A miniaturized broadband microstrip circulator with X-band nested ferrite

Abstract

This invention relates to the field of microwave ferrite device technology and discloses a miniaturized broadband microstrip circulator with X-band nested ferrite, comprising a magnetic sheet, a high-dielectric ceramic, a ferrite, a circuit, a ceramic sheet, and a permanent magnet. The high-dielectric ceramic is mounted on the upper surface of the magnetic sheet, the ferrite is placed on the high-dielectric ceramic with the circuit mounted on its upper surface, and the ceramic sheet is above the circuit with the permanent magnet mounted on its upper surface. In a preferred embodiment, the permanent magnet contains gadolinium alloy microparticles, and the bottom of the ferrite has a nanocrystalline ferrite coating. This circulator shortens the electromagnetic wave wavelength through the high-dielectric ceramic, reducing the size of the ferrite and the overall device; the magnetic sheet guides the magnetic field to improve utilization; the integration of the ferrite and the circuit optimizes signal transmission; and the ceramic sheet and permanent magnet ensure structural stability and provide a bias magnetic field. The synergistic effect of each layer extends the operating bandwidth, making it suitable for electronic countermeasures and other scenarios, thus contributing to the efficient operation of radar systems.

Description

Technical Field

[0001] This invention relates to the field of microwave ferrite device technology, specifically to a miniaturized broadband microstrip circulator with X-band nested ferrite. Background Technology

[0002] X-band circulators are key passive components in microwave communication and radar systems. With the increasing demands for miniaturization, lightweighting, and high reliability in modern electronic devices, the development of circulators with wideband operating capabilities and compact size has become an important direction for technological development.

[0003] Traditional X-band circulators suffer from numerous design limitations. The use of conventional dielectric materials results in longer electromagnetic wavelengths, forcing core components such as ferrites to have larger physical dimensions, making it difficult to compress the overall device size. This necessitates larger magnets or complex magnetic field designs to maintain performance, further limiting miniaturization. Insufficient integration between ferrites and circuitry leads to inadequate signal transmission path optimization, resulting in higher electromagnetic losses and impacting transmission efficiency. Poor support structure stability makes the bias magnetic field susceptible to external interference, reducing the reliability of ferrite operation. Furthermore, due to material and structural limitations, traditional circulators have narrow operating bandwidths and uneven frequency responses, making them unsuitable for wideband applications within the X-band. Their large size and weight also hinder their suitability for scenarios with extremely high system integration requirements, such as electronic warfare, thus restricting the efficient operation and portability of radar and other equipment. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a miniaturized broadband microstrip circulator with X-band nested ferrite, thus solving the problem of decreased ferrite operation reliability mentioned in the background art. Furthermore, due to material and structural limitations, traditional circulators have narrow operating bandwidths and uneven frequency responses, making it difficult to meet the broadband application requirements within the X-band. Moreover, their large overall size and weight make them unsuitable for scenarios with extremely high system integration requirements, such as electronic countermeasures, thus hindering the efficient operation and portability improvement of equipment such as radar.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a miniaturized broadband microstrip circulator with X-band nested ferrite, comprising:

[0006] A magnetic conductive sheet, wherein a high dielectric ceramic is mounted on the upper surface of the magnetic conductive sheet;

[0007] Ferrite is disposed on the upper surface of a high-dielectric ceramic, and a circuit is mounted on the upper surface of the ferrite.

[0008] A ceramic sheet is disposed on the upper surface of the circuit, and a permanent magnet is mounted on the upper surface of the ceramic sheet.

[0009] Preferably, gadolinium alloy microparticles are installed inside the permanent magnet, and a nanocrystalline ferrite coating is installed on the bottom of the ferrite.

[0010] Gadolinium alloy microparticles are uniformly mixed with the permanent magnet matrix material. High-energy ball milling is used to refine and disperse the gadolinium alloy microparticles within the matrix powder. Then, unidirectional pressing or isostatic pressing techniques from powder metallurgy are employed to press the mixed powder into a permanent magnet blank of the desired shape. High-temperature sintering further ensures a tight atomic-level bond between the gadolinium alloy microparticles and the permanent magnet matrix, ultimately forming a composite permanent magnet structure with uniformly embedded gadolinium alloy microparticles. Simultaneously, in the bottom surface treatment stage of the ferrite substrate, physical vapor deposition or chemical solution methods are used. By precisely controlling the deposition parameters, a coating with a nanocrystalline structure is formed on the ferrite substrate surface. This coating, through the high-density grain boundary effect of the nanocrystals, effectively optimizes the magnetic permeability and loss characteristics of the ferrite and ensures a good interfacial bond between the coating and the ferrite substrate, avoiding coating peeling or cracking problems caused by thermal or mechanical stress.

[0011] Preferably, a three-dimensional gradient nested array is mounted on the upper surface of the ferrite, and a multiferroic thin film is mounted on the upper surface of the three-dimensional gradient nested array.

