YIG amplitude limiter with low threshold power

Abstract

The invention relates to the technical field of YIG magnetic modulation devices, in particular to a low-threshold-power YIG amplitude limiter which comprises a GGG substrate, a YIG film and a grounding metal plate, an excitation strip line set is arranged on the other face of the GGG substrate, and the YIG film and the GGG substrate serve as combined media to form a microstrip line structure; the excitation strip line group comprises a first excitation strip line and a second excitation strip line, the first excitation strip line and the second excitation strip line are arranged in parallel, and the excitation strip line group is etched on the GGG substrate within a certain thickness range, so that the non-uniformity of a radio frequency magnetic field generated by direct contact of the excitation strip line group with the YIG thin film can be reduced, and the uniformity of the YIG thin film is improved. When a non-consistent amplitude limiting effect occurs, high-power energy can be coupled to a half-frequency spin wave for dissipation, and the purpose that the amplitude limiting power threshold value is lower than that of a YIG amplitude limiting structure in which the excitation strip line group is directly manufactured on a YIG thin film is further achieved.

Description

Technical Field

[0001] The invention relates to the technical field of YIG magnetic tuning devices, and in particular to a YIG limiter with low threshold power. Background Art

[0002] With the development of YIG material research in recent decades, many institutions at home and abroad have conducted extensive research on YIG material devices, especially YIG devices have been widely studied abroad. The performance of YIG filters developed by Microlambda Corporation in the United States still occupies the top position in the industry, but in addition to YIG filters, YIG isolators, YIG delay lines, YIG limiters, etc. are also being developed.

[0003] A Chinese patent document with publication number CN116154434B discloses a complementary open resonant ring YIG limiter and proposes a YIG limiter designed using YIG film to achieve the purpose of compact structure, planarization and easy integration, overcoming the integration problem faced by YIG balls. The structure can achieve a limiting threshold power of about -10dBm and intercept small interfering signals.

[0004] At the same time, in the literature Jr SNS, Carter PS, Goldie H. A High Power X-Band Frequency Selective Passive YIG Limiter [C] / /

[0005] Microwave Symposium Digest, 1977 IEEE MTT-S International.IEEE,1977.DOI:10.1109 / MWSYM.1977.1124510. A high-power X-band selective passive limiter based on YIG ball design is proposed, which has a limiting dynamic range of 28dBm and good selectivity. It is suitable for high-power FW / CW single-station radar to simultaneously transmit and receive, level RF signals, common limiting, and overload devices to protect communication receivers from strong RF signals without losing reception. However, the problem is that YIG balls are difficult to prepare and not easy to assemble, and the cascade of multiple structures leads to a large overall volume. The most important thing is that the limiting threshold is high and it is unable to limit interference signals with lower power. Summary of the invention

[0006] In view of the above problems, the present invention provides a YIG limiter with low threshold power.

[0007] The technical solution adopted is a low-threshold power YIG limiter, comprising a GGG substrate, a YIG film, and a grounded metal plate, wherein one side of the YIG film is connected to the back side of the GGG substrate, and the other side of the YIG film contacts the grounded metal plate, wherein an excitation strip line group is arranged on the other side of the GGG substrate, and a microstrip line structure is formed by using the YIG film and the GGG substrate as a combined medium;

[0008] The excitation strip line group includes a first excitation strip line and a second excitation strip line, and the first excitation strip line and the second excitation strip line are arranged parallel to each other, the first excitation strip line and the second excitation strip line are respectively close to two sides of the GGG substrate, one end of the first excitation strip line is a ground end, and the other end is an input port or an output port, and one end of the second excitation strip line is a ground end, and the other end is an output port or an input port.

[0009] Optionally, the length and width of the first excitation strip line and the second excitation strip line are consistent.

[0010] Optionally, the first excitation strip line and the second excitation strip line are symmetrical about the center point of the GGG substrate.

[0011] Optionally, the excitation strip line further includes a third microstrip line, and the third microstrip line is arranged between the first excitation strip line and the second excitation strip line, and the third microstrip line is parallel to the first excitation strip line and the second excitation strip line.

