A miniaturized circulator

Abstract

The present invention discloses a miniaturized circulator, and relates to the technical field of electronic components. The present invention includes a dielectric substrate, a thin film circuit board, a copper plate, an alumina ceramic sheet, a yttrium iron garnet ferrite disc, and ST epoxy glue. The thin film circuit board is arranged on the top of the dielectric substrate, the copper plate is located on the top of the thin film circuit board, and the ferrite is located on the top of the copper plate. The preparation method of the miniaturized circulator includes the following steps: raw material selection, ferrite preparation, and circulator preparation. The present invention is a miniaturized circulator. The ST epoxy glue is used to bond the yttrium iron garnet ferrite disc to the alumina ceramic sheet, the copper plate to the thin film circuit board, and the ferrite to the copper plate. As the temperature rises, the viscosity between the various components of the circulator is normally distributed, which reflects the high temperature resistance of the ST epoxy glue, thereby improving the heat resistance of the circulator. The ferrite is prepared by the yttrium iron garnet ferrite disc and the alumina ceramic sheet, so that the circulator receiver is in a sensitive state.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, and in particular to a miniaturized circulator. Background Art

[0002] The circulator is a three-port device. When port 1 is input and port 2 is output, port 3 is an isolated port and energy can hardly pass through. Similarly, the circulator used on the UHF reader is generally used for clockwise flow. When port 1 is TX output, the RF signal will flow through port 2, and port 3, i.e., the RX port, is the isolated port. The specific isolation degree needs to refer to the device parameters and LAYOUT effect. On the contrary, when port 2 is used as the transceiver multiplexer to receive the signal, the signal will enter port 3 in a clockwise direction. At this time, the energy leaked to the TX port is very small and can be ignored, while the energy leaked from the TX to the RX port greatly affects the receiver. Sensitivity refers to the actual recognition effect. Therefore, according to the LNA parameters at the receiving end, an attenuator should be added at the RX end to effectively isolate the TX leakage signal. However, this creates a problem. Because the useful signal received by RX itself is already very small, while attenuating the leakage signal at the TX end, the useful signal at the RX end is further weakened, which will also affect the reception of LNA. Therefore, using a circulator for transceiver isolation can only produce an effect to a certain extent. When the TX output power is given and the ERP does not exceed the relevant regulations, in order to improve the sensitivity of the receiver, it is necessary to consider increasing the isolation between the transmit and receive paths. There are many ways to do this, depending on the specific needs.

[0003] Circulators include ferrites. Due to their non-reciprocity, ferrite circulators can allow the transmitter and receiver to share the same antenna and play a role in isolating and protecting important devices. They are essential components of radar and communication systems. Ferrite is a material with magnetic, electrical and optical effects. It is divided into five categories according to its characteristics: soft magnetic, permanent magnetic, gyromagnetic, moment magnetic and piezomagnetic ferrites. Ferrite circulators are simple and compact ferrite devices. Their main feature is that they exhibit different characteristics for electromagnetic waves transmitted in different directions, so that electromagnetic waves are transmitted in a certain circular direction. If they are transmitted in the opposite circular direction, there will be a great attenuation. The fundamental reason for the non-reciprocal characteristic of ferrite circulators is that there is a ferrite material under the action of a constant magnetic field in the circular junction. Due to the non-reciprocal characteristic, ferrite circulators are widely used in millimeter wave systems, phased array antenna components and microwave communications, and can realize duplex and switching functions. At present, most ferrite circulators are all-ferrite type: a ferrite substrate is used, and a conductor pattern is made on it.

[0004] Existing circulators depositing circuits on ferrite substrates may result in poor metal adhesion, and the surface of ferrite is relatively rough relative to the dielectric substrate, which increases the difficulty of printing circuits. Ferrite circulators and other different components have impedance mismatches due to different substrate materials, and using circulators for transceiver isolation can only produce effects to a certain extent. For a given TX output power and ERP not exceeding relevant regulations, the receiver sensitivity is not high. Therefore, it is necessary to provide a miniaturized circulator. Summary of the invention

