A quick-release waveguide structure for ferrite ferromagnetic resonance linewidth testing

Abstract

The application relates to a quick-disassembly waveguide structure for testing the line width of ferrite ferromagnetic resonance, belonging to the field of microwave and millimeter wave band magnetic material parameter testing. The quick-disassembly waveguide structure comprises a main waveguide tube and a quick-disassembly resonant cavity, and the main waveguide tube comprises a first rectangular waveguide, a second rectangular waveguide, a connecting bridge, a waveguide flange and a positioning pin. The quick-disassembly waveguide structure for testing the line width of ferrite ferromagnetic resonance is characterized in that the rectangular waveguide, the waveguide flange, the connecting bridge and the coupling sheet of the resonant cavity are integrally connected to form the main waveguide tube, the quick-disassembly resonant cavity is placed in the gap formed by the connecting bridge, and the quick-disassembly resonant cavity is achieved; the sample loading method of 'filling medium in the cavity and loading the sample through the medium sheet' is adopted, and the loading problem of the 30GHz and above millimeter wave band ferrite FMR test sample is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of microwave and millimeter wave magnetic material parameter testing, and particularly relates to a quick-release waveguide structure for testing ferromagnetic resonance line width of ferrite. BACKGROUND

[0002] Microwave ferrite is widely used in electronic information systems in radar, communication, navigation, telemetry and other fields due to its unique gyromagnetic property. Ferromagnetic resonance line width (FMR) as an important parameter for characterizing the magnetic loss of gyromagnetic material has a decisive influence on the performance of microwave ferrite devices working at or close to a certain microwave frequency. With the continuous development of electronic information systems towards integration and high frequency, higher requirements are put forward for the high frequency characteristics of microwave ferrite, and therefore the ferromagnetic resonance line width of gyromagnetic crystal material in the whole wave band needs to be measurable and controllable. The current national standard GB / T 9633-2012 Performance Test Method for Gyromagnetic Materials for Microwave Frequency Applications involves the ferromagnetic resonance line width test frequency of ferrite at about 9.3 GHz. The data tested by this method and the magnetic loss of the material in a high frequency device have a large deviation, which brings difficulty to the design of the device. Therefore, the material testing technical problem that must be solved in the current field is how to push the ferromagnetic loss test frequency band of green ceramic material tape or LTCF electromagnetic material from the microwave band to the millimeter wave band. At present, there is no complete ferromagnetic loss test theory system for microwave ferrite electromagnetic material in the millimeter wave band in the world. With the development of new materials and devices in the millimeter wave band, there is an urgent need for the realization of ferromagnetic resonance line width test in the millimeter wave band (above 30 GHz) at home and abroad.

[0003] For FMR test in the millimeter wave band, the main problem at the present stage is that with the increase of the microwave frequency band, the physical size of the resonant cavity waveguide also decreases. The traditional sample loading method is to open a hole in the side wall of the resonant cavity and then load a dielectric rod to the center position of the resonant cavity. With the decrease of the physical size of the resonant cavity waveguide (the physical size of the resonant cavity side wall suitable for the millimeter wave band is about 3 mm), the influence of the physical opening (the diameter of the hole is about 1 mm) on the test results cannot be ignored, so the method of opening a hole in the side wall of the resonant cavity is no longer suitable for high-precision test systems. Therefore, the resonant cavity perturbation method is used to test the ferromagnetic resonance line width of ferrite in the millimeter wave band, and the problems of "difficulty in opening a hole in the cavity and difficulty in loading a sample" are currently faced, and improvement is still needed in the sample loading method. SUMMARY

[0004] The purpose of the present application is to solve the problems in the background art, and provide a quick-release waveguide structure for ferrite ferromagnetic resonance line width testing.

[0005] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0006] The quick-release waveguide structure for ferrite ferromagnetic resonance line width testing comprises a main waveguide tube and a quick-release resonant cavity 6, wherein the main waveguide tube comprises a first rectangular waveguide 1, a second rectangular waveguide 7, two connecting bridges 2, a waveguide flange 4 and a positioning pin 5.

