Stripline resonator structure and magnetically tuned trap composed of the resonator structure

Abstract

The invention discloses a stripline resonator structure and a magnetic tuning trap composed of the resonator structure, belonging to the technical field of electronic components; the stripline resonator structure consists of a stripline central conductor, a stripline outer conductor, a gadolinium gallium garnet crystal and a YIG single crystal film, wherein the stripline central conductor, the YIG single crystal film and the gadolinium gallium garnet crystal are arranged in sequence in the stripline outer conductor; the invention realizes the planarization of the resonator of the magnetic tuning trap, simplifies the design of the stripline resonant circuit structure; adopts the stripline transmission mode, expands the passband operating frequency of the magnetic tuning trap; multiple stripline resonant circuits can be arranged on the same plane, which is easy to integrate multi-channel traps; the resonant circuit adopts multiple single crystal film blocks to form a resonator cascade, effectively suppresses multiple excitation modes of the single crystal film, increases the stopband depth of the trap, and improves the performance of the trap.

Description

Technical Field

[0001] The invention relates to the technical field of electronic components, and in particular to a stripline resonator structure and a magnetically tuned trap composed of the resonator structure. Background Art

[0002] YIG (yttrium iron garnet) band-stop filters are broadband magnetically tuned devices, mainly used in electronic warfare systems. Whether it is electronic reconnaissance, electronic attack or electronic defense, YIG band-stop filters are essential components. YIG band-stop filters have broadband tuning characteristics, which can filter out or suppress unnecessary interference signals in electronic support (ESM) and electronic countermeasure (ECM) systems to ensure the normal operation of the system. They are widely used in electronic intelligence systems and microwave receiving front ends. Application platforms include airborne broadband receivers, electronic jammers, communication systems; ground and shipborne radars; and missile electronic systems.

[0003] Currently, most YIG notch filters use a ring-and-sphere coupled resonance structure. Figure 1 , generally including multiple YIG beads 3, multi-stage resonant coupling rings 2 and resonant cavities. Its structure is complex, the assembly process is numerous, the production cycle is long, and the debugging is difficult. Due to the large volume of the resonator of the YIG trap with a ring-shaped coupling resonance structure, and the influence of the YIG ball goal direction and the debugging process, it is difficult to achieve multi-channel and array integration. And due to the limitations of the coupling ring inductance and distributed capacitance, the direct pass frequency of the existing YIG trap with a ring-shaped coupling resonance structure is generally lower than 20GHz.

[0004] As mentioned above, most of the current magnetically tuned traps use YIG single crystal spheres as resonators, and adopt a ring-and-sphere coupling structure to achieve the trap function through the principle of ferromagnetic resonance in a magnetic field. Usually, the YIG magnetically tuned trap includes an electromagnet structure and a resonator structure. The electromagnet structure is composed of a soft magnetic alloy material with high magnetic permeability and an excitation coil 6. The soft magnetic alloy material is magnetized under the action of the magnetic field generated by the magnetic circuit coil, and a continuously adjustable strong magnetic field is generated in the air gap of the upper and lower magnetic circuits 5, and the resonator is placed in the air gap of the upper and lower magnetic circuits. The YIG single crystal sphere 3, the coupling ring 2, and the resonant cavity 1 together constitute the resonator of the magnetically tuned trap. Under the action of the magnetic field, the YIG single crystal sphere will produce ferromagnetic resonance. When a microwave signal is coupled in through the coupling ring 2 and is consistent with the ferromagnetic resonance frequency of the YIG single crystal sphere 3, resonance will occur, forming a trap frequency point; the trap frequency can be changed by changing the size of the magnetic field;

[0005] The ring-shaped coupled resonance structure is usually composed of three parts: a YIG single crystal ball 3, a coupling ring 2, and a resonant cavity 1. The YIG single crystal ball 3 is bonded to a support rod 4, and the YIG single crystal ball 3 is placed at the center of the coupling ring 2 through the support rod 4. The direction of the YIG single crystal ball 3 can be adjusted by rotating the support rod 4. The YIG single crystal ball 3 and the coupling ring 2 are placed at the center of the resonant cavity 1, and the direction of the external magnetic field needs to be perpendicular to the coupling ring 2, such as Figure 2 shown.

