The first metal layer (1) is superimposed on the upper surface of the first SiO2 dielectric layer (2), and the second metal layer (5) is superimposed on the lower surface of the second SiO2 dielectric layer (4).

8. The silicon-based ultrawide passband / dual passband tunable microwave filter according to claim 1, characterized in that, The first metal layer (1) and the second metal layer (5) are both made of copper.

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