[0012] The three-dimensional gradient structure parameters, including the nesting hierarchy of the array and the compositional or geometric gradient of each layer of material, are defined using computer-aided design software. Then, a micro / nano structure template with a gradient distribution is fabricated on the ferrite surface using laser direct writing or nanoimprinting techniques. Next, material layers with different compositions or structures are deposited layer by layer on the template surface using physical vapor deposition or chemical solution methods. By precisely controlling the deposition thickness and gradient transition of each layer, a three-dimensional nested array structure with continuously changing composition / structure is formed. Subsequently, a multiferroic thin film is deposited on the upper surface of the three-dimensional gradient nested array using pulsed laser deposition or metal-organic chemical vapor deposition. By adjusting the deposition temperature, atmosphere, and laser energy density, a uniform and dense multiferroic thin film is formed on the array surface. Simultaneously, in-situ annealing is used to optimize the crystallinity and multiferroic coupling performance of the film, ultimately achieving functional integration of the three-dimensional gradient nested array and the multiferroic thin film, improving the circulator's broadband characteristics and magnetoelectric control capabilities.

[0013] Preferably, the surface of the high-dielectric ceramic is provided with a mounting groove, and the ferrite is mounted inside the mounting groove;

[0014] Based on the geometric dimensions and electromagnetic performance requirements of the ferrite, the depth, width, and shape parameters of the mounting groove are determined using computer-aided design to ensure a complete fit between the groove and the bottom surface of the ferrite, minimizing air gaps. Subsequently, precision machining or laser micromachining techniques are used to precisely etch the mounting groove, conforming to the design dimensions, onto the upper surface of the high-dielectric ceramic. During processing, the machining accuracy must be controlled to avoid damaging the ceramic substrate. After grooving, the interior of the groove and the bottom surface of the ferrite are subjected to plasma cleaning or ultrasonic cleaning to remove residual debris and contaminants. Next, the ferrite is embedded in the mounting groove and fixed using low-temperature conductive adhesive bonding or vacuum brazing. The conductive adhesive must be selected with a coefficient of thermal expansion matching that of the ceramic and ferrite to prevent mechanical stress caused by temperature changes. Finally, the assembly accuracy of the ferrite and mounting groove is verified by microscopic inspection or a three-dimensional coordinate measuring machine to ensure a gapless interface and a continuous electromagnetic coupling path, thereby optimizing the magnetic circuit design and broadband characteristics of the circulator.

[0015] Preferably, a low-temperature co-fired ceramic layer is installed inside the high-dielectric ceramic, and an iron-based amorphous alloy thin film is installed on the upper surface of the high-dielectric ceramic.

[0016] Low-temperature co-fired ceramic slurry was prepared into green ceramic tapes using a tape casting method. These tapes were then cut and stacked according to the required thickness of the high-dielectric ceramic. Low-temperature sintering was then performed to form an internally embedded low-temperature co-fired ceramic layer. During sintering, the heating rate and atmosphere were carefully controlled to prevent cracking due to differences in thermal expansion coefficients between the high-dielectric ceramic substrate and the low-temperature co-fired ceramic layer. After the integration of the low-temperature co-fired ceramic layer, the upper surface of the high-dielectric ceramic was pretreated to remove impurities and activate the surface. Then, a thin film of iron-based amorphous alloy was deposited on the pretreated surface using magnetron sputtering or pulsed laser deposition. By adjusting the sputtering power, substrate temperature, and target composition, the amorphous structure and thickness of the film were controlled. Simultaneously, in-situ magnetic field annealing or rapid cooling was used to suppress crystallization, ensuring the film remained amorphous to achieve excellent soft magnetic properties. Finally, X-ray diffraction and scanning electron microscopy were used to verify the interfacial bonding between the low-temperature co-fired ceramic layer and the high-dielectric ceramic, as well as the structural uniformity of the iron-based amorphous alloy film. This demonstrated the compatible integration of the multilayer structure within the high-dielectric ceramic and the functional optimization of the surface film.

[0017] Preferably, a temperature sensor is installed at the bottom of the high-dielectric ceramic, and a magnetic field sensor is also installed at the bottom of the high-dielectric ceramic.

[0018] Based on the circulator's operating environment and monitoring requirements, computer-aided design was used to determine the installation positions and spacing of the temperature and magnetic field sensors, ensuring alignment of the sensor's sensitive area with the heat source or concentrated magnetic field change area of ​​the high-dielectric ceramic. Subsequently, the bottom surface of the high-dielectric ceramic was pre-treated using plasma cleaning or chemical etching to remove the surface oxide layer and contaminants, improving the bonding strength between the sensor and the ceramic substrate. Next, the temperature and magnetic field sensors were fixed in their predetermined positions using low-temperature conductive silver paste bonding or laser spot welding. The conductive silver paste used had to be of a type matching the ceramic's coefficient of thermal expansion to avoid mechanical stress caused by temperature changes. After fixing, the sensor pins were connected to the circulator's main control circuit using gold wire ball soldering, ensuring stable signal transmission and low noise. Finally, the sensors were functionally verified by testing their response characteristics through external heating or the application of a magnetic field, while simultaneously checking the mechanical fit with the bottom of the high-dielectric ceramic. This ensured that the sensors could accurately monitor temperature and magnetic field changes during circulator operation, providing data support for dynamic control of broadband performance.

