Miniaturized LTCC circulator with high out-of-band rejection
By adopting LTCC technology and stacked structure in the circulator, the low-pass filter and circulator are effectively combined, which solves the problem of poor out-of-band harmonic suppression performance of traditional circulators, and realizes high out-of-band suppression and device miniaturization. Effect.
Patent Information
- Application Number
- CN202421256612.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2034-06-04
AI Technical Summary
The harmonic suppression performance of traditional circulators in the out-of-band frequency band is poor, which leads to the system requiring more filters, limiting the miniaturization and lightweighting of the system.
LTCC technology is used to design a laminated structure circulator, and combine a low-pass filter in the circulator to achieve effective connection between the center conductor and the filter circuit through the dielectric ring and the conduction structure, forming a high out-of-band rejection performance.
It significantly improves the suppression capability of the circulator in the out-of-band frequency band, reduces the use of filters in the system, and realizes the miniaturization of the device and high out-of-band performance.
Smart Images
Figure CN222463400U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of microwave passive devices, in particular to a miniaturized LTCC circulator with high out-of-band suppression. Background Art
[0002] A circulator is a passive, non-reciprocal ferrite device that can control the unidirectional transmission of signals in a circular manner. It is used to achieve inter-stage isolation, antenna sharing and other problems. Due to the limitations of circuit design, traditional circulators have relatively poor out-of-band performance caused by second and third harmonics. If the circulator has an appropriate filtering function and achieves a certain degree of out-of-band harmonic suppression, the amount of system filters can be reduced, and the system can be miniaturized and lightweight. In order to improve the harmonic frequency band performance of the circulator, there are usually two ways: the first method is to reduce the harmonic excitation of the ferrite under the action of the external bias magnetic field and microwave field; the second method is to suppress the harmonic components generated by the ferrite and other external nonlinear devices. The first method involves the selection and optimization of the circulator gyromagnetic substrate material. This method is usually restricted by the device size and in-band performance, and the range of variation is narrow, and it is impossible to fundamentally achieve good out-of-band harmonic suppression characteristics. The second method involves designing the matching circuit as a low-pass filter (LPF) in the matching output loop of the circulator to increase the attenuation of the harmonic components. This LPF will form additional insertion loss and is limited by the device size.
[0003] As a multi-layer wiring substrate technology, LTCC technology has the advantages of high packaging density, good RF characteristics, and high reliability. Introducing this technology into ferrite circulators will help overcome the structural and design shortcomings of existing ferrite circulators in harmonic suppression. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a miniaturized LTCC circulator with high out-of-band suppression.
[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a miniaturized LTCC circulator with high out-of-band suppression, comprising:
[0006] A circulator layer, the circulator layer comprising a central ferrite and a dielectric ring sleeved on the central ferrite, a first metal grounding layer being provided on the bottom surface of the circulator layer, a central conductor being provided on the top surface of the circulator layer, the central conductor comprising three branches, and the three branches being rotationally symmetrical around a Z axis at intervals of 120°;
[0007] A filter layer, wherein the filter layer comprises a dielectric plate with a laminated structure, wherein the top surface of the dielectric plate is fixedly connected to the first metal grounding layer, and the bottom surface of the dielectric plate is provided with a second metal grounding layer, and three low-pass filters are provided in the dielectric plate, and the three low-pass filters correspond one-to-one to the three branches, and the low-pass filter comprises a filter circuit structure and a plurality of grounding structures arranged around the filter circuit structure, and the grounding structure conducts the first metal grounding layer and the second metal grounding layer, and the second metal grounding layer has three avoidance areas arranged corresponding to the three filter circuit structures, and the filter circuit structure comprises a grounding conductor and a metal conductor, and the grounding conductor is conducted with the first metal grounding layer, and the metal conductor is conducted with the branches, and a part of the metal conductor is exposed in the avoidance area to form a feeding port.
[0008] Furthermore, a conducting structure is provided in the dielectric ring, and the branch is conducted with the metal conductor via the conducting structure.
[0009] Furthermore, the conductive structure is a metallized hole or a through hole filled with a conductive filler.