[0007] One end of the first rectangular waveguide is a coupling sheet with a coupling hole 3, and the other end is a waveguide flange 4; one end of the second rectangular waveguide is a coupling sheet with a coupling hole 3, and the other end is a waveguide flange; the two connecting bridges are used to fixedly connect the first rectangular waveguide and the second rectangular waveguide, wherein the coupling sheet of the first rectangular waveguide faces the coupling sheet of the second rectangular waveguide; the positioning pin is arranged at the end of the waveguide flange away from the rectangular waveguide, and is used to realize the connection between the quick-release waveguide structure and a waveguide-coaxial converter.

[0008] The quick-release resonant cavity is a standard rectangular waveguide structure without waveguide flanges at both ends; during testing, the quick-release resonant cavity is placed in the gap formed by the two connecting bridges.

[0009] Two stacked dielectric sheets are used to load the test sample, and a hemispherical groove is formed in the center of each dielectric sheet; during testing, the ferrite ball sample is placed in the spherical groove formed by the two dielectric sheets, so that the ferrite ball sample is located at the center of the quick-release resonant cavity; then, the two dielectric sheets loaded with the ferrite ball sample are placed in the quick-release resonant cavity, and the two dielectric sheets fill the quick-release resonant cavity; finally, the quick-release resonant cavity with the ferrite ball sample is pushed into the gap formed by the two connecting bridges, and the ferromagnetic resonance line width of the ferrite ball sample can be tested.

[0010] Further, the inner walls of the first rectangular waveguide, the second rectangular waveguide and the quick-release resonant cavity are plated with gold with a thickness of 0.01-0.05 mm, which prolongs the service life of the waveguide structure, increases the Q value of the resonant cavity and improves the testing accuracy.

[0011] Further, the radius of the ferrite ball sample is equal to the radius of the spherical groove formed by the two dielectric sheets.

[0012] Further, the resonant frequency of the quick-release resonant cavity can be adjusted by changing the relative dielectric constant of the two dielectric sheets, thereby widening the test frequency point of the quick-release resonant cavity for testing the ferrite ferromagnetic resonance line width.

[0013] Compared with the prior art, the application has the following beneficial effects:

[0014] 1. The quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application integrates a rectangular waveguide, a waveguide flange, a connecting bridge and a coupling sheet of a resonant cavity to form a main waveguide tube, and a quick disassembly resonant cavity is placed in the gap formed by the connecting bridge, so that the resonant cavity can be quickly disassembled and assembled.

[0015] 2. The quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application can adjust the resonant frequency of the quick disassembly resonant cavity by changing the relative dielectric constants of the two dielectric sheets, thereby widening the test frequency points of the quick disassembly resonant cavity for testing the ferrite ferromagnetic resonance line width, and facilitating the research on the damping coefficient ω of the ferrite material. α A new idea is opened up.

[0016] 3. The quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application is provided with a positioning pin at the end of the waveguide flange away from the rectangular waveguide, which is used to realize the accurate connection of the quick disassembly waveguide structure and the waveguide-coaxial converter; and the inner walls of the first rectangular waveguide, the second rectangular waveguide and the quick disassembly resonant cavity are plated with gold with a thickness of 0.01-0.05 mm, which prolongs the service life of the waveguide structure, increases the Q value of the resonant cavity and improves the test accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a structural schematic diagram of the disassembly state of the quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application;

[0018] Figure 2 FIG. 2 is a structural schematic diagram of the assembly state of the quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application;

[0019] Figure 3 FIG. 3 is a structural schematic diagram of the main waveguide tube in the quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application;

[0020] Figure 4 FIG. 4 is a structural schematic diagram of the quick disassembly resonant cavity in the quick disassembly waveguide structure for ferrite ferromagnetic resonance line width test provided by the application;

[0021] Figure 5 FIG. 5 is a test system diagram of the ferrite ferromagnetic resonance line width test achieved by the quick disassembly waveguide structure in the embodiment;

[0022] Figure 6The following is an example of the sample loading steps when using a quick-release waveguide structure to perform ferrite ferromagnetic resonance linewidth testing.

[0023] Wherein, 1 is the first rectangular waveguide, 2 is the connecting bridge, 3 is the coupling hole, 4 is the waveguide flange, 5 is the positioning pin, 6 is the quick-release resonant cavity, and 7 is the second rectangular waveguide. Detailed Implementation

[0024] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example

[0026] The quick-release waveguide structure in this embodiment is designed for ferrite FMR testing in the 39.2GHz–59.6GHz band. For example... Figure 1 As shown, it includes a main waveguide and a quick-release resonant cavity 6. The main waveguide includes a first rectangular waveguide 1, a second rectangular waveguide 7, a connecting bridge 2, a waveguide flange 4, and a positioning pin 5.