[0005] The main purpose of the present invention is to provide a miniaturized circulator, which can effectively solve the background technology that the existing circulator deposits the circuit on the ferrite substrate, which may lead to poor metal adhesion, and the ferrite is relatively rough relative to the dielectric substrate surface, which will increase the difficulty of printing the circuit. The ferrite circulator and other different components have impedance mismatch due to the different substrate materials, and the use of the circulator for transceiver isolation can only produce an effect to a certain extent. When the TX output power is given and the ERP does not exceed the relevant regulations, the receiver sensitivity is not high.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a miniaturized circulator, comprising a dielectric substrate, a thin film circuit board, a copper plate, an alumina ceramic sheet, a yttrium iron garnet ferrite disc and ST epoxy glue, wherein the thin film circuit board is arranged on the top of the dielectric substrate, the copper plate is arranged on the top of the thin film circuit board, and the alumina ceramic sheet is arranged on the top of the copper plate;

[0007] The preparation method of the miniaturized circulator comprises the following steps:

[0008] S1: Raw material selection

[0009] S1.1: Select an alumina ceramic sheet with low dielectric loss and a dielectric constant of 9.8, cut it into alumina ceramic sheets with a diameter of 6.4 mm and a thickness of 2.2 mm by a slicer, and polish the outer peripheral side of the alumina ceramic sheet by a polishing machine for 1 minute;

[0010] S1.2: Select a yttrium iron garnet ferrite disc with a diameter of 3.2 mm and a thickness of 1.05 mm, a dielectric substrate with a radius of 4 mm and a thickness of 3 mm, and a copper plate with a radius of 2 mm and a thickness of 1.5 mm for standby use;

[0011] S1.3: Soak the dielectric substrate, copper plate, alumina ceramic sheet and yttrium iron garnet ferrite disc in alcohol for 3 minutes, then clean them by ultrasonic for 5 minutes, and dry them in a dryer for later use;

[0012] S2: Preparation of ferrite

[0013] S2.1: Use a hole digger to dig a circular groove with a radius of 1.6 mm and a thickness of 1.05 mm at the center of the top of the alumina ceramic sheet;

[0014] S2.2: Select ST epoxy glue and apply it evenly on the inner wall of the circular groove with a brush, and let it stand for 2 seconds;

[0015] S2.3: Then, the suction cup is sucked on the top of the yttrium iron garnet ferrite disc, and the yttrium iron garnet ferrite disc is embedded in the center of the alumina ceramic sheet, so that the yttrium iron garnet ferrite disc fits with the inner wall of the circular groove, and the suction cup is powered off to obtain the ferrite;

[0016] S3: Preparation of circulator

[0017] S3.1: placing the dielectric substrate on a workbench and fixing it by a clamp;

[0018] S3.2: embed the small Y junction into the thin film circuit board, and solder the thin film circuit board to the dielectric substrate;

[0019] S3.3: Use a brush to adhere ST epoxy glue and evenly apply the ST epoxy glue to the bottom surface of the copper plate, and attach the bottom of the copper plate coated with ST epoxy glue to the top of the dielectric substrate. The copper plate is located above the thin film circuit board and connected to the thin film circuit board to form a transmission structure similar to a strip line.

[0020] S3.4: Then, ST epoxy glue is applied on the bottom of the prepared ferrite with the center as the origin and a radius of 2 mm, and then the center of the bottom of the ferrite is bonded with the center of the top of the copper plate to make the ferrite and the copper plate bonded and connected to obtain a circulator.

[0021] Preferably, the polishing machine in step S1.1 has a rotation speed of 800-1200 r / min, and the polishing machine is distributed in a circle on the outer peripheral side of the alumina ceramic sheet, and is used to evenly grind and polish the outer peripheral side of the alumina ceramic sheet.

[0022] Preferably, the alcohol in step S1.3 has a purity of 75% and a volume of 10 ml, and the dielectric substrate, copper plate, alumina ceramic sheet and yttrium iron garnet ferrite disc in the alcohol are stirred by a cotton swab to make them fully contact with the alcohol.

[0023] Preferably, the dryer in step S1.3 is provided with a filter screen that carries a dielectric substrate, a copper plate, an alumina ceramic sheet and a yttrium iron garnet ferrite disc, the temperature in the dryer is set to a constant temperature of 35° C., and the drying time is 20 minutes.

[0024] Preferably, in step S2.1, after the hole digger digs a circular groove with a radius of 1.6 mm and a thickness of 1.05 mm at the center of the top of the alumina ceramic sheet, the inner wall of the circular groove is polished by a polishing rod at a speed of 1400 r / min for 1 minute.

[0025] Preferably, in step S2.2, the ST epoxy glue is stirred evenly by a mixer, a brush is placed in a glass bottle carrying the ST epoxy glue so that the brush is immersed in the ST epoxy glue, one end of the brush is slid on the inner wall of the circular groove, and left to stand for 2S to facilitate the leveling of the ST epoxy glue.

