Composite ultra-wideband circulator based on LiZnTi ferrite homogeneous structure

Abstract

The invention discloses a composite ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure. The composite ultra-wideband circulator sequentially comprises a ferrite substrate, a ferrite cylinder and a microstrip circuit from bottom to top, the ferrite cylinder is nested in the ferrite substrate, and the microstrip circuit is arranged on the upper surface of the ferrite cylinder; the ferrite substrate comprises a magnetizing body and a non-magnetizing body, and the magnetizing body is of a circular structure surrounding the ferrite cylinder; the microstrip circuit is of a single Y junction structure and comprises a sheet-shaped central round junction and three extending ends evenly distributed in the circumferential direction of the sheet-shaped central round junction, and each extending end sequentially comprises a coupling line, a converter and a microstrip line outwards with the sheet-shaped central round junction as a node. And the sheet-shaped central round knot is arranged at the center of the upper surface of the ferrite cylinder. Compared with a single ferrite circulator, the LiZnTi ferrite composite ferrite structure circulator provided by the invention has the advantage that the bandwidth is improved by 18.4%.

Description

Technical Field

[0001] The present application relates to the field of microwave communications, and in particular to an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite. Background Art

[0002] Miniaturized, broadband ferrite circulators are in high demand in applications such as radar communications and electronic countermeasures systems. However, current magnetic ferrite circulators are mostly single-ferrite structures, typically consisting of a central ferrite cylinder as the core material for device performance, surrounded by impedance-matching layers. These traditional ferrite circulators typically utilize a central circuit design to achieve miniaturization, wide bandwidth, and low loss. However, the design process for these devices is complex, the circuit patterns are complex, and processing is difficult. Furthermore, due to the performance limitations of single-structure ferrite (composite) materials, achieving wide bandwidth requirements is difficult.

[0003] In recent years, some research has reported on the use of ferrite composite structures to achieve miniaturization and broadband circulator design. For example, a composite structure of garnet YIG ferrite and Ni-based spinel ferrite has been used. However, this heterogeneous material composite structure is plagued by significant differences in material properties, varying thermal expansion coefficients, and difficulties in heterogeneous composite integration, limiting its application. Therefore, this paper proposes a circulator design based on a homogeneous composite structure of LiZnTi ferrites with different gyromagnetic properties. Summary of the Invention

[0004] To solve the above problems, the present application provides an ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite, aiming to provide an ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite with a bandwidth increased by 18.4% compared with a single ferrite circulator.

[0005] In a first aspect, an embodiment of the present invention provides an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite, which comprises, from bottom to top, a ferrite substrate, a ferrite cylinder, and a microstrip circuit; the ferrite cylinder is nested inside the ferrite substrate, and the microstrip circuit is arranged on the upper surface of the ferrite cylinder; The ferrite substrate includes a magnetized body and a non-magnetized body, wherein the magnetized body is a ring-shaped structure surrounding the ferrite cylinder; The microstrip circuit is a single Y-junction structure, comprising a sheet-shaped central circular junction and three extension ends evenly distributed along the circumference of the sheet-shaped central circular junction. Each extension end includes a coupling line, a converter, and a microstrip line in sequence outward from the sheet-shaped central circular junction. The sheet-shaped central circular junction is located at the center of the upper surface of the ferrite cylinder. The ferrite substrate and the ferrite cylinder are both homogeneous LiZnTi microwave ferrite.

[0006] In an optional embodiment, the outer radius R2 of the ferrite substrate magnetized body and the radius R1 of the ferrite cylinder satisfy: R2 ≥ 1.2R1.

[0007] In an optional embodiment, the radius R of the sheet center circle is c The radius of the ferrite cylinder R1 satisfies: R c = 0.8R1.

[0008] In an optional embodiment, the saturation magnetization intensity of the ferrite cylinder is 4200-4500 Gs, and the saturation magnetization intensity of the ferrite substrate magnet is 2500-2800 Gs.