[0012] Optionally, the third microstrip line is provided with spur line defect ground structures whose number is an integer multiple of four, and half of the spur line defect ground structures are arranged on a side of the third microstrip line close to the first excitation strip line, and the other half of the spur line defect ground structures are arranged on a side of the third microstrip line close to the second excitation strip line.

[0013] Optionally, four spur line defect ground structures are arranged on the third microstrip line, namely a first spur line defect ground structure, a second spur line defect ground structure, a third spur line defect ground structure and a fourth spur line defect ground structure;

[0014] The first spur line defect ground structure and the third spur line defect ground structure are arranged close to the first excitation strip line;

[0015] The second spur line defect ground structure and the fourth spur line defect ground structure are arranged close to the second excitation strip line.

[0016] Optionally, the first spur line defect ground structure, the second spur line defect ground structure, the third spur line defect ground structure and the fourth spur line defect ground structure have the same width.

[0017] Optionally, the first spur line defect ground structure, the second spur line defect ground structure, the third spur line defect ground structure and the fourth spur line defect ground structure each include a short segment and a long segment, and the short segment is vertically connected to the long segment, and the open end of the short segment is flush with the horizontal axis direction of the third microstrip line.

[0018] Optionally, the shape of the first spur line defect ground structure is the same as that of the fourth spur line defect ground structure, and they are arranged diagonally with respect to the center of the third microstrip line, and the long section of the first spur line defect ground structure faces the third spur line defect ground structure;

[0019] The second spur line defect ground structure has the same shape as the third spur line defect ground structure and is arranged diagonally at the center of the third microstrip line, with the long section of the third spur line defect ground structure facing the first spur line defect ground structure.

[0020] Optionally, the shape of the first spur line defect ground structure is the same as that of the fourth spur line defect ground structure, and they are arranged diagonally with respect to the center of the third microstrip line, and the long section of the first spur line defect ground structure faces away from the third spur line defect ground structure;

[0021] The second spur line defect ground structure has the same shape as the third spur line defect ground structure and is arranged diagonally with respect to the center of the third microstrip line. The long section of the third spur line defect ground structure faces away from the first spur line defect ground structure.

[0022] The beneficial effects of the present invention include at least one of the following:

[0023] 1. By etching an excitation strip line group on a GGG substrate within a certain thickness range, a microstrip line structure is formed with YIG film and GGG substrate as a combined medium, which can reduce the inhomogeneity of the radio frequency magnetic field generated by the excitation strip line group directly contacting the YIG film. When the non-uniform limiting effect occurs, more high-power energy can be coupled to the half-frequency spin wave for dissipation, further achieving a lower limiting power threshold than the YIG limiting structure in which the excitation strip line group is directly made on the YIG film.

[0024] 2. During the energy conversion process, the parallel double-line transducer structure composed of the first excitation strip line and the second excitation strip line will couple the energy into the asymmetric spur line defect structure to realize secondary excitation of the YIG film. Usually, the capacitance effect is controlled by the width of the spur line, and the inductance effect is controlled by the length of the spur line. Therefore, the effective dielectric constant of the combined dielectric substrate will be affected by the size of the spur line, further reducing the insertion loss within the strip.

[0025] 3. By setting an asymmetric spur line defect ground structure between the parallel double-line transducer structure, the YIG limiter can suppress the clutter within the passband and the harmonics outside the passband, and optimize the flatness of the standing wave and insertion loss within the band. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of a YIG limiter with low threshold power;

[0027] Figure 2 It is a schematic diagram of the front structure of a low threshold power YIG limiter;

[0028] Figure 3 This is a schematic diagram of the front structure of another low-threshold power YIG limiter;

[0029] Figure 4 It is a local detail of the dielectric substrate of a YIG limiter circuit with low threshold power;

[0030] Figure 5 It is an S-parameter simulation result of low threshold power.

