Multilayer dual-channel substrate integrated waveguide filter
By designing a cross slot in a multi-layer dual-channel substrate integrated waveguide filter, orthogonal coupling and energy transmission of the TE102 and TE201 modes are achieved, solving the size and isolation problems of traditional filters and realizing high-performance dual-passband filtering.
Patent Information
- Application Number
- CN202510956522.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-10-17
AI Technical Summary
Traditional multi-band filter designs face problems such as excessive size, high insertion loss, or insufficient inter-mode isolation, making it difficult to achieve high-isolation dual-passband response and flexible frequency adjustment in a compact structure.
A multilayer dual-channel substrate integrated waveguide filter is designed. A cross slot is opened on the metal substrate between adjacent SIW cavities. The intersection is located at the center of the SIW cavity and at the point where the magnetic fields of the TE102 mode and TE201 mode are the strongest. This forms a vertical electromagnetic coupling channel. The modal coupling amount is controlled by adjusting the slot length, and orthogonal mode coupling is achieved by combining a multilayer structure.
It achieves high isolation and good frequency selection characteristics in a compact structure, avoids mode interference and crosstalk, and supports dual-passband filtering with flexible frequency adjustment.
Smart Images
Figure CN120810205A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to a multilayer double-channel substrate integrated waveguide filter and belongs to the technical field of microwave communication. BACKGROUND
[0002] With the rapid development of 5G communication, millimeter wave radar and satellite communication systems, the demand for high-performance, miniaturized and multi-band filters in radio frequency front-ends is increasing. Traditional multi-band filter design methods, such as cascaded filter groups or single-cavity multi-mode structures, often face problems such as excessive size, high insertion loss or insufficient mode isolation. In recent years, SIW has become an ideal choice for realizing high-performance filters due to its low loss, high Q value and compatibility with planar circuits. However, how to realize high-isolation double-passband response in a compact structure while supporting flexible frequency adjustment remains one of the current research challenges. SUMMARY
[0003] The application provides a multilayer double-channel substrate integrated waveguide filter, which solves the problems disclosed in the background art.
[0004] According to one aspect of the application, a multilayer double-channel substrate integrated waveguide filter is provided, comprising a plurality of stacked SIW cavities, a cross-slot is formed on the metal substrate between adjacent SIW cavities, the intersection of the cross-slot is located at the center of the SIW cavity and at the position of the strongest magnetic field of the TE 102 mode and the TE 201 mode.
[0005] Further, the first direction slots of all cross-slots are arranged at equal intervals and form vertical electromagnetic coupling channels. The second direction slots of all cross-slots are arranged at equal intervals and form vertical electromagnetic coupling channels.
[0006] Further, the top metal substrate of the filter is provided with a first direction input port and a second direction input port, and the bottom metal substrate of the filter is provided with a first direction output port and a second direction output port. The first direction input port, the first direction slots of all cross-slots, and the first direction output port constitute a first channel, and the second direction input port, the second direction slots of all cross-slots, and the second direction output port constitute a second channel.
[0007] Further, the first channel couples the TE 102 mode to suppress the TE 201 mode, and the second channel couples the TE 102 mode to suppress the TE 201 mode.
[0008] Further, the working frequency of the first channel is controlled by the length of the SIW cavity, and the working frequency of the second channel is controlled by the width of the SIW cavity.
[0009] Further, the input port and the output port both adopt a transition structure from a microstrip line to a coplanar waveguide.
[0010] Further, the magnetic coupling amount of the TE 102 mode is controlled by adjusting the length of the first direction slot of the cross slot, and the magnetic coupling amount of the TE 201 mode is controlled by adjusting the length of the second direction slot of the cross slot.
[0011] Further, the first direction slot and the second direction slot of the cross slot are both parallel to the side wall of the SIW cavity.
[0012] Further, the first direction slots of all the cross slots are arranged at equal intervals, and the second direction slots of all the cross slots are arranged at equal intervals.
[0013] The present application has the following beneficial effects: the present application opens a cross slot on the metal substrate between adjacent SIW cavities, the intersection of the cross slot is located at the center of the SIW cavity and at the position where the magnetic field of the TE 102 mode and the TE 201 mode is the strongest, not only can the TE 102 / TE 201 mode and the TE 101 mode be physically separated to improve the isolation degree, but also the strong coupling and energy transmission of the TE 102 and TE 201 two orthogonal modes can be realized, and this unique orthogonal mode coupling mechanism combined with the multi-layer structure makes the structure not only maintain compact size, but also exhibit good frequency selection characteristics and high channel isolation, without mode interference and crosstalk of traditional multi-channel filters, realizing high-performance double-passband filtering function. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 is an exploded view of the multi-layer double-channel substrate integrated waveguide filter; Figure 2 is a top view of the multi-layer double-channel substrate integrated waveguide filter; Figure 3 is an S parameter diagram of the multi-layer double-channel substrate integrated waveguide filter. DETAILED DESCRIPTION
[0015] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. The following description of at least one example embodiment is merely illustrative in nature and not intended to be limiting on the present application and its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present application.
