LTCC high pass filter and radio frequency communication link
By introducing cross-coupling capacitors and equivalent inductors into the LTCC high-pass filter, the problem of volume increase resulting in increased order of the prior art and slow stopband attenuation is solved, and smaller volumes and steeper stopband attenuation characteristics are achieved.
Patent Information
- Application Number
- CN202411978694.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-29
AI Technical Summary
When existing LTCC high-pass filters realize steep stopband attenuation characteristics, they need to increase the order of the filter, resulting in volume increase and insertion loss, making it difficult to achieve smaller volume and steeper stopband attenuation under the same order conditions.
By introducing cross-coupling capacitors and cross-coupling equivalent inductors into the LTCC high-pass filter, a double transmission zero structure is formed, thereby increasing the number of transmission zero points of the filter, achieving faster stopband attenuation and better rectangular coefficients and steep characteristics.
Under the same order conditions, steeper stopband attenuation characteristics are achieved, reducing insertion losses, increasing bandwidth width, and achieving these effects in smaller volumes.
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Figure CN119906380A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of electronic technology, and in particular to an LTCC high-pass filter and a radio frequency communication link. Background Art
[0002] High-pass filter is one of the important components in RF communication links. It can pass high-frequency signals (such as signals above a certain frequency) with low loss and block the passage of low-frequency signals, thereby filtering low-frequency signals. In situations where there are high requirements for volume, LTCC (low-temperature co-fired ceramic) high-pass filters are widely used because they occupy a small area and can achieve the smallest possible volume.
[0003] However, in order to achieve better filtering and screening effects on signals, the LTCC high-pass filter must have the characteristics of low insertion loss and steep stopband attenuation, so as to improve the passing capacity of effective signals and attenuate interference signals. However, in order to obtain steep stopband attenuation characteristics, the commonly used approach is to increase the order of the filter, which will increase the overall size of the filter and increase the insertion loss in the passband.
[0004] Therefore, it is particularly important to obtain a steeper stopband attenuation characteristic under the same order conditions, that is, to achieve the smallest possible volume. Summary of the invention
[0005] In view of this, the embodiments of the present application provide a LTCC high-pass filter and a radio frequency communication link to solve at least one problem existing in the background technology.
[0006] In a first aspect, an embodiment of the present application provides a LTCC high-pass filter, the LTCC high-pass filter comprising:
[0007] A LTCC multilayer structure formed by stacking green ceramic sheets with printed metal layers on the surface;
[0008] The internal formation of the LTCC multilayer structure includes at least one of the following:
[0009] A cross-coupled capacitor structure, used to form a series capacitor group, and at least one cross-coupled capacitor realized based on mutual coupling of preset capacitors in the capacitor group and connected in parallel with the capacitor group; the capacitor group is connected between the input electrode and the output electrode of the LTCC high-pass filter;
[0010] A cross-coupled inductor structure is used to form an inductor group connected in parallel to the ground, and at least one first cross-coupled equivalent inductor and / or at least one second cross-coupled equivalent inductor realized based on the mutual coupling of preset inductors in the inductor group; the first cross-coupled equivalent inductor is equivalent to a capacitor connected in parallel with the input electrode in an equivalent circuit, and the second cross-coupled equivalent inductor is equivalent to a capacitor connected in parallel with the output electrode in an equivalent circuit; each inductor in the inductor group is connected between each end of each capacitor in the capacitor group and the ground terminal.
[0011] In combination with the first aspect, in an optional implementation,
[0012] The capacitor group and the inductor group form a 2N+1-order high-pass filter basic circuit of the LTCC high-pass filter; wherein N is a natural number greater than or equal to 1.
[0013] In combination with the first aspect, in an optional implementation,
[0014] The LTCC high-pass filter includes a seventh-order high-pass filter basic circuit, a twelfth cross-coupling capacitor, a thirteenth cross-coupling equivalent inductor and a twenty-fourth cross-coupling equivalent inductor;
[0015] The capacitor group includes a thirteenth capacitor, a thirty-fourth capacitor and a twenty-fourth capacitor connected in series between the input electrode and the output electrode; the inductor group includes a tenth inductor, a thirtieth inductor, a fortieth inductor and a twentieth inductor to form the seventh-order high-pass filter basic circuit;
[0016] Wherein, based on the parallel plate capacitor structure, a thirteenth capacitor, a thirty-fourth capacitor and a twenty-fourth capacitor are formed between the multilayer sheets and connected in series between the input electrode and the output electrode; and a twelfth cross-coupling capacitor connected in parallel with the capacitor group is formed by mutual coupling of the thirteenth capacitor and the twenty-fourth capacitor;
[0017] Based on the spiral winding inductor structure, a tenth inductor, a thirtieth inductor, a fortieth inductor and a twentieth inductor are formed between the multilayer sheets, and the first end of the tenth inductor is connected to the input electrode, the first end of the thirtieth inductor is connected to the series node between the thirteenth capacitor and the thirty-fourth capacitor, the first end of the fortieth inductor is connected to the series node between the thirty-fourth capacitor and the twenty-fourth capacitor, the first end of the twentieth inductor is connected to the output electrode, and the second ends of the tenth inductor, the thirtieth inductor, the fortieth inductor and the twentieth inductor are respectively connected to the ground terminal; and a thirteenth cross-coupled equivalent inductor connected in parallel with the thirteenth capacitor is formed by mutual coupling between the tenth inductor and the thirtieth inductor, and a twenty-fourth cross-coupled equivalent inductor connected in parallel with the twenty-fourth capacitor is formed by mutual coupling between the twentieth inductor and the fortieth inductor.
[0018] In combination with the first aspect, in an optional implementation,
[0019] The cross-coupled inductor structure comprises:
[0020] At least two first inductor sheet layers with inductor winding wires are arranged to form a tenth inductor and a twentieth inductor of a spiral winding inductor structure; and the tenth inductor and the twentieth inductor are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure; and
[0021] A second inductor sheet group having at least two layers of inductor winding wires is used to form a 30th inductor and a 40th inductor of a spiral winding inductor structure; and the 30th inductor and the 40th inductor are mirror-symmetrical about the symmetry plane; and the 30th inductor and the tenth inductor overlap in the stacking direction of the sheets to achieve mutual coupling between the 30th inductor and the tenth inductor; and the 40th inductor and the 20th inductor overlap in the stacking direction of the sheets to achieve mutual coupling between the 40th inductor and the 20th inductor.
