Ultra-wideband miniaturized four-port single-junction circulator and electronic device

Abstract

The application provides an ultra-wideband miniaturized four-port single-junction circulator and electronic equipment, which comprises, in sequence, an upper bias magnetic circuit assembly, a ceramic gasket, a nested composite structure substrate, a ground metal layer and a lower bias magnetic circuit assembly, and a microstrip main circuit is arranged between the ceramic gasket and the nested composite structure substrate; the microstrip main circuit comprises a circular central junction circuit, and four uniformly distributed fan-shaped gradient circuits are arranged outside the circular central junction circuit and connected with the circular central junction circuit; each fan-shaped gradient circuit is connected with a plurality of microstrip circuits with varying widths, and each microstrip circuit is connected with an impedance transition circuit; the four impedance transition circuits are respectively used for connecting a transmitting end, an antenna, a receiving end and an absorption load for absorbing reflected signals. The scheme can achieve the isolation of the transmitting and receiving channels, realize the compact design of the device, realize the ultra-wideband operation of the circulator, and greatly improve the bandwidth and integration performance of modern radars, electronic countermeasures and communication systems.

Description

Technical Field

[0001] This invention relates to the field of circulator technology, and more particularly to an ultra-wideband miniaturized four-port single-junction circulator and electronic device. Background Technology

[0002] Circulators are core components in wireless communication and phased array radar transceiver (T / R) modules. Based on the transmission line type, circulators can be classified into microstrip lines, striplines, waveguides, and coaxial lines. Compared to other types of circulators, microstrip line circulators have become a focus of research and application due to their advantages such as low insertion loss, ease of integration, and good bandwidth characteristics. However, with the rapid development of integrated circuits, the size requirements of various devices are becoming increasingly smaller, making the miniaturization and integration of circulators increasingly important performance indicators. In addition, achieving broadband operation while keeping the circulator size as small as possible is equally important to meet the needs of the current frequency range. Summary of the Invention

[0003] The purpose of this invention is to provide an ultra-wideband miniaturized four-port single-junction circulator and electronic device. By using a four-port single-junction circulator configuration, it is possible to achieve isolation between the transmit and receive channels while realizing a compact device design. At the same time, it adopts a smaller circular center junction circuit and opens a fan-shaped gradient circuit. Through the fan-shaped gradient geometry, the impedance value is transitioned to the ideal value to realize the ultra-wideband operation of the circulator, thereby significantly improving the bandwidth and integration performance of modern radar, electronic countermeasures and communication systems.

[0004] The technical solution provided by this invention is as follows: In a first aspect, this application provides an ultrawideband miniaturized four-port single-junction circulator, comprising an upper bias magnetic circuit assembly, a ceramic pad, a nested composite structure substrate, a grounding metal layer, and a lower bias magnetic circuit assembly stacked sequentially along a first direction, wherein a microstrip line main circuit is provided between the ceramic pad and the nested composite structure substrate. The microstrip line main circuit includes a circular central junction circuit. Four evenly distributed fan-shaped gradient circuits connected to the circular central junction circuit are arranged on the outside of the circular central junction circuit. The edge of the circular central junction circuit is provided with periodic loading branches located between two adjacent fan-shaped gradient circuits. Each of the fan-shaped gradient circuits is connected to a microstrip line circuit with varying widths. Each of the microstrip line circuits is connected to an impedance transition circuit. Each of the impedance transition circuits is provided with several step impedance transformer stubs for loading the step impedance transformer. The four impedance transition circuits are respectively used to connect the transmitter, the antenna, the receiver, and the absorbing load for absorbing reflected signals.

[0005] In some embodiments, the nested composite structure substrate includes a ceramic dielectric substrate, and an inner cylindrical ferrite penetrating along the first direction is disposed on the surface of the ceramic dielectric substrate. A plurality of outer annular ferrites penetrating along the first direction are sequentially sleeved on the outside of the inner cylindrical ferrite, and the saturation magnetization of the inner cylindrical ferrite and the outer annular ferrite decreases sequentially from the inside to the outside. The circular central junction circuit is located at the center of the surface of the inner cylindrical ferrite, and the radius of the circular central junction circuit is not greater than the radius of the inner cylindrical ferrite.