[0026] Preferably, in step S2.3, after the suction cup is powered off, a press machine is used to apply pressure to the yttrium iron garnet ferrite disc, and the pressure is 10N, so that the yttrium iron garnet ferrite disc is easily in close contact with the alumina ceramic sheet.

[0027] Preferably, in step S3.1, the clamping member contacts the bottom of the dielectric substrate to clamp the outer peripheral side of the dielectric substrate, and the height is lower than the top of the dielectric substrate.

[0028] Preferably, three groups of connectors are provided on the outer peripheral side of the thin film circuit board, the three groups of connectors are distributed in a circle, and the angle between adjacent connectors is 120°.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention embeds a yttrium iron garnet ferrite disc into the center of an alumina ceramic sheet so that the yttrium iron garnet ferrite disc fits the inner wall of the circular groove, and the suction cup is powered off. After the suction cup is powered off, the yttrium iron garnet ferrite disc is pressed by a press machine with a pressure of 10N, so that the yttrium iron garnet ferrite disc is in close contact with the alumina ceramic sheet to obtain ferrite, thereby reducing the total amount of ferrite material and reducing the overall insertion loss of the circulator;

[0031] 2. In the present invention, a thin film circuit board is first embedded in a dielectric substrate, and a copper plate is covered on the outside of the thin film circuit board to form a metal layer, thereby forming a transmission structure similar to a strip line, so that the ring circuit and other device circuits are in the same plane, while avoiding the loss caused by the roughness of the ferrite surface. This circulator structure does not require drilling holes on the dielectric substrate, thereby simplifying the manufacturing process and saving costs;

[0032] 3. In the present invention, ferrite is prepared by using yttrium iron garnet ferrite discs and alumina ceramic sheets. The ferrite is located above the thin film circuit board. This design makes the circulator receiver in a sensitive state, increases the isolation of the circulator, reduces the influence of electromagnetic wave transmission energy in the circulator, and improves the ring performance of the circulator;

[0033] 4. In the present invention, ST epoxy glue is used to bond the yttrium iron garnet ferrite disc to the alumina ceramic sheet, the copper plate to the thin film circuit board, and the ferrite to the copper plate. As the temperature rises, the viscosity between the various components of the circulator is normally distributed, reflecting the high temperature resistance of the ST epoxy glue, thereby improving the heat resistance of the circulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a miniaturized circulator of the present invention;

[0035] Figure 2 A flow chart of a method for preparing a miniaturized circulator according to the present invention;

[0036] In the figure: 1. dielectric substrate; 2. thin film circuit board; 3. copper plate; 4. alumina ceramic sheet; 5. ST epoxy glue; 6. yttrium iron garnet ferrite disc; 7. circular groove. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0038] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Please refer to Figure 1As shown in FIG. 2 , the present invention is a miniaturized circulator, comprising a dielectric substrate 1, a thin film circuit board 2, a copper plate 3, an alumina ceramic sheet 4, a yttrium iron garnet ferrite disc 6 and an ST epoxy adhesive 5. The thin film circuit board 2 is arranged on the top of the dielectric substrate 1, the copper plate 3 is located on the top of the thin film circuit board 2, the alumina ceramic sheet 4 is located on the top of the copper plate 3, and three groups of joints are arranged on the outer peripheral side of the thin film circuit board 2. The three groups of joints are distributed in a circle, and the angle between adjacent joints is 120°.

[0041] The preparation method of the miniaturized circulator comprises the following steps:

[0042] S1: Raw material selection

[0043] S1.1: Select an alumina ceramic sheet 4 with low dielectric loss and a dielectric constant of 9.8, cut it into an alumina ceramic sheet 4 with a diameter of 6.4 mm and a thickness of 2.2 mm by a slicer, and polish the outer peripheral side of the alumina ceramic sheet 4 for 1 minute by a polishing machine with a rotation speed of 800-1200 r / min. The polishing machine moves in a circular motion to evenly and comprehensively polish the outer peripheral side of the alumina ceramic sheet 4;

[0044] S1.2: Select a yttrium iron garnet ferrite disc 6 with a diameter of 3.2 mm and a thickness of 1.05 mm, select a dielectric substrate 1 with a radius of 4 mm and a thickness of 3 mm, and a copper plate 3 with a radius of 2 mm and a thickness of 1.5 mm for standby use. The performance parameters of the yttrium iron garnet ferrite disc 6 are as follows: Figure 1 As shown;

