Cavity-magnon coupling based isolation rate tunable microwave isolator device

Abstract

The application discloses a cavity-magnon coupling-based microwave isolator device with adjustable isolation, and relates to the microwave isolator field.The device comprises a quadrupole microstrip line resonant cavity, a yttrium iron garnet ball, a power divider, a first complex amplitude adjusting device and a second complex amplitude adjusting device;an external magnetic field is applied at the yttrium iron garnet ball, so that the magnon mode frequency generated by the yttrium iron garnet ball is consistent with the cavity mode frequency, forming a cavity mode-magnon-cavity mode coupling configuration;the power divider divides the input signal into two paths, and the two paths of input signals are adjusted in complex amplitude by the first complex amplitude adjusting device and the second complex amplitude adjusting device;the quadrupole microstrip line resonant cavity outputs the output signal with the required isolation of the scene under the cavity mode-magnon-cavity mode coupling configuration according to the two paths of input signals after the complex amplitude adjustment ratio.The application can realize the adjustment of the isolation by controlling the complex amplitude ratio of the input signal, and meet the requirements of various application scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave isolators, in particular to a cavity-magnon coupling-based microwave isolator device with adjustable isolation. BACKGROUND

[0002] A microwave isolator is a passive device used in radio frequency and microwave circuits that enables one-way transmission of signals within a specific frequency range. It allows signals to be transmitted from the input to the output, but reverses the signal (such as reflected waves) will be absorbed or directed to other ports by the isolator, so as to avoid its return to the signal source or the front-end circuit. This feature is very important in many microwave systems, because the reverse signal may cause the signal source to be unstable or damage the front-end amplifier and other devices. The working principle of microwave isolator is usually based on the non-reciprocal property of ferrite material, when the microwave signal passes through the magnetized ferrite material, the propagation direction of the signal will be controlled, ensuring that the signal can only be transmitted in the predetermined direction. This makes the isolator widely used in radio frequency and microwave circuits, such as protecting the amplifier from the damage of reflected signals at the load end, or protecting the signal source in testing and measurement. However, most of the current microwave isolators have fixed isolation, which cannot meet the needs of application scenarios that require specific isolation or frequent adjustment of isolation. The theoretical isolation of traditional microwave isolators is limited (~77dB), and the actual highest isolation is generally lower than 40dB, which cannot meet the needs of application scenarios that require high isolation. SUMMARY

[0003] The purpose of the present application is to provide a cavity-magnon coupling-based microwave isolator device with adjustable isolation, which can adjust the isolation by controlling the input signal complex amplitude ratio, and meet the needs of various application scenarios.

[0004] To achieve the above purpose, the present application provides the following solutions:

[0005] The application provides a cavity-magnon coupling-based isolation rate adjustable microwave isolator device, comprising: a quadrature position microstrip line resonant cavity, a yttrium iron garnet ball, a power divider, a first complex amplitude adjustment device and a second complex amplitude adjustment device; the yttrium iron garnet ball is located at the quadrature center of the quadrature position microstrip line resonant cavity; the quadrature position microstrip line resonant cavity is used for generating two mutually orthogonal cavity modes; an external magnetic field is applied at the yttrium iron garnet ball, so that the magnon mode frequency generated by the yttrium iron garnet ball is consistent with the cavity mode frequency, forming a cavity mode-magnon-cavity mode coupling position; the output end of the power divider is connected with the input end of the first complex amplitude adjustment device and the input end of the second complex amplitude adjustment device respectively, and the output end of the first complex amplitude adjustment device and the output end of the second complex amplitude adjustment device are connected with two vertical input ports of the quadrature position microstrip line resonant cavity respectively; the power divider is used for dividing an input signal into two paths, the two paths of input signals are adjusted in complex amplitude by the first complex amplitude adjustment device and the second complex amplitude adjustment device respectively, two paths of input signals after adjustment in complex amplitude are obtained, and the two paths of input signals after adjustment in complex amplitude are input into the quadrature position microstrip line resonant cavity; the quadrature position microstrip line resonant cavity is used for outputting an output signal with a required isolation rate in a scene under the cavity mode-magnon-cavity mode coupling position according to the two paths of input signals after adjustment in complex amplitude.