[0006] In some embodiments, the microstrip line circuit includes an impedance-matching microstrip line circuit connected to the fan-shaped tapered circuit and a rectangular microstrip line circuit connected to the impedance-matching microstrip line circuit. The rectangular microstrip line circuit is arranged perpendicularly to the impedance matching microstrip line circuit, and the bending direction of the four rectangular microstrip line circuits is consistent around the circular central junction circuit.

[0007] In some embodiments, the connection between the end of the impedance matching microstrip line circuit and the rectangular microstrip line circuit is provided with a chamfer, which is either a rounded corner or a right angle. The width of the rectangular microstrip line circuit does not exceed the width of the impedance matching microstrip line circuit.

[0008] In some embodiments, the impedance transition circuit includes a first impedance transition main circuit, a second impedance transition main circuit, a third impedance transition main circuit, a fourth impedance transition main circuit, a fifth impedance transition main circuit, a sixth impedance transition main circuit, a folded impedance transition circuit, and an output microstrip line circuit with a fixed impedance value, connected in sequence. The first impedance transition main circuit is connected to the end of the microstrip line circuit, and the output microstrip line circuit is used to connect the transmitter, the antenna, the receiver and the absorption load respectively; The two ends of the folded impedance transition circuit are respectively perpendicular to the sixth impedance transition main circuit and the output microstrip line circuit.

[0009] In some embodiments, the step impedance transformer stubs are symmetrically arranged on both sides of the impedance transition main circuit and perpendicular to the impedance transition main circuit, and the step impedance transformer stubs are elongated or trident-shaped.

[0010] In some embodiments, the periodically loaded stubs include a central stub located at the center, gradient stubs located on both sides of the central stub, and edge stubs loaded on the fan-shaped gradient circuit. The edge of the circular central junction circuit has central junction circuit gaps between adjacent stubs of the periodically loaded stubs. The central branch is the longest, and the gradually decreasing branches decrease in length from the central branch outwards, with the length difference being a constant. The width of each branch in the periodically loaded branch is equal.

[0011] In some embodiments, a first gap is provided at the connection points between both sides of the fan-shaped gradient circuit and the circular central knot circuit. The first gap is rectangular or triangular.

[0012] In some embodiments, the upper bias magnetic circuit assembly includes a cylindrical magnet magnetized along the first direction; The lower bias magnetic circuit assembly includes an iron sheet with the same size as the nested composite structure substrate, or the lower bias magnetic circuit assembly includes a cylindrical magnet with the same size as the upper bias magnetic circuit assembly.

[0013] In a second aspect, this application provides an electronic device including the ultra-wideband miniaturized four-port single-junction circulator described in the first aspect.

[0014] The present invention provides an ultra-wideband miniaturized four-port single-junction circulator and electronic device. Through the configuration of the four-port single-junction circulator, the transmit and receive channels can be isolated while the device is compactly designed. At the same time, a smaller circular center junction circuit is used, and a fan-shaped gradient circuit is opened. The impedance value is transitioned to the ideal value through the fan-shaped gradient geometry to achieve ultra-wideband operation of the circulator, thereby significantly improving the bandwidth and integration performance of modern radar, electronic countermeasures and communication systems. Attached Figure Description

[0015] The preferred embodiments will now be described in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of this solution.

[0016] Figure 1 This is a schematic diagram of the overall structure of an ultrawideband miniaturized four-port single-junction circulator according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the main circuit structure of a microstrip line according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a circular central junction circuit structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of an impedance transition circuit structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a nested composite substrate structure according to an embodiment of the present invention; Figure 6This is a schematic diagram of the S-parameter simulation results of an ultrawideband miniaturized four-port single-junction circulator according to an embodiment of the present invention.

