Composite ferrite circulator and electronic equipment

Abstract

The invention provides a composite ferrite circulator and electronic equipment, the composite ferrite circulator comprises a first bias magnetic circuit assembly, a ceramic gasket, a composite material substrate and a second bias magnetic circuit assembly which are sequentially arranged along a first direction, and one side, close to the ceramic gasket, of the composite material substrate is provided with a microstrip circuit; one side, close to the second bias magnetic circuit assembly, of the composite material substrate is provided with a grounding metal layer, the composite material substrate comprises a ceramic dielectric substrate, the surface of the ceramic dielectric substrate is provided with a cylindrical ferrite penetrating along the first direction, and the outer side of the cylindrical ferrite is sequentially sleeved with a plurality of circular ring ferrites; the saturation magnetization intensity of the cylindrical ferrite and the saturation magnetization intensity of the circular ferrite are sequentially reduced from inside to outside. According to the scheme, a higher relative bandwidth of the circulator can be realized, and the non-reciprocal transmission performance of the circulator is improved, so that the overall working performance of the electronic equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of circulators, in particular to a composite ferrite circulator and electronic equipment. Background Art

[0002] Frequency range is the primary performance indicator for measuring electromagnetic suppression, electronic interference and anti-interference equipment. As a key and important microwave non-reciprocal device in electronic equipment and components, the bandwidth characteristics of the circulator greatly affect the working performance of the overall equipment. With the rapid development of components and integrated circuits in recent years, the technical update and application needs of ultra-wideband circulators have become issues that need to be urgently addressed. Compared with other circulators such as waveguide circulators and stripline circulators, ferrite-based microstrip circulators / isolators have become the mainstream components of current electronic equipment due to their excellent performance such as good frequency response, low insertion loss and easy integration.

[0003] However, improving the working bandwidth of the circulator is still a very difficult problem. Since the gyromagnetism of ferrite is related to frequency, the rotation mode inside the ferrite will change within the ultra-wideband working range, thus affecting the non-reciprocal transmission of the circulator. In order to further improve the bandwidth of the circulator and enhance the performance and industry competitiveness of the circulator, a circulator design scheme that can achieve a higher relative bandwidth is particularly important. Summary of the invention

[0004] The object of the present invention is to provide a composite ferrite circulator and an electronic device to achieve a higher relative bandwidth of the circulator, improve the non-reciprocal transmission performance of the circulator, and thus improve the overall working performance of the electronic device.

[0005] The technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present application provides a composite ferrite circulator, comprising a first bias magnetic circuit component, a ceramic gasket, a composite material substrate, and a second bias magnetic circuit component sequentially arranged along a first direction, wherein a microstrip circuit is arranged on a side of the composite material substrate close to the ceramic gasket, and a grounding metal layer is arranged on a side of the composite material substrate close to the second bias magnetic circuit component:

[0007] The microstrip circuit includes a center junction circuit, and three endpoints of the center junction circuit are connected to a first port, a second port, and a third port through a first metal conductor transmission circuit, a second metal conductor transmission circuit, and a third metal conductor transmission circuit, respectively;

[0008] The composite material substrate includes a ceramic dielectric substrate, and a cylindrical ferrite penetrating along the first direction is arranged on the surface of the ceramic dielectric substrate, and a plurality of annular ferrites are sequentially sleeved on the outer side of the cylindrical ferrite, and the saturation magnetization intensity of the cylindrical ferrite and the annular ferrite decreases sequentially from the inside to the outside.

[0009] In some embodiments, the central junction circuit includes three curved sides, and the three curved sides are 120° rotationally symmetric about the center of the central junction circuit.

[0010] In some embodiments, a plurality of curved SSPPs branches with fixed lengths are disposed on each of the three curved edges.

[0011] In some embodiments, the first metal conductor transmission circuit, the second metal conductor transmission circuit and the third metal conductor transmission circuit are all straight-edge metal conductor transmission circuits; or,

[0012] The first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both formed by combining at least two straight-edge metal conductor transmission circuits at a preset angle.

[0013] In some embodiments, the first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both bent metal conductor transmission circuits with a preset curvature.