[0031] The reference numerals are:

[0032] 1 is a GGG substrate, 2 is a YIG film, 3 is a grounded metal plate, 4 is a first excitation strip line, 5 is a second excitation strip line, 6 is a third microstrip line, 7 is a first spur line defect ground structure, 8 is a second spur line defect ground structure, 9 is a third spur line defect ground structure, 10 is a fourth spur line defect ground structure, and 11 is a center point. DETAILED DESCRIPTION

[0033] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0034] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0035] like Figure 1 , Figure 2 and Figure 4As shown, a low threshold power YIG limiter comprises a GGG substrate 1, a YIG film 2, and a grounded metal plate 3, wherein one side of the YIG film 2 is connected to the back side of the GGG substrate 1, and the other side of the YIG film 2 contacts the grounded metal plate 3, wherein an excitation strip line group is arranged on the other side of the GGG substrate 1, and a microstrip line structure is formed by taking the YIG film 2 and the GGG substrate 1 as a combined medium;

[0036] The excitation strip line group includes a first excitation strip line 4 and a second excitation strip line 5, and the first excitation strip line 4 and the second excitation strip line 5 are arranged parallel to each other, the first excitation strip line 4 and the second excitation strip line 5 are respectively close to the two sides of the GGG substrate 1, one end of the first excitation strip line 4 is a ground end, and the other end is an input port or an output port, and one end of the second excitation strip line 5 is a ground end, and the other end is an output port or an input port.

[0037] The purpose of such design is to form a microstrip line structure with YIG film and GGG substrate as the combined medium by etching an excitation strip line group on the GGG substrate within a certain thickness range, so as to reduce the inhomogeneity of the radio frequency magnetic field generated by the direct contact of the excitation strip line group with the YIG film, and to achieve the coupling of high-power energy to the half-frequency spin wave for dissipation when the non-uniform limiting effect occurs, thereby further achieving a lower limiting power threshold than the YIG limiting structure in which the excitation strip line group is directly made on the YIG film.

[0038] At the same time, during the transduction process, the energy of the parallel double-line transducer structure composed of the first excitation strip line and the second excitation strip line will be coupled to the asymmetric spur line defect structure to achieve secondary excitation of the YIG film. Usually, the capacitance effect is regulated by the width of the spur line, and the inductance effect is regulated by the length of the spur line. Therefore, the effective dielectric constant of the combined dielectric substrate will be affected by the size of the spur line, further reducing the insertion loss within the strip.

[0039] In a specific implementation scenario, the first excitation strip line and the second excitation strip line realize signal input, transmission, conversion and output. The first excitation microstrip line and the second excitation microstrip line are parallel to each other, and their lengths and widths are consistent and symmetrical about the center point of the GGG substrate.

[0040] In addition, one end of each of the two excitation microstrip lines is set as the ground terminal, and the other end is used as the input port or output port. The purpose of this is to excite a strong RF magnetic field on the transmission line under the condition of an external bias magnetic field to ensure that more energy is coupled to the YIG film.

[0041] In this embodiment, the excitation strip line further includes a third microstrip line 6 , and the third microstrip line 6 is disposed between the first excitation strip line 4 and the second excitation strip line 5 , and the third microstrip line 6 is parallel to the first excitation strip line 4 and the second excitation strip line 5 .

[0042] Furthermore, the third microstrip line 6 is provided with spur line defect ground structures whose number is an integer multiple of four, and half of the spur line defect ground structures are arranged on the side of the third microstrip line 6 close to the first excitation strip line 4, and the other half of the spur line defect ground structures are arranged on the side of the third microstrip line 6 close to the second excitation strip line 5.

[0043] The purpose of this design is to achieve the suppression of clutter within the passband and harmonics outside the passband of the YIG limiter by setting an asymmetric spur line defect ground structure between the parallel double-line transducer structure, thereby optimizing the flatness of the in-band standing wave and insertion loss.