[0022] In combination with the first aspect, in an optional implementation,
[0023] The cross-coupled inductor structure includes, from top to bottom, a sixth layer, a seventh layer, an eighth layer and a ninth layer;
[0024] The surface of the sixth layer is provided with a first inductor winding wire of the 30th inductor, and a first end of the first inductor winding wire is connected to a series node between the 13th capacitor and the 34th capacitor through a hole column; and a first inductor winding wire of the 40th inductor, and a first end of the first inductor winding wire is connected to a series node between the 34th capacitor and the 24th capacitor through a hole column;
[0025] The surface of the seventh layer is provided with a second inductor winding wire of the 30th inductor, and the first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the 30th inductor through a hole column; and a second inductor winding wire of the 40th inductor, and the first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the 40th inductor through a hole column; and the second end of the second inductor winding wire of the 30th inductor and the second end of the second inductor winding wire of the 40th inductor are respectively connected to the third grounding electrode through the hole column;
[0026] The surface of the eighth layer is provided with a first inductor winding wire of a tenth inductor, and a first end of the first inductor winding wire is connected to the input electrode; and a first inductor winding wire of a twentieth inductor, and a first end of the first inductor winding wire is connected to the output electrode;
[0027] The surface of the ninth layer is provided with a second inductor winding wire of the tenth inductor, and a first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the tenth inductor through a hole column; and a second inductor winding wire of the twentieth inductor, and a first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the twentieth inductor through a hole column; and the second end of the second inductor winding wire of the tenth inductor and the second end of the second inductor winding wire of the twentieth inductor are respectively connected to the third grounding electrode through the hole column.
[0028] In combination with the first aspect, in an optional implementation,
[0029] The cross-coupling capacitor structure comprises:
[0030] At least two first capacitor layer groups with capacitor plates are used to form a thirteenth capacitor and a twenty-fourth capacitor of a parallel plate capacitor structure; and the thirteenth capacitor and the twenty-fourth capacitor are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure;
[0031] at least two layers of a second capacitor layer group with capacitor plates arranged therein, for forming a thirty-fourth capacitor of a parallel plate capacitor structure; and the thirty-fourth capacitor is mirror-symmetrical about the symmetry plane; and
[0032] At least one third capacitor layer group with capacitor plates arranged thereon is used to form a twelfth cross-coupling capacitor that is mutually coupled with the thirteenth capacitor and the twenty-fourth capacitor, and the capacitor plates of the twelfth cross-coupling capacitor overlap with the capacitor plates of the thirteenth capacitor and the capacitor plates of the twenty-fourth capacitor in the stacking direction of the layers, and the capacitor plates of the twelfth cross-coupling capacitor are mirror-symmetrical about the symmetry plane.
[0033] In combination with the first aspect, in an optional implementation,
[0034] The cross-coupling capacitor structure comprises a first layer, a second layer and a third layer from top to bottom;
[0035] The surface of the second layer is provided with a first capacitor plate of a thirteenth capacitor, and the first capacitor plate of the thirteenth capacitor is connected to the input electrode; and a first capacitor plate of a twenty-fourth capacitor, and the first capacitor plate of the twenty-fourth capacitor is connected to the output electrode;
[0036] The surface of the third layer is provided with the second capacitor plate of the thirteenth capacitor and the second capacitor plate of the twenty-fourth capacitor; the first capacitor plate of the thirteenth capacitor and the second capacitor plate of the thirteenth capacitor are coupled in parallel to form the thirteenth capacitor; the first capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the twenty-fourth capacitor are coupled in parallel to form the twenty-fourth capacitor;
[0037] The surface of the first layer is provided with a first capacitor plate and a second capacitor plate of a twelfth cross-coupling capacitor which are connected to each other; the first capacitor plate of the twelfth cross-coupling capacitor is respectively coupled to at least one of the first capacitor plate of the thirteenth capacitor and the second capacitor plate of the thirteenth capacitor, and the second capacitor plate of the twelfth cross-coupling capacitor is respectively coupled to at least one of the first capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the twenty-fourth capacitor to form the twelfth cross-coupling capacitor.
[0038] In combination with the first aspect, in an optional implementation,
[0039] The cross-coupling capacitor structure further includes a fourth layer and a fifth layer from top to bottom;
[0040] The third layer surface arrangement also includes a first capacitor plate and a second capacitor plate of a thirty-fourth capacitor; the first capacitor plate of the thirty-fourth capacitor is connected to the second capacitor plate of the thirteenth capacitor, and the second capacitor plate of the thirty-fourth capacitor is connected to the second capacitor plate of the twenty-fourth capacitor;
[0041] The surface of the fourth sheet layer is provided with a third capacitor plate and a fourth capacitor plate of a thirty-fourth capacitor connected to each other;
[0042] The surface of the fifth layer is arranged with the fifth capacitor plate and the sixth capacitor plate of the thirty-fourth capacitor; the fifth capacitor plate of the thirty-fourth capacitor is connected to the series node between the second capacitor plate of the thirteenth capacitor and the first capacitor plate of the thirty-fourth capacitor through a hole column; the sixth capacitor plate of the thirty-fourth capacitor is connected to the series node between the second capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the thirty-fourth capacitor through a hole column; and there is overlap between the first capacitor plate, the third capacitor plate and the fifth capacitor plate, and between the second capacitor plate, the fourth capacitor plate and the sixth capacitor plate of the thirty-fourth capacitor in the stacking direction of the layers.
[0043] In combination with the first aspect, in an optional implementation,
[0044] The LTCC high pass filter comprises:
[0045] A left metal strip, arranged on the left side of the LTCC multilayer structure and with two ends of the left metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as the input electrode;
[0046] A right metal strip, arranged on the right side of the LTCC multilayer structure and with two ends of the right metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as the output electrode;
[0047] A front metal strip, arranged on the front side of the LTCC multilayer structure, with two ends of the front metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, to serve as a first grounding electrode;
[0048] A rear metal strip, arranged on the rear side of the LTCC multilayer structure and with two ends of the rear metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as a second grounding electrode; and
[0049] The tenth layer has a third grounding electrode disposed on its surface, with two ends thereof respectively connected to the first grounding electrode and the second grounding electrode.
[0050] In a second aspect, an embodiment of the present application provides a radio frequency communication link, comprising the LTCC high-pass filter as described in the first aspect.
[0051] The beneficial effects of the technical solution provided by the embodiment of the present application include: the number of transmission zeros of the filter can be increased by cross-coupling capacitors; the number of transmission zeros of the filter can also be increased by cross-coupling equivalent inductors, so that the stop band can achieve faster decline attenuation under the same order conditions as the traditional LTCC high-pass filter, obtain steep characteristics, and increase the bandwidth. For example, by adding cross-coupling inductor branches and cross-coupling capacitor branches to the filter, a dual transmission zero structure can be formed, which can solve the problems of large insertion loss and slow stop band attenuation of the traditional LTCC high-pass filter, accelerate the attenuation speed of the stop band, obtain better rectangular coefficients and steep characteristics, and obtain better filtering characteristics and bandwidth.