[0017] Numbering on the map: 1- Upper bias magnetic circuit assembly; 2-Ceramic gasket; 3-Microstrip line main circuit; 31-Circular center junction circuit; 32-Center junction circuit slot; 33-Periodic loading stub; 331-Center stub; 332-Gradual stub; 333-Edge stub; 34-Fan-shaped gradual stub; 35-First slot; 36-Impedance matching microstrip line circuit; 37-Chamfer; 38-Rectangular microstrip line circuit; 39-Impedance transition circuit; 391-First stage impedance transition main circuit; 392-Step impedance transformer stub; 393-Second stage impedance transition main circuit; 394-Third stage impedance transition main circuit; 395-Fourth stage impedance transition main circuit; 396-Fifth stage impedance transition main circuit; 397-Sixth stage impedance transition main circuit; 398-Folded impedance transition circuit; 399-Output microstrip line circuit; 4- Nested composite structure substrate; 41- Ceramic dielectric substrate; 42- Outer ring ferrite; 43- Inner cylindrical ferrite; 5-Grounded metal layer; 6-Lower bias magnetic circuit assembly. Detailed Implementation

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0019] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0020] Circulators are core components in wireless communication and phased array radar T / R modules. Their primary function is to enable directional signal transmission and full-duplex transmission / reception within the system. A circulator allows signals to travel from one port to the next, but prevents reverse transmission. For example, signal transmission from port 1 to port 2 and from port 2 to port 3 is conductive, while reverse transmission (from 2 to 1, from 3 to 2, and from 1 to 3) is isolated. This characteristic makes circulators crucial in radar / communication systems, enabling isolation between transmitted and received signals and allowing the sharing of a single antenna. The principle of a circulator is based on the anisotropic properties of magnetically biased ferrite materials. It utilizes the Faraday rotation effect, where the polarization plane rotates when electromagnetic waves propagate through a gyromagnetic ferrite material under an applied DC magnetic field. Through design, the polarization plane of the electromagnetic wave is perpendicular to the grounded resistive plate during forward transmission, resulting in minimal attenuation; during reverse transmission, the polarization plane is parallel to the grounded resistive plate, leading to almost complete absorption.

[0021] Circulators can be categorized into microstrip lines, striplines, waveguides, and coaxial lines based on their transmission line configuration. Compared to other types of circulators, microstrip line circulators have become a focus of research and application due to their advantages such as low insertion loss, ease of integration, and good bandwidth characteristics. However, with the rapid development of integrated circuits, the size requirements of various devices are becoming increasingly smaller, making the miniaturization and integration of circulators increasingly important performance indicators. In addition, achieving broadband operation while minimizing circulator size is equally important to meet the needs of current frequency operating ranges. Frequency operating range is a 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 circulators greatly affect the overall performance of the equipment.

[0022] When the receiving and transmitting modules share a single antenna, the circulator can generate non-reciprocal energy propagation under the influence of an external magnetic field, thereby achieving unidirectional transmission between the antenna and receiver, and between the transmitter and antenna, ensuring simultaneous operation of the receiving and transmitting channels. In traditional T / R assemblies, the circulator is designed as a three-port device, connected to the antenna, receiving module, and transmitting module respectively. However, in practical operation, the matching performance of the antenna itself is not optimal, and the cascading between the antenna and the circulator can also lead to impedance mismatch at the antenna end. These two impedance mismatches adversely affect the three-port circulator. When the signal in the transmitting module is transmitted to the antenna end through the circulator, some of the signal is reflected back into the circulator and crosstalks to the receiver along the circumferential direction. The signal transmitted from the antenna to the receiver and some reflected signals are mixed together, which greatly affects subsequent signal processing. Therefore, in practical applications, to avoid crosstalk between signals, one method of physical isolation is to replace the original three-port single-junction circulator with a four-port circulator composed of two cascaded three-port circulators, i.e., a three-port dual-junction circulator. When the signal reflected from the antenna propagates along the circumferential direction, it will be absorbed by the load end of the second junction, thereby improving the isolation performance between the transmit and receive channels. However, this configuration undoubtedly increases the size of the device, affects the overall performance of the integrated circuit, and is not conducive to application.