[0016] Unless specifically stated otherwise, the relative arrangements of the components and steps, numerical expressions, and values shown in the drawings described in these embodiments do not limit the scope of the present application.
[0017] It should be understood that the sizes of the various portions shown in the drawings are not necessarily drawn to scale for ease of description.
[0018] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail in order to avoid obscuring the present application.
[0019] In all of the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of example embodiments can have different values.
[0020] It should be noted that like symbols and letters in the drawings represent like items, such that once an item is defined in one drawing, it is not necessary to discuss it further in subsequent drawings.
[0021] In the description of the embodiments of the present application, the terms "first", "second", and the like are used only to distinguish descriptions, and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features.
[0022] The embodiments of the present application provide a multi-layer double-channel substrate integrated waveguide filter, which can at least include a plurality of stacked SIW cavities, and a cross slot is formed on the metal substrate between adjacent SIW cavities, the intersection of the cross slot is located at the center of the SIW cavity and at the position where the magnetic field of the TE 102 mode and the TE 201 mode is the strongest.
[0023] Since the orthogonal degenerate modes (TE 102 and TE 201 ) have a 90-degree orthogonal magnetic field distribution but the magnetic field intensity at the center of the cavity is high, and the TE 101The magnetic field strength is weak in the center, so the adjacent SIW cavities are magnetically coupled through the cross slots, which can effectively magnetically couple the TE 102 and TE 201 Inhibit TE 101 , physically split TE 102 / TE 201 Die and TE 101 mode, improve isolation, and combine TE 102 Mould and TE 201 Due to the orthogonal characteristics of the modes, this design can achieve excellent frequency selectivity and channel isolation.
[0024] It should be noted that the structure of all SIW cavities is consistent, including a dielectric substrate with a metallized through hole array on two metal substrates and between the two metal substrates. The metallized through holes in the metallized through hole array can be enclosed into a rectangle, and the radius of all metallized through holes is consistent.
[0025] In some embodiments, the first direction slots of all cross slots are arranged at equal intervals and form a vertical portion of the first channel, and the second direction slots of all cross slots are arranged at equal intervals and form a vertical portion of the second channel.
[0026] It should be noted that an innovative through-slot design is adopted in the multi-layer SIW cavity. Specifically, a cross slot is etched on the metal substrate between the first layer SIW cavity and the second layer SIW cavity, and a cross slot of the same specification is etched on the metal substrate between the second layer SIW cavity and the third layer SIW cavity.
[0027] It should be noted that the first direction slot and the second direction slot of the cross slot are parallel to the side wall of the SIW cavity. The TE can be controlled by adjusting the length of the first direction slot of the cross slot. 102 The magnetic coupling of the mode can be controlled by adjusting the length of the second direction slot of the cross slot. 201 The magnetic coupling of the modes.
[0028] Taking a four-layer SIW cavity as an example, the X-axis direction is the first direction and the Y-axis direction is the second direction. Figure 1In the figure, the top SIW cavity of the filter is composed of a top metal substrate 1, a first dielectric substrate 2 and a metallized through-hole array provided therein, and a middle first metal substrate 4; the middle first-layer SIW cavity is composed of the middle first metal substrate 4, the second dielectric substrate 5 and a metallized through-hole array provided therein, and the middle second metal substrate 6; the middle second-layer SIW cavity is composed of the middle second metal substrate 6, the third dielectric substrate 7 and a metallized through-hole array provided therein, and the middle third metal substrate 8; the bottom SIW cavity is similar to the top layer, and is composed of the middle third metal substrate 8, the fourth dielectric substrate 9 and a metallized through-hole array provided therein, and the bottom metal substrate 10; wherein the radius of the metallized through-holes on the dielectric substrates is uniform, which can be 0.5 mm, and the spacing between the centers of the metallized through-holes can be approximately 1.4 mm.
[0029] A cross slot is precisely etched on the first metal substrate 4 in the middle. The cross slot is composed of an X-direction slot 11 and a Y-direction slot 12 orthogonally. At the same time, cross slots of the same specifications are etched at the corresponding positions of the second metal substrate 6 and the third metal substrate 8 in the middle. These slots arranged at equal intervals form a vertical electromagnetic coupling channel. 102 / TE 201 Mixed-mode excitation enables controllable energy coupling between the four-layer cavities.
[0030] like Figure 2 As shown, the intersection of all cross slots is located at the center of the SIW cavity and is at TE 102 Mould and TE 201 At the point where the magnetic field of the die is the strongest, the cross slot is parallel to the side wall of the SIW cavity. By adjusting the length of the X-direction slot 11 and the Y-direction slot 12, the TE 102 Mould and TE 201 The magnetic coupling of the mode.
[0031] In some embodiments, the ports of the above-mentioned filter adopt a dual-input dual-output architecture. Specifically, the top metal substrate 1 of the filter is provided with a first direction input port and a second direction input port, and the bottom metal substrate 10 of the filter is provided with a first direction output port and a second direction output port. Both the input port and the output port adopt a transition structure from microstrip line to coplanar waveguide.