[0014] In some embodiments, both sides of the end of the first metal conductor transmission circuit close to the first port are provided with straight-edge SSPPs branches with gradually varying lengths, and both sides of the connection between the central junction circuit and the first metal conductor transmission circuit are provided with first curved arrangement SSPPs branches with gradually varying lengths;

[0015] Second curved SSPPs branches with gradually varying lengths are arranged on both sides of the second metal conductor transmission circuit and the third metal conductor transmission circuit.

[0016] In some embodiments, the SSPPs branches are any one or a combination of rectangular, T-shaped, trapezoidal, or trident-shaped structures.

[0017] In some embodiments, the number of the annular ferrites is two.

[0018] The end surfaces of both ends of the annular ferrite and the cylindrical ferrite along the first direction are flush with the end surfaces of both ends of the ceramic dielectric substrate along the first direction.

[0019] In some embodiments, the first bias magnetic circuit assembly includes a cylindrical magnetic steel magnetized along the first direction;

[0020] The second bias magnetic circuit component includes an iron sheet having a size consistent with that of the composite material substrate, or the second bias magnetic circuit component includes a cylindrical magnetic steel having a size consistent with that of the first bias magnetic circuit component.

[0021] In a second aspect, the present application provides an electronic device, comprising the composite ferrite circulator of the first aspect.

[0022] The composite ferrite circulator and electronic device provided by the present invention can achieve a higher relative bandwidth of the circulator, improve the non-reciprocal transmission performance of the circulator, and thus improve the overall working performance of the electronic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The preferred implementation scheme will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present solution.

[0024] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of a top view of a microstrip circuit according to an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of several structural forms of SSPPs branches according to an embodiment of the present invention;

[0027] Figure 4 It is a full-wave simulation schematic diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0029] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0030] Frequency range is the primary performance indicator for measuring electromagnetic suppression, electronic interference and anti-interference equipment. As a key and important microwave non-reciprocal device in electronic equipment and components, the bandwidth characteristics of the circulator greatly affect the working performance of the overall equipment. The circulator is a three-port device with unidirectional transmission characteristics. Its main function is to realize the directional transmission and duplex function of signals in the system. The circulator allows signals to be transmitted from one port to the next port, but prevents reverse transmission. For example, the signal is conductive from port 1 to port 2 and from port 2 to port 3, while the reverse transmission (from 2 to 1, from 3 to 2, from 1 to 3) is isolated. This characteristic makes the circulator very important in radar / communication systems, which can achieve isolation of transmit and receive signals and allow the same antenna to be shared by the transmitter and receiver. The principle of the circulator is based on the anisotropic characteristics of magnetic field biased ferrite materials. It uses the Faraday rotation effect of the rotation of the polarization plane when electromagnetic waves are transmitted in the gyromagnetic ferrite material with an external DC magnetic field. Through design, the polarization plane of the electromagnetic wave is perpendicular to the grounding resistance plug plate during forward transmission, and the attenuation is very small; during reverse transmission, the polarization plane of the electromagnetic wave is parallel to the grounding resistance plug plate and is almost completely absorbed.

[0031] With the rapid development of components and integrated circuits in recent years, the technical update and application demand of ultra-wideband circulators have become urgent problems to be solved. Compared with other circulators such as waveguide circulators and stripline circulators, ferrite-based microstrip circulators / isolators have become the mainstream components of current electronic equipment due to their excellent performance such as good frequency response, low insertion loss and easy integration. However, improving the working bandwidth of the circulator is still a very difficult problem. Since the gyromagnetism of ferrite is related to frequency, the internal rotation mode of the ferrite will change within the ultra-wideband working range, thereby affecting the non-reciprocal transmission of the circulator. In order to further increase the bandwidth of the circulator and improve the performance and industry competitiveness of the circulator, a circulator design scheme that can achieve a higher relative bandwidth is particularly important.

[0032] In order to improve the bandwidth of the circulator, the continuous tracking technology based on a single ferrite structure was proposed to achieve wide-band matching of the ferrite and dielectric wave impedance, providing an optimal design scheme for the selection of coupling angle parameters and dielectric constant. However, due to the gyromagnetic and frequency response characteristics of the single ferrite material itself, the maximum relative bandwidth of the continuous tracking technology circulator does not exceed 66%.