[0052] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below and in part will become apparent from the description below or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0054] Figure 1 A schematic diagram of an equivalent circuit of a specific example of a π-type circuit of an LTCC high-pass filter in the related art;
[0055] Figure 2 An exploded schematic diagram of a specific example of an inductor structure of an LTCC high-pass filter in the related art;
[0056] Figure 3A schematic diagram of the appearance of a multilayer structure of a specific example of a LTCC high-pass filter in an embodiment of the present application;
[0057] Figure 4 A perspective schematic diagram of a specific example of a LTCC high-pass filter in an embodiment of the present application;
[0058] Figure 5 An exploded schematic diagram of a specific example of a LTCC high-pass filter in an embodiment of the present application;
[0059] Figure 6 For Figure 5 Schematic diagram of the equivalent circuit corresponding to the LTCC high-pass filter;
[0060] Figure 7 For Figure 5 Schematic diagram of the printed structure of each layer corresponding to the LTCC high-pass filter;
[0061] Figure 8 For Figure 5 A simulation schematic diagram of a specific example corresponding to the LTCC high-pass filter;
[0062] Fig. 9 This is a schematic diagram of an equivalent circuit of a specific example of a ninth-order LTCC high-pass filter in an embodiment of the present application;
[0063] Fig.10 Schematic diagram of an equivalent circuit of a specific example of an eleventh-order LTCC high-pass filter in an embodiment of the present application. DETAILED DESCRIPTION
[0064] In order to make the technical solutions and beneficial effects of the present application more obvious and easy to understand, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which the present application belongs.
[0065] The embodiments of the present application are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present application. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, in a certain embodiment, the solution after removing some steps can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementations in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementations of other embodiments.
[0066] In each embodiment of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.
[0067] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.
[0068] In the embodiments of the present application, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.
[0069] In the embodiments of the present application, "plurality" refers to two or more.
[0070] In some embodiments, the terms "at least one", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.
[0071] The prefixes such as "first" and "second" in the embodiments of the present application are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, value or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute unnecessary restrictions due to the use of prefixes. For example, the numerical value of the description object is not limited by the ordinal number, and can be one or more. Take "first device" as an example, where the numerical value of "device" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different.
[0072] In some embodiments, the term "connection" may indicate that an electrical signal or data is transmitted between a connected end and a connected end, and may be understood as "electrical connection", "communication connection", etc. "Connection" may be a direct connection between two components, an indirect connection established through other components, internal communication between two components, or any other possible connection form.
[0073] In the drawings, the sizes of layers, regions, and elements and their relative sizes may be exaggerated for clarity.
[0074] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.
[0075] Figure 1 The equivalent circuit diagram of a specific example of a π-type circuit of an LTCC high-pass filter in the related art is shown. As shown in the figure, the traditional LTCC high-pass filter multilayer structure generally includes a π-type circuit equivalent circuit composed of a capacitor and an inductor, wherein the capacitor is located on the transmission channel between the input end and the output end, and the inductor is connected in parallel between one end of the capacitor and the ground end.
[0076] In a conventional LTCC high-pass filter multilayer structure, a capacitor structure and an inductor structure are usually provided in sequence between the uppermost layer and the lowermost layer. Figure 2 An exploded schematic diagram of a specific example of an inductor structure of an LTCC high-pass filter in the related art is shown. As shown in the figure, multiple inductors in a traditional LTCC high-pass filter multilayer structure are usually arranged in parallel on at least two adjacent layers. For example, inductors L1 and L2 are arranged in parallel along the extension direction of the layers, and vertical spiral inductors are used, so there is no cross-coupling inductor among the multiple inductors.
[0077] Moreover, in the traditional LTCC high-pass filter multilayer structure, multiple capacitors in the capacitor structure are usually arranged in parallel along the extension direction of the sheet layer, and there is no cross-coupling capacitance between them.
[0078] Well, this traditional multilayer structure usually has a relatively slow decrease in stopband suppression, so in order to obtain a steep stopband attenuation characteristic, it is necessary to increase the filter order, which increases the overall size of the filter, increases the insertion loss in the passband, and affects the bandwidth.
[0079] To this end, an embodiment of the present application provides an LTCC high-pass filter that can be applied to a radio frequency communication link of a spectrum analyzer, such as a preselection filter of a radio frequency receiving link of a spectrum analyzer. Figure 3 A schematic diagram of the appearance of a multilayer structure of a specific example of an LTCC high-pass filter in an embodiment of the present application is shown. Figure 4 A perspective schematic diagram of a specific example of the LTCC high-pass filter in the embodiment of the present application is shown. Figure 5 An exploded schematic diagram of a specific example of an LTCC high-pass filter in an embodiment of the present application is shown. Figure 6 Shown with Figure 5 The equivalent circuit diagram of the LTCC high-pass filter in Figure 2 is shown in Figure 2. Figure 3 , Figure 4 , Figure 5 and Figure 6 , the LTCC high pass filter comprises:
[0080] A LTCC multilayer structure formed by stacking green ceramic sheets with printed metal layers on the surface;
[0081] The internal formation of the LTCC multilayer structure includes at least one of the following:
[0082] A cross-coupled capacitor structure, used to form a series capacitor group 101, and at least one cross-coupled capacitor 102 realized based on the mutual coupling of preset capacitors in the capacitor group 101 and connected in parallel with the capacitor group 101; the capacitor group 101 is connected between the input electrode IN and the output electrode OUT of the LTCC high-pass filter;
[0083] A cross-coupled inductor structure is used to form a parallel-connected inductor group 103, and at least one first cross-coupled equivalent inductor 104 and / or at least one second cross-coupled equivalent inductor 105 realized based on the mutual coupling of preset inductors in the inductor group 103; the first cross-coupled equivalent inductor 104 is equivalent to a capacitor connected in parallel with the input electrode IN in the equivalent circuit, and the second cross-coupled equivalent inductor 105 is equivalent to a capacitor connected in parallel with the output electrode OUT in the equivalent circuit; each inductor in the inductor group 103 is connected between each end of each capacitor in the capacitor group 101 and the ground terminal.
[0084] In this way, the embodiment of the present application can increase the number of transmission zeros of the filter by cross-coupling capacitors; and can also increase the number of transmission zeros of the filter by cross-coupling equivalent inductors, so that the stop band can achieve faster decline attenuation under the same order conditions as the traditional LTCC high-pass filter, obtain steep characteristics, and increase the bandwidth. For example, by adding cross-coupling inductor branches and cross-coupling capacitor branches to the filter, a dual transmission zero structure can be formed, which can solve the problems of large insertion loss and slow stop band attenuation of the traditional LTCC high-pass filter, speed up the attenuation speed of the stop band, obtain better rectangular coefficients and steep characteristics, and obtain better filtering characteristics and bandwidth.
[0085] In an exemplary embodiment, the LTCC multilayer structure can use a raw ceramic sheet with a dielectric constant of 7.8 and a loss tangent of 0.003, and the circuit layer can be obtained by using silver paste in combination with screen printing. The interlayer circuit connection can be achieved by punching and filling silver paste, and finally it is made through lamination, static pressing, sintering, external electrode production, etc. The size of the LTCC multilayer structure can be 4mm*2mm*1.1mm.