[0045] Figure 1 : Performance parameters of Yttrium Iron Garnet Ferrite Disc 6 material

[0046] 4πMs ΔH e′ tan6 1950Gs ≤16Oe 14.6 ≤0.0002

[0047] S1.3: Soak the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 in 10 ml of alcohol with a purity of 75% for 3 minutes, stir the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 in the alcohol with a cotton swab to make them fully contact with the alcohol, and then use ultrasonic cleaning for 5 minutes, and then put the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 into a dryer, and the dryer is provided with a filter screen for carrying the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6. The temperature in the dryer is set to a constant temperature of 35°C, the drying time is 20 minutes, and it is used for standby after drying;

[0048] S2: Preparation of ferrite

[0049] S2.1: A circular groove 7 with a radius of 1.6 mm and a thickness of 1.05 mm is dug at the center of the top of the alumina ceramic sheet 4 by a hole digger, and the inner wall of the circular groove 7 is polished at a speed of 1400 r / min for 1 min by a polishing rod to keep the inner wall of the circular groove 7 smooth;

[0050] S2.2: Select ST epoxy glue 5, stir the ST epoxy glue 5 evenly with a mixer, put a brush into the glass bottle carrying the ST epoxy glue 5, immerse the brush in the ST epoxy glue 5, slide one end of the brush on the inner wall of the circular groove 7, and let it stand for 2S to facilitate the leveling of the ST epoxy glue 5;

[0051] S2.3: Then use the suction cup to suck on the top of the yttrium iron garnet ferrite disc 6, embed the yttrium iron garnet ferrite disc 6 into the center of the alumina ceramic sheet 4, so that the yttrium iron garnet ferrite disc 6 fits with the inner wall of the circular groove 7, and cut off the power of the suction cup. After the suction cup is powered off, the yttrium iron garnet ferrite disc 6 is pressed by a press machine with a pressure of 10N, which makes it easy for the yttrium iron garnet ferrite disc 6 to be in close contact with the alumina ceramic sheet 4 to obtain ferrite; this step reduces the total amount of ferrite material while reducing the overall insertion loss of the circulator.

[0052] S3: Preparation of circulator

[0053] S3.1: placing the dielectric substrate 1 on a workbench, with the clamping member contacting the bottom of the dielectric substrate 1 and clamping the outer peripheral side of the dielectric substrate 1 at a height lower than the top of the dielectric substrate 1;

[0054] S3.2: embed the small Y junction into the thin film circuit board 2, and solder the thin film circuit board 2 to the dielectric substrate 1;

[0055] S3.3: Use a brush to adhere ST epoxy glue 5, and evenly apply ST epoxy glue 5 to the bottom surface of the copper plate 3, and attach the bottom of the copper plate 3 coated with ST epoxy glue 5 to the top of the dielectric substrate 1. The copper plate 3 is located above the thin film circuit board 2 and connected to the thin film circuit board 2 to form a transmission structure similar to a strip line.

[0056] S3.4: Then, ST epoxy glue 5 is coated on the bottom of the prepared ferrite with the center as the origin and a radius of 2 mm, and then the center of the bottom of the ferrite is bonded with the center of the top of the copper plate 3, so that the ferrite and the copper plate 3 are bonded and connected to obtain a circulator.

[0057] Embodiment 1:

