Patent Application
20250066255
Embodiments of the present application relate to the technical field of materials, for example, a ferrite material, and especially relate to a microwave ferrite material, a preparation method therefor and an application thereof.
In view of the trend that 5G communication is going to be an important part of the future information infrastructure, the miniaturization and lightweight is particularly vital for circulators and isolators which serve as indispensable devices. The size of various distributed parameter junction circulators, no matter what type, should be significantly reduced with the increase in frequency. It has become a research hotspot of miniaturization about how to effectively reduce the device size to increase the use frequency. However, the related miniaturized lumped parameter circulators have narrow bandwidth and do not meet the broadband requirements of 5G communication.
CN112759380A discloses a microwave ferrite material and a preparation method therefor and an application thereof. The preparation method comprises the following steps: (1) subjecting a transition metal oxide to primary ball milling, primary drying, primary screen and pre-sintering to obtain an intermediate ferrite; and (2) subjecting the intermediate ferrite obtained in step (1) to secondary ball milling, secondary drying, secondary screening, granulating, molding and sintering to obtain the microwave ferrite material; in the method, the transition metal oxide in step (1) comprises yttrium oxide, calcium oxide, iron oxide, vanadium oxide, aluminum oxide and zirconium oxide. Although in a 3.4-3.8 GHz miniaturized circulator the bandwidth of the microwave ferrite material reaches 400 MHz, its 4πMs and Tc need to be further improved, and meanwhile, there is room for ΔH to be further reduced.
CN112358290A discloses a ferrite material and a preparation method therefor and an application thereof. The ferrite material has a chemical formula of Bi1.3Cax+2yY1.7−x−2yFe5−x−yZrxWyO12, and y is 0.01-1. The preparation method comprises the following steps: (1) mixing and sintering raw materials of the ferrite material to obtain a precursor of the ferrite material; and (2) mixing the precursor of the ferrite material in step (1) again, and performing drying, molding and sintering to obtain the ferrite material. In the ferrite material, the Bi and Ca elements can partially replace the Y element, and the Zr and W elements can partially replace Fe ions; their electromagnetic characteristics and compensation points are used to obtain proper 4πMs, ΔH, Tc and other parameters. However, its ΔH is close to 50 Oe, and the loss is relatively large.
With the rapid increase in communication frequency, the high integration of electronic products has high requirements on the device volume; the market has put forward higher performance requirements for microwave ferrite materials, while the materials prepared by the traditional formulation and process have failed to satisfy the market requirements, and thus there is an urgent need to upgrade the material. Therefore, a microwave ferrite material having low loss and high Curie temperature is required, which enables the circulator to realize miniaturization, low loss, and broadband.
The following is a summary of the subject detailed herein. This summary is not intended to limit the scope of the claims.
An embodiment of the present application provides a microwave ferrite material and a preparation method therefor and an application thereof. The microwave ferrite material has the characteristics of low loss, high Curie temperature and low magnetic moment, by which the isolator and circulator can meet the requirements of miniaturization, low loss and broadband.
In a first aspect, an embodiment of the present application provides a preparation method for a microwave ferrite material, and the preparation method comprises:
An iron-deficiency formulation is selected to mix the raw materials for the preparation method of the present application, and thus the prepared microwave ferrite material has the characteristics of low loss, high Curie temperature and low magnetic moment, by which the isolator and circulator can meet the requirements of miniaturization, low loss and broadband.
Moreover, by adjusting the composition of the microwave Ferrite material in the present application, namely, using Ca to partially replace Y, Zr and V and using Al to partially replace Fe, based on the properties of Ca, Y, Zr, V, Al and Fe, the obtained microwave ferrite material is given proper saturation magnetic induction, ferromagnetic resonance line width and Curie temperature; additionally, the specific amounts of V and Al synergistically added ensure that the loss of the obtained microwave ferrite material is not more than 0.5 dB in the temperature range of −55° C. to 125° C. and the frequency range of 700 MHz to 5 GHz.