[0044] In this embodiment, taking four spur line defect ground structures as an example, four spur line defect ground structures are arranged on the third microstrip line 6, namely, a first spur line defect ground structure 7, a second spur line defect ground structure 8, a third spur line defect ground structure 9 and a fourth spur line defect ground structure 10;

[0045] The first spur line defect ground structure 7 and the third spur line defect ground structure 9 are arranged close to the first excitation strip line 4;

[0046] The second spur line defect ground structure 8 and the fourth spur line defect ground structure 10 are arranged close to the second excitation strip line 5 .

[0047] The first spur line defect ground structure 7 , the second spur line defect ground structure 8 , the third spur line defect ground structure 9 and the fourth spur line defect ground structure 10 have the same width.

[0048] At the same time, the first spur line defect ground structure 7, the second spur line defect ground structure 8, the third spur line defect ground structure 9 and the fourth spur line defect ground structure 10 all include a short segment and a long segment, and the short segment is vertically connected to the long segment, and the open end of the short segment is flush with the horizontal axis direction of the third microstrip line 6.

[0049] In some specific usage scenarios, the first defect ground spur line structure and the second defect ground spur line structure can be of different lengths or of equal length. Setting an asymmetric spur line means that its application frequency is also different. When used in a YIG limiter, it can more widely suppress in-band clutter and out-of-band harmonics.

[0050] Furthermore, the four spur line defect structures do not intersect each other, keep a predetermined distance from each other, and their shorter open ends are flush with the horizontal axis direction of the third microstrip line. The widths of the first defect spur line structure, the second defect spur line structure, the third defect spur line structure, and the fourth defect spur line structure are all the same.

[0051] like Figure 2 and Figure 3, two distribution modes of four spur line defect ground structures are provided respectively, one of which is that the shape of the first spur line defect ground structure 7 is the same as the shape of the fourth spur line defect ground structure 10, and they are arranged diagonally at the center of the third microstrip line 6, and the long section of the first spur line defect ground structure 7 faces the third spur line defect ground structure 9;

[0052] The second spur line defect ground structure 8 has the same shape as the third spur line defect ground structure 9 and is disposed diagonally to the center of the third microstrip line 6 , with the long section of the third spur line defect ground structure 9 facing the first spur line defect ground structure 7 .

[0053] Another is that the shape of the first spur line defect ground structure 7 is the same as that of the fourth spur line defect ground structure 10, and they are arranged diagonally at the center of the third microstrip line 6, and the long section of the first spur line defect ground structure 7 faces away from the third spur line defect ground structure 9;

[0054] The second spur line defect ground structure 8 has the same shape as the third spur line defect ground structure 9 and is disposed diagonally to the center of the third microstrip line 6 . The long section of the third spur line defect ground structure 9 faces away from the first spur line defect ground structure 7 .

[0055] In a specific usage scenario, when the external bias magnetic field is set to be parallel to the first excitation microstrip line and the second excitation microstrip line, the RF signal is input from the first excitation microstrip line and output from the second excitation microstrip line. According to the magnetostatic wave theory, under the excitation of the external bias magnetic field in this direction, magnetostatic surface waves can be excited, and the signal is coupled with the YIG film through the first excitation microstrip line. The signal propagates on the surface of the YIG film in the form of a spin wave. In the process of propagating to the coupling with the second excitation microstrip line, it will couple with the central symmetrical defect spur line structure located between the parallel double-line transducer structure composed of the first excitation strip line 4 and the second excitation strip line 5 to achieve further energy exchange, and finally couple to the second excitation microstrip line to output the signal through the output port.

[0056] like Figure 5 As shown, the passband frequency band of the YIG limiter is controlled by the field strength of the external bias magnetic field. At an intensity of 200 Oersteds, the structure provided in this embodiment achieves a center frequency of 2 GHz, a bandwidth of approximately 400 MHz, an insertion loss of approximately 0.9 dB, a standing wave of less than -10 dB, and a simulation result with good out-of-band suppression.

