CN118299779A

CN118299779A - High-selectivity broadband superconducting filter based on double-feeder resonator method and application

Info

Publication number: CN118299779A
Application number: CN202410454581.XA
Authority: CN
Inventors: 陆喜龙; 方雪阳; 魏光松; 周世钢; 陶涢熙; 高艳红; 陈东博; 张睿; 孔庆羽; 翁博楷
Original assignee: Northwestern Polytechnical University; Taicang Yangtze River Delta Research Institute of Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University; Taicang Yangtze River Delta Research Institute of Northwestern Polytechnical University
Filing date: 2024-04-16
Publication date: 2024-07-05

Abstract

The invention relates to a high-selectivity broadband superconducting filter based on a double-feeder resonator method and application thereof. The connecting line resonator is formed by connecting two microstrip lines. Due to the symmetrical structure, the odd and even mode methods can be used to analyze the resonant modes. When two tri-mode CLRs are arranged in opposite directions and coupled by a gap S, six peaks are produced and the amplitude of S ₂₁ presents a very sharp skirt at the upper band edge. The invention designs the high-temperature superconductive wideband filter by adopting a double feeder resonator method, and improves the selectivity and the bandwidth by creating additional transmission poles in the passband. Meanwhile, the double feeder resonator method is also suitable for various filter designs, including designs with medium bandwidth and ultra-wideband requirements.

Description

High-selectivity broadband superconducting filter based on double-feeder resonator method and application

Technical Field

The invention belongs to the technical field of microwave communication, and relates to a high-selectivity broadband superconducting filter based on a double-feeder resonator method and application thereof

Background

Filters play an indispensable role in electronic systems, especially when dealing with the large bandwidth requirements of high-speed communications. Currently, the research of broadband filters has made remarkable progress. According to the design theory of the coupled resonator filter, the more the number of transmission poles in the passband, the wider the bandwidth and the stronger the selectivity. In the conventional approach, there are two main strategies for introducing more transmission poles: the first method adopts a multimode resonator and fully utilizes the first few resonant modes; the second approach involves increasing the number of resonators, but this may lead to an increase in the volume of the filter while reducing the insertion loss.

Therefore, a more efficient method is highly desirable to introduce additional transmission poles within the passband, thereby improving the performance of the filter. The gap-coupled feed line structure is the most common one, however, in general it cannot generate a transmission pole within the passband. In the present invention, the gap-coupled feed is modified to a resonator, as part of a dual-feed resonator, to introduce additional transmission poles within the passband. The design and manufacture of the present invention involves demonstration of two superconducting filters to demonstrate the effectiveness of the dual feed resonator approach.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a high-selectivity broadband superconducting filter based on a double-feeder resonator method and application thereof. Filters designed by this method have a number of significant features including, but not limited to, additional transmission poles, wide passband, low loss, wide stopband, miniaturized design, strong out-of-band rejection, high sharpness, and simplified design. The invention aims to introduce an innovative design method for the field of high-temperature superconductive broadband filters so as to improve the performance and solve the limitations of the prior art.

Technical proposal

A high-selectivity broadband superconducting filter based on a double-feeder resonator method comprises a dielectric substrate and a high-temperature superconducting thin film layer positioned on the dielectric substrate; the method is characterized in that: the superconducting filter of the high-temperature superconducting film layer structure comprises a double feeder resonator and a plurality of connecting line resonators CLR; the input end and the output end of the superconducting filter are connected with double-feeder resonators by adopting 50 omega microstrip feeder lines, and a plurality of connecting line resonators CLR are arranged between the double-feeder resonators at the two ends; the coupling gap between the connecting double feeder line resonators and the connecting line resonators CLR is S, and the coupling gap between two adjacent connecting line resonators CLR is S _i; the connecting line resonator CLR is a three-mode resonator formed by connecting two microstrip lines, and a connecting line is arranged between the two microstrip lines; the superconducting filter is of a central symmetry structure.

The minimum of the connecting wire resonators CLR is 1, and the maximum is not.

The number of the connecting line resonators CLR is even or odd.

The superconducting filter with the symmetrical structure adopts an odd mode method and an even mode method to analyze the resonance mode.

In the superconducting filter with the symmetrical structure, when two three-mode CLRs are reversely arranged and coupled through a gap s, cross coupling occurs between an odd mode and an even mode of the two CLRs, an additional transmission zero point is generated, and a very sharp skirt edge is displayed at the edge of a band.

The superconducting filter with the symmetrical structure adopts a four-stage connecting line resonator, and converts a feeder into a resonator, and the double feeder resonator structure at the input end and the double feeder resonator at the output end generate two additional transmission poles.

The position of the connecting line between the two microstrip lines of the connecting line resonator CLR is adjusted according to the broadband and performance of the resonator designed according to the requirement.