[0010] Furthermore, the grounding structure is a metallized hole or a through hole filled with a conductive filler.
[0011] Furthermore, the circulator layer, the first metal grounding layer, the filter layer and the second metal grounding layer are formed into an integrated structure through a LTCC process.
[0012] Furthermore, the central ferrite is a low temperature sintered spin magnet ferrite, with a relative dielectric constant of 22 to 28 and a 4πMs of 800 to 1200Gs.
[0013] Furthermore, the dielectric ring is a low-temperature sintered dielectric ceramic ring, and its relative dielectric constant is 20-40.
[0014] Furthermore, the dielectric plate is a low temperature sintered dielectric ceramic plate, and its relative dielectric constant is 4.5-10.
[0015] Further, the material of the central conductor is gold, silver or silver-palladium alloy; and / or,
[0016] The filter circuit structure is made of gold, silver or silver-palladium alloy; and / or,
[0017] The material of the first metal grounding layer is gold, silver or silver-palladium alloy; and / or,
[0018] The second metal grounding layer is made of gold, silver or silver-palladium alloy.
[0019] Furthermore, the central conductor is printed on the top surface of the circulator layer.
[0020] The beneficial effect of the utility model is that the circulator utilizes the laminated structure of the LTCC process to effectively combine the low-pass filter into the circulator, thereby improving the performance of the circulator in the harmonic frequency band, so that the circulator has a higher out-of-band suppression capability in the out-of-band frequency band, and at the same time, the miniaturization of the device is achieved while meeting certain in-band performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic structural diagram of the overall structure of a miniaturized LTCC circulator with high out-of-band suppression according to the first embodiment;
[0022] Figure 2 It is a schematic structural diagram of the overall structure of the miniaturized LTCC circulator with high out-of-band suppression in Example 1 from another perspective;
[0023] Figure 3 It is a schematic structural diagram of a circulator layer in a miniaturized LTCC circulator with high out-of-band suppression according to the first embodiment;
[0024] Figure 4 It is a structural schematic diagram of a part of the structure of the filter layer in the miniaturized LTCC circulator with high out-of-band suppression in Example 1;
[0025] Figure 5 It is an overall S parameter curve diagram of the miniaturized LTCC circulator with high out-of-band suppression of Example 1;
[0026] Figure 6 It is a graph of the in-band performance S parameter of the miniaturized LTCC circulator with high out-of-band suppression in Example 1;
[0027] Figure 7 This is an S parameter curve diagram of the out-of-band suppression performance of the miniaturized LTCC circulator with high out-of-band suppression of Example 1.
[0028] Description of labels:
[0029] 1. circulator layer; 11. central ferrite; 12. dielectric ring; 13. first metal grounding layer; 14. central conductor; 141. branch; 15. conduction structure;
[0030] 2. Filter layer; 21. Dielectric plate; 22. Second metal grounding layer; 221. Avoidance area; 23. Low-pass filter; 231. Filter circuit structure; 2311. Grounding conductor; 2312. Metal conductor; 2313. Feeding port; 232. Grounding structure. DETAILED DESCRIPTION
[0031] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.
[0032] Please refer to Figures 1 to 7 , a miniaturized LTCC circulator with high out-of-band suppression, comprising:
[0033] A circulator layer 1, the circulator layer 1 comprising a central ferrite 11 and a dielectric ring 12 sleeved on the central ferrite 11, a first metal grounding layer 13 being provided on the bottom surface of the circulator layer 1, a central conductor 14 being provided on the top surface of the circulator layer 1, the central conductor 14 comprising three branches 141, and the three branches 141 being rotationally symmetrical around the Z axis at intervals of 120°;
[0034] The filter layer 2 comprises a dielectric plate 21 having a laminated structure, the top surface of the dielectric plate 21 is fixedly connected to the first metal grounding layer 13, the bottom surface of the dielectric plate 21 is provided with a second metal grounding layer 22, three low-pass filters 23 are provided in the dielectric plate 21, the three low-pass filters 23 correspond to the three branches 141 one by one, the low-pass filters 23 comprise a filter circuit structure 231 and a plurality of grounding structures 232 arranged around the filter circuit structure 231, the grounding structure 232 The first metal grounding layer 13 and the second metal grounding layer 22 are connected, and the second metal grounding layer 22 has three avoidance areas 221 corresponding to the three filter circuit structures 231. The filter circuit structure 231 includes a grounding conductor 2311 and a metal conductor 2312. The grounding conductor 2311 is connected to the first metal grounding layer 13, and the metal conductor 2312 is connected to the branch 141. Part of the metal conductor 2312 is exposed in the avoidance area 221 to form a feeding port 2313.