Specifically, in Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12, a is 0.3-0.6, such as 0.3, 0.35, 0.4, 0.45, 0.5, 0.55 or 0.6; however, a is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and a is preferably 0.4-0.45.
In Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12, b is 0.1-0.4, such as 0.1, 0.15, 0.18, 0.2, 0.21, 0.24, 0.25, 0.3, 0.35 or 0.4; however, b is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and b is preferably 0.18-0.21.
In Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12, C is 0.001-0.1, such as 0.001, 0.005, 0.01, 0.015, 0.02, 0.05, 0.08 or 0.1; however, c is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and c is preferably 0.01-0.02.
In Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12, d is 0.1-0.3, such as 0.1, 0.15, 0.2, 0.21, 0.24, 0.25 or 0.3; however, d is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and d is preferably 0.2-0.25.
Preferably, when the value of a is about twice that of d, the obtained microwave ferrite material will have the optimum performance.
Preferably, the raw materials of the microwave ferrite material comprise an oxygen-containing compound of Y, an oxygen-containing compound of Ca, an oxygen-containing compound of V, an oxygen-containing compound of Zr, In, an oxygen-containing compound of Al and an oxygen-containing compound of Fe.
Preferably, the raw materials of the microwave ferrite material comprise Y2O3, CaCO3, ZrO2, Fe2O3, V2O5, Al2O3 and In.
Preferably, the primary ball milling in step (1) comprises wet ball milling.
Preferably, a mass ratio of the raw materials, a solvent and mill balls for the primary ball milling in step (1) is 1:(0.8-1.2):(4-6), such as 1:0.8:6, 1:0.9:5.5, 1:1:5, 1:1.1:4.5 or 1:1.2:4; however, the mass ratio is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
The solvent used for the primary ball milling of the present application is the conventional solvent in the art, including but not limited to water and/or anhydrous ethanol.
Preferably, the mill balls used for the primary ball milling in step (1) comprise zirconia balls.
Preferably, the primary ball milling in step (1) has a rotation speed of 40-80 r/min, such as 40 r/min, 45 r/min, 50 r/min, 55 r/min, 60 r/min, 65 r/min, 70 r/min, 75 r/min or 80 r/min; however, the rotation speed is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the rotation speed is preferably 50-70 r/min.
Preferably, the primary ball milling in step (1) has a time of 25-35 h, such as 25 h, 26 h, 27 h, 28 h, 29 h, 30 h, 31 h or 32 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 28-32 h.
By the primary ball milling of the present application, the obtained primary ball-milled material has a median particle size X500f 0.9-1 μm, such as 0.9 μm, 0.92 μm, 0.95 μm, 0.98 μm or 1 μm; however, the median particle size is not limited to the listed values, and other unlisted values within the numerical range are also applicable. Such median particle size facilitates the subsequent drying and screening steps and also guarantees the preparation method proceeding steadily.
Preferably, the drying in step (2) has a temperature of 120-160° C., such as 120° C., 130° C., 140° C., 150° C. or 160° C.; however, the temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the temperature is preferably 130-150° C.
Preferably, the drying in step (2) has a time of 12-20 h, such as 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h or 20 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 14-16 h.
Preferably, the screening is performed with a sieve of 40-100 mesh; the sieve used for the screening in step (2) has a size of 40-100 mesh, such as 40 mesh, 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh or 100 mesh; however, the size is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
By the screening in step (2) in the present application, the material with large particle size can be screened off, reducing the energy consumption for the pre-sintering, and improving the pre-sintering efficiency.
Preferably, the pre-sintering in step (3) has a heating rate of 1-2° C./min, such as 1° C./min, 1.2° C./min, 1.5° C./min, 1.6° C./min, 1.8° C./min or 2° C./min; however, the heating rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and preferably the heating rate is 1.2-1.6° C./min
Preferably, the pre-sintering in step (3) has a temperature of 1100-1200° C., such as 1100° C., 1110° C., 1120° C., 1130° C., 1140° C., 1150° C., 1160° C., 1170° C., 1180° C., 1190° C. or 1200° C.; however, the temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the temperature is preferably 1120-1180° C.