[0006] The existing magnetically tuned trap with a ring-shaped coupled resonance structure uses a YIG single crystal ball 3 and a coupling ring 2 to form a resonator. The structure is three-dimensionally coupled, and is complex to assemble and difficult to debug. The passband frequency is lower than 20 GHz. Since the direction of the magnetic field is perpendicular to the position of the ball support rod 4, and the ball support rod 4 needs to be rotated to adjust the position of the YIG single crystal ball 3 during debugging, it is difficult to achieve multi-channel integration of the YIG trap with a ring-shaped coupled resonance structure in the same magnetic circuit structure. Summary of the invention

[0007] One of the objectives of the present invention is to provide a stripline resonator structure to solve the above-mentioned problem.

[0008] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a stripline resonator structure, composed of a stripline central conductor, a stripline outer conductor, a gadolinium gallium garnet crystal and a YIG single crystal thin film, wherein the YIG single crystal thin film and the gadolinium gallium garnet crystal are arranged in sequence inside the stripline, between the inner and outer conductors, and along the stripline central conductor.

[0009] As a preferred technical solution: the YIG single crystal film is in block form, the saturation magnetization intensity of the YIG single crystal film is 1000-1750Gs, and the resonance line width is 0.3-0.6 Oe , film thickness 10~20μm.

[0010] As a further preferred technical solution: the saturation magnetization intensity of the YIG single crystal film is 1750Gs, and the resonance line width is 0.5Oe.

[0011] The wave trap resonant circuit of the present invention adopts a stripline transmission mode and uses a YIG single crystal film as a resonator; one end of the stripline is a radio frequency input and the other end is a radio frequency output, and the length of the stripline is designed according to the required wave trap performance.

[0012] A second object of the present invention is to provide a magnetically tuned trap composed of the above-mentioned stripline resonator structure, comprising an upper magnetic circuit and a lower magnetic circuit, an air gap is arranged between the upper magnetic circuit and the lower magnetic circuit, the stripline resonator structure is arranged at the air gap, and an excitation coil is arranged in the lower magnetic circuit.

[0013] Compared with the prior art, the advantages of the present invention are as follows: the present invention adopts stripline and single crystal film to jointly form a resonant circuit structure of a novel magnetically tuned trap, realizes the planarization of the resonator of the magnetically tuned trap, and simplifies the resonant circuit structure design of the magnetically tuned trap; adopts a stripline transmission mode, and the pass-through frequency is as high as 40GH, which expands the passband operating frequency of the magnetically tuned trap; multiple stripline resonant circuits can be arranged on the same plane, and the integrated design of multi-channel magnetically tuned traps is realized in the same magnetic circuit structure, which facilitates the integration of multi-channel traps; the resonant circuit adopts multiple single crystal film blocks to form a resonator cascade, effectively suppresses multiple excitation modes of the single crystal film, increases the stopband depth of the trap, and improves the performance of the trap. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A diagram showing the structure of a ring-and-globe coupling resonant circuit of a YIG trap in the prior art;

[0015] Figure 2 It is a structural diagram of the existing YIG trap with a ring-shaped coupled resonance structure;

[0016] Figure 3 The cross-sectional structure diagram of the YIG single crystal thin film resonator for stripline transmission of the present invention;

[0017] Figure 4 This is a structural diagram of the tank-shaped magnetic circuit of the present invention;

[0018] Figure 5 This is a schematic diagram of a YIG single crystal thin film block of the present invention;

[0019] Figure 6 This is a structural diagram of a stripline resonant circuit of a single crystal thin film trap of the present invention;

[0020] Figure 7 It is a cross-sectional view of a stripline resonant circuit of a single crystal thin film trap of the present invention;

[0021] Figure 8 It is a structural diagram of the magnetically tuned trap of the present invention.