[0019] Preferably, an encapsulation component is mounted on the surface of the magnetic conductive sheet, and a miniature dipole antenna is mounted on the upper surface of the magnetic conductive sheet;

[0020] Based on the overall dimensions of the circulator and electromagnetic shielding requirements, the structure of the package was designed using 3D modeling software to ensure a perfect match with the geometric contours of the magnetic sheet without affecting the magnetic circuit closure. The surface of the magnetic sheet was then pre-treated by chemical cleaning or plasma bombardment to remove the oxide layer, followed by coating with a thin layer of polymer adhesive to enhance the adhesion of the package. Next, the pre-fabricated package was fixed to the surface of the magnetic sheet using hot pressing or ultrasonic welding. Temperature and pressure were controlled during welding to prevent degradation of the magnetic properties of the magnetic sheet. After package installation, a pattern for a miniature dipole antenna was fabricated on the upper surface of the magnetic sheet using photolithography or laser direct writing technology. A metal antenna structure was then formed using electroplating or chemical deposition, and the antenna pins were connected to the main circuit of the circulator using gold wire ball bonding or conductive adhesive. Finally, the sealing performance of the package was tested, and the radiation characteristics of the miniature dipole antenna were verified to ensure its coordinated operation with the magnetic circuit of the magnetic sheet, achieving miniaturization and broadband signal transmission / reception capabilities for the circulator.

[0021] Preferably, a diode array is mounted on the upper surface of the magnetic conductive sheet, and a flexible circuit board is also mounted on the upper surface of the magnetic conductive sheet;

[0022] Based on the functional requirements and spatial layout of the circulator, the arrangement of the diode array and the routing path of the flexible circuit board are planned using circuit design software to ensure that the magnetic circuit distribution of the diode array and the existing components are free from electromagnetic interference. Subsequently, the upper surface of the magnetic sheet is pre-treated by plasma cleaning or chemical polishing to remove the oxide layer and contaminants, and a thin layer of polymer insulating adhesive is applied to improve the adhesion between the diodes and the circuit board. Next, the pre-fabricated diode array is fixed in the predetermined position using low-temperature conductive silver paste bonding or laser spot welding. Temperature and time must be controlled during the welding process to prevent degradation of the magnetic properties of the magnetic sheet. After the diode array is installed, the flexible circuit board is connected to the diode pins and pads on the surface of the magnetic sheet using gold wire ball bonding or anisotropic conductive adhesive film lamination to ensure low signal loss and high reliability. Finally, the conduction characteristics of the diode array and the connection reliability of the flexible circuit board are tested to ensure that they work in tandem with the magnetic sheet to achieve the signal modulation and broadband adaptation functions of the circulator.

[0023] Preferably, a connector is mounted on the upper surface of the magnetic conductive sheet, and a connecting groove is formed at the bottom of the high dielectric ceramic.

[0024] Based on the overall structure and assembly precision requirements of the circulator, the geometry, dimensions, and corresponding parameters of the connecting groove at the bottom of the high-dielectric ceramic were determined using computer-aided design to ensure the proper fit between the connecting part and the connecting groove to prevent electromagnetic leakage. Subsequently, the upper surface of the magnetic sheet was pre-treated by chemical cleaning or plasma bombardment to remove the oxide layer, and the connecting part was fabricated using precision machining or laser micromachining. The material selection had to match the permeability of the magnetic sheet to maintain magnetic circuit continuity. Simultaneously, the bottom of the high-dielectric ceramic was machined with the same precision, and the connecting groove was created by CNC grinding or laser etching. During the manufacturing process, the dimensions of the tank must be monitored in real time to avoid damaging the ceramic substrate. After processing, the connecting slot of the high-dielectric ceramic is aligned with the connector of the magnetic sheet, and precise assembly is achieved through an optical positioning system or mechanical positioning fixture. Subsequently, it is fixed by low-temperature conductive adhesive bonding or interference fit process. The conductive adhesive must be selected with a model that matches the thermal expansion coefficient of the ceramic and the magnetic sheet to prevent stress cracking caused by temperature changes. Finally, the assembly accuracy of the connector and the connecting slot is verified by microscopic inspection or a three-dimensional coordinate measuring machine, and the magnetic circuit closure and electric field distribution uniformity of the circulator are tested to ensure that the connection structure does not affect the realization of broadband performance.