[0009] In an optional embodiment, the Ti 4+ Ion pair Fe 3+ The ion substitution amount is 0.20-0.40.

[0010] In an optional embodiment, the ferrite cylinder is prepared by a hot pressing sintering method, and the ferrite substrate is prepared by a solid phase method.

[0011] In an optional embodiment, the microstrip circuit is formed on the upper surface of the ferrite cylinder by photolithography and magnetron sputtering processes.

[0012] In an optional implementation, the converter is a single-section impedance converter, and the impedance of the microstrip line is 50 Ω.

[0013] In an optional embodiment, the ferrite cylinder and the magnetized body are active magnetization units, which are magnetized by an external magnetic field source.

[0014] In an embodiment of the present disclosure, a composite ferrite circulator is provided, in which a high saturation magnetization intensity ferrite cylinder is composited with a low saturation magnetization intensity ferrite substrate. A low saturation magnetization intensity ferrite ring is formed by magnetizing a partial area on the low saturation magnetization intensity ferrite substrate, thereby realizing composite integration of ferrites with different saturation magnetization intensities, thereby enhancing the bandwidth effect of the circulator.

[0015] Based on the homogeneous LiZnTi ferrite material, it is different from the general garnet ferrite / spinel ferrite composite structure. Only LiZnTi ferrite homogeneous material is used for composite. This is because the saturation magnetization intensity of LiZnTi ferrite is convenient and adjustable, which can easily meet the use requirements of the band. And because it has the same crystal structure, it is easier to co-fire and integrate. At the same time, compared with Ni-based ferrite, it has a smaller effective linewidth, and the developed device loss will be smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a schematic structural diagram of an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite proposed in one embodiment of the present application; Figure 2 This is a schematic diagram of the multi-stage structure of a circulator composite ferrite substrate proposed in one embodiment of the present application; Figure 3 is a schematic diagram of a ferrite substrate of a circulator proposed in one embodiment of the present application; Figure 4 is a schematic diagram of a microstrip circuit of a circulator proposed in one embodiment of the present application; Figure 5 is the simulation result of the HFSS simulation software proposed in one embodiment of the present application; Among them, 1-ferrite substrate, 2-ferrite cylinder, 3-microstrip circuit, 4-magnetized body, 5-non-magnetized body, 6-sheet center circle junction, 7-coupling line, 8-converter, 9-microstrip line. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic structural diagram of an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite proposed in one embodiment of the present application. Figure 2 This is a schematic diagram of the multi-level structure of the circulator composite ferrite substrate proposed in one embodiment of the present application. Figure 1 and Figure 2 As shown, an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite comprises, from bottom to top, a ferrite substrate 1, a ferrite cylinder 2, and a microstrip circuit 3; the ferrite cylinder 2 is nested inside the ferrite substrate 1, and the microstrip circuit 3 is arranged on the upper surface of the ferrite cylinder 2; Please refer to Figure 3 , Figure 3FIG. 1 is a schematic diagram of a ferrite substrate of a circulator according to an embodiment of the present application. Figure 3 As shown, the ferrite substrate 1 includes a magnetized body 4 and a non-magnetized body 5, wherein the magnetized body 4 is a circular ring structure surrounding the ferrite cylinder 2; Please refer to Figure 4 , Figure 4 Schematic diagram of a microstrip circuit of a circulator proposed in one embodiment of the present application. Figure 4 As shown, the microstrip circuit 3 is a single Y-junction structure, including a sheet-shaped central circular junction 6 and three extended ends evenly distributed along the circumference of the sheet-shaped central circular junction 6, wherein each extended end includes a coupling line 7, a transformer 8 and a microstrip line 9 in sequence outward from the sheet-shaped central circular junction 6; the sheet-shaped central circular junction 6 is provided at the center of the upper surface of the ferrite cylinder 2; The ferrite substrate 1 and the ferrite cylinder 2 are both homogeneous LiZnTi microwave ferrite.