[0033] In one embodiment, in order to further improve the bandwidth, a cylindrical-ring double nested ferrite circulator composed of ferrites with two saturation magnetization values ​​is a relatively novel solution. Compared with a single ferrite structure, the nested ferrites are divided into ring ferrites with low saturation magnetization and cylindrical ferrites with high saturation magnetization. The two change the effective magnetic permeability in different frequency ranges, regulate the action characteristics and resonant frequency of the high-order rotation mode, and thus form a stable working mode within a wide bandwidth. In theory, this double nested ferrite structure circulator / isolator can achieve 100% relative working bandwidth, but the working bandwidth of the double nested ferrite circulator depends on the difference in saturation magnetization of the double nested ferrite. When the difference in saturation magnetization between the cylindrical ferrite and the ring is too large, the outer ring ferrite will be in an oversaturated state. At this time, the surge in the magnetic field value in the ring ferrite will lead to an increase in the ferromagnetic resonance frequency, and the appearance of the ferromagnetic resonance zone will greatly deteriorate the lower band performance of the circulator. In addition, the double nested ferrite structure also leads to difficulties in magnetic bias. In order to saturate the magnetization of both the annular ferrite and the cylindrical ferrite, a higher external bias magnetic field is required, which requires a bulky magnet for magnetic bias. In this case, it is necessary to study a new composite ferrite structure to further improve the bandwidth of the circulator.

[0034] In one embodiment, a multi-nested ferrite circulator is designed based on a double-nested ferrite circulator, and a number of circular ferrites with gradually decreasing saturation magnetization are sequentially arranged outside a cylindrical ferrite with high saturation magnetization. For example, a triple-nested ferrite circulator includes a cylindrical ferrite with high saturation magnetization and two circular ferrites with gradually decreasing magnetization. It can achieve a higher relative bandwidth of the circulator and improve the non-reciprocal transmission performance of the circulator, thereby greatly improving the bandwidth performance of modern radars, electronic countermeasures and communication systems. The following will be described in detail with reference to the accompanying drawings:

[0035] In one embodiment, the reference specification Figure 1 and attached Figure 2 A composite ferrite circulator comprises a first bias magnetic circuit component 1, a ceramic gasket 2, a composite material substrate 4 and a second bias magnetic circuit component 6 arranged in sequence along a first direction, a microstrip circuit 3 is arranged on the side of the composite material substrate 4 close to the ceramic gasket 2, and a grounding metal layer 5 is arranged on the side of the composite material substrate 4 close to the second bias magnetic circuit component 6. The first direction is, for example, a vertical direction. In this case, the first bias magnetic circuit component 1 is an upper bias magnetic circuit component, and the second bias magnetic circuit component 6 is a lower bias magnetic circuit component. In the vertical direction, the first bias magnetic circuit component 1, the ceramic gasket 2, the microstrip circuit 3, the composite material substrate 4, the grounding metal layer 5 and the second bias magnetic circuit component 6 are stacked and fixed in sequence.

[0036] The microstrip circuit 3 includes a center junction circuit 31, and the center junction circuit 31 includes three curved sides, and the three curved sides are 120° rotationally symmetrical about the center of the center junction circuit 31. The size of the center junction circuit 31 is not limited, and can be larger or smaller. In theory, the curvature of the center junction circuit 31 is directly related to the effective bandwidth.

[0037] The three endpoints of the center junction circuit 31 are connected to the first port, the second port and the third port respectively through the first metal conductor transmission circuit, the second metal conductor transmission circuit and the third metal conductor transmission circuit. The specific forms of the first metal conductor transmission circuit, the second metal conductor transmission circuit and the third metal conductor transmission circuit are not limited. For example, in a specific implementation, the first metal conductor transmission circuit, the second metal conductor transmission circuit and the third metal conductor transmission circuit are all straight-edge metal conductor transmission circuits; for another example, in a specific implementation, the first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both composed of at least two straight-edge metal conductor transmission circuits combined at a preset angle; for another example, in a specific implementation, Figure 1 and Figure 2 As shown, the first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit 33, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both bent metal conductor transmission circuits 32 with a preset curvature. The main function of the bent metal conductor transmission circuit 32 is to miniaturize the topology to achieve the final rectangular cross-sectional size.

