Composite ferrite ultra-wideband microstrip circulator

Abstract

The invention belongs to the technical field of passive microwave devices, and particularly relates to a composite ferrite ultra-wideband microstrip circulator, which comprises a metal grounding substrate, a full ferrite substrate, a microstrip circuit, a ferrite wafer with high saturation magnetization and a permanent magnet, the microstrip circuit is tightly clamped between the full ferrite substrate and the ferrite wafer with high saturation magnetization. The composite ferrite ultra-wideband microstrip circulator is simple in production process, low in technical requirement, low in production cost and high in reliability.

Description

Technical Field

[0001] The invention belongs to the technical field of passive microwave devices, and in particular relates to a composite ferrite ultra-wideband microstrip circulator. Background Art

[0002] Microstrip circulators are widely used in active phased array antenna systems. With the development of microwave electronic technology, the bandwidth of phased array antennas is getting wider and wider, and the corresponding bandwidth requirements for microstrip circulators are also getting higher and higher. The bandwidth of existing mature all-ferrite substrate microstrip circulators can generally reach 40% to 60%, and the bandwidth requirements of the new generation of phased array antennas are above 80%, which poses a challenge to the design and production of microstrip circulators.

[0003] The bandwidth of the circulator is proportional to the saturation magnetic moment of the ferrite material used. However, high saturation magnetic moment ferrite will have zero field loss when working at low frequency, resulting in excessive circulator loss. In order to achieve broadband microstrip circulators, the industry usually adopts low saturation magnetic moment ferrite substrate embedded with high saturation magnetic moment ferrite or microwave ceramic substrate embedded with high saturation magnetic moment ferrite to achieve this. It can also be achieved by embedding high saturation magnetic moment ferrite in silicon through-holes through silicon vias through silicon MEMS process. The prior art closest to the present invention is a microstrip circulator with two upper and lower high and low saturation magnetic moment ferrite composites proposed in Chinese patent application number CN201810093628.9 "Upper and Lower Composite Structure Microstrip Circulator".

[0004] The circulators of the above structures can avoid the zero field loss of the high saturation magnetic moment ferrite materials required for ultra-wideband circulators in the low frequency band, but they also have a series of disadvantages, which can be summarized as follows:

[0005] (1) The circulator microstrip circuit nested in ferrite and ceramic substrates needs to span two materials, and the two materials need to be integrated through bonding or sintering, which places very high demands on the nesting process and the consistency of the thermal expansion coefficient of the materials. In addition, it is necessary to drill holes in the hard and brittle ferrite or ceramic substrate with very high precision, which makes the processing very difficult. The thin film microstrip circuit of the circulator needs to be deposited on three materials at the same time, and sufficient adhesion must be ensured, which places very high demands on the process. Different materials have different thermal conductivity and heat capacity. When the circulator works under high-power pulse conditions, there will inevitably be a temperature difference between the three materials, which will generate large stress and there is a risk of cracking and failure. Due to the complexity of the process, the research and production cost is much higher than that of traditional all-ferrite substrate microstrip circulators.

[0006] (2) The silicon MEMS circulator process line requires the use of expensive and sophisticated microelectronic equipment. The cost of building the production line is very high, and the corresponding circulator development and production cost is also very high.

[0007] (3) The upper and lower composite structure microstrip circulator proposed in patent application number CN201810093628.9

[0008] High-precision cylindrical grooves need to be processed on the base plate; the grounding metallization layer of the ferrite substrate at the corresponding position needs to be removed, which requires two masks and two exposures; high-precision alignment is required when welding the ferrite substrate to the base plate, and the process is complicated; the processing accuracy of the ferrite embedded in the base plate must be very high, otherwise it will have a great impact on the electrical performance; now the miniaturization of circulators has increasingly higher requirements for height, the base plate thickness of some circulators is only 0.2mm, and there are even microstrip circulators without base plates, and the ferrite embedded in the base plate of this patent will cause the height of the circulator to increase significantly.

[0009] Some of the public documents related to the present invention are as follows:

[0010]

[01] Chinese patent application number CN20110999154.X "A composite substrate microstrip circulator"

[0011]

[02] Chinese Patent Application No. CN201810093628.9 “Upper and Lower Composite Structure Microstrip Circulator”

[0012]

[03] Chinese patent application number CN201911039613.5 “A packaging method for a MEMS circulator”

[0013]

[04] Chinese patent application number CN202010356121.5 "A microstrip circulator and its preparation method"

[0014]

[05] Chinese patent application number CN202010481647.6 “A broadband circulator”

[0015]

[06] Chinese patent application number CN202020989557.3 “A novel stacked broadband microstrip circulator” Summary of the invention

[0016] In view of this, in order to overcome the shortcomings of existing ultra-wideband microstrip circulators such as complex production process, high technical requirements, high production cost, and high failure risk, the present invention provides a composite ferrite ultra-wideband microstrip circulator with simple production process, low technical requirements, low production cost, and high reliability.