[0023] Compared to a three-port dual-junction circulator, this application provides a four-port single-junction circulator to achieve isolation between the transmit and receive channels. The four ports of the four-port single-junction circulator are respectively connected to the transmitter, antenna, receiver, and absorption load. The absorption load can absorb part of the reflected signal, thereby ensuring good isolation between the transmit and receive channels. This configuration significantly reduces the size of the device. Furthermore, considering the difficulty of simultaneously achieving wide bandwidth and miniaturization in the design of a four-port single-junction circulator, to address the problems of narrow bandwidth and large size in existing four-port single-junction circulators, this application employs a smaller circular center junction circuit and incorporates a fan-shaped gradient circuit. The impedance value is transitioned to the ideal value through the fan-shaped gradient geometry, thereby achieving ultra-wideband operation of the circulator. The following will describe this solution in detail with reference to the accompanying drawings: In one embodiment, refer to the appendix to the specification. Figures 1 to 5 This application provides an ultrawideband miniaturized four-port single-junction circulator, including an upper bias magnetic circuit assembly 1, a ceramic pad 2, a nested composite structure substrate 4, a ground metal layer 5 and a lower bias magnetic circuit assembly 6 stacked sequentially along a first direction. A microstrip main circuit 3 is provided between the ceramic pad 2 and the nested composite structure substrate 4. The first direction is, for example, a vertical direction.

[0024] The upper bias magnetic circuit assembly 1 includes a cylindrical magnet magnetized along a first direction. In one specific implementation, the upper bias magnetic circuit assembly 1 is composed of a cylindrical samarium cobalt permanent magnet with a radius of 3.2-3.5 mm and a thickness of 0.5-1 mm, and the ceramic pad 2 has a radius of 1.5-3 mm and a thickness of 0.5-1 mm. The lower bias magnetic circuit assembly 6 includes an iron sheet with the same dimensions as the nested composite structure substrate 4 for magnetic biasing, or the lower bias magnetic circuit assembly 6 may also include a cylindrical magnet with the same dimensions as the upper bias magnetic circuit assembly 1 for magnetic biasing.

[0025] The nested composite structure substrate 4 includes a ceramic dielectric substrate 41, and an inner cylindrical ferrite 43 penetrating along a first direction is disposed on the surface of the ceramic dielectric substrate 41. A plurality of outer annular ferrites 42 penetrating along the first direction are sequentially sleeved on the outer side of the inner cylindrical ferrite 43, and the saturation magnetization of the inner cylindrical ferrite 43 and the outer annular ferrites 42 decreases sequentially from the inside to the outside. This application does not limit the number of outer annular ferrites 42; for example, in one specific implementation, the number of outer annular ferrites 42 is one. The components of the nested composite structure substrate 4 of this application are highly consistent and are joined together by adhesive bonding.

[0026] The microstrip line main circuit 3 is fabricated using thin-film technology. The microstrip line main circuit 3 includes a circular central junction circuit 31, which is located at the center of the surface of the inner cylindrical ferrite 43, and the radius of the circular central junction circuit 31 is no greater than the radius of the inner cylindrical ferrite 43. The circular central junction circuit 31 of this application is smaller in size than conventional three-port circulators. In one specific implementation, the thickness of the nested composite structure substrate 4 is between 0.3 and 0.8 mm, the dielectric constant of the ceramic dielectric substrate 41 is between 13 and 17, and the cross-sectional dimensions are within 25 mm × 25 mm. The material parameters of the outer ring ferrite 42 are: saturation magnetization of 1500-2000 Gauss, dielectric constant of approximately 15, and radius of 2-2.6 mm; the material and dimensional parameters of the inner cylindrical ferrite 43 are: saturation magnetization of 2800-3500 Gauss, dielectric constant of approximately 15, and radius of 3-3.5 mm. The cross-sectional dimensions of the grounding metal layer 5 are consistent with those of the ceramic substrate. The lower bias magnetic circuit assembly 6 uses an iron sheet with a cross-sectional dimension of less than 12mm × 12mm and a thickness of 0.5-1mm to achieve a longitudinal closed magnetic circuit.

[0027] Four evenly distributed fan-shaped gradient circuits 34 connected to the circular central junction circuit 31 are arranged on the outer side of the circular central junction circuit 31. A first gap 35 is provided at the connection points between the fan-shaped gradient circuits 34 and the circular central junction circuit 31 on both sides. This application does not limit the shape of the first gap 35. For example, the first gap 35 can be rectangular or triangular. Periodically loaded branches 33 are provided on the edge of the circular central junction circuit 31, located between adjacent fan-shaped gradient circuits 34. The periodically loaded branches 33 can be elongated, etc., and this application does not impose any limitations. In one specific implementation, the radius of the circular central junction circuit 31 is between 1.5 and 2 mm, the fan-shaped arc of the fan-shaped gradient circuits 34 connected to the circular central junction circuit 31 does not exceed 0.25, and the first gaps 35 with slots on both sides of the fan-shaped gradient circuits 34 are rectangular, with a length between 0.3 and 0.4 mm and a width between 0.15 and 0.2 mm.