[0058] First, a yttrium iron garnet ferrite disc 6 with a diameter of 3.2 mm and a thickness of 1.05 mm is embedded in an alumina ceramic sheet 4 with low dielectric loss and a dielectric constant of 9.8 to form a ferrite heterostructure, thereby reducing the total amount of ferrite material and reducing the overall insertion loss of the circulator. Then, a small Y junction is added to the central junction part of the thin film circuit for impedance matching to achieve the purpose of reducing return loss and improving isolation. The dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are immersed in 10 ml of alcohol with a purity of 75% for 3 minutes, and the alcohol is stained with a cotton swab. The dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 are stirred to make them fully contact with alcohol, and then ultrasonically cleaned for 5 minutes. The dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 are placed in a dryer. The dryer is provided with a filter screen for carrying the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6. The temperature in the dryer is set to a constant temperature of 35°C, the drying time is 20 minutes, and after drying, it is used for standby use. A hole digger is used to dig a hole with a radius of 1.6mm and a thickness of 1.05mm round groove 7, grind the inner wall of the round groove 7 with a grinding rod at a speed of 1400r / min for 1min to keep the inner wall of the round groove 7 smooth, select ST epoxy glue 5, stir the ST epoxy glue 5 evenly with a mixer, put the brush into the glass bottle carrying the ST epoxy glue 5, immerse the brush in the ST epoxy glue 5, slide one end of the brush on the inner wall of the round groove 7, let it stand for 2S to make the ST epoxy glue 5 level, and then suck it on the glass bottle with a suction cup. The top of the yttrium iron garnet ferrite disc 6 is embedded in the center of the alumina ceramic sheet 4, so that the yttrium iron garnet ferrite disc 6 fits the inner wall of the circular groove 7, and the suction cup is powered off. After the suction cup is powered off, the yttrium iron garnet ferrite disc 6 is pressed by a press machine, and the pressure is 10N, which is easy for the yttrium iron garnet ferrite disc 6 to be in close contact with the alumina ceramic sheet 4 to obtain ferrite; this step reduces the total amount of ferrite material while reducing The insertion loss of the whole circulator is low. The dielectric substrate 1 is placed on the workbench, and the clamping piece contacts the bottom of the dielectric substrate 1. The outer peripheral side of the dielectric substrate 1 is clamped, and the height is lower than the top of the dielectric substrate 1. The thin film circuit board 2 is welded on the dielectric substrate 1. The ST epoxy glue 5 is adhered to the brush, and the ST epoxy glue 5 is evenly coated on the bottom surface of the copper plate 3. The bottom of the copper plate 3 coated with the ST epoxy glue 5 is attached to the top of the dielectric substrate 1. The copper plate 3 is located above the thin film circuit board 2 and connected to the thin film circuit board 2 to form a transmission structure similar to a strip line. Then, ST epoxy glue 5 is applied to the bottom of the prepared ferrite with the center as the origin and a radius of 2mm. Then the center of the bottom of the ferrite is attached to the center of the top of the copper plate 3, so that the ferrite and the copper plate 3 are attached and connected to obtain a circulator; the obtained circulator is placed in a uniform magnetic bias internal field with 95000A / m applied. The S parameters simulated in HFSS are shown in Table 1.

[0059] Comparative Example 1:

[0060] First, the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are placed in 10 ml of alcohol with a purity of 75% and immersed for 3 minutes, and the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 in the alcohol are stirred with a cotton swab to make them fully contact with the alcohol, and then ultrasonically cleaned for 5 minutes, and the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are placed in a drying oven. In the machine, a filter screen carrying a medium substrate 1, a copper plate 3, an alumina ceramic sheet 4 and a yttrium iron garnet ferrite disc 6 is provided in the dryer. The temperature in the dryer is set to a constant temperature of 35°C, and the drying time is 20 minutes. After drying, the yttrium iron garnet ferrite disc 6 is welded to the top of the alumina ceramic sheet 4 to obtain a ferrite structure. ST epoxy glue 5 is selected and stirred evenly by a mixer. A brush is placed in a glass bottle carrying the ST epoxy glue 5 so that the brush is immersed in the ST epoxy glue. The ST epoxy glue 5 is placed in the workbench, one end of the brush is slid on the inner wall of the circular groove 7, and it is easy to level the ST epoxy glue 5 after standing for 2S. The dielectric substrate 1 is placed on the workbench, and the clamping piece contacts the bottom of the dielectric substrate 1. The outer peripheral side of the dielectric substrate 1 is clamped, and the height is lower than the top of the dielectric substrate 1. The thin film circuit board 2 is welded on the dielectric substrate 1. The brush adheres to the ST epoxy glue 5, and the ST epoxy glue 5 is evenly coated on the bottom surface of the copper plate 3. The bottom of the copper plate 3 coated with the ST epoxy glue 5 is attached to the dielectric substrate 1. At the top, the copper plate 3 is located above the thin film circuit board 2 and connected to the thin film circuit board 2 to form a transmission structure similar to a strip line. Then, ST epoxy glue 5 is applied to the bottom of the prepared ferrite with the center as the origin and a radius of 2 mm. Then, the center of the bottom of the ferrite is bonded to the center of the top of the copper plate 3, so that the ferrite and the copper plate 3 are bonded and connected to obtain a circulator. The obtained circulator is placed in a uniform magnetic bias internal field with 95000A / m applied. The S parameters simulated in HFSS are shown in Table 1.