[0017] The technical solution of the present invention is:

[0018] A composite ferrite ultra-wideband microstrip circulator, comprising:

[0019] Metal ground substrate;

[0020] A full ferrite substrate is bonded to the metal substrate;

[0021] A microstrip circuit is arranged on a side of the all-ferrite substrate away from the metal ground substrate;

[0022] A ferrite disc with high saturation magnetization intensity has one end bonded to the full ferrite substrate;

[0023] A permanent magnet is arranged at one end of the ferrite disc away from the full ferrite substrate;

[0024] Wherein: the microstrip circuit is tightly clamped between the full ferrite substrate and the ferrite disc with high saturation magnetization intensity.

[0025] Furthermore, the permanent magnet is used to saturate the magnetization of the ferrite disc.

[0026] Furthermore, the saturation magnetization intensity of the ferrite disc is 1.2-3 times the saturation magnetization intensity of the ferrite substrate.

[0027] Furthermore, the normalized saturation magnetic moment of the all-ferrite substrate at the low frequency end is not greater than 0.75.

[0028] Furthermore, the permanent magnet structure is a disc samarium cobalt permanent magnet.

[0029] Furthermore, the ferrite disc is 0.5-1.5 times thicker than the ferrite substrate.

[0030] Furthermore, the radius of the ferrite disc is smaller than the radius of the circulator junction of the microstrip circulator.

[0031] Furthermore, the radius of the ferrite disc is 0.4-0.9 times the radius of the toroidal junction.

[0032] Furthermore, the permanent magnet is concentrically arranged with the ferrite disc, and the radius of the permanent magnet is not less than the radius of the ferrite disc.

[0033] The beneficial effects of the present invention are:

[0034] 1. The present invention can effectively improve the broadband performance of the circulator;

[0035] 2. The structure of the present invention is the same as that of the traditional microstrip circulator. The only difference is that a piece of ferrite is used to replace the insulating medium sheet between the ferrite substrate and the permanent magnet of the traditional circulator, which has almost no effect on the structural size and production cost of the circulator. Its performance is better than that of the traditional all-ferrite microstrip circulator.

[0036] 3. The present invention does not involve the nesting and compounding of heterogeneous materials, nor does it involve the production of thin-film microstrip circuits on heterogeneous materials. It has low production process requirements, high product reliability, and low product cost.

[0037] 4. The ferrite sheets added in the present invention are very convenient to process and assemble, which brings flexibility to the later debugging of the circulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a structural schematic diagram of a composite ferrite ultra-wideband microstrip circulator in a specific embodiment of the present invention;

[0040] Figure 2 is a cross-sectional schematic diagram of a composite ferrite ultra-wideband microstrip circulator in a specific embodiment of the present invention;

[0041] Figure 3 is a schematic cross-sectional view of a conventional all-ferrite microstrip circulator;

[0042] Among them: 1. All-ferrite substrate; 2. Metal grounded substrate; 3. Microstrip circuit; 4. Ferrite disc; 5. Permanent magnet; 6. Insulating dielectric sheet; 7. Ferrite substrate. DETAILED DESCRIPTION

[0043] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0044] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0045] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0046] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0047] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0048] In one embodiment of the present invention, a composite ferrite ultra-wideband microstrip circulator is provided. Figure 1 , 2 As shown, including:

[0049] Metal ground substrate 2;

[0050] The all-ferrite substrate 1 is bonded to the metal substrate;

[0051] A microstrip circuit 3 is arranged on a side of the all-ferrite substrate 1 away from the metal ground substrate 2;

[0052] A ferrite disc 4 with high saturation magnetization intensity has one end bonded to the full ferrite substrate 1;

[0053] A permanent magnet 5 is arranged at one end of the ferrite disc 4 away from the full ferrite substrate 1;

[0054] Wherein: the microstrip circuit 3 is tightly clamped between the full ferrite substrate 1 and the ferrite disc 4 with high saturation magnetization intensity.

[0055] In this embodiment, the permanent magnet 5 is used to saturate the magnetization of the ferrite disc 4 .

[0056] In this embodiment, the saturation magnetization intensity of the ferrite disc 4 is 1.2-3 times the saturation magnetization intensity of the ferrite substrate 7 .

[0057] In this embodiment, the normalized saturation magnetic moment of the all-ferrite substrate 1 at the low frequency end is not greater than 0.75.

[0058] In this embodiment, the permanent magnet 5 is a disc-shaped samarium cobalt permanent magnet.

[0059] In this embodiment, the thickness of the ferrite disc 4 is 0.5-1.5 times the thickness of the ferrite substrate 7 .

[0060] In this embodiment, the radius of the ferrite disc 4 is smaller than the radius of the circulator junction of the microstrip circulator.

[0061] In this embodiment, the radius of the ferrite disc 4 is 0.4-0.9 times the radius of the toroidal junction.

[0062] In this embodiment, the permanent magnet 5 is concentrically arranged with the ferrite disc 4 , and the radius of the permanent magnet 5 is not less than the radius of the ferrite disc 4 .