[0028] Each of the fan-shaped gradient circuits 34 is connected to a microstrip line circuit with varying widths. Each microstrip line circuit is connected to an impedance transition circuit 39. Each impedance transition circuit 39 is provided with several step impedance transformer stubs 392 for loading the step impedance transformer. The four impedance transition circuits 39 are respectively used to connect the transmitter, the antenna, the receiver, and the absorption load for absorbing reflected signals.

[0029] The working principle of the circulator proposed in this application is as follows: To achieve a broadband, miniaturized four-port single-junction circulator structure, a circular center junction circuit 31 is used as the main structure of the ferrite resonant cavity. Unlike traditional circular center junctions, this scheme uses a smaller circular center junction. Due to the selection of a compact center junction shape, the wave impedance of the center junction has a large imaginary component. To compensate for this imaginary component, periodically loaded stubs 33 are applied to the edge of the circular center junction. In this way, the overall wave impedance of the ferrite resonant cavity is close to a purely real impedance value.

[0030] To achieve broadband matching, a fan-shaped tapered circuit 34 with gaps on both sides is used. The impedance value is transitioned to the ideal value through the fan-shaped tapered geometry. At this point, the circulator can achieve ultra-wideband operation simply by connecting the wave impedance matching microstrip line circuit to the fan-shaped tapered circuit 34. The linewidth of the wave impedance matching microstrip line circuit can be obtained using the microstrip line impedance calculation formula. Since the circulator needs to be connected to a 50-ohm microstrip line, an additional impedance matching terminal is required to ensure impedance matching between the wave impedance matching microstrip line circuit and the 50-ohm microstrip line. For this purpose, a multi-segment impedance transformer is used for matching. Unlike a quarter-impedance transformer, the multi-segment impedance transformer used is very short, and the topology size is further reduced through bending techniques. This application also proposes a very small circuit matching method, namely, using a step impedance transformer stub 392 to construct a complete matching network. The step impedance transformer stub 392 introduces a parallel LC branch into the original equivalent circuit, changing the resonant frequency of the resonant circuit. Compared to traditional broadband matching techniques, this technology offers a very compact circulator structure. Specifically, this solution achieves both transmit and receive channel isolation and a compact device design through a four-port single-junction circulator configuration. It also employs a small circular center junction circuit and incorporates a fan-shaped gradient circuit. This fan-shaped gradient geometry transitions the impedance value to an ideal value, enabling ultra-wideband operation of the circulator and significantly improving the bandwidth and integration performance of modern radar, electronic countermeasures, and communication systems.

[0031] Figure 6 Full-wave simulation results of the four-port single-junction circulator are provided. The circulator configuration described above can achieve operating performance exceeding 66% of the relative bandwidth, while ensuring in-band return loss and isolation of less than -15dB and insertion loss of less than -1dB. This example proposed in this invention provides a novel broadband miniaturized four-port single-junction circulator design with a compact size and good performance, meeting the needs of current integrated circuit systems.

[0032] In one embodiment, based on the foregoing embodiments, such as Figure 2 and Figure 4 As shown, the microstrip line circuit of this application includes a wave impedance matching microstrip line circuit 36 ​​connected to the fan-shaped gradient circuit 34 and a rectangular microstrip line circuit 38 connected to the wave impedance matching microstrip line circuit 36; the rectangular microstrip line circuit 38 is arranged perpendicularly to the wave impedance matching microstrip line circuit 36, and the bending direction of the four rectangular microstrip line circuits is consistent around the circular central junction circuit.

[0033] The connection points between the end of the impedance matching microstrip line circuit 36 ​​and the rectangular microstrip line circuit 38 are provided with chamfers 37, which can be rounded corners or right angles; the width of the rectangular microstrip line circuit 38 does not exceed the width of the impedance matching microstrip line circuit 36.