[0006] Optionally, the dynamic equation of the quadrature position microstrip line resonant cavity is as follows:

[0007]

[0008] In the formula, r x is displacement of a microwave mode in a cross resonator in the direction of y expressed by a vibrator, is a first derivative of r x , is a second derivative of r x , r y is displacement of a microwave mode in a cross resonator in the direction of x expressed by a vibrator, is a first derivative of r y , is a second derivative of r y , r m is displacement of a magnon mode expressed by a vibrator, is a first derivative of r m , is a second derivative of r m , ω c is a resonant frequency of a microwave mode, ω is a frequency of an external magnetic field, ω m is a resonant frequency of a magnon mode, β is a dissipation coefficient of a microwave mode, g is a coupling strength between a microwave mode and a magnon mode, f x is a force amplitude of an external magnetic field on a microwave mode vibrator in the direction of x of a cross resonator, f yis the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the y-oriented cross resonator, and i represents two orthogonal microwave modes.

[0009] Optionally, the relationship between the isolation rate and the complex amplitude ratio is:

[0010] iso = 20lg(|S21 / S12|);

[0011]

[0012] In the formula, iso is the isolation rate, S21 is the output signal complex amplitude, S12 is the reverse output signal, f y is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the y-oriented cross resonator, and f x is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the x-oriented cross resonator, ω is the frequency of the external magnetic field, and ω m is the resonance frequency of the magnon mode, and ω c is the resonance frequency of the microwave mode, α is the dissipation coefficient of the magnon mode, β is the dissipation coefficient of the microwave mode, g is the coupling strength between the microwave mode and the magnon mode, and i represents two orthogonal microwave modes.

[0013] Optionally, when the isolation rate approaches positive infinity, the corresponding complex amplitude ratio is:

[0014]

[0015] When the isolation rate approaches negative infinity, the corresponding complex amplitude ratio is:

[0016]

[0017] Optionally, the external magnetic field applied at the yttrium iron garnet ball does not change with time reversal, and for the reverse output signal, it is equivalent to reversing the direction of the external magnetic field, and the spin direction of the yttrium iron garnet ball changes from right-handed to left-handed.

[0018] According to the specific embodiments provided in the application, the application has the following technical effects:

[0019] The application provides an isolation rate adjustable microwave isolator device based on cavity-magnon coupling, which breaks the time reversal symmetry by arranging a yttrium iron garnet ball at the orthogonal center of the orthogonal position microstrip line resonant cavity, and gives the device non-reciprocity, and then adjusts the complex amplitude ratio of two input signals by using a first complex amplitude adjusting device and a second complex amplitude adjusting device, so that the orthogonal position microstrip line resonant cavity can output an output signal with a required isolation rate. Since the regulation range of the input signal complex amplitude ratio is large, it can not only meet the application scene requirements of specific isolation rate or the need to frequently adjust the isolation rate, but also meet the application scene requirements of high isolation rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic structural diagram of a microwave isolator device with adjustable isolation rate based on cavity-magnon coupling provided in one embodiment of the present application;

[0022] Figure 2 A schematic diagram of the isolation rate experimental results of a microwave isolator device with adjustable isolation rate based on cavity-magnon coupling provided in one embodiment of the present application;

[0023] Figure 3 A schematic diagram of the relationship between isolation rate and frequency provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0026] In an exemplary embodiment, Figure 1 As shown, a microwave isolator device with adjustable isolation rate based on cavity-magnon coupling is provided, including: an orthogonal microstrip line resonant cavity, a yttrium iron garnet ball, a power divider, a first complex amplitude adjustment device and a second complex amplitude adjustment device.

[0027] The yttrium iron garnet sphere is located at the orthogonal center of an orthogonal configuration microstrip line resonant cavity; the orthogonal configuration microstrip line resonant cavity is used to generate two mutually orthogonal cavity modes; an external magnetic field is applied to the yttrium iron garnet sphere so that the frequency of the magnon mode generated by the yttrium iron garnet sphere is consistent with the frequency of the cavity mode, forming a configuration of cavity mode-magnon-cavity mode coupling.

[0028] The output ends of the power divider are connected with the input ends of the first complex amplitude adjusting device and the input ends of the second complex amplitude adjusting device respectively, and the output ends of the first complex amplitude adjusting device and the output ends of the second complex amplitude adjusting device are connected with the two vertical input ports of the orthogonal microstrip resonant cavity respectively.

