Interdigital tuning-free superconducting filter

Abstract

The invention, which relates to the technical field of the filter, discloses an interdigital tuning-free superconducting filter comprising a plurality of resonators arranged side by side along a first direction. Each resonator comprises a capacitance coupling structure and a first spot welding plate, the capacitance coupling structure comprises a superconducting block, a second spot welding plate and an interdigital capacitor arranged between the superconducting block and the second spot welding plate, and the first spot welding plate is arranged on the side, away from the superconducting block, of the second spot welding plate in the second direction and is in coupling connection with the superconducting block; and the first spot welding plate is also electrically connected with the second spot welding plate. The interdigital tuning-free superconducting filter provided by the invention does not need to be tuned through a tuning screw, can meet the index requirement after being manufactured, and saves time, manpower and material resources.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to an interdigital tuning-free superconducting filter. Background Art

[0002] Since the discovery of superconducting materials, their characteristic of vanishing resistance has attracted the attention of many researchers. However, the transition temperature of early materials was very low, making it difficult to apply them in practice. Since the discovery of high-temperature superconductors, the transition temperature has been raised to above 90K. This achievement has greatly stimulated the research on superconductivity and made the application of superconductors have broad prospects. The surface resistance of high-temperature superconducting thin film materials in the microwave frequency range is generally more than two orders of magnitude smaller than that of conventional metal materials such as copper (Cu), and even less than one thousandth of copper in the low-frequency range of less than 1GHz. Therefore, the resonator circuit made of high-temperature superconducting thin film materials such as YBCO has a very high unloaded Q value, which greatly improves the performance of superconducting filters relative to ordinary filters. The performance of the filter will affect the processing capability of the entire signal system. These excellent characteristics make superconducting filters have very good performance in various fields, such as mobile communications, satellite reception, radio astronomy, etc., and have been widely developed and have practical applications.

[0003] After the traditional filter is manufactured, it needs further debugging to make the bandwidth frequency and other indicators meet the requirements. The method used is to control the depth of the tuning screw to change the electromagnetic environment of the internal resonator to meet the indicators. However, the tuning process is cumbersome and the filter may be damaged during the tuning process. Summary of the invention

[0004] The purpose of the present invention is to provide an interdigital tuning-free superconducting filter to solve the problems existing in the above-mentioned prior art. It does not need to be tuned by tuning screws and can meet the required indicators after being manufactured, thus saving time, manpower and material resources.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an interdigital tuning-free superconducting filter, comprising a plurality of resonators arranged side by side along a first direction; each of the resonators comprises a capacitive coupling structure and a first spot welding plate, the capacitive coupling structure comprises a superconducting block, a second spot welding plate and an interdigital capacitor arranged between the superconducting block and the second spot welding plate, the first spot welding plate is arranged along a second direction on a side of the second spot welding plate away from the superconducting block and is coupled and connected to the superconducting block, and the first spot welding plate is also electrically connected to the second spot welding plate.

[0007] Preferably, the first spot welding plate is coupled to the superconducting block via a spiral wire.

[0008] Preferably, the capacitive coupling structure is arranged between the spiral lines.

[0009] Preferably, the first spot welding plate is electrically connected to the second spot welding plate through a plurality of spot welding wires.

[0010] Preferably, the device further comprises an input feeder line arranged at one side of the plurality of resonators along the first direction, wherein the input feeder line is connected to the resonators at the side.

[0011] Preferably, it also includes an output feeder line arranged in the first direction at the other side of the plurality of resonators, wherein the output feeder line is connected to the resonators on this side.

[0012] Preferably, the first direction is perpendicular to the second direction.

[0013] Preferably, the number of the resonators is set to an even number.

[0014] Preferably, a plurality of the resonators are arranged on a superconducting film.

[0015] Preferably, the plurality of resonators are etched on the superconducting thin film by photolithography or dry etching.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The interdigital tuning-free superconducting filter provided by the present invention forms a self-interdigital structure by electrically connecting the first spot welding plate with the second spot welding plate of the capacitive coupling structure, thereby realizing strong capacitance and strong inductance inside the resonator, realizing strong coupling, and then realizing a tuning-free filter. There is no need to tune by a tuning screw, and no tuning is required. After the production is completed, the required indicators can be achieved, saving time, manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of an interdigital tuning-free superconducting filter provided in Embodiment 1;

[0020] Figure 2 This is a simulated measured characteristic diagram of the interdigital tuning-free superconducting filter provided in Example 1.

[0021] In the figure: 1-resonator; 2-capacitive coupling mechanism; 21-superconducting block; 22-second spot welding plate; 23-interdigital capacitor; 3-first spot welding plate; 4-spiral wire; 5-spot welding wire; 6-input feed line; 7-output feed line. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The purpose of the present invention is to provide an interdigital tuning-free superconducting filter to solve the problems existing in the above-mentioned prior art. It does not need to be tuned by tuning screws and can meet the required indicators after being manufactured, thus saving time, manpower and material resources.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Embodiment 1

[0026] This embodiment provides an interdigital tuning-free superconducting filter. Figure 1 , comprising a plurality of resonators 1 arranged side by side along a first direction; each resonator 1 comprises a capacitive coupling mechanism 2 and a first spot welding plate 3, the capacitive coupling mechanism 2 comprises a superconducting block 21, a second spot welding plate 22 and a finger capacitor 23 arranged between the superconducting block 21 and the second spot welding plate 22, the first spot welding plate 3 is arranged along the second direction on a side of the second spot welding plate 22 away from the superconducting block 21 and is coupled to the superconducting block 21, and the first spot welding plate 3 is also electrically connected to the second spot welding plate 22.