[0032] The first direction input port, the first direction slots of all cross slots, and the first direction output port constitute a first channel. The first channel couples TE 102 Mode suppression TE 201 The second direction input port, the second direction slots of all cross slots, and the second direction output port constitute a second channel, and the second channel suppresses TE 102 Mode-coupled TE 201The combination can separate TE 102 modes and TE 201 modes, so as to separately couple TE 102 modes or TE 201 modes, and realize double channels and high isolation by cooperating with the cross-slot gap. The working frequency of the double channels is adjusted by the length and width of the SIW cavity. The length of the SIW cavity mainly controls the frequency of the TE 102 mode, thereby controlling the working frequency of the first channel, and the width of the SIW cavity mainly controls the frequency of the TE 201 mode, thereby controlling the working frequency of the second channel. The TE 102 / TE 201 mixed mode excitation realizes controllable energy coupling between the multi-layer cavities.
[0033] It should be noted that, by accurate design, the first channel can be symmetrical along the X axis, and the second channel can be symmetrical along the Y axis. In combination with the optimization of the SIW cavity size, the first channel can support TE 102 mode and suppress TE 201 mode, and the second channel can support TE 201 mode and suppress TE 102 mode. Different channels support different working modes (TE 102 and TE 201 ) respectively, like two independent signal channels, which can work simultaneously and do not interfere with each other.
[0034] Taking the structure of Figure 1 as an example, the X-direction input port 13 (center frequency 10 GHz) and the Y-direction input port 14 (center frequency 12 GHz) are integrated on the top metal substrate 1, and the X-direction output port 15 and the Y-direction output port 3 are correspondingly arranged on the bottom metal substrate 10. All the ports adopt an optimized tapered microstrip-coplanar waveguide transition structure, in which the microstrip line impedance is set to 50 Ω. The X-direction input port 13 and the X-direction output port 15 constitute the first channel, which works in the TE 102 mode. The Y-direction input port 14 and the Y-direction output port 3 constitute the second channel, which works in the TE 201 mode.
[0035] Referring to Figure 3 , the S parameter test curve of the filter in the figure shows that the center frequencies of the double channels are stably set at 10 GHz of the first channel and 12 GHz of the second channel, and the 3-dB relative bandwidth is accurately controlled at 5%±0.2% (the measured value: 4.96% of the first channel and 5.1% of the second channel). The in-band return loss S 11All are better than -20 (the first channel -20.1dB, the second channel -21.5dB). As can be seen from the S parameter curve of the filter, the filter can be used to independently control the passband size without affecting the isolation, greatly expanding the center frequency ratio range.
[0036] The filter above opens a cross slot on the metal substrate between adjacent SIW cavities, the intersection of the cross slot is located at the center of the SIW cavity and at the position of the magnetic field of the TE 102 and TE 201 mode is the strongest, not only can physically separate TE 102 / TE 201 and TE 101 mode, improve the isolation, but also can realize the strong coupling and energy transmission of TE 102 and TE 201 two orthogonal modes, this unique orthogonal mode coupling mechanism combined with multi-layer structure, makes the structure not only keep compact size, but also shows good frequency selection characteristics and high channel isolation, there is no mode interference and crosstalk of traditional multi-channel filter, realizes the high performance of double passband filter function.
[0037] The above only describes the preferred embodiments of the present application, it should be noted that for those skilled in the art, without departing from the technical principles of the present application, can make several improvements and modifications, these improvements and modifications should also be considered as the protection scope of the present application.
Claims
1. A multi-layer dual-channel substrate integrated waveguide filter, characterized in that: It includes multiple stacked SIW cavities, a cross slot is opened on the metal substrate between adjacent SIW cavities, and the intersection of the cross slot is located at the center of the SIW cavity and at the TE 102 Mould and TE 201 The magnetic field of the mold is the strongest.
2. The filter according to claim 1, wherein The top metal substrate of the filter is provided with a first direction input port and a second direction input port, and the bottom metal substrate of the filter is provided with a first direction output port and a second direction output port. The first direction input port, the first direction slots of all cross slots, and the first direction output port constitute a first channel, and the second direction input port, the second direction slots of all cross slots, and the second direction output port constitute a second channel.
3. The filter according to claim 2, characterized in that The first channel is coupled to TE 102 Mode suppression TE 201 mode, the second channel suppresses TE 102 Mode-coupled TE 201 mold.
4. The filter according to claim 2 or 3, characterized in that The operating frequency of the first channel is controlled by the length of the SIW cavity, and the operating frequency of the second channel is controlled by the width of the SIW cavity.
5. The filter according to claim 2, wherein Both the input port and the output port adopt a transition structure from microstrip line to coplanar waveguide.
6. The filter according to claim 1 or 2, characterized in that By adjusting the length of the first direction of the cross slot, the TE 102 The magnetic coupling of the mode; By adjusting the length of the second direction slot of the cross slot, the TE 201 The magnetic coupling of the mode.
7. The filter according to claim 6, characterized in that The first direction slots and the second direction slots of the cross slot are both parallel to the side wall of the SIW cavity.
8. The filter according to claim 6, characterized in that The first direction slots of all the cross slots are arranged at equal intervals, and the second direction slots of all the cross slots are arranged at equal intervals.