[0038] The composite material substrate 4 includes a ceramic dielectric substrate 44, and a cylindrical ferrite penetrating along a first direction is arranged on the surface of the ceramic dielectric substrate 44, and a plurality of annular ferrites are sequentially sleeved on the outer side of the cylindrical ferrite, and the saturation magnetization of the cylindrical ferrite and the annular ferrite decreases from the inside to the outside, and the end faces of the annular ferrite and the cylindrical ferrite along the first direction are flush with the end faces of the ceramic dielectric substrate 4 along the first direction. For example, when the multi-nested ferrite circulator is a three-nested ferrite circulator, the number of annular ferrites is two, including a cylindrical ferrite 41 with a high saturation magnetization, an inner annular ferrite 42 with a relatively high saturation magnetization, and an outer annular ferrite 43 with a low saturation magnetization.

[0039] In a specific implementation, a plurality of SSPPs branches 34 with fixed lengths are arranged on the three curved sides of the central junction circuit 31; when the first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit 33, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both bent metal conductor transmission circuits 32 with preset curvatures, straight-edge SSPPs branches 37 with gradually varying lengths are arranged on both sides of one end of the first metal conductor transmission circuit close to the first port, first curved-arranged SSPPs branches 35 with gradually varying lengths are arranged on both sides of the connection between the central junction circuit 31 and the first metal conductor transmission circuit, and second curved-arranged SSPPs branches 36 with gradually varying lengths are arranged on both sides of the second metal conductor transmission circuit and the third metal conductor transmission circuit. SSPPs (Spoof Surface Plasmon Polaritons) is an artificial periodic structure that simulates the propagation of natural surface plasmons (SPPs) at the metal-dielectric interface, and it decays exponentially in the terahertz and low-frequency microwave regions. SSPPs have the advantages of broadband, low cross-coupling, low cost, low loss, and strong field confinement. They exhibit the same dispersion characteristics as natural SPPs, and their cutoff frequency can be changed by adjusting the shape and size of the groove.

[0040] The shape of SSPPs branches is not restricted, such as Figure 3 As shown, the branch can be any one of a rectangular structure, a T-shaped structure, a trapezoidal structure, and a trident-shaped structure, or a combination of several of them.

[0041] The working principle of the circulator provided in this application is to take a three-nested ferrite circulator as an example. The saturation magnetization intensity and radius of the three-nested composite ferrite determine the actual working bandwidth of the circulator. The upper sideband and lower sideband of the working bandwidth are respectively expressed as f high and f low The saturation magnetization value of each ferrite of the three-nested composite ferrite can be obtained by the formula Determine, where 4πM s (1) , 4πM s (2) , 4πM s (3) represents the saturation magnetization values ​​of the outermost ring ferrite, the middle ring ferrite and the inner cylindrical ferrite respectively. The saturation magnetization of the outermost ring ferrite determines the basic rotation mode of the circulator, corresponding to f 1 0.25f high +0.75f low , p 1 The value of is between 0.5 and 1, which determines the degree of splitting of the basic rotation mode. It can be fine-tuned according to different forms of microstrip transmission circuits and substituted into the formula to obtain 4πM s(1) The saturation magnetization of the innermost cylindrical ferrite can regulate the high-order modes of the circulator, corresponding to f 3 0.75f high +0.25f low The value of is also between 0.5 and 1. Substituting it into the formula, we can get 4πM s (3) Different from the double nested composite ferrite, the middle ring ferrite of the triple nested composite ferrite is used to improve the magnetic field value inside the outermost ring ferrite. The saturation magnetization value of the middle ring ferrite is between the saturation magnetization values ​​of the innermost cylindrical ferrite and the outermost ring ferrite, corresponding to f 2 is 0.5(f high +f low ), the value of is also between 0.5 and 1. Therefore, the frequency response of the three-nested composite ferrite covers the entire bandwidth. For the initial value of the radius of the three-nested composite ferrite, the formula can be used. Calculation is performed, where the effective magnetic permeability μ eff ≈1-p x 2 . For the circuit part, a stable impedance matching network is realized by periodically loading the transmission circuit with SSPPs branches. Each SSPPs unit branch is equivalent to a low-pass LC filter circuit. By periodically arranging SSPPs units, a multi-stage series LC equivalent circuit is generated. This circuit has very stable transmission characteristics and shows a clustered impedance matching effect in the Smith chart. The SSPPs matching branches are divided into a fixed-length transmission part and a gradually changing length matching part, and a compact circuit topology is achieved through the slow-wave transmission effect.