The high-temperature superconducting film layer material is a superconducting material with the critical temperature above 77K and the resistance close to zero in a liquid nitrogen (77K) refrigeration environment.

The high-temperature superconductive film layer is made of yttrium barium copper oxide YBCO or bismuth strontium calcium copper oxide.

An application of the high-selectivity broadband superconducting filter based on the double-feeder resonator method is characterized in that: the superconducting filter converts a conventional feeder into a resonator by adding additional lines to compensate for the electrical length, allowing additional transmission poles to be created within the passband, thereby enhancing selectivity and bandwidth for various design filters, including designing filters with medium and ultra-wideband requirements.

Advantageous effects

The invention provides a high-selectivity broadband superconducting filter based on a double-feeder resonator method and application thereof, and belongs to the technical field of microwave communication. The invention provides a new concept and a new design method of the double feeder resonator for the first time. The feed line of the traditional filter is only used for external coupling, and the double feed line resonator design method provided by the invention realizes the function of the double feed line resonator by improving the gap coupling feed line and converting the gap coupling feed line into a resonator. The dual feed resonator can exhibit a large attenuation slope at the high band edge and introduce additional transmission poles within the passband, thereby significantly improving the performance of the filter without increasing the physical size of the filter. The design method provided by the invention comprises a connecting line resonator CLR, eight-stage filtering based on a double-feeder resonator and a fourteen-pole HTS filter based on the double-feeder resonator. The connecting line resonator is formed by connecting two microstrip lines. Due to the symmetrical structure, the odd and even mode methods can be used to analyze the resonant modes. When two tri-mode CLRs are arranged in opposite directions and coupled by a gap S, six peaks are produced and the amplitude of S ₂₁ presents a very sharp skirt at the upper band edge. To convert the feed line to a resonator, an additional transmission line is connected to a 50Ω terminal line near the gap-coupled feed line. The combination of the additional line and the gap-coupled feeder line forms a double feeder resonator structure. The invention designs the high-temperature superconductive wideband filter by adopting a double feeder resonator method, and improves the selectivity and the bandwidth by creating additional transmission poles in the passband. Meanwhile, the double feeder resonator method is also suitable for various filter designs, including designs with medium bandwidth and ultra-wideband requirements.

The invention has the specific characteristics that:

1. By adding additional lines to compensate for the feeder length, a conventional feeder can be converted to a resonator. This allows additional transmission poles to be created within the passband, enhancing selectivity and bandwidth.

2. When two three-modes CLR are reversely arranged and coupled through a gap S, under different gaps S, the amplitude of S ₂₁ can generate obvious sharp offset at the edge of an upper frequency band due to the generation of transmission zero, and a filter with asymmetric frequency response can be designed by fully utilizing the unique characteristic. And the transmission zero is related to the direction of the two CLRs. The two CLRs must be aligned in opposite directions, resulting in cross-coupling between the odd and even modes of the two CLRs.

3. Has the characteristics of flexible design, compact structure and easy integration, and is suitable for manufacturing high-temperature superconductive films with high quality factors

Drawings

Fig. 1: the high-selectivity broadband superconducting filter structure schematic diagram designed based on the double-feeder resonator method in the embodiment of the invention;

Fig. 2: the embodiment of the invention discloses a specific dimensional parameter structure schematic diagram of a high-selectivity broadband superconducting filter designed based on a double feeder resonator method;

fig. 3: the geometry of the Connecting Line Resonator (CLR) in the embodiments of the present invention;

fig. 4: the even mode equivalent circuit of the CLR in the embodiment of the invention;

fig. 5: the odd mode equivalent circuit of the CLR in the embodiment of the invention;

Fig. 6: in l₁＝l₂＝4.12mm,w₁＝w₂＝0.1mm,l₄＝l₅＝3.02mm,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm embodiments of the present invention, the simulated resonant frequency of the line resonator (CLR);

Fig. 7: when l₁＝l₂＝4.12mm,w₁＝w₂＝0.1mm,l₄＝l₅＝3.02mm,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm is adopted in the embodiment of the invention, two coupling three-mode CLR structures under weak excitation are adopted;

Fig. 8: when two CLRs in the embodiment of the invention are coupled through different gaps, the relation between the size of S ₂₁ and the frequency is that;

Fig. 9: when w₁＝w₂＝0.1mm,l₄＝l₅＝3.02mm,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm is adopted, the geometry of the six-stage filter designed based on the double feeder resonator method is adopted;

fig. 10: the simulation performance of the filter with six transmission poles in the embodiment of the invention;

Fig. 11: when w₁＝w₂＝0.1mm,l₄＝l₅＝3.02mm,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm is adopted in the embodiment of the invention, the geometry of the eight-stage filter based on the double feeder resonator is adopted;

Fig. 12: the simulation performance of the eight-stage filter based on the double feeder resonator in the embodiment of the invention;

Fig. 13: the current density distribution of the two-stage filter based on the double feeder resonator in the embodiment of the invention is at 5.5GHz, 4.7GHz and 10.06 GHz;

Fig. 14: the size and layout of a fourteen-pole HTS filter based on a double feeder resonator in the embodiment of the invention;

fig. 15: simulation results of fourteen-stage filters in the embodiment of the invention;

Fig. 16: and a comparison graph of the simulated frequency response result and the actual measured frequency response result of the fourteen-pole filter is provided.