[0061] Table 1: Circulator S parameter simulation table

[0062]

[0063] It can be seen from Table 1 that when electromagnetic waves of the same frequency are input into the circulators prepared in Example 1 and Comparative Example 1, the center frequencies of the circulators increase from 11 to 14 GHz. The isolation in Example 1 varies from 10-15-35-50-28-10-4. When the center frequency is 12.5 GHz, the isolation is maximum, so that the circulator receiver is in a sensitive state, thereby improving the use effect of the circulator. The isolation in Comparative Example 1 varies from 3-5-7-9-7-5-4. The greater the isolation, the less the impact on the electromagnetic wave transmission energy in the circulator. It can be seen that the circulator prepared in Example 1 has good ring performance.

[0064] Embodiment 2:

[0065] First, a yttrium iron garnet ferrite disc 6 with a diameter of 3.2 mm and a thickness of 1.05 mm is embedded in an alumina ceramic sheet 4 with low dielectric loss and a dielectric constant of 9.8 to form a ferrite heterostructure, thereby reducing the total amount of ferrite material and reducing the overall insertion loss of the circulator. Then, a small Y junction is added to the central junction part of the thin film circuit for impedance matching to achieve the purpose of reducing return loss and improving isolation. The dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are immersed in 10 ml of alcohol with a purity of 75% for 3 minutes, and the alcohol is stained with a cotton swab. The dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 are stirred to make them fully contact with alcohol, and then ultrasonically cleaned for 5 minutes. The dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6 are placed in a dryer. The dryer is provided with a filter screen for carrying the dielectric substrate 1, copper plate 3, alumina ceramic sheet 4 and yttrium iron garnet ferrite disc 6. The temperature in the dryer is set to a constant temperature of 35°C, the drying time is 20 minutes, and after drying, it is used for standby use. A hole digger is used to dig a hole with a radius of 1.6mm and a thickness of 1.05mm round groove 7, grind the inner wall of the round groove 7 with a grinding rod at a speed of 1400r / min for 1min to keep the inner wall of the round groove 7 smooth, select ST epoxy glue 5, stir the ST epoxy glue 5 evenly with a mixer, put the brush into the glass bottle carrying the ST epoxy glue 5, immerse the brush in the ST epoxy glue 5, slide one end of the brush on the inner wall of the round groove 7, let it stand for 2S to make the ST epoxy glue 5 level, and then suck it on the glass bottle with a suction cup. The top of the yttrium iron garnet ferrite disc 6 is embedded in the center of the alumina ceramic sheet 4, so that the yttrium iron garnet ferrite disc 6 fits the inner wall of the circular groove 7, and the suction cup is powered off. After the suction cup is powered off, the yttrium iron garnet ferrite disc 6 is pressed by a press machine, and the pressure is 10N, which is easy for the yttrium iron garnet ferrite disc 6 to be in close contact with the alumina ceramic sheet 4 to obtain ferrite; this step reduces the total amount of ferrite material while reducing The insertion loss of the whole circulator is low. The dielectric substrate 1 is placed on the workbench, the clamping piece contacts the bottom of the dielectric substrate 1, and the outer peripheral side of the dielectric substrate 1 is clamped, and the height is lower than the top of the dielectric substrate 1. The thin film circuit board 2 is welded on the dielectric substrate 1. The brush adheres the ST epoxy glue 5, and the ST epoxy glue 5 is evenly coated on the bottom surface of the copper plate 3. The bottom of the copper plate 3 coated with the ST epoxy glue 5 is attached to the top of the dielectric substrate 1. The copper plate 3 is located above the thin film circuit board 2 and connected to the thin film circuit board 2 to form a transmission structure similar to a strip line. Then, the ST epoxy glue 5 is applied to the bottom of the prepared ferrite with the center as the origin and the radius of 2mm. Then the center of the bottom of the ferrite is attached to the center of the top of the copper plate 3, so that the ferrite is attached and connected to the copper plate 3 to obtain a circulator; five groups of circulator samples prepared by the above steps are selected, fixed on the eutectic table, and tested by a shear strength tester. The results are shown in Table 2;.