[0042] The composite ferrite circulator provided in the present application can achieve a higher relative bandwidth of the circulator, improve the non-reciprocal transmission performance of the circulator, thereby improving the overall working performance of the electronic device, and further, can greatly improve the bandwidth performance of modern radar, electronic countermeasures and communication systems.

[0043] like Figure 4 The full-wave simulation verification results shown show that the composite ferrite circulator provided by the present application can achieve working performance exceeding 100% relative bandwidth, while ensuring that the return loss and isolation within the band are less than -15dB, and the insertion loss is less than -1.5dB. This example proposed by the present invention effectively demonstrates the advantages of the three-nested composite ferrite circulator, and the SSPPs branch-loaded circuit provides a more compact topology.

[0044] In one embodiment, based on the above-mentioned embodiment, the first bias magnetic circuit component 1 includes a cylindrical magnetic steel magnetized along a first direction; the second bias magnetic circuit component 6 includes an iron sheet having the same size as the composite material substrate 4, or the second bias magnetic circuit component 6 includes a cylindrical magnetic steel having the same size as the first bias magnetic circuit component 1.

[0045] In one embodiment, based on the foregoing embodiments, the present application does not limit the size of the first bias magnetic circuit component 1, the ceramic gasket 2, the microstrip circuit 3, the composite substrate 4, the grounded metal layer 5, the second bias magnetic circuit component 6, the center junction circuit 31, and the SSPPs branch, and can be adjusted according to the actual use scenario. For example, the first bias magnetic circuit component 1 uses a cylindrical magnet with a radius value of 8-9mm and a thickness of 1.5-2.5mm. The radius value of the ceramic gasket 2 is also 8-9mm, and the thickness is 1-2mm. The microstrip circuit 3 is composed of multiple parts, and the curvature of the curved edge of the center junction circuit 31 is 4-6mm, and the three curved edges are 120° rotationally symmetrical about the junction center. The bent metal conductor transmission circuit 32 provides a more compact circuit arrangement with a line width of 0.4-0.5mm; the line width of the straight-edge metal conductor transmission circuit 33 is also 0.4-0.5mm, and the length is 10-12mm; the length of the fixed-length curved arrangement SSPPs branch 34 is 1.5-2.5mm, the width is 0.4-1mm, and the spacing between each branch is 0.8-1.2mm; the shape parameters of the gradually varying length curved arrangement SSPPs branch 35, the gradually varying length curved arrangement SSPPs branch 36 and the gradually varying length straight-edge SSPPs branch 37 are all consistent with the fixed-length curved arrangement SSPPs branch 34. The thickness of the composite substrate 4 is 0.5-1mm, and the material and size parameters of the innermost cylindrical ferrite 41 are: saturation magnetization value 2500-3000Gauss, dielectric constant about 15, radius value 3-4mm; the material parameters of the middle ring ferrite 42 are: saturation magnetization value 1500-2000Gauss, dielectric constant about 15, radius value 5-6mm; the material parameters of the outer ring ferrite 43 are: saturation magnetization value 1000-1500Gauss, dielectric constant about 15, radius value 7-8mm; the dielectric constant of the ceramic dielectric substrate 44 is about 15, and the cross-sectional size is within 25mm×25mm. The second magnetic circuit component uses an iron sheet with a cross-sectional size of less than 25mm×25mm and a thickness of 0.5-1mm to realize a longitudinal closed magnetic circuit. In a specific implementation, the first bias magnetic circuit component 1 uses a cylindrical magnet with a radius value of 8mm and a thickness of 2.5mm. The radius of the ceramic spacer 2 is also 8 mm, and the thickness is 2 mm. The curvature of the curved side of the central junction circuit 31 of the microstrip circuit 3 is 5 mm.The line width of the bent metal conductor transmission circuit 32 is 0.46mm; the line width of the straight-edge metal conductor transmission circuit 33 is also 0.46mm, and the length is 11mm; the length of the fixed-length curved arrangement SSPPs branch 34 is 1.62mm, the width is 0.4mm, and the spacing between each branch is 0.96mm; the shape parameters of the gradually varying length curved arrangement SSPPs branch 35, the gradually varying length curved arrangement SSPPs branch 36, and the gradually varying length straight-edge SSPPs branch 37 are all consistent with the fixed-length curved arrangement SSPPs branch 34. The thickness of the composite substrate 4 is 0.8 mm. The material and size parameters of the innermost cylindrical ferrite 41 are: saturation magnetization value 2800 Gauss, dielectric constant 13, radius value 3.7 mm; the material parameters of the middle ring ferrite 42 are: saturation magnetization value 1900 Gauss, dielectric constant 12.4, radius value 5.7 mm; the material parameters of the outer ring ferrite 43 are: saturation magnetization value 1000 Gauss, dielectric constant 13.6, radius value 7.7 mm; the dielectric constant of the ceramic dielectric substrate 44 is 15, and the cross-sectional size is 22 mm×22 mm. The second magnetic circuit component uses an iron sheet with a cross-sectional size of 22 mm×22 mm and a thickness of 1 mm.