Preferably, the pre-sintering in step (3) has a time of 6-10 h, such as 6 h, 7 h, 8 h, 9 h or 10 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 7-9 h.
Preferably, furnace cooling is performed after the pre-sintering in step (3) to obtain the pre-sintered material.
Preferably, oxygen introduction is performed when the temperature of the pre-sintering in step (3) reaches more than or equal to 500° C., and the oxygen introduction has an oxygen flow rate of 20-40 L/min, and preferably 25-35 L/min.
The oxygen-introducing temperature of the pre-sintering in step (3) is more than or equal to 500° C., such as 500° C., 510° C., 520° C., 530° C., 540° C. or 550° C.; however, the oxygen-introducing temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
The flow rate of the oxygen introduction is 20-40 L/min, such as 20 L/min, 25 L/min, 30 L/min, 35 L/min or 40 L/min; however, the flow rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
Preferably, the secondary ball milling in step (4) is wet ball milling.
Preferably, a mass ratio of the pre-sintered material, a solvent and mill balls for the secondary ball milling in step (4) is 1:(0.8-1.2):(4-6).
The solvent used for the secondary ball milling of the present application is the conventional solvent in the art, including but not limited to water and/or anhydrous ethanol.
Preferably, the mill balls used for the secondary ball milling in step (4) comprise zirconia balls.
Preferably, the secondary ball milling in step (4) has a rotation speed of 60-80 r/min, such as 60 r/min, 65 r/min, 70 r/min, 75 r/min or 80 r/min; however, the rotation speed is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the rotation speed is preferably 65-75 r/min.
Preferably, the secondary ball milling in step (4) has a time of 28-32 h, such as 28 h, 29 h, 30 h, 31 h or 32 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 29-31 h.
With the above conditions of the secondary ball milling of the present application, the obtained secondary ball-milled material has a median particle size X50 of 0.5-1 μm, such as 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm; however, the median particle size is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
Preferably, the preparation method further comprises drying and sieving sequentially between the secondary ball milling and the granulating in step (4).
Preferably, the drying has a temperature of 100-150° C., such as 100° C., 110° C., 120° C., 130° C., 140° C. or 150° C.; however, the temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the temperature is preferably 110-130° C.
Preferably, the drying has a time of 12-20 h, such as 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h or 20 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 15-18 h.
Preferably, the screening is performed with a sieve of 40-80 mesh; the sieve used for the screening has a size of 40-80 mesh, such as 40 mesh, 50 mesh, 60 mesh, 70 mesh or 80 mesh; however, the size is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
In the present application, the drying and sieving sequentially performed between the secondary ball milling and the granulating guarantees the molding density of the molded material, satisfying the actual application requirements.
Preferably, the molding has a molding density of 3.4-3.6 g/cm3, such as 3.4 g/cm3, 3.45 g/cm3, 3.5 g/cm3, 3.55 g/cm3 or 3.6 g/cm3; however, the molding density is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
Preferably, the sintering in step (5) comprises a heating stage, a heat preserving stage and a cooling stage which are performed sequentially, wherein the heating stage comprises at least three heating steps, and the cooling stage comprises at least two cooling steps.
Preferably, the heating stage comprises a first heating, a second heating and a third heating which are performed sequentially.
Preferably, the first heating has a heating rate of 1-2° C./min, such as 1° C./min, 1.2° C./min, 1.5° C./min, 1.6° C./min, 1.8° C./min or 2° C./min; however, the heating rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the heating rate is preferably 1.2-1.8° C./min.
Preferably, the first heating has an endpoint temperature of 480-540° C., such as 480° C., 490° C., 500° C., 510° C., 520° C., 530° C. or 540° C.; however, the endpoint temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the endpoint temperature is preferably 500-520° C.
Preferably, the second heating has a heating rate of 1.5-2.5° C./min, such as 1.5° C./min, 1.8° C./min, 2° C./min, 2.1° C./min, 2.4° C./min or 2.5° C./min; however, the heating rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the heating rate is preferably 1.8-2.2° C./min.