[0086] In an optional implementation manner, the capacitor group 101 and the inductor group 103 form a 2N+1-order high-pass filter basic circuit of the LTCC high-pass filter; wherein N is a natural number greater than or equal to 1.
[0087] In this way, the embodiment of the present application can realize an LTCC high-pass filter of any order above the third order, and increase the cross-coupling capacitance and / or the cross-coupling equivalent inductance to accelerate the stop-band attenuation speed.
[0088] refer to Figure 5 , in an exemplary embodiment, the LTCC high-pass filter includes a seventh-order high-pass filter basic circuit, a twelfth cross-coupling capacitor C12, a thirteenth cross-coupling equivalent inductor L13 and a twenty-fourth cross-coupling equivalent inductor L24;
[0089] The capacitor group 101 includes a thirteenth capacitor C13, a thirty-fourth capacitor C34 and a twenty-fourth capacitor C24 connected in series between the input electrode IN and the output electrode OUT; the inductor group 103 includes a tenth inductor L10, a thirtieth inductor L30, a fortieth inductor L40 and a twentieth inductor L20, so as to form the seventh-order high-pass filter basic circuit;
[0090] Wherein, based on the parallel plate capacitor structure, a thirteenth capacitor C13, a thirty-fourth capacitor C34 and a twenty-fourth capacitor C24 are formed between the multilayer sheets and connected in series between the input electrode IN and the output electrode OUT; and a twelfth cross-coupling capacitor C12 connected in parallel with the capacitor group 101 is formed by coupling the thirteenth capacitor C13 and the twenty-fourth capacitor C24 with each other;
[0091] Based on the spiral winding inductor structure, a tenth inductor L10, a thirtieth inductor L30, a fortieth inductor L40 and a twentieth inductor L20 are formed between the multilayer sheets, and a first end of the tenth inductor L10 is connected to the input electrode IN, a first end of the thirtieth inductor L30 is connected to a series node between a thirteenth capacitor C13 and a thirty-fourth capacitor C34, a first end of the fortieth inductor L40 is connected to a series node between the thirty-fourth capacitor C34 and the twenty-fourth capacitor C24, a first end of the twentieth inductor L20 is connected to the output electrode OUT, and second ends of the tenth inductor L10, the thirtieth inductor L30, the fortieth inductor L40 and the twentieth inductor L20 are respectively connected to the ground terminal; and a thirteenth cross-coupled equivalent inductor L13 connected in parallel with the thirteenth capacitor C13 is formed by mutual coupling between the tenth inductor L10 and the thirtieth inductor L30, and a twenty-fourth cross-coupled equivalent inductor L24 connected in parallel with the twenty-fourth capacitor C24 is formed by mutual coupling between the twentieth inductor L20 and the fortieth inductor L40.
[0092] refer to Figure 6 In the equivalent circuit of the LTCC high-pass filter, the first end of the tenth inductor L10 is respectively connected to the input electrode IN, that is, the first connection node 1, and the first end of the thirteenth capacitor C13; the first end of the thirteenth inductor L30 is respectively connected to the second end of the thirteenth capacitor C13 and the first end of the thirty-fourth capacitor C34, that is, connected to the third connection node 3 between the thirteenth capacitor C13 and the thirty-fourth capacitor C34; the first end of the fortieth inductor L40 is respectively connected to the second end of the thirty-fourth capacitor C34 and the second end of the twenty-fourth capacitor C24, that is, the first end of the fortieth inductor L40 is connected to the fourth connection node 4 between the thirty-fourth capacitor C34 and the twenty-fourth capacitor C24; the first end of the twentieth inductor L20 is respectively connected to the first end of the twenty-fourth capacitor C24 and the output electrode OUT, that is, the second connection node 2.
[0093] Thus, the embodiment of the present application is based on a seventh-order high-pass filter circuit (four inductors L10, L20, L30, L40, three capacitors C13, C34, C24), each inductor in the inductor group 103 is connected between one end of different capacitors in the capacitor group 101 and the ground terminal, and on this basis, a cross-coupling capacitor C12 (corresponding to the cross-coupling capacitor 102) is added, and cross-coupling equivalent inductors L13 and L24 (corresponding to the first cross-coupling equivalent inductor 104 and the second cross-coupling equivalent inductor 105) are added. And the structure is realized by the multi-layer circuit technology of LTCC low-temperature co-fired ceramics to form cross-coupling capacitors and cross-coupling equivalent inductors.
[0094] refer to Figure 5 In an optional implementation, the cross-coupled inductor structure includes:
[0095] At least two first inductor sheet groups with inductor winding wires are used to form a tenth inductor L10 and a twentieth inductor L20 of a spiral winding inductor structure; and the tenth inductor L10 and the twentieth inductor L20 are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure; and
[0096] A second inductor sheet group having at least two layers of inductor winding wires is used to form a 30th inductor L30 and a 40th inductor L40 of a spiral winding inductor structure; and the 30th inductor L30 and the 40th inductor L40 are mirror-symmetrical about the symmetry plane; and the 30th inductor L30 and the tenth inductor L10 overlap in the stacking direction of the sheets, and the 40th inductor L40 and the 20th inductor L20 overlap in the stacking direction of the sheets, so as to achieve mutual coupling between the 30th inductor L30 and the tenth inductor L10, and mutual coupling between the 40th inductor L40 and the 20th inductor L20.
[0097] In the embodiment of the present application, the number of layers of the spiral winding inductor structure of the tenth inductor L10, the twentieth inductor L20, the thirtieth inductor L30 and the fortieth inductor L40 can be set according to actual needs, such as 2 layers, 3 layers, or more layers. The upper and lower positions of the thirtieth inductor L30 and the tenth inductor L10, and the symmetrical fortieth inductor L40 and the twentieth inductor L20 can be set according to actual needs, for example, the thirtieth inductor L30 can be set above or below the tenth inductor L10, or the tenth inductor L10 (or the thirtieth inductor L30) can be sandwiched between the thirtieth inductor L30 (or the tenth inductor L10), and the overlap in the stacking direction of the layers can be full or partial overlap to meet the mutual coupling to achieve equivalent cross-coupling inductance characteristics.