[0034] In one specific implementation, the impedance matching microstrip line circuit 36 ​​connected to the fan-shaped tapered circuit 34 has a width between 0.8 and 1.2 mm and a length between 1.3 and 1.7 mm. The chamfer 37 of the impedance matching microstrip line circuit 36 ​​is a right angle, with the two sides of the chamfer between 0.3 and 0.5 mm and 0.8 and 1.05 mm, respectively. The rectangular microstrip line circuit 38, which forms a 90° angle with the impedance matching microstrip line circuit 36, has a length between 1.1 and 1.3 mm and a width between 0.6 and 0.8 mm.

[0035] The impedance transition circuit 39 includes a first impedance transition main circuit 391, a second impedance transition main circuit 393, a third impedance transition main circuit 394, a fourth impedance transition main circuit 395, a fifth impedance transition main circuit 396, a sixth impedance transition main circuit 397, a folded impedance transition circuit 398, and an output microstrip line circuit 399 with a fixed impedance value, connected in sequence. The first impedance transition main circuit 391 is connected to the end of the microstrip line circuit. The output microstrip line circuit 399 is used to connect the transmitter, antenna, receiver, and absorption load, respectively. The two ends of the folded impedance transition circuit 398 are perpendicular to the sixth impedance transition main circuit 397 and the output microstrip line circuit 399, respectively.

[0036] The step impedance transformer stubs 392 are symmetrically arranged on both sides of the main impedance transition circuit and perpendicular to the main impedance transition circuit. The step impedance transformer stubs 392 can be elongated or trident-shaped.

[0037] In one specific implementation, the length of the first impedance transition main circuit 391 is between 0.6-1 mm, and the width is between 0.4-0.6 mm. The length of the step impedance transformer stub 392 is between 1-1.4 mm, and the width is between 0.05-0.15 mm. The length of the second impedance transition main circuit 393 is between 0.4-0.8 mm, and the width is between 0.3-0.5 mm. The length of the third impedance transition main circuit 394 is between 0.2-0.4 mm, and the width is between 0.2-0.4 mm. The length of the fourth impedance transition main circuit 395 is between 0.3-0.5 mm, and the width is between 0.3-0.5 mm. The length of the fifth impedance transition main circuit 396 is between 0.3-0.5 mm, and the width is between 0.3-0.5 mm. The length of the sixth impedance transition main circuit 397 is between 0.4-0.8 mm, and the width is between 0.2-0.3 mm. The length of the folded impedance transition circuit 398 is between 1 and 1.5 mm, and the width is between 0.1 and 0.25 mm. The length of the output microstrip line circuit 399 with a fixed impedance value is between 1 and 1.5 mm, and the width is between 0.1 and 0.25 mm.

[0038] In one embodiment, based on the foregoing embodiments, such as Figure 3 As shown, the periodically loaded branch 33 includes a central branch 331 located in the center, gradient branches 332 located on both sides of the central branch, and edge branches 333 loaded on the fan-shaped gradient circuit 34. The edge of the circular central junction circuit 31 has a central junction circuit gap 32 between two adjacent branches of the periodically loaded branch 33. The central branch 331 has the longest length. The length of the gradient branches 332 decreases from the inside to the outside starting from the central branch 331, and the length difference is a constant value. The width of each branch of the periodically loaded branch 33 is equal. In one specific implementation, the length and width of the central junction circuit gap 32 are between 0.1mm and 0.3mm. The periodic loading stub 33 loaded on the circular central junction circuit 31 consists of no less than three stub units. The length of the middle loading stub is between 2.7 and 3mm, the width of the stub is between 0.1 and 0.2mm, the periodic distance between the loading stubs is between 0.3 and 0.5mm, and the length difference between two adjacent loading stubs is between 0.02 and 0.05mm.

[0039] In one embodiment, this application provides an electronic device including the ultrawideband miniaturized four-port single-junction circulator of the foregoing embodiments.

[0040] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, 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 within the scope of protection of the present invention.