[0020] In this embodiment, the ferrite cylinder 2 is nested within the ferrite substrate 1, and a tight fit is achieved through a secondary co-firing method. Since the two are made of the same material, co-firing is less difficult and a tight fit at the interface is easier to achieve. The microstrip circuit is formed on the ferrite cylinder through methods such as photolithography and magnetron sputtering. The ferrite material used is LiZnTi microwave ferrite. Li-based ferrite has conveniently adjustable saturation magnetization, a high Curie temperature, and a low effective linewidth. The use of this material can effectively improve the performance of ferrite circulators.

[0021] Furthermore, the outer radius R2 of the magnetized body 4 of the ferrite substrate 1 and the radius R1 of the ferrite cylinder 2 satisfy: R2 ≥ 1.2R1.

[0022] In this embodiment, a ferrite cylinder is located at the center of the ferrite substrate. This cylinder primarily contributes to the circulator's performance, and the circulator design is based on this material's properties. Nested within the periphery of this ferrite cylinder is a ferrite ring, formed by magnetizing only a portion of the ferrite substrate. The outer radius of this ring is at least 1.2 times the radius of the high-saturation magnetization ferrite cylinder. The outer portion of the ring is the unmagnetized area of ​​the ferrite substrate and is considered ordinary dielectric ceramic.

[0023] Furthermore, the radius R of the sheet-shaped center circle knot 6 is c The radius R1 of the ferrite cylinder 2 satisfies: R c = 0.8R1.

[0024] Furthermore, the saturation magnetization intensity of the ferrite cylinder 2 is 4200-4500 Gs, and the saturation magnetization intensity of the magnetized body of the ferrite substrate 1 is 2500-2800 Gs.

[0025] Furthermore, the Ti 4+ Ion pair Fe3+ The ion substitution amount is 0.20-0.40.

[0026] In this embodiment, the preparation of a ferrite substrate with low saturation magnetization is achieved by adjusting the amount of Ti ion substitution.

[0027] Furthermore, the ferrite cylinder 2 is prepared by a hot pressing sintering method, and the ferrite substrate 1 is prepared by a solid phase method.

[0028] In this embodiment, the ferrite cylinder is prepared by hot pressing and sintering to achieve high density and high performance, thereby ensuring the main performance of the circulator.

[0029] Furthermore, the microstrip circuit 3 is formed on the upper surface of the ferrite cylinder 2 by photolithography and magnetron sputtering processes.

[0030] Furthermore, the converter 8 is a single-section impedance converter, and the impedance of the microstrip line 9 is 50 Ω.

[0031] In this embodiment, to achieve better impedance matching, the length of all microstrip lines is set to one-quarter the wavelength of the operating frequency. For the X / Ku band, this frequency is chosen to be 17 GHz. The coupled line width is determined through initial circulator design. Impedance matching techniques are then employed, and microstrip line calculation software is used to determine the width of the impedance transformer. Finally, the width of a standard 50 Ω microstrip line is obtained. This microstrip circuit utilizes only a single impedance transformer, effectively reducing the device size while increasing bandwidth.

[0032] Furthermore, the ferrite cylinder 2 and the magnetized body 4 are active magnetization units, which are magnetized by an external magnetic field source.

[0033] In this embodiment, during actual commissioning, by replacing external permanent magnets with different diameters or field strengths, the ferrite's magnetization intensity and range can be precisely controlled, thereby adjusting the magnetization level of the magnetized body and optimizing the overall circulator performance. In the simulation model, the external bias magnetic field source simply needs to be configured using HFSS software to determine the magnetization area and intensity of the ferrite cylinder.