[0066] Comparative Example 2:

[0067] The materials are the same as those in Example 2. The epoxy connections in Example 2 are replaced by welding. First, a yttrium iron garnet ferrite disc 6 with a diameter of 3.2 mm and a thickness of 1.05 mm is embedded in an alumina ceramic sheet 4 with low dielectric loss and a dielectric constant of 9.8 to form a ferrite heterostructure. While reducing the total amount of ferrite material, the insertion loss of the circulator as a whole is reduced. Then, a small Y junction is added to the central junction of the thin film circuit for impedance matching to achieve the purpose of reducing return loss and improving isolation. The dielectric substrate 1, the copper plate 3, and the alumina ceramic sheet are connected to the dielectric substrate 1. 4 and the yttrium iron garnet ferrite disc 6 are placed in 75% purity and 10ml of alcohol and soaked for 3 minutes, and the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 in the alcohol are stirred by a cotton swab to make them fully contact with the alcohol, and then ultrasonically cleaned for 5 minutes, and the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are placed in a drying machine, and a filter screen for carrying the dielectric substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 is provided in the drying machine, and the medium substrate 1, the copper plate 3, the alumina ceramic sheet 4 and the yttrium iron garnet ferrite disc 6 are dried. The temperature in the machine is set to a constant temperature of 35°C, the drying time is 20 minutes, and it is set aside after drying. A circular groove 7 with a radius of 1.6mm and a thickness of 1.05mm is dug at the center of the top of the alumina ceramic sheet 4 by a hole digger, and the inner wall of the circular groove 7 is polished for 1 minute at a speed of 1400r / min by a grinding rod to keep the inner wall of the circular groove 7 smooth, and the yttrium iron garnet ferrite disc 6 is welded to the center of the alumina ceramic sheet 4, so that the yttrium iron garnet ferrite disc 6 is fixedly connected to the inner wall of the circular groove 7 to obtain ferrite; this step reduces the total amount of ferrite material while To reduce the overall insertion loss of the circulator, a dielectric substrate 1 is placed on a workbench, a clamp is in contact with the bottom of the dielectric substrate 1, the outer peripheral side of the dielectric substrate 1 is clamped, and the height is lower than the top of the dielectric substrate 1, a thin film circuit board 2 is welded on the dielectric substrate 1, and a copper plate 3 is welded on the top of the thin film circuit board 2 to form a transmission structure similar to a strip line, and then the prepared ferrite is welded to the top center of the copper plate 3 to obtain a circulator; five groups of circulator samples prepared by the above steps are selected, fixed on a eutectic table, and tested by a shear strength tester, and the results are shown in Table 2;

[0068] Table 2: Effect of heating on viscosity between circulator components

[0069]

[0070] As can be seen from Table 2, Example 2 uses ST epoxy adhesive 5 to bond the yttrium iron garnet ferrite disc 6 to the alumina ceramic sheet 4, the copper plate 3 to the thin film circuit board 2, and the ferrite to the copper plate 3. As the temperature increases, the viscosity between the components of the circulator is normally distributed, reflecting the high temperature resistance of the ST epoxy adhesive 5. Comparative Example 2 welds the yttrium iron garnet ferrite disc 6 to the alumina ceramic sheet 4, the copper plate 3 to the thin film circuit board 2, and the ferrite to the copper plate 3. In Comparative Example 2, the viscosity between the components of the circulator decreases with increasing temperature. The higher the temperature, the faster the welding material melts. When preparing the circulator, using ST epoxy adhesive 5 for bonding can ensure the bonding strength of the circulator, thereby improving the quality of the circulator.