Detailed Description

The invention will now be further described with reference to examples, figures:

The feeder line of the traditional filter is only used for external coupling, and the double feeder line resonator design method of the high-temperature superconductive broadband filter of the embodiment realizes the function of the double feeder line resonator by improving the gap coupling feeder line and converting the gap coupling feeder line into the resonator. The dual feed resonator can exhibit a large attenuation slope at the high band edge and introduce additional transmission poles within the passband, thereby significantly improving the performance of the filter without increasing the physical size of the filter.

The invention provides a new concept and a new design method of a double feeder resonator for the first time, so that a feeder can be converted into the resonator, the double feeder resonator can be used for providing external coupling, and an additional transmission pole can be generated in a passband to increase bandwidth and selectivity, and a filter designed based on the double feeder resonator method comprises: the dielectric substrate 1 and the high-temperature superconductive film layer positioned on the dielectric substrate are used for constructing a filter circuit.

Fig. 1 is a schematic diagram of a four-stage filter of a high-selectivity wideband superconducting filter designed by a double-feeder resonator method according to an embodiment of the present invention. The filter circuit includes: the first additional line 3, the second additional line 16, the first gap coupling feeder 4, the second gap coupling feeder 15, the first connecting line resonator composed of the first microstrip opening line 5, the second microstrip opening line 6, the third microstrip opening line 7, the fourth microstrip opening line 8 and the first connecting line 9, the second connecting line resonator composed of the fifth microstrip opening line 10, the sixth microstrip opening line 11, the seventh microstrip opening line 12, the eighth microstrip opening line 13 and the second connecting line 14, the third and fourth connecting line resonators obtained by the first resonator and the second resonator through center symmetry, the input 50Ω microstrip feeder 2, and the output 50Ω microstrip feeder 17, wherein:

The first additional line 3 is formed by connecting three sections of microstrip opening lines, the upper sides of the first additional line 3 and the first microstrip opening line 4 are connected with a 50Ω microstrip feeder 2 at an input end, the first microstrip opening line 5, the second microstrip opening line 6, the third microstrip opening line 7 and the fourth microstrip opening line 8 are connected through a first connecting line 9 to form a first connecting line resonator CLR, the distance between the first microstrip opening line 4 and the first connecting line resonator CLR is S, the fifth microstrip opening line 10, the sixth microstrip opening line 11, the seventh microstrip opening line 12 and the eighth microstrip opening line 13 are connected through a second connecting line 14 to form a second connecting line resonator CLR, in addition, the first connecting line resonator CLR and the second connecting line resonator CLR are formed through center symmetry to form a third connecting line resonator CLR and a fourth connecting line resonator CLR, the distance between the second connecting line resonator CLR and the third connecting line resonator CLR is S ₁, the distance between the second connecting line resonator CLR and the third connecting line resonator CLR is S ₂, and the second additional line 16 is also formed by connecting the third microstrip opening line 10 and the second microstrip opening line 12, and the eighth microstrip opening line 13 is connected with the lower side of the microstrip opening line 50 at the output end.

The resonator circuit of the filter employs a connecting line resonator CLR structure formed by four microstrip open lines, which can create additional transmission poles within the passband to enhance selectivity and bandwidth.

The resonator circuit of the filter employs a first connecting line resonator CLR and a second connecting line resonator CLR arranged in opposite directions, resulting in cross coupling between the odd and even modes of the two CLRs, creating additional transmission zeros, presenting a very sharp skirt at the band edges.

The resonator circuit of the filter adopts a four-stage connecting line resonator and converts the feed line into a resonator, the first additional line 3 and the first gap coupling feed line 4 are combined to form a double feed line resonator structure, the second additional line 16 and the second gap coupling feed line 15 are also combined to form a double feed line resonator structure, and two additional transmission poles can be generated by the two double feed line resonators.

The whole circuit structure of the filter is in a central symmetry relationship.

The high-temperature superconducting film layer can be made of Yttrium Barium Copper Oxide (YBCO) or bismuth strontium calcium copper oxide.