[0035] From the above description, it can be seen that the beneficial effect of the utility model is that the circulator utilizes the laminated structure of the LTCC process to effectively combine the low-pass filter 23 into the circulator, thereby improving the performance of the circulator in the harmonic frequency band, so that the circulator has a higher out-of-band suppression capability in the out-of-band frequency band, and at the same time, the miniaturization of the device is achieved while meeting certain in-band performance.
[0036] Furthermore, a conducting structure 15 is provided in the dielectric ring 12 , and the branch 141 is conducted to the metal conductor 2312 via the conducting structure 15 .
[0037] It can be seen from the above description that embedding the conducting structure 15 in the dielectric ring 12 is beneficial to miniaturization of the overall volume of the circulator.
[0038] Furthermore, the conductive structure 15 is a metallized hole or a through hole filled with a conductive filler.
[0039] It can be seen from the above description that there are many options for the specific structure of the conducting structure 15 .
[0040] Furthermore, the grounding structure 232 is a metallized hole or a through hole filled with a conductive filler.
[0041] It can be seen from the above description that the specific structure of the grounding structure 232 can be set as needed.
[0042] Furthermore, the circulator layer 1, the first metal grounding layer 13, the filter layer 2 and the second metal grounding layer 22 are formed into an integrated structure through a LTCC process.
[0043] From the above description, it can be seen that the circulator is manufactured by the LTCC process, so that the circulator has the advantages of high packaging density, good radio frequency characteristics, and high reliability.
[0044] Furthermore, the central ferrite 11 is a low temperature sintered spin magnet ferrite, with a relative dielectric constant of 22 to 28 and a 4πMs of 800 to 1200Gs.
[0045] Furthermore, the dielectric ring 12 is a low temperature sintered dielectric ceramic ring, and its relative dielectric constant is 20-40.
[0046] Furthermore, the dielectric plate 21 is a low-temperature sintered dielectric ceramic plate, and its relative dielectric constant is 4.5-10.
[0047] Further, the material of the central conductor 14 is gold, silver or silver-palladium alloy; and / or,
[0048] The filter circuit structure 231 is made of gold, silver or silver-palladium alloy; and / or,
[0049] The material of the first metal grounding layer 13 is gold, silver or silver-palladium alloy; and / or,
[0050] The second metal grounding layer 22 is made of gold, silver or silver-palladium alloy.
[0051] From the above description, it can be seen that gold, silver, and silver-palladium alloy have the advantage of high electrical conductivity, which is beneficial to improve the performance of the circulator to a greater extent.
[0052] Furthermore, the central conductor 14 is printed on the top surface of the circulator layer 1 .
[0053] It can be seen from the above description that the molding method of the center conductor 14 is novel and simple, which is convenient for assembling and manufacturing the circulator.