[0025] Preferably, the connecting end of the connector is equipped with a locking element, and the inner cavity of the connecting groove is provided with a locking groove;

[0026] Based on the mechanical stability requirements of the circulator, the geometry of the locking component and the matching shape of the locking groove are designed using 3D modeling software to ensure that the fit between the locking component and the locking groove meets the requirements for vibration resistance and temperature deformation resistance. Subsequently, the connecting end of the connector is pre-treated by chemical cleaning or plasma bombardment to remove the oxide layer, and the locking component is fabricated using precision machining or laser micromachining technology. The material selected must possess elasticity and fatigue resistance. Simultaneously, the inner cavity of the connecting groove at the bottom of the high-dielectric ceramic is machined with the same precision, and the locking groove is created using CNC milling or EDM. During machining, the groove dimensions must be monitored in real time to avoid damaging the ceramic substrate. After machining, the locking component is fixed to the connecting end of the connector using a low-temperature welding process. Then, the connecting groove of the high-dielectric ceramic is aligned with the connector of the magnetic sheet, and the locking component is engaged into the locking groove by rotation or axial pressing, forming a mechanical lock. Finally, the connection reliability is verified through tensile testing or vibration table testing, and the magnetic circuit closure and electric field distribution uniformity of the circulator are tested to ensure that the locking structure does not affect the broadband performance.

[0027] Compared with the prior art, the present invention provides a miniaturized broadband microstrip circulator with X-band nested ferrite, which has the following advantages:

[0028] This miniaturized broadband microstrip circulator with X-band nested ferrite cores shortens the electromagnetic wave wavelength through the high dielectric constant of the high-dielectric ceramic, thereby reducing the physical size of the ferrite and the overall device volume. Simultaneously, the magnetic sheet guides the magnetic field distribution, improving magnetic field utilization. The ferrite, as the core non-reciprocal material, is integrated with the upper-layer circuitry. The microstrip structure of the circuitry optimizes the signal transmission path, reducing unnecessary electromagnetic losses. The ceramic sheet, as a support layer, combined with the permanent magnet, ensures structural stability and provides a stable bias magnetic field through the permanent magnet, enhancing the reliability of the ferrite. The synergistic effect of the material properties and structure of each layer expands the operating bandwidth, giving the device a flatter frequency response in the X-band. Ultimately, it achieves small size, light weight, and high reliability, making it suitable for scenarios with high system integration requirements, such as electronic warfare, effectively reducing the overall size and weight of the device. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention;

[0030] Figure 2 This is an exploded perspective view of the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the permanent magnet of the present invention;

[0032] Figure 4 This is a schematic diagram of the ferrite structure of the present invention;

[0033] Figure 5This is a schematic diagram of the structure of the high-dielectric ceramic of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the magnetic conductive sheet of the present invention;

[0035] Figure 7 This is a cross-sectional view of the high-dielectric ceramic of the present invention.

[0036] In the diagram: 1. Magnetic sheet; 2. High-dielectric ceramic; 3. Ferrite; 4. Circuit; 5. Ceramic sheet; 6. Permanent magnet; 7. Gadolinium alloy microparticles; 8. Nanocrystalline ferrite coating; 9. Three-dimensional gradient nested array; 10. Multiferroic thin film; 11. Iron-based amorphous alloy thin film; 12. Mounting groove; 13. Low-temperature co-fired ceramic layer; 14. Temperature sensor; 15. Magnetic field sensor; 16. Package; 17. Miniature dipole antenna; 18. Diode array; 19. Flexible circuit board; 20. Connector; 21. Connecting groove; 22. Locking component; 23. Locking groove. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This invention provides a technical solution: a miniaturized broadband microstrip circulator with X-band nested ferrite. Please refer to [link to relevant documentation]. Figure 1 It includes a magnetic conductive sheet 1, and a high dielectric ceramic 2 is mounted on the upper surface of the magnetic conductive sheet 1;

[0039] As the magnetic circuit substrate of the circulator, the magnetic conductive sheet 1 has high permeability, which can effectively guide and concentrate the magnetic field, reduce magnetic leakage, and thus improve the magnetic coupling efficiency. At the same time, the flat surface of the magnetic conductive sheet 1 provides a stable mounting base for the upper high dielectric ceramic 2, ensuring the mechanical stability of the overall structure.

[0040] Please see Figure 2 Ferrite 3 is disposed on the upper surface of high dielectric ceramic 2, and circuit 4 is mounted on the upper surface of ferrite 3.

[0041] High-dielectric ceramic 2, through its high dielectric constant, can effectively reduce the equivalent resonant size of the circulator, enabling miniaturized design. Simultaneously, its unique dielectric properties can regulate the propagation speed of electromagnetic waves, optimize impedance matching, thereby expanding the operating bandwidth, suppressing higher-order mode interference, and improving the purity of signal transmission. Ferrite 3, as the core functional material of the circulator, utilizes its gyromagnetic properties to achieve non-reciprocal transmission of electromagnetic waves. Through a specific magnetization direction design, ferrite 3 can generate a stable gyromagnetic effect under the action of an external magnetic field, ensuring the isolation and insertion loss performance of the circulator. The nested structure of ferrite 3 further optimizes the uniformity of the magnetic field distribution, improving the operating stability of the circulator.