[0027] One end of the first rectangular waveguide has a coupling plate with a coupling hole 3, and the other end has a waveguide flange 4; one end of the second rectangular waveguide has a coupling plate with a coupling hole 3, and the other end has a waveguide flange. The coupling hole is used to couple the quick-release resonant cavity to the main waveguide. Two connecting bridges are used to achieve a fixed connection (welding) between the first and second rectangular waveguides, wherein the coupling plate of the first rectangular waveguide faces the coupling plate of the second rectangular waveguide; a positioning pin is provided at the end of the waveguide flange away from the rectangular waveguide to achieve the connection between the quick-release waveguide structure and the waveguide-coaxial converter.

[0028] The quick-release resonant cavity is a standard rectangular waveguide structure without waveguide flanges at both ends, such as... Figure 4 As shown, during testing, the quick-release resonant cavity is placed within the gap formed by the two connecting bridges;

[0029] The test sample is loaded using two stacked dielectric sheets, each with a hemispherical groove at its center. During testing, the ferrite ball sample is placed within the spherical groove formed by the two dielectric sheets, ensuring the ferrite ball sample is centered in the quick-release resonant cavity. Then, the two dielectric sheets containing the ferrite ball sample are placed into the quick-release resonant cavity, filling it completely. Finally, the quick-release resonant cavity with the ferrite ball sample is pushed into the gap formed by the two connecting bridges, allowing the ferromagnetic resonance linewidth of the ferrite ball sample to be measured.

[0030] The inner wall size of the first rectangular waveguide and the second rectangular waveguide is 4.775*2.388 mm, and the wall thickness is 1 mm; the length of the quick-release resonant cavity is 15 mm, and the diameter of the coupling hole is 0.75 mm; the two pieces of dielectric sheets can be made of polytetrafluoroethylene, and the relative dielectric constant is 2.55, and the dielectric loss angle is 0.001; the two pieces of dielectric sheets can also be made of polycarbonate, and the relative dielectric constant is 3.0, and the dielectric loss angle is 0.001; the size of each dielectric sheet is 15*4.775*1.194 mm, and the diameter of the spherical groove formed by the two pieces of dielectric sheets is 0.8 mm.

[0031] The inner walls of the first rectangular waveguide, the second rectangular waveguide and the quick-release resonant cavity are plated with gold with a thickness of 0.01 mm, which prolongs the service life of the extended waveguide structure while increasing the resonant cavity Q value and improving the test precision.

[0032] HFSS simulation is performed on the quick-release waveguide structure of the embodiment, and it is found that the quick-release waveguide structure of the embodiment has four effective resonance peaks in the 39.2 GHz-59.6 GHz band; when the dielectric sheet is made of polytetrafluoroethylene, the four resonance peaks are 41.50 GHz, 47.66 GHz, 54.00 GHz and 60.42 GHz, and the corresponding resonant cavity working modes are TE 105 , TE 106 , TE 107 and TE 108 mode; when the dielectric sheet is made of polycarbonate, the four resonance peaks are 39.66 GHz, 44.57 GHz, 50.14 GHz and 54.73 GHz, and the corresponding resonant cavity working modes are TE 106 , TE 107 , TE 108 and TE 109 mode. The return loss at each resonance peak is lower than -10 dB, which meets the requirements of the ferromagnetic resonance linewidth test system; wherein the resonant cavity working mode TE 10p , when p is even, the resonance peaks can be used for ferrite FMR test, i.e., the testable frequency points are 47.66 GHz and 60.42 GHz when polytetrafluoroethylene is used, and the testable frequency points are 39.66 GHz and 50.14 GHz when polycarbonate is used. FMR test is performed on the same ferrite sample at the four testable frequency points, and the damping coefficient ω α of the sample can be extracted by using the following fitting formula:

[0033]

[0034] In the formula, ΔH is the ferromagnetic resonance linewidth of the ferrite sample; ω α is the damping coefficient of the sample; f ris the test frequency of the sample ferromagnetic resonance linewidth; γ is the gyromagnetic ratio of the sample; ΔH0 is the non-uniform broadening item of the ferromagnetic resonance linewidth.