[0054] Embodiment 1
[0055] Please refer to Figures 1 to 7 , Embodiment 1 of the present utility model is: Figures 1 to 4As shown, a miniaturized LTCC circulator with high out-of-band suppression includes a circulator layer 1 and a filter layer 2, wherein the circulator layer 1 includes a central ferrite 11 and a dielectric ring 12 sleeved on the central ferrite 11, a first metal grounding layer 13 is provided on the bottom surface of the circulator layer 1, a central conductor 14 is provided on the top surface of the circulator layer 1, and the central conductor 14 includes three branches 141, and the three branches 141 are rotationally symmetrical around the Z axis at intervals of 120°. Specifically, the three branches 141 have an intersection position that intersects with each other, and the intersection position is located on the central axis of the central ferrite 11; the filter layer 2 includes a dielectric plate 21 with a laminated structure, the top surface of the dielectric plate 21 is fixedly connected to the first metal grounding layer 13, the bottom surface of the dielectric plate 21 is provided with a second metal grounding layer 22, and three low-pass filters 23 are provided in the dielectric plate 21, and the three low-pass filters 23 are connected to the three The branches 141 correspond to each other one by one, the low-pass filter 23 includes a filter circuit structure 231 and a plurality of grounding structures 232 arranged around the filter circuit structure 231, the grounding structure 232 conducts the first metal grounding layer 13 and the second metal grounding layer 22, the grounding structure 232 is a metallized hole or a through hole filled with conductive filler; the second metal grounding layer 22 has three empty areas 221 corresponding to the three filter circuit structures 231, the filter circuit structure 231 is a laminated structure arranged in the dielectric plate 21, the filter circuit structure 231 includes a grounding conductor 2311 and a metal conductor 2312, the grounding conductor 2311 is connected to the first metal grounding layer 13, the metal conductor 2312 is connected to the branches 141, and a part of the metal conductor 2312 is exposed in the empty area 221 to form a feeding port 2313. Optionally, the three empty areas 221 are rotationally symmetrical around the Z axis at intervals of 120°.
[0056] Specifically, a conducting structure 15 is provided in the dielectric ring 12 , and the branch 141 is electrically connected to the metal conductor 2312 via the conducting structure 15 . Preferably, the conducting structure 15 is a metallized hole or a through hole filled with a conductive filler.
[0057] The circulator layer 1, the first metal grounding layer 13, the filter layer 2 and the second metal grounding layer 22 are formed into an integrated structure through the LTCC process, which can facilitate the production of miniaturized LTCC circulators with high out-of-band suppression.
[0058] The central ferrite 11 is a low-temperature sintered rotary magnetic ferrite, with a relative dielectric constant of 22-28, 4πMs of 800-1200Gs, and a sintering temperature of about 900°C. The dielectric ring 12 is a low-temperature sintered dielectric ceramic ring, with a relative dielectric constant of 20-40, and a sintering temperature of about 900°C. The dielectric plate 21 is a low-temperature sintered dielectric ceramic plate, with a relative dielectric constant of 4.5-10, and a sintering temperature of about 900°C. The sintering temperatures of the dielectric ring 12 and the dielectric plate 21 are both about 900°C, and can be matched and co-fired with the central ferrite 11.
[0059] The material of the central conductor 14 is gold, silver or silver-palladium alloy; and / or, the material of the filter circuit structure 231 is gold, silver or silver-palladium alloy; and / or, the material of the first metal grounding layer 13 is gold, silver or silver-palladium alloy; and / or, the material of the second metal grounding layer 22 is gold, silver or silver-palladium alloy.
[0060] Optionally, the central conductor 14 is printed on the top surface of the circulator layer 1. Compared with the central conductor 14 made of metal sheet material, the printed central conductor 14 is more convenient for the production of miniaturized LTCC circulators with high out-of-band suppression.
[0061] In this embodiment, the central ferrite 11 is a low-temperature sintered YIG ferrite with a relative dielectric constant of 24 and a saturation magnetization of 63.7 kA / m (800 Gs), with a diameter of 9.2 mm and a thickness of 1.1 mm; the dielectric ring 12 is a low-temperature sintered dielectric ceramic ring with a relative dielectric constant of 30 and a loss tangent of 0.002, with an outer diameter of 16 mm and a thickness of 1.1 mm; the thickness of the central conductor 14 is 0.01 mm; the conductive structure 15 is a metallized hole, The diameter of the conductive structure 15 is 0.4mm; the thickness of the first metal grounding layer 13 and the thickness of the second metal grounding layer 22 are both 0.01mm; the dielectric plate 21 is a dielectric ceramic plate with a relative dielectric constant of 5.5 and a loss tangent value of 0.002, with a diameter of 16mm and a thickness of 0.9mm. A filter circuit structure 231 is made at an appropriate position in the dielectric plate 21, wherein the grounding structure 232 is a metallized hole and the diameter of the grounding structure 232 is 0.6mm. The overall diameter of the miniaturized LTCC circulator with high out-of-band suppression in this embodiment is 16mm and the thickness is 2.06mm.