[0042] A ceramic sheet 5 is disposed on the upper surface of the circuit 4, and a permanent magnet 6 is mounted on the upper surface of the ceramic sheet 5.

[0043] Circuit 4 employs a microstrip structure design, achieving efficient signal transmission and coupling through a specific wiring layout. Its tight integration with ferrite 3 fully utilizes the non-reciprocal characteristics of ferrite to achieve unidirectional transmission. Simultaneously, the impedance design of circuit 4, in conjunction with the high-dielectric ceramic 2 and the magnetic sheet 1, further expands the bandwidth and reduces the overall size. The ceramic sheet 5, serving as an intermediate transition layer, provides a flat mounting surface for the upper permanent magnet 6 and enhances the temperature stability of the circulator through its low coefficient of thermal expansion. Furthermore, the insulation performance of the ceramic sheet 5 prevents electrical interference between circuit 4 and permanent magnet 6, ensuring reliable signal transmission. Permanent magnet 6 provides a stable static bias magnetic field for ferrite 3, enabling it to reach a saturated magnetization state, thereby ensuring the continuous effectiveness of the gyromagnetic effect. By optimizing the magnetic field strength and distribution of permanent magnet 6, hysteresis loss can be reduced, improving the energy conversion efficiency of the circulator. At the same time, the permanent magnet characteristics of permanent magnet 6 ensure the long-term operational stability of the circulator without an external power supply.

[0044] The miniaturized broadband microstrip circulator with X-band nested ferrite cores achieves performance optimization through a compact nested design of multiple layers: the magnetic sheet 1 works in conjunction with the high-dielectric ceramic 2, whose high dielectric constant shortens the electromagnetic wave wavelength, thereby reducing the physical size of the ferrite 3 and the overall device volume. Simultaneously, the magnetic sheet 1 guides the magnetic field distribution, improving magnetic field utilization. The ferrite 3, as the core non-reciprocal material, is integrated with the upper-layer circuit 4. The microstrip structure of circuit 4 optimizes the signal transmission path and reduces unnecessary electromagnetic losses. The ceramic sheet 5, as a support layer, combined with the permanent magnet 6, ensures structural stability and provides a stable bias magnetic field through the permanent magnet 6, enhancing the operational reliability of the ferrite 3. The synergistic effect of the material properties and structure of each layer expands the operating bandwidth, giving the device a flatter frequency response in the X-band. Ultimately, this results in a small size, light weight, and high reliability, making it suitable for scenarios with high system integration requirements, such as electronic warfare, effectively reducing the overall device size and weight.

[0045] Please see Figure 3 The permanent magnet 6 contains gadolinium alloy microparticles 7. Please refer to [link / reference]. Figure 4 The bottom of the ferrite 3 is fitted with a nanocrystalline ferrite coating 8;

[0046] Gadolinium alloy microparticles 7 are uniformly mixed with the permanent magnet matrix material. High-energy ball milling is used to refine and disperse the gadolinium alloy microparticles 7 within the matrix powder. Then, unidirectional pressing or isostatic pressing techniques in powder metallurgy are employed to press the mixed powder into a permanent magnet blank of the desired shape. This blank is then subjected to high-temperature sintering to achieve a tight atomic-level bond between the gadolinium alloy microparticles 7 and the permanent magnet matrix, ultimately forming a composite permanent magnet 6 structure with uniformly embedded gadolinium alloy microparticles 7. Simultaneously, in the bottom surface treatment stage of ferrite 3, physical vapor deposition or chemical solution methods are used. By precisely controlling the deposition parameters, a coating with a nanocrystalline structure is formed on the surface of the ferrite 3 substrate. This coating, through the high-density grain boundary effect of the nanocrystals, effectively optimizes the magnetic permeability and loss characteristics of the ferrite 3 and ensures a good interfacial bond between the coating and the ferrite 3 substrate, avoiding coating peeling or cracking problems caused by thermal or mechanical stress.

[0047] A three-dimensional gradient nested array 9 is mounted on the upper surface of the ferrite 3, and a multiferroic thin film 10 is mounted on the upper surface of the three-dimensional gradient nested array 9.

[0048] The three-dimensional gradient structure parameters, including the nesting level of the array and the compositional or geometric gradient of each layer of material, are defined using computer-aided design software. Then, a micro / nano structure template with a gradient distribution is fabricated on the ferrite 3 surface using laser direct writing or nanoimprinting techniques. Next, material layers with different compositions or structures are deposited layer by layer on the template surface using physical vapor deposition or chemical solution methods. By precisely controlling the deposition thickness and gradient transition of each layer, a three-dimensional nested array structure with continuously changing composition / structure is formed. Subsequently, a multiferroic thin film 10 is deposited on the upper surface of the three-dimensional gradient nested array 9 using pulsed laser deposition or metal-organic chemical vapor deposition. By adjusting the deposition temperature, atmosphere, and laser energy density, a uniform and dense multiferroic thin film 10 is formed on the array surface. Simultaneously, in-situ annealing is used to optimize the crystallinity and multiferroic coupling performance of the film, ultimately achieving functional integration of the three-dimensional gradient nested array 9 and the multiferroic thin film 10, improving the circulator's broadband characteristics and magnetoelectric control capabilities.