[0029] The power divider is used to divide the input signal into two paths, the two paths of input signals are adjusted in complex amplitude by the first complex amplitude adjusting device and the second complex amplitude adjusting device respectively, the two paths of input signals after the complex amplitude adjustment ratio are obtained, and the two paths of input signals are input into the orthogonal microstrip resonant cavity.

[0030] The orthogonal microstrip resonant cavity is used to output the output signal with the required isolation rate of the scene in the cavity mode-magnetic mode-cavity mode coupling mode according to the two paths of input signals after the complex amplitude adjustment ratio.

[0031] As an optional implementation, the orthogonal microstrip resonant cavity comprises a cross resonator, a PCB substrate and four feeding lines. The back surface of the PCB substrate is entirely covered with copper as a ground wire; the cross resonator and the four feeding lines are arranged on the front surface of the PCB substrate; a yttrium iron garnet ball is located at the center of the cross resonator, and the center of the yttrium iron garnet ball has a preset distance to the front surface of the PCB substrate. The four feeding lines are arranged one by one along the four extension directions of the cross resonator; each feeding line has a spacing from the cross resonator. The ports of the two mutually perpendicular feeding lines away from the cross resonator are used as the two vertical input ports of the orthogonal microstrip resonant cavity. The port of one of the remaining two feeding lines away from the cross resonator is used as the output port of the orthogonal microstrip resonant cavity, and is used to output the output signal with the required isolation rate of the scene.

[0032] As another optional implementation, the orthogonal microstrip resonant cavity further comprises a shielding shell. The shielding shell covers the cross resonator, the PCB substrate and the four feeding lines.

[0033] As another optional implementation, the first complex amplitude adjusting device comprises a first adjustable attenuator and a first phase shifter; the second complex amplitude adjusting device comprises a second adjustable attenuator and a second phase shifter. The output ends of the power divider are connected with the input ends of the first adjustable attenuator and the input ends of the second adjustable attenuator respectively, the output end of the first adjustable attenuator is connected with the input end of the first phase shifter, the output end of the second adjustable attenuator is connected with the input end of the second phase shifter, and the output ends of the first phase shifter and the second phase shifter are connected with the two vertical input ports of the orthogonal microstrip resonant cavity respectively. The first adjustable attenuator and the second adjustable attenuator are used to adjust the ratio of the complex amplitude mode of the two paths of input signals. The first phase shifter and the second phase shifter are used to adjust the phase difference of the complex amplitude of the two paths of input signals.

[0034] Reference Figure 1The two vertical input ports of the orthogonal microstrip resonant cavity are port A and port B, respectively, the whole input signal is divided into two paths by the power divider, enters the orthogonal microstrip resonant cavity through port A and port B, and the two paths of input are connected to the phase shifter and the adjustable attenuator, respectively, the microwave phase is adjusted by the phase shifter to adjust the phase difference of the two paths of microwave input complex amplitude; the adjustable attenuator is used for adjusting the ratio of the input microwave complex amplitude mode to adjust the amplitude ratio of the two paths of microwave input.

[0035] As another optional implementation, the cavity-magnon coupling based isolation adjustable microwave isolator device further comprises a vector network analyzer. The signal output end of the vector network analyzer is connected with the input end of the power divider, and the signal input end of the vector network analyzer is connected with the output port of the orthogonal microstrip resonant cavity. The vector network analyzer is used for outputting the input signal to the power divider and receiving the output signal of the required isolation rate of the scene output by the orthogonal microstrip resonant cavity.

[0036] The vector network analyzer is like Figure 1 the VNA in the figure.