[0057] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-threshold power YIG limiter, comprising a GGG substrate (1), a YIG film (2), and a grounded metal plate (3), wherein one side of the YIG film (2) is connected to the back side of the GGG substrate (1), and the other side of the YIG film (2) is in contact with the grounded metal plate (3), characterized in that: An excitation strip line group is provided on the other side of the GGG substrate (1), and a microstrip line structure is formed by using the YIG film (2) and the GGG substrate (1) as a combined medium; The excitation strip line group comprises a first excitation strip line (4) and a second excitation strip line (5), and the first excitation strip line (4) and the second excitation strip line (5) are arranged in parallel with each other, the first excitation strip line (4) and the second excitation strip line (5) are respectively close to two sides of the GGG substrate (1), one end of the first excitation strip line (4) is a ground end, and the other end is an input port or an output port, and one end of the second excitation strip line (5) is a ground end, and the other end is an output port or an input port.

2. A low threshold power YIG limiter according to claim 1, characterized in that: The length and width of the first excitation strip line (4) and the second excitation strip line (5) are consistent.

3. A low threshold power YIG limiter according to claim 1, characterized in that: The first excitation strip line (4) and the second excitation strip line (5) are symmetrical about a center point (11) of the GGG substrate (1).

4. A low threshold power YIG limiter according to claim 1, characterized in that: The excitation strip line further comprises a third microstrip line (6), and the third microstrip line (6) is arranged between the first excitation strip line (4) and the second excitation strip line (5), and the third microstrip line (6) is parallel to the first excitation strip line (4) and the second excitation strip line (5).

5. A low threshold power YIG limiter according to claim 4, characterized in that: The third microstrip line (6) is provided with spur line defect ground structures whose number is an integral multiple of four, and half of the spur line defect ground structures are arranged on a side of the third microstrip line (6) close to the first excitation strip line (4), and the other half of the spur line defect ground structures are arranged on a side of the third microstrip line (6) close to the second excitation strip line (5).

6. A low threshold power YIG limiter according to claim 5, characterized in that: The third microstrip line (6) is provided with four spur line defect ground structures, namely a first spur line defect ground structure (7), a second spur line defect ground structure (8), a third spur line defect ground structure (9) and a fourth spur line defect ground structure (10); The first spur line defect ground structure (7) and the third spur line defect ground structure (9) are arranged close to the first excitation strip line (4); The second spur line defect ground structure (8) and the fourth spur line defect ground structure (10) are arranged close to the second excitation strip line (5).

7. A low threshold power YIG limiter according to claim 6, characterized in that: The first spur line defect ground structure (7), the second spur line defect ground structure (8), the third spur line defect ground structure (9) and the fourth spur line defect ground structure (10) have the same width.

8. A low threshold power YIG limiter according to claim 6, characterized in that: The first spur line defect ground structure (7), the second spur line defect ground structure (8), the third spur line defect ground structure (9) and the fourth spur line defect ground structure (10) each comprise a short segment and a long segment, wherein the short segment is vertically connected to the long segment, and the open end of the short segment is flush with the horizontal axis direction of the third microstrip line (6).

9. A low threshold power YIG limiter according to claim 8, characterized in that: The shape of the first spur line defect ground structure (7) is the same as that of the fourth spur line defect ground structure (10), and is arranged diagonally at the center of the third microstrip line (6), with the long section of the first spur line defect ground structure (7) facing the third spur line defect ground structure (9); The shape of the second spur line defect ground structure (8) is the same as that of the third spur line defect ground structure (9), and is arranged diagonally at the center of the third microstrip line (6), with the long section of the third spur line defect ground structure (9) facing the first spur line defect ground structure (7).

10. A low threshold power YIG limiter according to claim 8, characterized in that: The shape of the first spur line defect ground structure (7) is the same as that of the fourth spur line defect ground structure (10), and is arranged diagonally at the center of the third microstrip line (6), with the long section of the first spur line defect ground structure (7) facing away from the third spur line defect ground structure (9); The shape of the second spur line defect ground structure (8) is the same as that of the third spur line defect ground structure (9), and is arranged diagonally at the center of the third microstrip line (6), with the long section of the third spur line defect ground structure (9) facing away from the first spur line defect ground structure (7).

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