[0098] Figure 7 Shown with Figure 5Schematic diagram of the printed structure of each layer corresponding to the LTCC high-pass filter. As shown in the figure, in an optional embodiment, the cross-coupled inductor structure includes the sixth layer layer6, the seventh layer layer7, the eighth layer layer8 and the ninth layer layer9 from top to bottom;
[0099] The surface of the sixth layer layer6 is provided with a first inductor winding wire L30_1 of the 30th inductor L30, and a first end thereof is connected to a series node between the 13th capacitor C13 and the 34th capacitor C34 through a hole column; and a first inductor winding wire L40_1 of the 40th inductor L40, and a first end thereof is connected to a series node between the 34th capacitor C34 and the 24th capacitor C24 through a hole column;
[0100] The surface of the seventh layer layer7 is provided with a second inductor winding wire L30_2 of the 30th inductor L30, and a first end thereof is connected to a second end of the first inductor winding wire L30_1 of the 30th inductor L30 through a hole column; and a second inductor winding wire L40_2 of the 40th inductor L40, and a first end thereof is connected to a second end of the first inductor winding wire L40_1 of the 40th inductor L40 through a hole column; and a second end of the second inductor winding wire L30_2 of the 30th inductor L30 and a second end of the second inductor winding wire L40_2 of the 40th inductor L40 are respectively connected to the third ground electrode GND3 through the hole column;
[0101] The surface of the eighth layer layer8 is provided with a first inductor winding wire L10_1 of the tenth inductor L10, and a first end thereof is connected to the input electrode IN; and a first inductor winding wire L20_1 of the twentieth inductor L20, and a first end thereof is connected to the output electrode OUT;
[0102] The surface of the ninth layer layer9 includes the second inductor winding wire L10_2 of the tenth inductor L10, and the first end of which is connected to the second end of the first inductor winding wire L10_1 of the tenth inductor L10 through a hole column; and the second inductor winding wire L20_2 of the twentieth inductor L20, and the first end of which is connected to the second end of the first inductor winding wire L20_1 of the twentieth inductor L20 through a hole column; and the second end of the second inductor winding wire L10_2 of the tenth inductor L10 and the second end of the second inductor winding wire L20_2 of the twentieth inductor L20 are respectively connected to the third ground electrode GND3 through the hole column.
[0103] In the embodiment of the present application, the second inductor winding wire L30_2 of the 30th inductor L30 and the second inductor winding wire L40_2 of the 40th inductor L40 can be connected and then connected to the third ground electrode GND3 through a hole column; or, the second inductor winding wire L30_2 of the 30th inductor L30 can be connected to the third ground electrode GND3 through a hole column, and the second inductor winding wire L40_2 of the 40th inductor L40 can be connected to the third ground electrode GND3 through another hole column; and so on. The specific settings can be made according to actual needs.
[0104] Similarly, the second inductor winding wire L10_2 of the tenth inductor L10 and the second inductor winding wire L20_2 of the twentieth inductor L20 can be connected and then connected to the third ground electrode GND3 through a hole column; or, the second inductor winding wire L10_2 of the tenth inductor L10 can be connected to the third ground electrode GND3 through a hole column, and the second inductor winding wire L20_2 of the twentieth inductor L20 can be connected to the third ground electrode GND3 through another hole column; and so on. The specific settings can be made according to actual needs.
[0105] refer to Figure 5 In an optional implementation, the cross-coupling capacitor structure includes:
[0106] At least two first capacitor layer groups with capacitor plates are used to form a thirteenth capacitor C13 and a twenty-fourth capacitor C24 of a parallel plate capacitor structure; and the thirteenth capacitor C13 and the twenty-fourth capacitor C24 are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure;
[0107] at least two layers of a second capacitor layer group with capacitor plates arranged therein, for forming a thirty-fourth capacitor C34 of a parallel plate capacitor structure; and the thirty-fourth capacitor C34 is mirror-symmetrical about the symmetry plane; and
[0108] A third capacitor layer group having at least one layer of capacitor plates is used to form a twelfth cross-coupling capacitor C12 that is mutually coupled with a thirteenth capacitor C13 and a twenty-fourth capacitor C24, and the capacitor plates of the twelfth cross-coupling capacitor C12 overlap with the capacitor plates of the thirteenth capacitor C13 and the twenty-fourth capacitor C24 in the stacking direction of the layers, and the capacitor plates of the twelfth cross-coupling capacitor C12 are mirror-symmetrical about the symmetry plane.
[0109] In the embodiment of the present application, the number of layers of the parallel plate capacitor structure of the thirteenth capacitor C13, the twenty-fourth capacitor C24, the thirty-fourth capacitor C34, and the twelfth cross-coupling capacitor C12 can be set according to actual needs, such as 2 layers, 3 layers, or more layers. The upper and lower positions of the capacitor plates of the thirteenth capacitor C13, the twenty-fourth capacitor C24, and the twelfth cross-coupling capacitor C12 can be set according to actual needs. For example, the capacitor plate of the twelfth cross-coupling capacitor C12 can be located above or below the capacitor plates of the thirteenth capacitor C13 and the twenty-fourth capacitor C24, or sandwiched in the middle of the multilayer capacitor plates of the thirteenth capacitor C13 and the twenty-fourth capacitor C24, and the overlap in the stacking direction of the layers can be full or partial overlap to meet the mutual coupling to achieve equivalent cross-coupling capacitor characteristics.
[0110] refer to Figure 7 In an optional implementation, the cross-coupling capacitor structure includes, from top to bottom, a first layer layer1, a second layer layer2 and a third layer layer3;
[0111] The surface of the second layer layer2 is provided with a first capacitor plate C13_1 of a thirteenth capacitor C13, and the first capacitor plate C13_1 of the thirteenth capacitor C13 is connected to the input electrode IN; and a first capacitor plate C24_1 of a twenty-fourth capacitor C24, and the first capacitor plate C24_1 of the twenty-fourth capacitor C24 is connected to the output electrode OUT;
[0112] The surface of the third layer layer3 is provided with the second capacitor plate C13_2 of the thirteenth capacitor C13 and the second capacitor plate C24_2 of the twenty-fourth capacitor C24; the first capacitor plate C13_1 of the thirteenth capacitor C13 and the second capacitor plate C13_2 of the thirteenth capacitor C13 are coupled in parallel to form the thirteenth capacitor C13; the first capacitor plate C24_1 of the twenty-fourth capacitor C24 and the second capacitor plate C24_2 of the twenty-fourth capacitor C24 are coupled in parallel to form the twenty-fourth capacitor C24;
[0113] The surface of the first layer layer1 is provided with a first capacitor plate C12_1 and a second capacitor plate C12_2 of a twelfth cross-coupling capacitor C12 that are connected to each other; the first capacitor plate C12_1 of the twelfth cross-coupling capacitor C12 is respectively coupled to at least one of the first capacitor plate C13_1 of the thirteenth capacitor C13 and the second capacitor plate C13_2 of the thirteenth capacitor C13, and the second capacitor plate C12_2 of the twelfth cross-coupling capacitor C12 is respectively coupled to at least one of the first capacitor plate C24_1 of the twenty-fourth capacitor C24 and the second capacitor plate C24_2 of the twenty-fourth capacitor C24 to form the twelfth cross-coupling capacitor C12.