[0022] In the figure: 1. resonant cavity; 2. coupling ring; 3. YIG single crystal ball; 4. support rod; 5. magnetic circuit; 6. excitation coil; 7. coaxial cable; 8. stripline center conductor; 9. YIG single crystal film; 10. gadolinium gallium garnet crystal; 11. stripline outer conductor; 12. lower magnetic circuit; 13. upper magnetic circuit; 14. SMA connector; 15. stripline resonant circuit; 16. fixing screw; 17. magnetic circuit air gap. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] Embodiment 1:

[0025] A stripline resonator structure, comprising a stripline central conductor 8, a stripline outer conductor 11, a gadolinium gallium garnet crystal 10 and a YIG single crystal thin film 9, wherein the stripline central conductor 8, the YIG single crystal thin film 9 and the gadolinium gallium garnet crystal 10 are arranged in sequence in the stripline outer conductor 11; that is, the YIG single crystal thin film 9 is placed on the stripline central conductor 8, and its end surface structure is as follows: Figure 3 As shown;

[0026] The YIG single crystal film 9 and the strip line together form a resonator structure. The entire resonator structure is placed in a uniform magnetic field. An adjustable electromagnet is used to provide a uniform magnetic field. The electromagnet can be designed with a pot-shaped magnetic circuit structure, such as Figure 4 As shown;

[0027] A continuously adjustable uniform magnetic field is generated in the air gap between the upper and lower magnetic poles of the pot-shaped magnetic circuit. Figure 3 The resonator structure shown is placed in the air gap between the upper and lower magnetic poles (i.e., the upper magnetic circuit 13 and the lower magnetic circuit 12); when a microwave signal passes through the stripline and no current passes through the magnetic circuit excitation coil 6, the resonator circuit is in a straight-through state, and its straight-through frequency is higher than 40GHz; when a current passes through the excitation coil 6, a uniform magnetic field is generated in the air gap between the upper and lower magnetic poles, and the direction of the magnetic field is perpendicular to the surface of the YIG single crystal film 9; the YIG single crystal film 9 generates ferromagnetic resonance, and when the resonant frequency is the same as the frequency of the electromagnetic wave passing through the stripline, resonance is generated, thereby absorbing the electromagnetic wave energy to form a notch stopband, and the resonant frequency is related to factors such as the external magnetic field strength and the saturation magnetization strength of the single crystal film. Among them, the external magnetic field strength is linearly related to the resonant frequency, and the resonant frequency can be changed by changing the external magnetic field strength, thereby realizing a broadband continuously adjustable magnetic tuning notch filter.

[0028] The specific implementation steps are as follows:

[0029] (1) A YIG single crystal film 9 is produced by liquid phase epitaxy. A YIG single crystal film 9 is grown on the surface of a gadolinium gallium garnet crystal 10 as a substrate by liquid phase epitaxy. In this embodiment, the YIG single crystal film has a saturation magnetization intensity of 1750 Gs, a resonance line width of 0.5 Oe, and a film thickness of 10 to 20 microns. The YIG single crystal film is cut into rectangular small pieces (2 mm×1 mm) by cutting. Figure 5 As shown;

[0030] (2) Designing a stripline resonator: A high dielectric constant dielectric substrate is selected to prepare the stripline. In this embodiment, the dielectric constant of the dielectric substrate is 9.8, the thickness is 0.6 mm, the characteristic impedance of the stripline is calculated as 50 ohms, and the width of the stripline center conductor is calculated based on the dielectric substrate parameters; the stripline is prepared by removing a piece of dielectric substrate at a certain distance along the center conductor to expose the stripline center conductor 8. The size of the cavity removed from the dielectric substrate should be able to accommodate the single crystal thin film block prepared in step 1. The number of cavities is determined based on the technical indicators such as the operating frequency and stopband depth of the designed notch filter. The deeper the stopband depth requirement, the more cavities there are, and the more single crystal thin film blocks can be installed, that is, the more resonance levels there are;

[0031] The working frequency of this embodiment is 10-12 GHz, and the stopband depth is greater than 30 dB; the designed resonance level is 5, such as Figure 6 As shown; the cross-sectional view along the center conductor is as follows Figure 7 As shown, it can be seen that along the direction of the stripline center conductor 8, a plurality of single crystal thin film resonators form a cascade structure;

[0032] (3) Design the magnetic field required for the resonant circuit to work: Use high magnetic permeability iron-nickel alloy material and enameled wire coil to make the magnetic circuit and excitation coil, adopt a pot-shaped magnetic circuit structure design, which is divided into an upper magnetic circuit 13 and a lower magnetic circuit 12. The uniform magnetic field area at the air gap 17 of the upper and lower magnetic circuits should be larger than the resonant circuit. The resonant circuit is placed at the air gap 17 of the magnetic circuit, and the magnetic field direction is perpendicular to the surface of the stripline resonator.