[0046] In one embodiment, the present application provides an electronic device, comprising the composite ferrite circulator of the aforementioned embodiment.

[0047] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A composite ferrite circulator, characterized in that: The invention comprises a first bias magnetic circuit component, a ceramic gasket, a composite material substrate and a second bias magnetic circuit component which are sequentially arranged along a first direction, wherein a microstrip circuit is arranged on a side of the composite material substrate close to the ceramic gasket, and a grounding metal layer is arranged on a side of the composite material substrate close to the second bias magnetic circuit component: The microstrip circuit includes a center junction circuit, and three endpoints of the center junction circuit are connected to a first port, a second port, and a third port through a first metal conductor transmission circuit, a second metal conductor transmission circuit, and a third metal conductor transmission circuit, respectively; The composite material substrate includes a ceramic dielectric substrate, and a cylindrical ferrite penetrating along the first direction is arranged on the surface of the ceramic dielectric substrate, and a plurality of annular ferrites are sequentially sleeved on the outer side of the cylindrical ferrite, and the saturation magnetization intensity of the cylindrical ferrite and the annular ferrite decreases sequentially from the inside to the outside.

2. The composite ferrite circulator according to claim 1, characterized in that: The central junction circuit includes three curved sides, and the three curved sides are 120° rotationally symmetrical about the center of the central junction circuit.

3. A composite ferrite circulator according to claim 2, characterized in that: A plurality of curved SSPPs branches with fixed lengths are arranged on the three curved edges.

4. The composite ferrite circulator according to claim 1, characterized in that: The first metal conductor transmission circuit, the second metal conductor transmission circuit and the third metal conductor transmission circuit are all straight-edge metal conductor transmission circuits; or, The first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both formed by combining at least two straight-edge metal conductor transmission circuits at a preset angle.

5. The composite ferrite circulator according to claim 1, characterized in that: The first metal conductor transmission circuit is a straight-edge metal conductor transmission circuit, and the second metal conductor transmission circuit and the third metal conductor transmission circuit are both bent metal conductor transmission circuits with a preset curvature.

6. The composite ferrite circulator according to claim 5, characterized in that: Straight-edge SSPPs branches with gradually varying lengths are arranged on both sides of one end of the first metal conductor transmission circuit close to the first port, and first curved SSPPs branches with gradually varying lengths are arranged on both sides of the connection between the central junction circuit and the first metal conductor transmission circuit; Second curved SSPPs branches with gradually varying lengths are arranged on both sides of the second metal conductor transmission circuit and the third metal conductor transmission circuit.

7. The composite ferrite circulator according to claim 3 or 6, characterized in that: The SSPPs branches are any one of a rectangular structure, a T-shaped structure, a trapezoidal structure, and a trident-shaped structure, or a combination of several of them.

8. The composite ferrite circulator according to claim 1, characterized in that: The number of the annular ferrites is two. The end surfaces of both ends of the annular ferrite and the cylindrical ferrite along the first direction are flush with the end surfaces of both ends of the ceramic dielectric substrate along the first direction.

9. The composite ferrite circulator according to claim 1, characterized in that: The first bias magnetic circuit assembly includes a cylindrical magnetic steel magnetized along the first direction; The second bias magnetic circuit component includes an iron sheet having a size consistent with that of the composite material substrate, or the second bias magnetic circuit component includes a cylindrical magnetic steel having a size consistent with that of the first bias magnetic circuit component.

10. An electronic device, characterized in that: A composite ferrite circulator comprising any one of claims 1-9.

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