[0037] As another optional implementation, the orthogonal microstrip resonant cavity and the yttrium iron garnet (YIG) ball can be collectively referred to as an orthogonal cavity-magnon coupling system. The orthogonal microstrip resonant cavity is a PCB, the substrate material is RT / duroid5880, and the thickness is 1.75 mm. The metal layer is copper with a thickness of 0.0175 mm, and the back of the PCB is entirely covered with copper as the ground wire of the resonant cavity. The microstrip line width is 1 mm, the center is a cross-shaped resonator with a length of 10 mm, which is composed of two mutually perpendicular microstrip resonators. The two microstrip resonators are mutually orthogonal in the resonant cavity mode near 5.374 GHz. The cross-shaped resonator is surrounded by four feeding lines with a gap width of 2 mm between the feeding lines and the resonator. The weak coupling between the feeding lines and the resonator allows external microwave signals to excite the resonator mode through the feeding lines and read the cavity mode in the resonator through the feeding lines. In addition, due to the weak coupling between the resonator and the feeding line, the feeding line does not affect the cavity mode in the resonator. The YIG ball is placed at the center of the cross-shaped resonator, and the distance between the center of the YIG ball and the surface of the PCB is about 2 mm. An external magnetic field B0 is applied to the YIG ball, and the magnetic field strength is adjusted so that the magnon (also known as ferromagnetic resonance, FMR) frequency of the YIG ball is consistent with the cavity mode frequency, and the magnetic field direction is perpendicular to the paper surface outward. At this time, the YIG ball can produce strong coupling with the two orthogonal resonant cavity modes, thereby constructing a cavity mode-FMR-cavity mode coupling configuration. Due to the chiral coupling characteristics of the FMR mode, i.e., only right-handed circularly polarized microwaves can be coupled, the presence of YIG breaks the time reversal symmetry, thus endowing the coupling system with non-reciprocity, i.e., the microwave response will be inconsistent after swapping the input and output. An aluminum shell is used to cover the front of the resonant cavity as a shielding shell for the microwave system.

[0038] The relationship between isolation and complex amplitude ratio is derived as follows, which further proves that the device of the application can regulate the isolation of the system.

[0039] Since the magnetic field component amplitude directions of the microwaves in the x / y-oriented resonator are y / x respectively, the complex amplitudes of the microwaves in the x / y-oriented resonator are respectively denoted as a y , a x , the microwave input complex amplitudes connected to the two paths are respectively denoted as f y , f x . Port C is the output port of the orthogonal microstrip resonant cavity, and both the output and input ports are connected to a VNA (vector network analyzer). For the coupling system, a classical harmonic oscillator model can be used to describe the microwave modes in the x / y-oriented resonator and the FMR (ferromagnetic resonance) mode of the magnetic sub, and the oscillator displacements are respectively denoted as r y , r x , r m , the resonance frequencies of the microwave mode and the FMR mode are respectively denoted as ω c , ω m , the dissipation coefficients are respectively denoted as β, α, the coupling strength between the microwave mode and the FMR mode is denoted as g, and the force amplitudes of the external field on the microwave mode oscillator in the x / y-oriented resonator are respectively denoted as f x , f y , with a frequency of ω. The dynamic equation of the orthogonal microstrip resonant cavity is as follows:

[0040]

[0041] where the factor -i on the right side of the third row indicates that the two microwave modes are orthogonal. r x is the displacement of the microwave mode in the y-oriented cross-shaped resonator expressed by the oscillator, is the first derivative of r x , is the second derivative of r x , r y is the displacement of the microwave mode in the x-oriented cross-shaped resonator expressed by the oscillator, is the first derivative of r y , is the second derivative of r y , r m is the displacement of the magnetic sub mode expressed by the oscillator, is the first derivative of r m , is the second derivative of r m . Let r x = a x e -iωt , r y = ay e -iωt , the above equation can be expressed as:

[0042] Ω·A = -F;

[0043] where:

[0044]

[0045] A = (a x a m -ia y ) T ;

[0046] F = (f x 0 -if y ) T ;

[0047] F is the input vector, and A is the amplitude vector. From the above equation, A = Ω -1 F, and further:

[0048]

[0049] With S parameter representation, the output signal complex amplitude, i.e. S21, is proportional to a y . For the reverse output signal, i.e. S12, only the time reversal symmetry breaking brought by the YIG sphere needs to be considered. If the YIG sphere is also subjected to complete time reversal, i.e. the direction of the external magnetic field near the YIG sphere is reversed, the entire system will maintain time reversal symmetry, i.e. S12 = S21. However, in this system, the external field near the YIG sphere will not change with time reversal, and the time reversal symmetry breaking brought by the magnon will make S21 not equal to S12, and under certain parameters, S21 or S12 will become 0. Therefore, for the case of reverse transmission, this system is equivalent to reversing the direction of the external magnetic field near the YIG, and the corresponding change in the expression is:

[0050] A t = (a x a m ia y ) T ;

[0051] F t = (f x 0 if y ) T ;

[0052] where A t and F t are the amplitudes and input vectors of the time reversal state, and A t and F t are compared with the forward input system a yWith f y The front table orthogonally - i becomes i, indicating that the YIG spin direction changes from right-handed to left-handed. A t With F t In order to bring in the kinetic equation, the isolation rate of the system can be obtained:

[0053] iso=20lg(|S21 / S12|);

[0054]

[0055] The two formulas for calculating the isolation rate of the system also reflect the relationship between the isolation rate and the complex amplitude ratio.