[0033] The dimensions of the magnetic circuit designed in this embodiment are 45mm×45mm×25mm, and the magnetic circuit material is iron-nickel alloy with a grade of 1J50; the magnetic circuit air gap is 1.3mm, and the magnetic circuit excitation coil is made of enameled wire with a diameter of 0.31mm, and the number of coil turns is 900 to 1100 turns;

[0034] (4) Assemble the stripline resonant circuit 15, the tuning magnetic circuit, and the SMA connector 14. The specific assembly structure is that the upper and lower magnetic circuits are connected to the SMA connector 14 with fixing screws 16 to form a magnetic tuning trap. The structure of the magnetic tuning trap is as follows: Figure 8 shown.

[0035] Embodiment 2: A stripline resonator structure, comprising a stripline center conductor 8, a stripline outer conductor 11, a gadolinium gallium garnet crystal 10 and a YIG single crystal thin film 9, wherein the stripline center conductor 8, the YIG single crystal thin film 9 and the gadolinium gallium garnet crystal 10 are arranged in sequence in the stripline outer conductor 11; that is, the YIG single crystal thin film 9 is placed on the stripline center conductor 8, and its end surface structure is as follows: Figure 3 As shown;

[0036] The YIG single crystal film 9 and the strip line together form a resonator structure. The entire resonator structure is placed in a uniform magnetic field. An adjustable electromagnet is used to provide a uniform magnetic field. The electromagnet can be designed with a pot-shaped magnetic circuit structure, such as Figure 4 As shown;

[0037] A continuously adjustable uniform magnetic field is generated in the air gap between the upper and lower magnetic poles of the pot-shaped magnetic circuit. Figure 3 The resonator structure shown is placed in the air gap between the upper and lower magnetic poles (i.e., the upper magnetic circuit 13 and the lower magnetic circuit 12); when a microwave signal passes through the stripline and no current passes through the magnetic circuit excitation coil 6, the resonator circuit is in a straight-through state, and its straight-through frequency is higher than 40GHz; when a current passes through the excitation coil 6, a uniform magnetic field is generated in the air gap between the upper and lower magnetic poles, and the direction of the magnetic field is perpendicular to the surface of the YIG single crystal film 9; the YIG single crystal film 9 generates ferromagnetic resonance, and when the resonant frequency is the same as the frequency of the electromagnetic wave passing through the stripline, resonance is generated, thereby absorbing the electromagnetic wave energy to form a notch stopband, and the resonant frequency is related to factors such as the external magnetic field strength and the saturation magnetization strength of the single crystal film. Among them, the external magnetic field strength is linearly related to the resonant frequency, and the resonant frequency can be changed by changing the external magnetic field strength, thereby realizing a broadband continuously adjustable magnetic tuning notch filter.

[0038] The specific implementation steps are as follows:

[0039] (1) A YIG single crystal film 9 is prepared by liquid phase epitaxy. A YIG single crystal film 9 is grown on the surface of a gadolinium gallium garnet crystal 10 as a substrate by liquid phase epitaxy. In this embodiment, the YIG single crystal film has a saturation magnetization intensity of 1000 Gs, a resonance line width of 0.4 Oe, and a film thickness of 10 to 20 microns. The YIG single crystal film is cut into rectangular small pieces (3 mm × 1 mm) by cutting, such as Figure 5 As shown;