Preferably, the second heating has an endpoint temperature of 880-920° C., such as 880° C., 885° C., 890° C., 895° C., 900° C., 905° C., 910° C., 915° C. or 920° C.; however, the endpoint temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the endpoint temperature is preferably 890-910° C.
Preferably, the third heating has a heating rate of 2-3° C./min, such as 2° C./min, 2.1° C./min, 2.4° C./min, 2.5° C./min, 2.7° C./min, 2.8° C./min or 3° C./min; however, the heating rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the heating rate is preferably 2.4-2.8° C./min.
Preferably, the third heating has an endpoint temperature of 1300-1400° C., such as 1300° C., 1310° C., 1320° C., 1330° C., 1340° C., 1350° C., 1360° C., 1370° C., 1380° C., 1390° C. or 1400° C.; however, the endpoint temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the endpoint temperature is preferably 1320-1360° C.
As a preferred technical solution, the heating rate of the first heating is less than that of the second heating, and the heating rate of the second heating is less than that of the third heating.
Preferably, the heat preserving stage has a time of 15-30 h, such as 15 h, 16 h, 17 h, 18 h, 20 h, 21 h, 24 h, 25 h, 27 h, 28 h or 30 h; however, the time is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the time is preferably 18-25 h.
Preferably, the cooling stage comprises a first cooling and a second cooling which are performed sequentially.
Preferably, the first cooling has a cooling rate of 2-3° C./min, such as 2° C./min, 2.1° C./min, 2.4° C./min, 2.5° C./min, 2.7° C./min, 2.8° C./min or 3° C./min; however, the cooling rate is not limited to the listed values, and other unlisted values within the numerical range are also applicable, and the cooling rate is preferably 2.4-2.8° C./min.
Preferably, the first cooling has an endpoint temperature of 560-620° C., such as 560° C., 570° C., 580° C., 590° C., 600° C., 610° C. or 620° C., and the endpoint temperature is preferably 580-610° C.
Preferably, the second cooling is furnace cooling.
Preferably, during the sintering in step (5), oxygen introduction begins when the temperature increases to more than or equal to 880° C., and ends when the temperature decreases to less than or equal to 700° C., and the oxygen introduction has an oxygen flow rate of 20-40 L/min, and preferably 25-35 L/min.
The initial oxygen-introducing temperature of the sintering in step (5) is more than or equal to 880° C., such as 880° C., 890° C., 900° C., 910° C. or 920° C.; however, the initial oxygen-introducing temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
The final oxygen-introducing temperature of the sintering in step (5) is less than or equal to 700° C., such as 660° C., 670° C., 680° C., 690° C. or 700° C.; however, the final oxygen-introducing temperature is not limited to the listed values, and other unlisted values within the numerical range are also applicable.
As a preferred technical solution of the preparation method according to the first aspect of the present application, the preparation method comprises the following steps:
In a second aspect, an embodiment of the present application provides a microwave ferrite material obtained by the preparation method according to the first aspect.
In a third aspect, an embodiment of the present application provides an application of the microwave ferrite material according to the second aspect in a 5G circulator.
Compared with the related art, the embodiments of the present application have the following beneficial effect:
Other aspects will become apparent upon reading and understanding the drawings and detailed description.
The accompanying drawings provide a further understanding of the technical solutions herein, constitute a part of the specification, and explain the technical solutions herein in conjunction with examples of the present application, but should not be construed as limiting the technical solutions herein.
The technical solutions of the present application are further explained below through the specific examples. It should be apparent to those skilled in that art that the examples are merely used for a better understanding of the present application and should not be construed as a specific limitation to the present application.
This example provides a preparation method for a microwave ferrite material, and the preparation method comprises the following steps:
The SEM image of the microwave ferrite material obtained in this example is shown in
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.4, b was 0.21, c was 0.02, and d was 0.2.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.5, b was 0.18, c was 0.01, and d was 0.25.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.5, b was 0.2, c was 0.015, and d was 0.2.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.4, b was 0.2, c was 0.015, and d was 0.25.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.6, b was 0.1, c was 0.001, and d was 0.3.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.3, b was 0.4, c was 0.1, and d was 0.1.