[0114] refer to Figure 5 and Figure 7 , the first capacitor plate C12_1 of the twelfth cross-coupling capacitor C12 on the left side can be fully or partially overlapped with the first capacitor plate C13_1 of the thirteenth capacitor C13 to achieve mutual coupling; or, it can be fully or partially overlapped with the second capacitor plate C13_2 of the thirteenth capacitor C13 to achieve mutual coupling. The second capacitor plate C12_2 of the twelfth cross-coupling capacitor C12 on the right side can be fully or partially overlapped with the first capacitor plate C24_1 of the twenty-fourth capacitor C24 to achieve mutual coupling; or, it can be fully or partially overlapped with the second capacitor plate C24_2 of the twenty-fourth capacitor C24 to achieve mutual coupling. Thus, through the first capacitor plate C12_1 and the second capacitor plate C12_2 of the twelfth cross-coupling capacitor C12, the first capacitor plate C13_1 of the thirteenth capacitor C13 and the first capacitor plate C24_1 of the twenty-fourth capacitor C24 are coupled; or the second capacitor plate C13_2 of the thirteenth capacitor C13 and the second capacitor plate C24_2 of the twenty-fourth capacitor C24 are coupled to form the twelfth cross-coupling capacitor C12. And the capacitor plates on the left half and the capacitor plates on the right half can be mirror-symmetrical about the symmetric plane (such as the left-right symmetric plane) of the multilayer structure.
[0115] In an optional implementation, the cross-coupling capacitor structure further includes a fourth layer layer4 and a fifth layer layer5 from top to bottom;
[0116] The surface layout of the third layer layer3 also includes a first capacitor plate C34_1 and a second capacitor plate C34_2 of a thirty-fourth capacitor C34; the first capacitor plate C34_1 of the thirty-fourth capacitor C34 is connected to the second capacitor plate C13_2 of the thirteenth capacitor C13, and the second capacitor plate C34_2 of the thirty-fourth capacitor C34 is connected to the second capacitor plate C24_2 of the twenty-fourth capacitor C24;
[0117] The surface of the fourth layer layer4 is provided with a third capacitor plate C34_3 and a fourth capacitor plate C34_4 of a thirty-fourth capacitor C34 connected to each other;
[0118] The surface of the fifth layer layer5 is arranged with the fifth capacitor plate C34_5 and the sixth capacitor plate C34_6 of the thirty-fourth capacitor C34; the fifth capacitor plate C34_5 of the thirty-fourth capacitor C34 is connected to the series node between the second capacitor plate C13_2 of the thirteenth capacitor C13 and the first capacitor plate C34_1 of the thirty-fourth capacitor C34 through a hole column; the sixth capacitor plate C34_6 of the thirty-fourth capacitor C34 is connected to the series node between the second capacitor plate C24_2 of the twenty-fourth capacitor C24 and the second capacitor plate C34_2 of the thirty-fourth capacitor C34 through a hole column; and there is overlap in the stacking direction of the layers between the first capacitor plate C34_1, the third capacitor plate C34_3 and the fifth capacitor plate C34_5 of the thirty-fourth capacitor C34, and between the second capacitor plate C34_2, the fourth capacitor plate C34_4 and the sixth capacitor plate C34_6.
[0119] In the embodiment of the present application, the first capacitor plate C34_1, the third capacitor plate C34_3 and the fifth capacitor plate C34_5 on the left side of the thirty-fourth capacitor C34 overlap with each other in whole or in part, thereby achieving mutual coupling. The second capacitor plate C34_2, the fourth capacitor plate C34_4 and the sixth capacitor plate C34_6 on the right side of the thirty-fourth capacitor C34 overlap with each other in whole or in part, thereby achieving mutual coupling. And the capacitor plates on the left side and the capacitor plates on the right side can be mirror-symmetrical about the symmetric plane (such as the left-right symmetric plane) of the multilayer structure.
[0120] refer to Figure 5 and Figure 7 In an optional implementation, the LTCC high pass filter comprises:
[0121] A left metal strip is arranged on the left side of the LTCC multilayer structure and the two ends of the left metal strip extend to the top surface TOP and the bottom surface BOT of the LTCC multilayer structure respectively, and is used as the input electrode IN;
[0122] A right metal strip is arranged on the right side of the LTCC multilayer structure and two ends of the right metal strip extend to the top surface TOP and the bottom surface BOT of the LTCC multilayer structure respectively, and is used as the output electrode OUT;
[0123] A front metal strip, arranged on the front side of the LTCC multilayer structure and having two ends extending to the top surface TOP and the bottom surface BOT of the LTCC multilayer structure respectively, for serving as a first ground electrode GND1;
[0124] A rear metal strip, arranged on the rear side of the LTCC multilayer structure and with two ends of the rear metal strip extending to the top surface TOP and the bottom surface BOT of the LTCC multilayer structure respectively, for serving as a second ground electrode GND2; and
[0125] The third ground electrode GND3 having two ends respectively connected to the first ground electrode GND1 and the second ground electrode GND2 is arranged on the surface of the tenth layer layer10.
[0126] In the embodiment of the present application, a label MARK is also arranged on the top surface TOP of the LTCC multilayer structure, which is used to mark the surface direction, electrodes, etc. of the filter.
[0127] In an exemplary embodiment, the LTCC multilayer structure has at least 12 layers from top to bottom, namely: TOP, layer 1, layer 2, layer 3, layer 4, layer 5, layer 6, layer 7, layer 8, layer 9, layer 10, BOT. Among them, at least one blank sheet layer can be included between each layer, that is, a blank raw ceramic sheet without a metal conductor strip on the surface, which can be set according to actual needs to increase the distance between the capacitor and the inductor and the ground, reduce their parasitic capacitance to the ground, and improve the high-frequency characteristics of the filter.
[0128] refer to Figure 5 and Figure 7 , the input electrode IN is connected to L10 and C13 to realize signal input.
[0129] Among them, L10 uses a spiral winding inductor design, and the main body L10_1 / L10_2 is located on the left half of Layer8 and Layer9. The two layers are connected through a via and finally connected to GND3 of layer10 through the via.
[0130] C13 is formed by parallel coupling of C13_1 and C13_2 of layer2 and layer3 to form a parallel plate capacitor.
[0131] The output electrode OUT is connected to L20 and C24 to realize signal output.
[0132] Among them, L20 and C24 are located on the right half, symmetrical with L10 and C24 on the left half.
[0133] The main link capacitors C13, C34, and C24 are connected in series, the inductors L10, L20, L30, and L40 are connected in parallel to the ground, the cross-coupling capacitor C12 is connected in parallel by coupling with C13 and C24, and the cross-coupling equivalent inductors L13 and L24 are coupled with L10 and L30, and L40 and L20 respectively to realize equivalent inductance characteristics.
[0134] Among them, C34 is formed by coupling six capacitor plates C34_1, C34_2, C34_3, C34_4, C34_5, and C34_6 of layer3, layer4, and layer5. C34_1 is connected in series with C13_2, C34_2 is connected in series with C24_2, and C34_3 is connected in series with C34_4.
[0135] L30 is connected to C34_5 of layer5 through a hole column between C34_1 and C13_2 of layer3, and then connected to L30_1 of layer6 through a hole column, and is connected to L30_2 of layer7 through a hole column.