[0049] Please see Figure 5 The surface of the high dielectric ceramic 2 is provided with a mounting groove 12, and the ferrite 3 is installed inside the mounting groove 12.

[0050] Based on the geometric dimensions and electromagnetic performance requirements of ferrite 3, the depth, width, and shape parameters of the mounting groove 12 are determined through computer-aided design to ensure complete fit between the groove and the bottom surface of ferrite 3, minimizing air gaps. Subsequently, precision machining or laser micromachining technology is used to precisely etch the mounting groove 12, conforming to the design dimensions, onto the upper surface of the high-dielectric ceramic 2. Machining accuracy must be controlled during the process to avoid damaging the ceramic substrate. After grooving, the interior of the groove and the bottom surface of the ferrite 3 are subjected to plasma cleaning or ultrasonic cleaning to remove residual debris and contaminants. Next, the ferrite 3 is embedded into the mounting groove 12 and fixed using low-temperature conductive adhesive bonding or vacuum brazing. The conductive adhesive must be selected with a coefficient of thermal expansion matching that of the ceramic and ferrite 3 to prevent mechanical stress caused by temperature changes. Finally, the assembly accuracy of the ferrite 3 and the mounting groove 12 is verified by microscopic inspection or a three-dimensional coordinate measuring machine to ensure a gapless interface and a continuous electromagnetic coupling path, thereby optimizing the magnetic circuit design and broadband characteristics of the circulator.

[0051] The high-dielectric ceramic 2 has a low-temperature co-fired ceramic layer 13 installed inside, and an iron-based amorphous alloy thin film 11 installed on the upper surface of the high-dielectric ceramic 2.

[0052] Low-temperature co-fired ceramic slurry is prepared into green ceramic tape using a tape casting method. The green ceramic tape is then cut and stacked according to the required thickness of the high-dielectric ceramic 2. A low-temperature co-fired ceramic layer 13 is formed by low-temperature sintering. During sintering, the heating rate and atmosphere must be controlled to prevent cracking due to the difference in thermal expansion coefficients between the high-dielectric ceramic 2 substrate and the low-temperature co-fired ceramic layer 13. After the integration of the low-temperature co-fired ceramic layer 13, the upper surface of the high-dielectric ceramic 2 is pretreated to remove surface impurities and activate the surface. Then, magnetron sputtering or pulsed laser deposition is used on the pretreated surface. A thin iron-based amorphous alloy film 11 is deposited on the substrate. By adjusting the sputtering power, substrate temperature, and target composition, the amorphous structure and thickness of the film are controlled. At the same time, in-situ magnetic field annealing or rapid cooling process is used to suppress crystallization, ensuring that the film remains amorphous to obtain excellent soft magnetic properties. Finally, X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to verify the interface bonding state between the low-temperature co-fired ceramic layer 13 and the high-dielectric ceramic 2, as well as the structural uniformity of the iron-based amorphous alloy film 11. This achieves the compatible integration of the multilayer structure inside the high-dielectric ceramic 2 and the functional optimization of the surface film.

[0053] A temperature sensor 14 is installed at the bottom of the high-dielectric ceramic 2, and a magnetic field sensor 15 is also installed at the bottom of the high-dielectric ceramic 2.

[0054] Based on the circulator's operating environment and monitoring requirements, the installation positions and spacing of temperature sensor 14 and magnetic field sensor 15 were determined using computer-aided design, ensuring that the sensor's sensitive area was aligned with the heat source or concentrated magnetic field change area of ​​the high-dielectric ceramic 2. Subsequently, the bottom surface of the high-dielectric ceramic 2 was pre-treated by plasma cleaning or chemical etching to remove the surface oxide layer and contaminants, improving the bonding strength between the sensor and the ceramic substrate. Next, temperature sensor 14 and magnetic field sensor 15 were fixed in their predetermined positions using low-temperature conductive silver paste bonding or laser spot welding. The conductive silver paste must be of a type matching the ceramic's coefficient of thermal expansion to avoid mechanical stress caused by temperature changes. After fixing, the sensor pins were connected to the circulator's main control circuit using gold wire ball soldering, ensuring signal transmission stability and low noise. Finally, the sensors were functionally verified by testing their response characteristics through external heating or the application of a magnetic field, while simultaneously checking the mechanical fit with the bottom of the high-dielectric ceramic 2. This ensured that the sensors could accurately monitor temperature and magnetic field changes during circulator operation, providing data support for dynamic control of broadband performance.

[0055] Please see Figure 6 A package 16 is mounted on the surface of the magnetic sheet 1, and a miniature dipole antenna 17 is mounted on the upper surface of the magnetic sheet 1.