[0056] According to the two formulas for calculating the isolation rate of the system, the system has an isolation rate iso infinite point, and the complex amplitude condition corresponding to iso→+∞ is:

[0057]

[0058] The complex amplitude condition corresponding to iso→-∞ is:

[0059]

[0060] By adjusting the phase shifter and the attenuator, the complex amplitude ratio f y / f x of the input microwave can be controlled, and the isolation rate of the system and the frequency at which the maximum isolation rate point appears can be controlled.

[0061] Compared with the existing microwave isolator, the design can control the isolation rate by adjusting the phase and amplitude of the input microwave. It breaks through the upper limit of the theoretical isolation rate of the traditional microwave isolator (~77dB), and the theoretical isolation rate is infinite, and can achieve much higher isolation rate than the traditional microwave isolator. As shown in Figure 2 , the application achieves an isolation rate of 98dB near 5.373GHz, and as the application controls the complex amplitude ratio of the input, the application achieves a very high isolation rate at the lowest frequency of 5.275GHz and the highest frequency of 5.477GHz. The application can also control the isolation rate by controlling the complex amplitude ratio of the input, as shown in Figure 3 , the application gradually reduces the isolation rate of the device from 98dB to 47dB near 5.374GHz.

[0062] The technical features of the above embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictory, it should be considered as the scope of the present application.

[0063] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will have changes. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A cavity-magnon coupling based tunable microwave isolator device, characterized in that, The cavity-magnon coupling-based isolation rate adjustable microwave isolator device comprises a quadrature position microstrip line resonant cavity, a yttrium iron garnet ball, a power divider, a first complex amplitude adjustment device and a second complex amplitude adjustment device; The yttrium iron garnet ball is located at the quadrature center of the quadrature position microstrip line resonant cavity; the quadrature position microstrip line resonant cavity is used for generating two mutually orthogonal cavity modes; an external magnetic field is applied at the yttrium iron garnet ball, so that the magnon mode frequency generated by the yttrium iron garnet ball is consistent with the cavity mode frequency, forming a cavity mode-magnon-cavity mode coupling configuration; The output ends of the power divider are respectively connected with the input ends of the first complex amplitude adjustment device and the input ends of the second complex amplitude adjustment device, and the output ends of the first complex amplitude adjustment device and the output ends of the second complex amplitude adjustment device are respectively connected with two perpendicular input ports of the quadrature position microstrip line resonant cavity; The power divider is used for dividing the input signal into two paths, and the two paths of input signals are adjusted in complex amplitude by the first complex amplitude adjustment device and the second complex amplitude adjustment device respectively, so as to obtain two paths of input signals after adjusting the complex amplitude ratio, and input the quadrature position microstrip line resonant cavity; The quadrature position microstrip line resonant cavity is used for outputting the output signal with the required isolation rate of the scene under the cavity mode-magnon-cavity mode coupling configuration according to the two paths of input signals after adjusting the complex amplitude ratio.

2. The cavity-magnon coupling based isolation adjustable microwave isolator device of claim 1, wherein, The quadrature position microstrip line resonant cavity comprises a cross resonator, a PCB substrate and four feeding lines; The back surface of the PCB substrate is entirely covered with copper as a ground wire; the cross resonator and the four feeding lines are arranged on the front surface of the PCB substrate; the yttrium iron garnet ball is located at the center of the cross resonator, and the center of the yttrium iron garnet ball has a preset distance to the front surface of the PCB substrate; The four feeding lines are arranged one by one along the four extension directions of the cross resonator; each feeding line has a spacing with the cross resonator; The ports of two mutually perpendicular feeding lines away from the cross resonator are used as two perpendicular input ports of the quadrature position microstrip line resonant cavity; The port of one of the remaining two feeding lines away from the cross resonator is used as an output port of the quadrature position microstrip line resonant cavity, and is used for outputting the output signal with the required isolation rate of the scene.

3. The cavity-magnon coupling based isolation adjustable microwave isolator device of claim 2, wherein, The quadrature position microstrip line resonant cavity further comprises a shielding shell; The shielding shell covers the cross resonator, the PCB substrate and the four feeding lines.