[0136] L40 is symmetrical to L30. The two are connected at layer 7 and connected to GND3 through a via.
[0137] C12 is formed by coupling C12_1 and C12_2 of layer1 with C13_1 and C24_1 of layer2, where C12_1 and C12_2 are connected in series.
[0138] Inductors L10, L20, L30, and L40 are in the form of multi-layer coil inductors and are connected to each other through vias. The inductors are designed to be far away from the ground plane of the PCB circuit board to reduce parasitic parameters and ensure the realization of ultra-wideband characteristics.
[0139] Capacitors C13, C34, and C24 realize their functions through a parallel plate capacitor structure.
[0140] GND3 is the grounding layer, connected to GND1 and GND2. Inductors L10, L20, L30, and L40 are connected to GND3 through vias for grounding.
[0141] In the embodiment of the present application, by increasing the cross-coupling capacitor C12 and increasing at least one of the cross-coupling equivalent inductors L13 and L24, a signal with a phase opposite to the transmission signal can be generated, thereby increasing the transmission zero point. Figure 8 Shown with Figure 5 A simulation diagram of a specific example of the LTCC high-pass filter in FIG. As shown in the figure, two transmission zeros are added near the frequency of 2 GHz through C12, L13, and L24. At frequencies above 3.2 GHz, it has good passband performance, small insertion loss S(2,1), return loss S(1,1) and S(2,2) are both below -20 dB, small loss, and good performance outside the passband. The cross-coupling equivalent inductance and cross-coupling capacitance enable the filter to form two transmission zeros outside the passband (stopband), accelerate the attenuation speed of the stopband, obtain better rectangular coefficient and steep characteristics, and increase the bandwidth.
[0142] refer to Figure 5 and Figure 6 In an exemplary embodiment, the order of the LTCC high-pass filter can be determined as the seventh order according to the seventh-order high-pass filter basic circuit (including four inductors L10, L20, L30, L40, and three capacitors C13, C34, C24). In other embodiments, the order of the LTCC high-pass filter can also be the ninth order, the eleventh order, etc. Fig. 9 FIG. 1 shows a schematic diagram of an equivalent circuit of a specific example of a ninth-order LTCC high-pass filter in an embodiment of the present application. Fig.10 FIG. 1 shows a schematic diagram of an equivalent circuit of a specific example of an eleventh-order LTCC high-pass filter in an embodiment of the present application. Fig. 9 and Fig.10 The ninth-order LTCC high-pass filter and the eleventh-order LTCC high-pass filter are respectively provided with a cross-coupling equivalent inductor and a cross-coupling capacitor, just like the seventh-order LTCC high-pass filter.
[0143] Thus, compared with the LTCC high-pass filter of the traditional structure, the embodiment of the present application can realize the generation of cross-coupling equivalent inductance and cross-coupling capacitance, and thereby obtain two transmission zeros outside the passband (stopband), accelerate the attenuation speed of the stopband, and obtain better rectangular coefficient and steepness characteristics. The stopband characteristics of a higher-order high-pass filter are achieved by using fewer filter orders, and there is less insertion loss.
[0144] The embodiment of the present application also provides a radio frequency communication link, comprising the LTCC high-pass filter as described in the above embodiment.
[0145] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present application that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present application and do not limit the scope of protection of the patent of this application.
Claims
1. A LTCC high-pass filter, characterized in that: The LTCC high pass filter comprises: A LTCC multilayer structure formed by stacking green ceramic sheets with printed metal layers on the surface; The internal formation of the LTCC multilayer structure includes at least one of the following: A cross-coupled capacitor structure, used to form a series capacitor group, and at least one cross-coupled capacitor realized based on mutual coupling of preset capacitors in the capacitor group and connected in parallel with the capacitor group; the capacitor group is connected between the input electrode and the output electrode of the LTCC high-pass filter; A cross-coupled inductor structure is used to form an inductor group connected in parallel to the ground, and at least one first cross-coupled equivalent inductor and / or at least one second cross-coupled equivalent inductor realized based on the mutual coupling of preset inductors in the inductor group; the first cross-coupled equivalent inductor is equivalent to a capacitor connected in parallel with the input electrode in an equivalent circuit, and the second cross-coupled equivalent inductor is equivalent to a capacitor connected in parallel with the output electrode in an equivalent circuit; each inductor in the inductor group is connected between each end of each capacitor in the capacitor group and the ground terminal.
2. The LTCC high-pass filter according to claim 1, characterized in that: The capacitor group and the inductor group form a 2N+1-order high-pass filter basic circuit of the LTCC high-pass filter; wherein N is a natural number greater than or equal to 1.
3. The LTCC high-pass filter according to claim 1, characterized in that: The LTCC high-pass filter includes a seventh-order high-pass filter basic circuit, a twelfth cross-coupling capacitor, a thirteenth cross-coupling equivalent inductor and a twenty-fourth cross-coupling equivalent inductor; The capacitor group includes a thirteenth capacitor, a thirty-fourth capacitor and a twenty-fourth capacitor connected in series between the input electrode and the output electrode; the inductor group includes a tenth inductor, a thirtieth inductor, a fortieth inductor and a twentieth inductor to form the seventh-order high-pass filter basic circuit; Wherein, based on the parallel plate capacitor structure, a thirteenth capacitor, a thirty-fourth capacitor and a twenty-fourth capacitor are formed between the multilayer sheets and connected in series between the input electrode and the output electrode; and a twelfth cross-coupling capacitor connected in parallel with the capacitor group is formed by mutual coupling of the thirteenth capacitor and the twenty-fourth capacitor; Based on the spiral winding inductor structure, a tenth inductor, a thirtieth inductor, a fortieth inductor and a twentieth inductor are formed between the multilayer sheets, and the first end of the tenth inductor is connected to the input electrode, the first end of the thirtieth inductor is connected to the series node between the thirteenth capacitor and the thirty-fourth capacitor, the first end of the fortieth inductor is connected to the series node between the thirty-fourth capacitor and the twenty-fourth capacitor, the first end of the twentieth inductor is connected to the output electrode, and the second ends of the tenth inductor, the thirtieth inductor, the fortieth inductor and the twentieth inductor are respectively connected to the ground terminal; and a thirteenth cross-coupled equivalent inductor connected in parallel with the thirteenth capacitor is formed by mutual coupling between the tenth inductor and the thirtieth inductor, and a twenty-fourth cross-coupled equivalent inductor connected in parallel with the twenty-fourth capacitor is formed by mutual coupling between the twentieth inductor and the fortieth inductor.