[0056] Based on the overall dimensions of the circulator and electromagnetic shielding requirements, the structure of the package 16 was designed using 3D modeling software to ensure complete matching with the geometric contour of the magnetic sheet 1 and without affecting the magnetic circuit closure. Subsequently, the surface of the magnetic sheet 1 was pre-treated by chemical cleaning or plasma bombardment to remove the oxide layer, and a thin layer of polymer adhesive was applied to enhance the adhesion of the package 16. Next, the pre-fabricated package 16 was fixed to the surface of the magnetic sheet 1 using hot pressing or ultrasonic welding. Temperature and pressure were controlled during welding to prevent degradation of the magnetic properties of the magnetic sheet 1. After the package 16 was installed, a pattern for the miniature dipole antenna 17 was fabricated on the upper surface of the magnetic sheet 1 using photolithography or laser direct writing technology. Then, an electroplating or chemical deposition process was used to form a metal antenna structure, and the antenna pins were connected to the main circuit of the circulator using gold wire ball bonding or conductive adhesive. Finally, the sealing performance of the package 16 was tested, and the radiation characteristics of the miniature dipole antenna 17 were verified to ensure its coordinated operation with the magnetic circuit of the magnetic sheet 1, achieving miniaturization and broadband signal transmission / reception functionality of the circulator.

[0057] A diode array 18 is mounted on the upper surface of the magnetic sheet 1, and a flexible circuit board 19 is also mounted on the upper surface of the magnetic sheet 1.

[0058] Based on the functional requirements and spatial layout of the circulator, the arrangement of the diode array 18 and the routing path of the flexible circuit board 19 are planned using circuit design software to ensure that there is no electromagnetic interference between the magnetic circuit distribution of the magnetic sheet 1 and existing components. Subsequently, the upper surface of the magnetic sheet 1 is pre-treated by plasma cleaning or chemical polishing to remove the oxide layer and contaminants, and a thin layer of polymer insulating adhesive is applied to improve the adhesion between the diodes and the circuit board. Next, the pre-fabricated diode array 18 is fixed in the predetermined position using low-temperature conductive silver paste bonding or laser spot welding. Temperature and time must be controlled during welding to prevent degradation of the magnetic properties of the magnetic sheet 1. After the diode array 18 is installed, the flexible circuit board 19 is connected to the diode pins and the pads on the surface of the magnetic sheet 1 using gold wire ball bonding or anisotropic conductive adhesive film lamination to ensure low signal loss and high reliability. Finally, the conduction characteristics of the diode array 18 and the connection reliability of the flexible circuit board 19 are tested to ensure that they work together with the magnetic sheet 1 to achieve the signal modulation and broadband adaptation functions of the circulator.

[0059] A connector 20 is mounted on the upper surface of the magnetic conductive sheet 1. Please refer to [link / reference]. Figure 7 A connecting groove 21 is provided at the bottom of the high dielectric ceramic 2;

[0060] Based on the overall structure and assembly precision requirements of the circulator, the geometry and dimensions of the connector 20, as well as the corresponding parameters of the connecting groove 21 at the bottom of the high-dielectric ceramic 2, are determined through computer-aided design to ensure the fit clearance between the connector 20 and the connecting groove 21 to avoid electromagnetic leakage. Subsequently, the upper surface of the magnetic sheet 1 is pretreated by chemical cleaning or plasma bombardment to remove the oxide layer, and the connector 20 is fabricated by precision machining or laser micromachining. The material selection must match the permeability of the magnetic sheet 1 to maintain the continuity of the magnetic circuit. At the same time, the bottom of the high-dielectric ceramic 2 is machined with the same precision, and the connecting groove 21 is formed by CNC grinding or laser etching. During processing, the dimensions of the groove must be monitored in real time to avoid damaging the ceramic substrate. After processing, the connecting groove 21 of the high dielectric ceramic 2 is aligned with the connector 20 of the magnetic sheet 1. Precise assembly is achieved through an optical positioning system or mechanical positioning fixture. Then, it is fixed by low-temperature conductive adhesive bonding or interference fit process. The conductive adhesive must be selected with a model that matches the thermal expansion coefficient of the ceramic and the magnetic sheet 1 to prevent stress cracking caused by temperature changes. Finally, the assembly accuracy of the connector 20 and the connecting groove 21 is verified by microscopic inspection or a three-dimensional coordinate measuring machine, and the magnetic circuit closure and electric field distribution uniformity of the circulator are tested to ensure that the connection structure does not affect the realization of broadband performance.