4. The cavity-magnon coupling based isolation adjustable microwave isolator device of claim 1, wherein, The first complex amplitude adjustment device comprises a first adjustable attenuator and a first phase shifter; the second complex amplitude adjustment device comprises a second adjustable attenuator and a second phase shifter; The output ends of the power divider are respectively connected with the input ends of the first adjustable attenuator and the input ends of the second adjustable attenuator, the output end of the first adjustable attenuator is connected with the input end of the first phase shifter, the output end of the second adjustable attenuator is connected with the input end of the second phase shifter, and the output ends of the first phase shifter and the second phase shifter are respectively connected with the two perpendicular input ports of the quadrature position microstrip line resonant cavity; The first adjustable attenuator and the second adjustable attenuator are used for adjusting the ratio of the complex amplitude mode of the two paths of input signals; The first phase shifter and the second phase shifter are used for adjusting the phase difference of the complex amplitude of the two paths of input signals.

5. The cavity-magnon coupling based isolation ratio tunable microwave isolator device of claim 1, wherein, The cavity-magnon coupling-based isolation rate adjustable microwave isolator device further comprises a vector network analyzer; The signal output end of the vector network analyzer is connected with the input end of the power divider, and the signal input end of the vector network analyzer is connected with the output port of the orthogonal microstrip resonant cavity. The vector network analyzer is configured to output the input signal to the power divider and receive an output signal with a required isolation rate output by the orthogonal microstrip resonant cavity.

6. The cavity-magnon coupling based isolation ratio tunable microwave isolator device of claim 2, wherein, The diameter of the yttrium iron garnet ball is 1 mm; The material of the PCB substrate is RT / duroid 5880, and the thickness of the PCB substrate is 1.75 mm; The thickness of the copper is 0.0175 mm; The line width of the two perpendicular microstrip lines in the cross resonator is 1 mm, and the length of the microstrip line is 10 mm; The preset interval is 2 mm; The interval between each feed line and the cross resonator is 2 mm.

7. The cavity-magnon coupling based isolation ratio tunable microwave isolator device of claim 1, wherein, The dynamic equation of the orthogonal microstrip resonant cavity is: where r x is the displacement of the microwave mode in the cross resonator expressed in terms of the oscillator, is the first derivative of r x , is the second derivative of r x , r y is the displacement of the microwave mode in the cross resonator expressed in terms of the oscillator, is the first derivative of r y , is the second derivative of r y , r m is the displacement of the magnon mode expressed in terms of the oscillator, is the first derivative of r m , is the second derivative of r m , ω c is the resonance frequency of the microwave mode, ω is the frequency of the external magnetic field, ω m is the resonance frequency of the magnon mode, β is the dissipation coefficient of the microwave mode, g is the coupling strength between the microwave mode and the magnon mode, f x is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the x direction of the cross resonator, f y is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the y direction of the cross resonator, -i indicates that the two microwave modes are orthogonal, α is the dissipation coefficient of the magnon mode, and t is time.

8. The cavity-magnon coupling based isolation adjustable microwave isolator device of claim 1, wherein, The relationship between the isolation rate and the complex amplitude ratio is: iso = 20lg(|S21 / S12|); where iso is the isolation, S21 is the complex amplitude of the output signal, S12 is the reverse output signal, f y is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the y-oriented cross resonator, f x is the amplitude of the force exerted by the external magnetic field on the microwave mode oscillator in the x-oriented cross resonator, ω is the frequency of the external magnetic field, ω m is the resonance frequency of the magnon mode, ω c is the resonance frequency of the microwave mode, α is the dissipation coefficient of the magnon mode, β is the dissipation coefficient of the microwave mode, g is the coupling strength between the microwave mode and the magnon mode, i indicates the two orthogonal microwave modes.

9. The cavity-magnon coupling based isolation ratio tunable microwave isolator device of claim 8, wherein, When the isolation rate approaches positive infinity, the corresponding complex amplitude ratio is: When the isolation rate approaches negative infinity, the corresponding complex amplitude ratio is:

10. The cavity-magnon coupling based isolation adjustable microwave isolator device of claim 8, wherein, The external magnetic field applied at the yttrium iron garnet ball does not change with time reversal, and for the reverse output signal, it is equivalent to reversing the direction of the external magnetic field, and the spin direction of the yttrium iron garnet ball changes from right-handed to left-handed.

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