4. The LTCC high-pass filter according to claim 3, characterized in that: The cross-coupled inductor structure comprises: At least two first inductor sheet layers with inductor winding wires are arranged to form a tenth inductor and a twentieth inductor of a spiral winding inductor structure; and the tenth inductor and the twentieth inductor are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure; and A second inductor sheet group having at least two layers of inductor winding wires is used to form a 30th inductor and a 40th inductor of a spiral winding inductor structure; and the 30th inductor and the 40th inductor are mirror-symmetrical about the symmetry plane; and the 30th inductor and the tenth inductor overlap in the stacking direction of the sheets to achieve mutual coupling between the 30th inductor and the tenth inductor; and the 40th inductor and the 20th inductor overlap in the stacking direction of the sheets to achieve mutual coupling between the 40th inductor and the 20th inductor.
5. The LTCC high-pass filter according to claim 4, characterized in that: The cross-coupled inductor structure includes, from top to bottom, a sixth layer, a seventh layer, an eighth layer and a ninth layer; The surface of the sixth layer is provided with a first inductor winding wire of the 30th inductor, and a first end of the first inductor winding wire is connected to a series node between the 13th capacitor and the 34th capacitor through a hole column; and a first inductor winding wire of the 40th inductor, and a first end of the first inductor winding wire is connected to a series node between the 34th capacitor and the 24th capacitor through a hole column; The surface of the seventh layer is provided with a second inductor winding wire of the 30th inductor, and the first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the 30th inductor through a hole column; and a second inductor winding wire of the 40th inductor, and the first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the 40th inductor through a hole column; and the second end of the second inductor winding wire of the 30th inductor and the second end of the second inductor winding wire of the 40th inductor are respectively connected to the third grounding electrode through the hole column; The surface of the eighth layer is provided with a first inductor winding wire of a tenth inductor, and a first end of the first inductor winding wire is connected to the input electrode; and a first inductor winding wire of a twentieth inductor, and a first end of the first inductor winding wire is connected to the output electrode; The surface of the ninth layer is provided with a second inductor winding wire of the tenth inductor, and a first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the tenth inductor through a hole column; and a second inductor winding wire of the twentieth inductor, and a first end of the second inductor winding wire is connected to the second end of the first inductor winding wire of the twentieth inductor through a hole column; and the second end of the second inductor winding wire of the tenth inductor and the second end of the second inductor winding wire of the twentieth inductor are respectively connected to the third grounding electrode through the hole column.
6. The LTCC high-pass filter according to claim 3, characterized in that: The cross-coupling capacitor structure comprises: At least two first capacitor layer groups with capacitor plates are used to form a thirteenth capacitor and a twenty-fourth capacitor of a parallel plate capacitor structure; and the thirteenth capacitor and the twenty-fourth capacitor are mirror-symmetrical about the symmetric plane of the LTCC multilayer structure; at least two layers of a second capacitor layer group with capacitor plates arranged therein, for forming a thirty-fourth capacitor of a parallel plate capacitor structure; and the thirty-fourth capacitor is mirror-symmetrical about the symmetry plane; and At least one third capacitor layer group with capacitor plates arranged thereon is used to form a twelfth cross-coupling capacitor that is mutually coupled with the thirteenth capacitor and the twenty-fourth capacitor, and the capacitor plates of the twelfth cross-coupling capacitor overlap with the capacitor plates of the thirteenth capacitor and the capacitor plates of the twenty-fourth capacitor in the stacking direction of the layers, and the capacitor plates of the twelfth cross-coupling capacitor are mirror-symmetrical about the symmetry plane.
7. The LTCC high-pass filter according to claim 6, characterized in that: The cross-coupling capacitor structure comprises a first layer, a second layer and a third layer from top to bottom; The surface of the second sheet layer is provided with a first capacitor plate including a thirteenth capacitor, and the first capacitor plate of the thirteenth capacitor is connected to the input electrode; and a first capacitor plate of a twenty-fourth capacitor, wherein the first capacitor plate of the twenty-fourth capacitor is connected to the output electrode; The surface of the third layer is provided with the second capacitor plate of the thirteenth capacitor and the second capacitor plate of the twenty-fourth capacitor; the first capacitor plate of the thirteenth capacitor and the second capacitor plate of the thirteenth capacitor are coupled in parallel to form the thirteenth capacitor; the first capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the twenty-fourth capacitor are coupled in parallel to form the twenty-fourth capacitor; The surface of the first layer is provided with a first capacitor plate and a second capacitor plate of a twelfth cross-coupling capacitor which are connected to each other; the first capacitor plate of the twelfth cross-coupling capacitor is respectively coupled to at least one of the first capacitor plate of the thirteenth capacitor and the second capacitor plate of the thirteenth capacitor, and the second capacitor plate of the twelfth cross-coupling capacitor is respectively coupled to at least one of the first capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the twenty-fourth capacitor to form the twelfth cross-coupling capacitor.
8. The LTCC high-pass filter according to claim 7, characterized in that: The cross-coupling capacitor structure further includes a fourth layer and a fifth layer from top to bottom; The third layer surface arrangement also includes a first capacitor plate and a second capacitor plate of a thirty-fourth capacitor; the first capacitor plate of the thirty-fourth capacitor is connected to the second capacitor plate of the thirteenth capacitor, and the second capacitor plate of the thirty-fourth capacitor is connected to the second capacitor plate of the twenty-fourth capacitor; The surface of the fourth sheet layer is provided with a third capacitor plate and a fourth capacitor plate of a thirty-fourth capacitor connected to each other; The surface of the fifth layer is arranged with the fifth capacitor plate and the sixth capacitor plate of the thirty-fourth capacitor; the fifth capacitor plate of the thirty-fourth capacitor is connected to the series node between the second capacitor plate of the thirteenth capacitor and the first capacitor plate of the thirty-fourth capacitor through a hole column; the sixth capacitor plate of the thirty-fourth capacitor is connected to the series node between the second capacitor plate of the twenty-fourth capacitor and the second capacitor plate of the thirty-fourth capacitor through a hole column; and there is overlap between the first capacitor plate, the third capacitor plate and the fifth capacitor plate, and between the second capacitor plate, the fourth capacitor plate and the sixth capacitor plate of the thirty-fourth capacitor in the stacking direction of the layers.
9. The LTCC high-pass filter according to any one of claims 1 to 8, characterized in that: The LTCC high pass filter comprises: A left metal strip, arranged on the left side of the LTCC multilayer structure and with two ends of the left metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as the input electrode; A right metal strip, arranged on the right side of the LTCC multilayer structure and with two ends of the right metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as the output electrode; A front metal strip, arranged on the front side of the LTCC multilayer structure, with two ends of the front metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, to serve as a first grounding electrode; A rear metal strip, arranged on the rear side of the LTCC multilayer structure and with two ends of the rear metal strip extending to the top and bottom surfaces of the LTCC multilayer structure respectively, for serving as a second grounding electrode; and The tenth layer has a third grounding electrode disposed on its surface, with two ends thereof respectively connected to the first grounding electrode and the second grounding electrode.
10. A radio frequency communication link, characterized in that: The invention comprises the LTCC high-pass filter as claimed in any one of claims 1 to 9.