[0040] (2) Designing a stripline resonator: A high dielectric constant dielectric substrate is selected to prepare the stripline. In this embodiment, the dielectric constant of the dielectric substrate is 9.8, the thickness is 0.6 mm, the characteristic impedance of the stripline is calculated as 50 ohms, and the width of the stripline center conductor is calculated based on the dielectric substrate parameters; the stripline is prepared by removing a piece of dielectric substrate at a certain distance along the center conductor to expose the stripline center conductor 8. The size of the cavity removed from the dielectric substrate should be able to accommodate the single crystal thin film block prepared in step 1. The number of cavities is determined based on the technical indicators such as the operating frequency and stopband depth of the designed notch filter. The deeper the stopband depth requirement, the more cavities there are, and the more single crystal thin film blocks can be installed, that is, the more resonance levels there are;

[0041] The working frequency of this embodiment is 6-8 GHz, and the stopband depth is greater than 30 dB; the designed resonance level is 5, such as Figure 6 As shown; the cross-sectional view along the center conductor is as follows Figure 7As shown, it can be seen that along the direction of the stripline center conductor 8, a plurality of single crystal thin film resonators form a cascade structure;

[0042] (3) Design the magnetic field required for the resonant circuit to work: Use high magnetic permeability iron-nickel alloy material and enameled wire coil to make the magnetic circuit and excitation coil, adopt a pot-shaped magnetic circuit structure design, which is divided into an upper magnetic circuit 13 and a lower magnetic circuit 12. The uniform magnetic field area at the air gap 17 of the upper and lower magnetic circuits should be larger than the resonant circuit. The resonant circuit is placed at the air gap 17 of the magnetic circuit, and the magnetic field direction is perpendicular to the surface of the stripline resonator.

[0043] The dimensions of the magnetic circuit designed in this embodiment are 45mm×45mm×25mm, and the magnetic circuit material is iron-nickel alloy with a grade of 1J50; the magnetic circuit air gap is 1.3mm, and the magnetic circuit excitation coil is made of enameled wire with a diameter of 0.31mm, and the number of coil turns is 900 to 1100 turns;

[0044] (4) Assemble the stripline resonant circuit 15, the tuning magnetic circuit, and the SMA connector 14. The specific assembly structure is that the upper and lower magnetic circuits are connected to the SMA connector 14 with fixing screws 16 to form a magnetic tuning trap. The structure of the magnetic tuning trap is as follows: Figure 8 shown.

[0045] Embodiment 3:

[0046] A stripline resonator structure, comprising a stripline central conductor 8, a stripline outer conductor 11, a gadolinium gallium garnet crystal 10 and a YIG single crystal thin film 9, wherein the stripline central conductor 8, the YIG single crystal thin film 9 and the gadolinium gallium garnet crystal 10 are arranged in sequence in the stripline outer conductor 11; that is, the YIG single crystal thin film 9 is placed on the stripline central conductor 8, and its end surface structure is as follows: Figure 3 As shown;

[0047] The YIG single crystal film 9 and the strip line together form a resonator structure. The entire resonator structure is placed in a uniform magnetic field. An adjustable electromagnet is used to provide a uniform magnetic field. The electromagnet can be designed with a pot-shaped magnetic circuit structure, such as Figure 4 As shown;

[0048] A continuously adjustable uniform magnetic field is generated in the air gap between the upper and lower magnetic poles of the pot-shaped magnetic circuit. Figure 3The resonator structure shown is placed in the air gap between the upper and lower magnetic poles (i.e., the upper magnetic circuit 13 and the lower magnetic circuit 12); when a microwave signal passes through the stripline and no current passes through the magnetic circuit excitation coil 6, the resonator circuit is in a straight-through state, and its straight-through frequency is higher than 40GHz; when a current passes through the excitation coil 6, a uniform magnetic field is generated in the air gap between the upper and lower magnetic poles, and the direction of the magnetic field is perpendicular to the surface of the YIG single crystal film 9; the YIG single crystal film 9 generates ferromagnetic resonance, and when the resonant frequency is the same as the frequency of the electromagnetic wave passing through the stripline, resonance is generated, thereby absorbing the electromagnetic wave energy to form a notch stopband, and the resonant frequency is related to factors such as the external magnetic field strength and the saturation magnetization strength of the single crystal film. Among them, the external magnetic field strength is linearly related to the resonant frequency, and the resonant frequency can be changed by changing the external magnetic field strength, thereby realizing a broadband continuously adjustable magnetic tuning notch filter.