[0062] Figure 5 is an overall S-parameter curve diagram of the miniaturized LTCC circulator with high out-of-band suppression of this embodiment;
[0063] Figure 6 is an S parameter curve diagram of the in-band performance of the miniaturized LTCC circulator with high out-of-band suppression of the present embodiment;
[0064] Figure 7 FIG. 4 is an S-parameter curve diagram of the out-of-band suppression performance of the miniaturized LTCC circulator with high out-of-band suppression of the present embodiment.
[0065] pass Figure 5-Figure 7 It can be seen that the miniaturized LTCC circulator with high out-of-band suppression in the present embodiment has an isolation of more than -15dB, a return loss of less than -15dB, and an insertion loss of more than -0.5dB in the frequency range of 2.3GHz to 2.6Ghz. At the same time, the out-of-band suppression is greater than 40dB in the range of 4GHz to 9GHz, thus achieving the requirements of miniaturization and high out-of-band suppression of the circulator.
[0066] In summary, the circulator provided by the utility model utilizes the LTCC laminated structure, adopts the spinel ferrite material with a high dielectric constant and the dielectric ceramic material sintered at a low temperature, effectively combines the low-pass filter with the circulator, achieves higher out-of-band harmonic suppression performance, realizes the miniaturization of the device while meeting certain in-band performance, and improves the working bandwidth of the circulator.
[0067] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.
Claims
1. A miniaturized LTCC circulator with high out-of-band suppression, characterized in that: include A circulator layer, the circulator layer comprising a central ferrite and a dielectric ring sleeved on the central ferrite, a first metal grounding layer being provided on the bottom surface of the circulator layer, a central conductor being provided on the top surface of the circulator layer, the central conductor comprising three branches, and the three branches being rotationally symmetrical around a Z axis at intervals of 120°; A filter layer, wherein the filter layer comprises a dielectric plate with a laminated structure, wherein the top surface of the dielectric plate is fixedly connected to the first metal grounding layer, and the bottom surface of the dielectric plate is provided with a second metal grounding layer, and three low-pass filters are provided in the dielectric plate, and the three low-pass filters correspond one-to-one to the three branches, and the low-pass filter comprises a filter circuit structure and a plurality of grounding structures arranged around the filter circuit structure, and the grounding structure conducts the first metal grounding layer and the second metal grounding layer, and the second metal grounding layer has three avoidance areas arranged corresponding to the three filter circuit structures, and the filter circuit structure comprises a grounding conductor and a metal conductor, and the grounding conductor is conducted with the first metal grounding layer, and the metal conductor is conducted with the branches, and a part of the metal conductor is exposed in the avoidance area to form a feeding port.
2. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: A conducting structure is provided in the dielectric ring, and the branch is conducted with the metal conductor via the conducting structure.
3. The miniaturized LTCC circulator with high out-of-band suppression according to claim 2, characterized in that: The conductive structure is a metallized hole or a through hole filled with a conductive filler.
4. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The grounding structure is a metallized hole or a through hole filled with a conductive filler.
5. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The circulator layer, the first metal grounding layer, the filter layer and the second metal grounding layer are formed into an integrated structure through the LTCC process.
6. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The central ferrite is a low temperature sintered spin magnet ferrite, with a relative dielectric constant of 22 to 28 and a 4πMs of 800 to 1200Gs.
7. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The dielectric ring is a low temperature sintered dielectric ceramic ring, and its relative dielectric constant is 20-40.
8. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The dielectric plate is a low temperature sintered dielectric ceramic plate, and its relative dielectric constant is 4.5-10.
9. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The material of the central conductor is gold, silver or silver-palladium alloy; and / or, The filter circuit structure is made of gold, silver or silver-palladium alloy; and / or, The material of the first metal grounding layer is gold, silver or silver-palladium alloy; and / or, The second metal grounding layer is made of gold, silver or silver-palladium alloy.
10. The miniaturized LTCC circulator with high out-of-band suppression according to claim 1, characterized in that: The central conductor is printed on the top surface of the circulator layer.