[0063] The substrate of this embodiment is made of all ferrite, and the microstrip circuit 3 is made on the upper surface of the ferrite substrate 7; a piece of ferrite is added above the ring junction circuit of the ferrite substrate 7, and a permanent magnet 5 is installed above the ferrite; the ferrite sheet added between the ferrite substrate 7 and the permanent magnet 5, on the one hand, enhances the gyromagnetic effect, thereby increasing the equivalent saturation magnetic moment of the ferrite, thereby widening the circulator bandwidth, and also plays the role of replacing the insulating dielectric sheet 6 between the ferrite substrate 7 and the permanent magnet 5 of the traditional microstrip ferrite circulator, without adding additional structural components; a metallized grounding layer is made on the lower surface of the ferrite substrate 7, and the metallized grounding layer and the metal grounding substrate 2 are bonded or welded together by conductive adhesive.

[0064] In this embodiment, the ferrite substrate 7 uses a ferrite material with a relatively low saturation moment to ensure that the circulator has a relatively low loss at low frequency, and the saturation moment of the ferrite sheet added above the ferrite substrate 7 ring junction is greater than or equal to the saturation moment of the ferrite substrate 7. Figure 2 The composite ferrite ultra-wideband microstrip circulator of this embodiment includes a permanent magnet 5 and a ferrite disc 4 from top to bottom, the saturation magnetization intensity of the ferrite disc 4 is 2800Gs, a microstrip circuit 3 is made between the ferrite disc 4 and the full ferrite substrate 1, the saturation magnetization intensity of the full ferrite substrate 1 is 1800Gs, and there is a metal grounding substrate 2 below it.

[0065] The composite ferrite ultra-wideband microstrip circulator of this embodiment adopts all-ferrite as the all-ferrite substrate 1, the microstrip circuit 3 is made on the upper surface of the all-ferrite substrate 1 by thick film process, the metallized grounding layer is made on the lower surface of the all-ferrite substrate 1, the metallized grounding layer and the metal grounding substrate 2 are bonded or welded together by conductive adhesive; a ferrite disc 4 is bonded above the microstrip circuit 3 on the upper surface of the all-ferrite substrate 1, and a permanent magnet 5 is bonded above the ferrite disc 4; the ferrite disc 4 added between the all-ferrite substrate 1 and the permanent magnet 5, on the one hand, enhances the gyromagnetic effect, thereby achieving the effect of increasing the equivalent saturation magnetic moment of the ferrite, thereby widening the bandwidth of the circulator; on the other hand, it serves as a substitute for Figure 3 The role of the insulating dielectric sheet 6 between the ferrite substrate 7 and the permanent magnet 5 in the conventional microstrip ferrite circulator shown does not add any additional structural components;

[0066] The simulation results of this embodiment show that the circulator of this embodiment has a standing wave less than 1.4, an average loss less than 0.6dB, and an isolation greater than 16dB within a bandwidth range of 70% across the CX band, showing obvious performance advantages over traditional all-ferrite microstrip circulators.

[0067] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A composite ferrite ultra-wideband microstrip circulator, characterized in that: include: Metal ground substrate; A full ferrite substrate is bonded to the metal substrate; A microstrip circuit is arranged on a side of the all-ferrite substrate away from the metal ground substrate; A ferrite disc with high saturation magnetization intensity has one end bonded to the full ferrite substrate; A permanent magnet is arranged at one end of the ferrite disc away from the full ferrite substrate; Wherein: the microstrip circuit is tightly clamped between the full ferrite substrate and the ferrite disc with high saturation magnetization intensity.

2. The composite ferrite ultra-wideband microstrip circulator according to claim 1, characterized in that: The permanent magnet is used to saturate the magnetization of the ferrite disc.

3. The composite ferrite ultra-wideband microstrip circulator according to claim 2, characterized in that: The saturation magnetization intensity of the ferrite disc is 1.2-3 times the saturation magnetization intensity of the ferrite substrate.

4. The composite ferrite ultra-wideband microstrip circulator according to claim 3, characterized in that: The normalized saturation magnetic moment of the all-ferrite substrate at the low frequency end is no more than 0.

75.

5. The composite ferrite ultra-wideband microstrip circulator according to claim 4, characterized in that: The permanent magnet structure is a disc samarium cobalt permanent magnet.

6. The composite ferrite ultra-wideband microstrip circulator according to claim 5, characterized in that: The thickness of the ferrite disc is 0.5-1.5 times the thickness of the ferrite substrate.

7. The composite ferrite ultra-wideband microstrip circulator according to claim 6, characterized in that: The radius of the ferrite disc is smaller than the radius of the circulator junction of the microstrip circulator.

8. The composite ferrite ultra-wideband microstrip circulator according to claim 7, characterized in that: The radius of the ferrite disc is 0.4-0.9 times the radius of the ring junction.

9. The composite ferrite ultra-wideband microstrip circulator according to claim 8, characterized in that: The permanent magnet is concentrically arranged with the ferrite disc, and the radius of the permanent magnet is not less than the radius of the ferrite disc.

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