[0035] Based on the embodiment of the quick-release waveguide structure, the system shown in Figure 5 When the system shown in the embodiment tests the ferromagnetic resonance linewidth of a ferrite, the specific process is as follows:

[0036] Step 1: Connect the main waveguide tube with the waveguide coaxial converter through the four positioning pins on the waveguide flange, and connect the waveguide coaxial converter with the goniometer network through the 1.85mm coaxial line, so as to realize the connection between the quick-release waveguide and the test system. The structure of the system after the connection is completed is shown in Figure 5 .

[0037] Step 2: Load the sample.

[0038] Place the ferrite small ball with a diameter of 0.8mm in the hemispherical groove of the medium sheet 1, as shown in Figure 6 (a); then stack the medium sheet 2 on the medium sheet 1, as shown in Figure 6 (b); place the two medium sheets loaded with the ferrite small ball into the quick-release resonant cavity, and the two medium sheets fill the quick-release resonant cavity, as shown in Figure 6 (c); and place the quick-release resonant cavity with the ferrite small ball into the gap formed by the two connecting bridges, so as to realize the connection with the main waveguide tube, as shown in Figure 6 (d).

[0039] Step 3: Set the test frequency of the goniometer network as any value of the four resonance peaks.

[0040] Step 4: Control the current source through the computer program, increase the current applied by the electromagnet, and then increase the magnetic field at the quick-release resonant cavity; record the magnetic field and the S 21 value corresponding to the magnetic field at the goniometer network, so as to obtain the S 21 two-dimensional curve of the measured sample at the frequency point.

[0041] Step 5: According to the S 21 two-dimensional curve of the measured sample, the ferromagnetic resonance linewidth ΔH of the measured sample can be obtained.

[0042] Step 6: Change the test frequency set in step 3, and repeat steps 4-5, so as to obtain the ferromagnetic resonance linewidth ΔH at different test frequencies.

Claims

1. A quick-release waveguide structure for ferrite ferromagnetic resonance linewidth testing, characterized in that, It includes a main waveguide and a quick-release resonant cavity (6). The main waveguide includes a first rectangular waveguide (1), a second rectangular waveguide (7), a connecting bridge (2), a waveguide flange (4), and a positioning pin (5). One end of the first rectangular waveguide is a coupling plate with a coupling hole (3), and the other end is a waveguide flange; One end of the second rectangular waveguide is a coupling plate with a coupling hole, and the other end is a waveguide flange. Two connecting bridges are used to achieve a fixed connection between the first and second rectangular waveguides, wherein the coupling plate of the first rectangular waveguide faces the coupling plate of the second rectangular waveguide. A positioning pin is provided at the end of the waveguide flange away from the rectangular waveguide to realize the connection between the quick-release waveguide structure and the waveguide-coaxial converter. The quick-release resonant cavity is a standard rectangular waveguide structure without waveguide flanges at both ends. During testing, the quick-release resonant cavity is placed in the gap formed by two connecting bridges. The test sample is loaded using two stacked dielectric sheets, each with a hemispherical groove at its center. During testing, the ferrite ball sample is placed within the spherical groove formed by the two dielectric sheets, ensuring the ferrite ball sample is centered in the quick-release resonant cavity. Then, the two dielectric sheets containing the ferrite ball sample are placed into the quick-release resonant cavity, filling it completely. Finally, the quick-release resonant cavity with the ferrite ball sample is placed into the gap formed by the two connecting bridges, allowing the ferromagnetic resonance linewidth of the ferrite ball sample to be measured. The resonant frequency of the quick-release resonant cavity can be controlled by changing the relative permittivity of the two dielectric plates.

2. The quick-release waveguide structure for ferrite ferromagnetic resonance linewidth testing according to claim 1, characterized in that, The inner walls of the first rectangular waveguide, the second rectangular waveguide, and the quick-release resonant cavity are all plated with gold.

3. The quick-release waveguide structure for ferrite ferromagnetic resonance linewidth testing according to claim 1, characterized in that, The radius of the ferrite sphere sample is equal to the radius of the spherical groove formed by the two dielectric sheets.

Images