[0034] For example, please refer to Figure 5 , Figure 5 This is the simulation result of the HFSS simulation software proposed in one embodiment of the present application. Figure 5 As shown, a circulator sample was fabricated using the homogeneous LiZnTi composite ferrite substrate (saturation magnetization: 4300 Gs for the cylinder / 2700 Gs for the substrate magnetization region) and a single Y-junction microstrip circuit. By using regional magnetization to form a magnetized ring with an outer diameter ratio of 1.2, the sample was tested for performance in the X / Ku band (8-18 GHz). The results showed: The circulator's various performance parameters include the S31 parameter, or isolation, which reflects the interference resistance between the circulator's different ports. A -20 dB threshold means approximately 1% of the signal power can be transmitted to other ports. Under this requirement, the relative bandwidth is improved by 18.4% compared to a single ferrite circulator. The S11 parameter, or return loss, reflects the impedance matching between the input port and the microstrip line. A -20 dB threshold means approximately 1% of the signal power is reflected back to the signal source. The S21 parameter, or insertion loss, reflects the power loss from the input port to the output port. A -1 dB threshold means approximately 79.3% of the signal power is successfully transmitted to the output port. These performance indicators meet the requirements for use as an X / Ku-band ultra-wideband circulator.

[0035] In summary, the bandwidth performance of the circulator is significantly improved by combining a high-saturation magnetization ferrite cylinder with a partially magnetized low-saturation magnetization ferrite substrate in a homogeneous structure, and using a single-section impedance transformer for impedance matching. This application meets the requirements for ultra-wideband applications in the X / Ku band and other applications, making it particularly suitable for use in electronic countermeasures systems, which require high bandwidth to suppress enemy radar systems.

[0036] In terms of materials and integration, based on the homogeneous LiZnTi microwave ferrite material, by adjusting the non-magnetic Ti 4+ The amount of ion substitution can conveniently control the saturation magnetization, making the performance adaptability of ferrite components with high and low saturation magnetization better.

[0037] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0038] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0039] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0040] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements that are inherent to such process, method, article, or terminal device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0041] The above is a detailed introduction to an ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An ultra-wideband circulator based on a LiZnTi ferrite homogeneous structure composite, characterized in that: The structure comprises, from bottom to top, a ferrite substrate (1), a ferrite cylinder (2), and a microstrip circuit (3); the ferrite cylinder (2) is nested inside the ferrite substrate (1), and the microstrip circuit (3) is arranged on the upper surface of the ferrite cylinder (2); The ferrite substrate (1) comprises a magnetized body (4) and a non-magnetized body (5), wherein the magnetized body (4) is a circular ring structure surrounding the ferrite cylinder (2); The microstrip circuit (3) is a single Y-junction structure, comprising a sheet-shaped central circular junction (6) and three extension ends uniformly distributed along the circumference of the sheet-shaped central circular junction (6), wherein each extension end sequentially comprises a coupling line (7), a converter (8) and a microstrip line (9) outward from the sheet-shaped central circular junction (6) as a node; the sheet-shaped central circular junction (6) is arranged at the center of the upper surface of the ferrite cylinder (2); The ferrite substrate (1) and the ferrite cylinder (2) are both homogeneous LiZnTi microwave ferrite.

2. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The outer radius R2 of the magnetized body (4) and the radius R1 of the ferrite cylinder (2) satisfy: R2 ≥ 1.2R1.

3. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The radius R of the flaky center circle knot (6) c The radius R1 of the ferrite cylinder (2) satisfies: R c = 0.8R1.

4. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The saturation magnetization intensity of the ferrite cylinder (2) is 4200-4500 Gs, and the saturation magnetization intensity of the magnetized body (4) is 2500-2800 Gs.

5. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The Ti 4+ Ion pair Fe 3+ The ion substitution amount is 0.20-0.

40.

6. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The ferrite cylinder (2) is prepared by a hot pressing sintering method, and the ferrite substrate (1) is prepared by a solid phase method.

7. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The microstrip circuit (3) is formed on the upper surface of the ferrite cylinder (2) through photolithography and magnetron sputtering processes.

8. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to claim 1, characterized in that: The converter (8) is a single-section impedance converter, and the impedance of the microstrip line (9) is 50 Ω.

9. The ultra-wideband circulator based on LiZnTi ferrite homogeneous structure composite according to any one of claims 1 to 8, characterized in that: The ferrite cylinder (2) and the magnetized body (4) are active magnetization units and are magnetized by an external magnetic field source.

Images