[0071] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A miniaturized circulator, characterized in that: It comprises a dielectric substrate (1), a thin film circuit board (2), a copper plate (3), an alumina ceramic sheet (4), a yttrium iron garnet ferrite disc (6) and ST epoxy glue (5), wherein the thin film circuit board (2) is arranged on the top of the dielectric substrate (1), the copper plate (3) is located on the top of the thin film circuit board (2), and the alumina ceramic sheet (4) is located on the top of the copper plate (3); The preparation method of the miniaturized circulator comprises the following steps: S1: Raw material selection S1.1: Select an alumina ceramic sheet (4) with low dielectric loss and a dielectric constant of 9.8, cut it by a slicer, cut it into alumina ceramic sheets (4) with a diameter of 6.4 mm and a thickness of 2.2 mm, and grind and polish the outer peripheral side of the alumina ceramic sheet (4) by a polishing machine for 1 minute; S1.2: Select a yttrium iron garnet ferrite disc (6) with a diameter of 3.2 mm and a thickness of 1.05 mm, select a dielectric substrate (1) with a radius of 4 mm and a thickness of 3 mm, and a copper plate (3) with a radius of 2 mm and a thickness of 1.5 mm for standby use; S1.3: Soak the dielectric substrate (1), the copper plate (3), the alumina ceramic sheet (4) and the yttrium iron garnet ferrite disc (6) in alcohol for 3 minutes, then clean them by ultrasonic cleaning for 5 minutes, and dry them in a dryer for later use; S2: Preparation of ferrite S2.1: Use a hole digging machine to dig a circular groove (7) with a radius of 1.6 mm and a thickness of 1.05 mm at the center of the top of the alumina ceramic sheet (4); S2.2: Select ST epoxy glue (5), apply ST epoxy glue (5) evenly on the inner wall of the circular groove (7) with a brush, and let it stand for 2 seconds; S2.3: The suction cup is then sucked onto the top of the yttrium iron garnet ferrite disc (6), and the yttrium iron garnet ferrite disc (6) is embedded into the center of the alumina ceramic sheet (4), so that the yttrium iron garnet ferrite disc (6) fits the inner wall of the circular groove (7), and the suction cup is powered off to obtain the ferrite; S3: Preparation of circulator S3.1: placing the dielectric substrate (1) on a workbench and fixing it with a clamp; S3.2: embedding the small Y junction into the thin film circuit board (2), and soldering the thin film circuit board (2) to the dielectric substrate (1); S3.3: Using a brush to adhere ST epoxy glue (5), evenly apply ST epoxy glue (5) to the bottom surface of the copper plate (3), and attach the bottom of the copper plate (3) coated with ST epoxy glue (5) to the top of the dielectric substrate (1). The copper plate (3) is located above the thin film circuit board (2) and is connected to the thin film circuit board (2) to form a transmission structure similar to a strip line. S3.4: Then, ST epoxy glue (5) is coated on the bottom of the prepared ferrite with the center as the origin and a radius of 2 mm, and then the center of the bottom of the ferrite is bonded to the center of the top of the copper plate (3) so that the ferrite and the copper plate (3) are bonded and connected to obtain a circulator.

2. A miniaturized circulator according to claim 1, characterized in that: The polishing machine in step S1.1 rotates at a speed of 800-1200 r / min. The polishing machine is distributed in a circle on the outer peripheral side of the alumina ceramic sheet (4) and is used to evenly grind and polish the outer peripheral side of the alumina ceramic sheet (4).

3. The miniaturized circulator according to claim 1, characterized in that: The alcohol in step S1.3 has a purity of 75% and a volume of 10 ml. The dielectric substrate (1), the copper plate (3), the alumina ceramic sheet (4) and the yttrium iron garnet ferrite disc (6) in the alcohol are stirred by a cotton swab so as to be in full contact with the alcohol.

4. The miniaturized circulator according to claim 1, characterized in that: The drying machine in step S1.3 is provided with a filter screen that carries a dielectric substrate (1), a copper plate (3), an alumina ceramic sheet (4) and a yttrium iron garnet ferrite disc (6). The temperature in the drying machine is set to a constant temperature of 35° C. and the drying time is 20 minutes.

5. The miniaturized circulator according to claim 1, characterized in that: In step S2.1, after the hole digger digs a circular groove (7) with a radius of 1.6 mm and a thickness of 1.05 mm at the center of the top of the alumina ceramic sheet (4), the inner wall of the circular groove (7) is polished by a polishing rod at a speed of 1400 r / min for 1 minute.

6. The miniaturized circulator according to claim 1, characterized in that: In the step S2.2, the ST epoxy glue (5) is stirred evenly by a stirrer, a brush is placed in a glass bottle carrying the ST epoxy glue (5) so that the brush is immersed in the ST epoxy glue (5), one end of the brush is slid on the inner wall of the circular groove (7), and the brush is left to stand for 2S to facilitate the leveling of the ST epoxy glue (5).

7. The miniaturized circulator according to claim 1, characterized in that: In the step S2.3, after the suction cup is powered off, a press machine is used to apply pressure to the yttrium iron garnet ferrite disc (6) at a pressure of 10N, so that the yttrium iron garnet ferrite disc (6) is easily in close contact with the alumina ceramic sheet (4).

8. The miniaturized circulator according to claim 1, characterized in that: In the step S3.1, the clamping member contacts the bottom of the dielectric substrate (1) to clamp the outer peripheral side of the dielectric substrate (1), and the height is lower than the top of the dielectric substrate (1).

9. The miniaturized circulator according to claim 1, characterized in that: The outer peripheral side of the thin film circuit board (2) is provided with three groups of connectors, the three groups of connectors are distributed in a circle, and the angle between adjacent connectors is 120°.

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