[0061] Please see Figure 6 The connecting end of connector 20 is equipped with a locking element 22. Please refer to [link / reference]. Figure 7 The inner cavity of the connecting groove 21 is provided with a locking groove 23;

[0062] Based on the mechanical stability requirements of the circulator, the geometry of the locking element 22 and the matching shape of the locking groove 23 are designed using 3D modeling software to ensure that the fit between the locking element 22 and the locking groove 23 meets the requirements for vibration resistance and temperature deformation resistance. Subsequently, the connecting end of the connector 20 is pre-treated by chemical cleaning or plasma bombardment to remove the oxide layer, and the locking element 22 is fabricated using precision machining or laser micromachining technology. The material selected must possess elasticity and fatigue resistance. Simultaneously, the inner cavity of the connecting groove 21 at the bottom of the high-dielectric ceramic 2 is machined with the same precision using CNC milling. Alternatively, an electrical discharge machining (EDM) can be used to create the locking groove 23. During the machining process, the groove dimensions must be monitored in real time to avoid damaging the ceramic substrate. After machining, the locking component 22 is fixed to the connecting end of the connector 20 using a low-temperature welding process. Then, the connecting groove 21 of the high-dielectric ceramic 2 is aligned with the connector 20 of the magnetic sheet 1. The locking component 22 is then engaged in the locking groove 23 by rotation or axial pressing to form a mechanical lock. Finally, the connection reliability is verified by tensile testing or vibration table testing, and the magnetic circuit closure and electric field distribution uniformity of the circulator are tested to ensure that the locking structure does not affect the realization of broadband performance.

[0063] The workflow of this scheme is as follows: A magnetically conductive sheet 1 serves as the magnetic circuit substrate to guide the magnetic field distribution. A high-dielectric ceramic 2 is mounted on it. The high dielectric constant of the high-dielectric ceramic 2 shortens the electromagnetic wave wavelength, achieving miniaturization and optimizing impedance matching. A mounting groove 12 is formed in the high-dielectric ceramic 2 to fix a ferrite 3. The bottom of the ferrite 3 has a nanocrystalline ferrite coating 8 to optimize the magnetic permeability. A three-dimensional gradient nested array 9 and a multiferroic thin film 10 are mounted on it to enhance broadband characteristics and magnetoelectric control capabilities. A circuit 4 is mounted on the upper surface of the ferrite 3, and signal transmission is optimized through a microstrip structure. A ceramic sheet 5 is placed on the upper surface of the circuit 4, and a permanent magnet 6 is mounted on it. The embedded gadolinium alloy microparticles 7 provide a stable bias magnetic field; the high-dielectric ceramic 2 integrates a low-temperature co-fired ceramic layer 13, and the upper surface is deposited with an iron-based amorphous alloy thin film 11 to optimize performance. A temperature sensor 14 and a magnetic field sensor 15 are installed at the bottom to monitor environmental changes; the surface of the magnetic sheet 1 is equipped with an encapsulation component 16, and a miniature dipole antenna 17 is installed on the upper surface to realize signal transmission and reception. At the same time, a diode array 18 and a flexible circuit board 19 are installed to realize signal modulation. The connector 20 is precisely assembled with the connecting groove 21 at the bottom of the high-dielectric ceramic 2, and locked with the locking component 22 and the locking groove 23 to ensure mechanical stability and electromagnetic performance.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A miniaturized broadband microstrip circulator with X-band nested ferrite, characterized in that, include: A magnetic sheet (1) is provided, and a high dielectric ceramic (2) is mounted on the upper surface of the magnetic sheet (1). Ferrite (3) is disposed on the upper surface of high dielectric ceramic (2), and circuit (4) is mounted on the upper surface of the ferrite (3). A ceramic sheet (5) is disposed on the upper surface of the circuit (4). A permanent magnet (6) is mounted on the upper surface of the ceramic sheet (5). Gadolinium alloy microparticles (7) are mounted inside the permanent magnet (6). A nanocrystalline ferrite coating (8) is mounted on the bottom of the ferrite (3). A low-temperature co-fired ceramic layer (13) is mounted inside the high-dielectric ceramic (2). An iron-based amorphous alloy thin film (11) is mounted on the upper surface of the high-dielectric ceramic (2). A three-dimensional gradient nested array (9) is mounted on the upper surface of the ferrite (3). A multiferroic thin film (10) is mounted on the upper surface of the three-dimensional gradient nested array (9).

2. The miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 1, characterized in that: The surface of the high dielectric ceramic (2) is provided with an installation groove (12), and the ferrite (3) is installed inside the installation groove (12).

3. The miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 1, characterized in that: A temperature sensor (14) is installed at the bottom of the high dielectric ceramic (2), and a magnetic field sensor (15) is also installed at the bottom of the high dielectric ceramic (2).

4. The miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 1, characterized in that: The surface of the magnetic sheet (1) is fitted with a package (16), and a miniature dipole antenna (17) is fitted on the upper surface of the magnetic sheet (1).

5. A miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 1, characterized in that: A diode array (18) is mounted on the upper surface of the magnetic sheet (1), and a flexible circuit board (19) is also mounted on the upper surface of the magnetic sheet (1).

6. The miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 1, characterized in that: A connector (20) is installed on the upper surface of the magnetic sheet (1), and a connecting groove (21) is provided at the bottom of the high dielectric ceramic (2).

7. A miniaturized broadband microstrip circulator with X-band nested ferrite as described in claim 6, characterized in that: The connecting end of the connector (20) is equipped with a locking member (22), and the inner cavity of the connecting groove (21) is provided with a locking groove (23).

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