This example provides a preparation method for a microwave ferrite material, and the preparation method comprises the following steps:
This example provides a preparation method for a microwave ferrite material, and the preparation method comprises the following steps:
This example provides a preparation method for a microwave ferrite material, and the preparation method comprises the following steps:
This example provides a preparation method for a microwave ferrite material, and the preparation method comprises the following steps:
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the pre-sintering in step (3) had a temperature of 1000° C.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the pre-sintering in step (3) had a temperature of 1300° C.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the pre-sintering in step (3) did not have oxygen introduction.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that during the sintering in step (5), the third heating had an endpoint temperature of 1450° C.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that during the sintering in step (5), the third heating had an endpoint temperature of 1250° C.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the sintering in step (5) did not have oxygen introduction.
The SEM image of the microwave ferrite material obtained in this example is shown in
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the first heating, the second heating and the third heating all had a heating rate of 2° C./min.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the first heating had a heating rate of 2.5° C./min, the second heating had a heating rate of 2° C./min, and the third heating had a heating rate of 1.5° C./min.
This example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that the secondary ball milling had a time of 16 h to give a median particle size X50 of 1.2 km.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.25, b was 0.2, c was 0.015, and d was 0.21.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.65, b was 0.2, c was 0.015, and d was 0.21.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.42, b was 0.06, c was 0.015, and d was 0.21.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that in the chemical formula Y3−2a−bCa2a+bVaZrbIncAldFe4.97−a−b−c−dO12 in step (1), a was 0.42, b was 0.42, c was 0.015, and d was 0.21.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that CaCO3 in the raw materials in step (1) was replaced with an equimolar amount of ZnO.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that CaCO3 in the raw materials in step (1) was replaced with an equimolar amount of CuO.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that ZrO2 in the raw materials in step (1) was replaced with an equimolar amount of SnO2.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that ZrO2 in the raw materials in step (1) was replaced with an equimolar amount of TiO2.
This comparative example provides a preparation method for a microwave ferrite material, which is the same as in Example 1 except that In in the raw materials in step (1) was replaced with an equimolar amount of Fe.
The microwave ferrite materials provided in Examples 1-20 and Comparative Examples 1-9 are tested for density (ρ), saturation magnetic induction strength (4πMs), Curie temperature (Tc), dielectric constant (ε), and ferromagnetic resonance line width (ΔH); the density is tested by the water displacement method; the saturation magnetic induction strength and the Curie temperature are measured by a vibrating sample magnetometer, and the sample to be measured is processed into a spherical ball with a diameter of 2.5 mm for the measurement; the dielectric constant is tested with reference to Standard 4EC60556, the test frequency is 10.7 GHz and the sample is a φ 1.6 mm×22 mm cylinder; the ferromagnetic resonance line width is tested with reference to Standard GB/T 9633-88, and the sample to be tested is prepared into a spherical ball (Φ 1 mm); the test results are shown in Table 1.
In conclusion, by specifically configuring the elements of the microwave ferrite material in the present application, when the obtained microwave ferrite material is applied to the 5G circulator, the variation of 4πMs is not more than 100 Gs in the temperature range of −55° C. to 125° C., and the ΔH (Oe) of the material is less than 20 Oe, and by the matched design of the center conductor in conjunction with the material with basic characteristics guaranteed, the loss of the 5G circulator is lower than 0.5 dB in the frequency band of 700 MHz to 5 GHz.
The applicant has stated that although the specific examples of the present application are described above, the protection scope of the present application is not limited thereto. It should be apparent to those skilled in the art that any changes or substitutions that are obvious to those skilled in the art within the technical scope disclosed in the present application shall fall within the protection scope and disclosure scope of the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202111023866.0 | Sep 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/110188 | 8/4/2022 | WO |