Claims

1. An ultrawideband miniaturized four-port single-junction circulator, characterized in that, The device includes an upper bias magnetic circuit assembly, a ceramic pad, a nested composite structure substrate, a ground metal layer, and a lower bias magnetic circuit assembly, which are stacked sequentially along a first direction. A microstrip line main circuit is provided between the ceramic pad and the nested composite structure substrate. The microstrip line main circuit includes a circular central junction circuit. Four evenly distributed fan-shaped gradient circuits connected to the circular central junction circuit are arranged on the outside of the circular central junction circuit. A first gap is provided at the connection between the two sides of the fan-shaped gradient circuit and the circular central junction circuit. The first gap is rectangular or triangular. The edge of the circular central junction circuit is provided with periodic loading branches located between two adjacent fan-shaped gradient circuits. Each of the fan-shaped gradient circuits is connected to a microstrip line circuit with varying widths. Each of the microstrip line circuits is connected to an impedance transition circuit. Each of the impedance transition circuits is provided with several step impedance transformer stubs for loading the step impedance transformer. The four impedance transition circuits are respectively used to connect the transmitter, the antenna, the receiver, and the absorbing load for absorbing reflected signals.

2. The ultra-wideband miniaturized four-port single-junction circulator according to claim 1, characterized in that, The nested composite structure substrate includes a ceramic dielectric substrate, and an inner cylindrical ferrite penetrating along the first direction is disposed on the surface of the ceramic dielectric substrate. A plurality of outer annular ferrites penetrating along the first direction are sequentially sleeved on the outside of the inner cylindrical ferrite. The saturation magnetization of the inner cylindrical ferrite and the outer annular ferrite decreases sequentially from the inside to the outside. The circular central junction circuit is located at the center of the surface of the inner cylindrical ferrite, and the radius of the circular central junction circuit is not greater than the radius of the inner cylindrical ferrite.

3. The ultra-wideband miniaturized four-port single-junction circulator according to claim 1, characterized in that, The microstrip circuit includes a wave impedance matching microstrip circuit connected to the fan-shaped gradient circuit and a rectangular microstrip circuit connected to the wave impedance matching microstrip circuit. The rectangular microstrip line circuit is arranged perpendicularly to the impedance matching microstrip line circuit, and the bending direction of the four rectangular microstrip line circuits is consistent around the circular central junction circuit.

4. The ultra-wideband miniaturized four-port single-junction circulator according to claim 3, characterized in that, The connection points between the end of the impedance matching microstrip line circuit and the rectangular microstrip line circuit are all chamfered, and the chamfers are either rounded corners or right angles. The width of the rectangular microstrip line circuit does not exceed the width of the impedance matching microstrip line circuit.

5. The ultra-wideband miniaturized four-port single-junction circulator according to claim 1, characterized in that, The impedance transition circuit includes a first impedance transition main circuit, a second impedance transition main circuit, a third impedance transition main circuit, a fourth impedance transition main circuit, a fifth impedance transition main circuit, a sixth impedance transition main circuit, a folded impedance transition circuit, and an output microstrip line circuit with a fixed impedance value, connected in sequence. The first impedance transition main circuit is connected to the end of the microstrip line circuit, and the output microstrip line circuit is used to connect the transmitter, the antenna, the receiver and the absorption load respectively; The two ends of the folded impedance transition circuit are respectively perpendicular to the sixth impedance transition main circuit and the output microstrip line circuit.

6. The ultra-wideband miniaturized four-port single-junction circulator according to claim 5, characterized in that, The step impedance transformer stubs are symmetrically arranged on both sides of the impedance transition main circuit and perpendicular to the impedance transition main circuit, and the step impedance transformer stubs are elongated or trident-shaped.

7. The ultra-wideband miniaturized four-port single-junction circulator according to claim 1, characterized in that, The periodically loaded branches include a central branch, gradient branches on both sides of the central branch, and edge branches loaded on the fan-shaped gradient circuit. The edge of the circular central junction circuit has central junction circuit gaps between adjacent branches of the periodically loaded branches. The central branch is the longest, and the gradually decreasing branches decrease in length from the central branch outwards, with the length difference being a constant. The width of each branch in the periodically loaded branch is equal.

8. The ultra-wideband miniaturized four-port single-junction circulator according to claim 1, characterized in that, The upper bias magnetic circuit assembly includes a cylindrical magnet magnetized along the first direction; The lower bias magnetic circuit assembly includes an iron sheet with the same size as the nested composite structure substrate, or the lower bias magnetic circuit assembly includes a cylindrical magnet with the same size as the upper bias magnetic circuit assembly.

9. An electronic device, characterized in that, Includes the ultrawideband miniaturized four-port single-junction circulator as described in any one of claims 1-8.

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