[0027] By electrically connecting the first spot welding plate 3 with the second spot welding plate 22 of the capacitive coupling structure 2, a self-interdigitated structure is formed, strong capacitance and strong inductance are achieved inside the resonator 1, strong coupling is achieved, and then a tuning-free filter is realized. There is no need to tune with a tuning screw, and no tuning is required. After the production is completed, the required indicators can be achieved, saving time, manpower and material resources.

[0028] In the optional scheme of this embodiment, more preferably, the first spot welding plate 3 is coupled and connected with the superconducting block 21 through the spiral wire 4. Specifically, the spiral wire 4 is set as a copper foil coil.

[0029] In the optional solution of this embodiment, more preferably, the capacitive coupling mechanism 2 is arranged between the spiral lines 4.

[0030] In the optional scheme of this embodiment, more preferably, the first spot welding plate 3 is electrically connected to the second spot welding plate 22 through a plurality of spot welding wires 5, so that a self-interdigitated structure is formed between the first spot welding plate 3 and the second spot welding plate 22.

[0031] In the optional scheme of this embodiment, more preferably, the interdigital tuning-free superconducting filter provided in this embodiment also includes an input feeder 6 arranged on one side of the multiple resonators 1 along the first direction, and the input feeder 6 is connected to the resonator 1 on this side. The signal is input by setting the input feeder 6, and the loss and interference of the signal during the transmission process are reduced.

[0032] Among the optional schemes of this embodiment, it is more preferred that the interdigital tuning-free superconducting filter provided in this embodiment also includes an output feeder 7 arranged in a first direction on the other side of the multiple resonators 1, and the output feeder 7 is connected to the resonator 1 on this side. The signal is output by setting the input feeder 6, and the loss and interference of the signal during the transmission process are reduced.

[0033] In the optional solutions of this embodiment, it is more preferred that the first direction is perpendicular to the second direction, so as to improve the overall space utilization of the filter.

[0034] In the optional solution of this embodiment, it is more preferred that the number of resonators 1 is set to an even number, such as 4, 6 or more, and the distance between the resonators 1 can be changed according to the requirements of the simulation bandwidth; specifically, see Figure 2 , which is a characteristic diagram of the coupling of ten resonators 1, with the horizontal axis being frequency (MHz) and the vertical axis being magnitude value (dB), wherein the gray line is simulation data and the black line is actual data.

[0035] In the optional scheme of this embodiment, it is more preferred that multiple resonators 1 are arranged on the superconducting film, and the superconducting block 21 is used to utilize the characteristic of zero resistance of superconducting materials at low temperatures to produce a filter with extremely high Q value and extremely small passband insertion loss, thereby effectively suppressing various interferences and improving signal transmission quality and capacity.

[0036] In the optional solution of this embodiment, more preferably, a plurality of resonators 1 are etched on the superconducting film by photolithography or dry etching to achieve connection between the resonators 1 and the superconducting film.

[0037] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An interdigital tuning-free superconducting filter, characterized in that: It comprises a plurality of resonators (1) arranged side by side along a first direction; Each of the resonators (1) comprises a capacitive coupling mechanism (2) and a first spot welding plate (3); the capacitive coupling mechanism (2) comprises a superconducting block (21), a second spot welding plate (22), and an interdigital capacitor (23) arranged between the superconducting block (21) and the second spot welding plate (22); the first spot welding plate (3) is arranged along a second direction on a side of the second spot welding plate (22) away from the superconducting block (21) and is coupled to the superconducting block (21); and the first spot welding plate (3) is also electrically connected to the second spot welding plate (22).

2. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: The first spot welding plate (3) is coupled to the superconducting block (21) via a spiral wire (4).

3. The interdigital tuning-free superconducting filter according to claim 2, characterized in that: The capacitive coupling mechanism (2) is arranged between the spiral lines (4).

4. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: The first spot welding plate (3) is electrically connected to the second spot welding plate (22) via a plurality of spot welding wires (5).

5. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: It also comprises an input feeder (6) arranged on one side of the plurality of resonators (1) along the first direction, wherein the input feeder (6) is connected to the resonators (1) on this side.

6. The interdigital tuning-free superconducting filter according to claim 5, characterized in that: It also includes an output feeder (7) arranged in the first direction on the other side of the plurality of resonators (1), wherein the output feeder (7) is connected to the resonator (1) on this side.

7. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: The first direction is perpendicular to the second direction.

8. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: The number of the resonators (1) is set to an even number.

9. The interdigital tuning-free superconducting filter according to claim 1, characterized in that: A plurality of resonators (1) are arranged on a superconducting film.

10. The interdigital tuning-free superconducting filter according to claim 9, characterized in that: A plurality of resonators (1) are etched on the superconducting film by photolithography or dry etching.

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