[0049] The specific implementation steps are as follows:

[0050] (1) A YIG single crystal film 9 is prepared by liquid phase epitaxy. A YIG single crystal film 9 is grown on the surface of a gadolinium gallium garnet crystal 10 as a substrate by liquid phase epitaxy. In this embodiment, the YIG single crystal film has a saturation magnetization intensity of 1500 Gs, a resonance line width of 0.4 Oe, and a film thickness of 10 to 20 microns. The YIG single crystal film is cut into rectangular small pieces (2 mm×1 mm) by cutting, such as Figure 5 As shown;

[0051] (2) Designing a stripline resonator: A high dielectric constant dielectric substrate is selected to prepare the stripline. In this embodiment, the dielectric constant of the dielectric substrate is 9.8, the thickness is 0.6 mm, the characteristic impedance of the stripline is calculated as 50 ohms, and the width of the stripline center conductor is calculated based on the dielectric substrate parameters; the stripline is prepared by removing a piece of dielectric substrate at a certain distance along the center conductor to expose the stripline center conductor 8. The size of the cavity removed from the dielectric substrate should be able to accommodate the single crystal thin film block prepared in step 1. The number of cavities is determined based on the technical indicators such as the operating frequency and stopband depth of the designed notch filter. The deeper the stopband depth requirement, the more cavities there are, and the more single crystal thin film blocks can be installed, that is, the more resonance levels there are;

[0052] The working frequency of this embodiment is 8-10 GHz, and the stopband depth is greater than 30 dB; the designed resonance level is 5, such as Figure 6 As shown; the cross-sectional view along the center conductor is as follows Figure 7 As shown, it can be seen that along the direction of the stripline center conductor 8, a plurality of single crystal thin film resonators form a cascade structure;

[0053] (3) Design the magnetic field required for the resonant circuit to work: Use high magnetic permeability iron-nickel alloy material and enameled wire coil to make the magnetic circuit and excitation coil, adopt a pot-shaped magnetic circuit structure design, which is divided into an upper magnetic circuit 13 and a lower magnetic circuit 12. The uniform magnetic field area at the air gap 17 of the upper and lower magnetic circuits should be larger than the resonant circuit. The resonant circuit is placed at the air gap 17 of the magnetic circuit, and the magnetic field direction is perpendicular to the surface of the stripline resonator.

[0054] The dimensions of the magnetic circuit designed in this embodiment are 45mm×45mm×25mm, and the magnetic circuit material is iron-nickel alloy with a grade of 1J50; the magnetic circuit air gap is 1.3mm, and the magnetic circuit excitation coil is made of enameled wire with a diameter of 0.31mm, and the number of coil turns is 900 to 1100 turns;

[0055] (4) Assemble the stripline resonant circuit 15, the tuning magnetic circuit, and the SMA connector 14. The specific assembly structure is that the upper and lower magnetic circuits are connected to the SMA connector 14 with fixing screws 16 to form a magnetic tuning trap. The structure of the magnetic tuning trap is as follows: Figure 8 shown.

[0056] It can be seen from the above embodiments that when the saturation magnetization intensity of the single crystal thin film material of the present invention is between 1000 and 1750 Gs, the depth and width indicators can be achieved within the working frequency band, and the structure is basically the same.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A magnetically tuned trap, characterized in that: It comprises an upper magnetic circuit and a lower magnetic circuit, an air gap is arranged between the upper magnetic circuit and the lower magnetic circuit, a stripline resonator structure is arranged at the air gap, and an excitation coil is arranged in the lower magnetic circuit; The stripline resonator structure is composed of a stripline central conductor, a stripline outer conductor, a gadolinium gallium garnet crystal and a YIG single crystal thin film, wherein the stripline central conductor, the YIG single crystal thin film and the gadolinium gallium garnet crystal are arranged in sequence in the stripline outer conductor; The YIG single crystal film is in block shape, the saturation magnetization of the YIG single crystal film is 1000-1750Gs, the resonance line width is 0.3-0.6 Oe, and the film thickness is 10-20μm; A plurality of stripline resonator structures are arranged on the same plane, and the resonator structure uses a plurality of single crystal thin film blocks to form a resonator cascade.

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