The superconductive film is a superconductive material with critical temperature above 77K and resistance near zero, and can be used in liquid nitrogen (77K) refrigerating environment, and is mainly divided into two types: yttrium Barium Copper Oxide (YBCO) and bismuth strontium calcium copper oxide.

Compared with the conventional film material (such as copper), the high-temperature superconducting film has the characteristics of zero resistance, diamagnetism and the like in a superconducting state.

Fig. 2 is a top view of an upper layer radiating metal patch of a high temperature superconductive wideband single stage filter designed by a dual feed line resonator method according to an embodiment of the present invention, in which specific parameter names are marked, and it should be noted that the relevant simulation tool used in the present invention is Sonnet EM, the superconductive substrate used is MgO/YBCO, the dielectric constant of the substrate is 9.8, and this embodiment is only one of the solutions.

Fig. 3 shows the geometry of the connecting line resonator CLR, with two microstrip lines connected as a three-mode resonator. Due to the structural symmetry, the resonant modes can be analyzed using the odd mode and even mode methods.

Fig. 4 shows that even mode resonance occurs when the structure is placed with the magnetic wall on the middle symmetry plane. The even mode input admittance can be represented by the following formula:

Also, fig. 5 illustrates that when an electrical wall is placed, the structure exhibits odd mode resonance. The odd mode input admittance can be expressed by the formula:

the odd mode frequencies fodd1 and fodd2 can be calculated using the following formula

When l₁＝l₂＝4.12mm,w₁＝w₂＝0.1mm,l₃＝4.12mm,w₃＝0.1mm,l₄＝l₅＝4.12mm,w₄＝w₅＝0.1mm.

Wherein:

Y _in-even: even mode total input admittance

Y _ein1: input admittance sum of even mode microstrip line 3.4

Y _ein3: input admittance of even mode microstrip line 3

Y _in4: input admittance of microstrip line 4

Y _in-odd: odd mode total input admittance

Y _oin1: input admittance sum of odd mode microstrip line 3.4

Y _oin3: input admittance of odd mode microstrip line 3

Y _k: input admittance of microstrip line k (k=1, 3, 4)

Θ _k: impedance angle of microstrip line k (k=1, 3, 4)

Fig. 6 shows a diagram of simulation results of a Connecting Line Resonator (CLR) when the first three resonance frequencies are f _odd1＝6.41GHz、f_even1 =7.93 GHz and f _odd2 =8.99 GHz, respectively, in the embodiment of the present invention; wherein: at l₁＝l₂＝4.12mm,w₁＝w₂＝0.1mm,l₄＝l₅＝3.02mm,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm, the simulated resonant frequency of the line resonator (CLR) is found.

Fig. 7 and 8 show that when two three-mode LCRs are aligned opposite each other and coupled through a gap s, six peaks are generated. One of the significant features of l₁＝l₂＝4.12mm,w₁＝w₂＝0.1mm,l₄＝l₅＝3.02GHz,w₄＝w₅＝0.1mm,l₃＝1.38,w₃＝0.12mm. is that at different gaps S, the amplitude of S ₂₁ exhibits a sharp skirt at the upper band edge due to the transmission zero generated. This unique characteristic can be exploited when designing filters with asymmetric frequency response. We have also found that the transmission zero is related to the direction of the two CLRs. The two CLRs must be aligned in opposite directions, resulting in cross-coupling between the odd and even modes of the two CLRs. If the directions of the two CLRs are the same, the transmission zero near the upper band edge disappears.

Fig. 9 shows the geometry of a six-stage filter, wherein w₁＝w₂＝0.1mm,l₄＝l₅＝3.02GHz,w₄＝w₅＝0.1mm,l₃＝1.38mm,w₃＝0.12mm. based on the proposed CLR, a six-stage filter with a center frequency of 7-9.437 GHz (5.331 GHz) and an FBW (fractional bandwidth) of 55.4% was designed.

Fig. 10 shows that when S ₂₁ =0, six transmission poles can be determined. The filter exhibits excellent sharp corners at the high band edges, with an attenuation slope of 116.8dB/GHz from-3 dB (9.41 GHz) to-40 dB (9.75 GHz). However, the steepness of the low band edge is not sufficient, and the attenuation slope from-3 dB (5.325 GHz) to-40 dB (1.457 GHz) is only 10.26dB/GHz.

To further improve performance, we propose a dual feed resonator approach. In fig. 9, the electrical length of the gap-coupled feed lines (denoted by l7 and w 7) is about λg/4, where λg=16.65 mm corresponds to the wavelength at f ₀ =7.37 GHz. However, it does not create transmission poles in the passband, but only six transmission poles are determined in the passband. To convert the feed line into a resonator we have an additional transmission line connected to the 50Ω terminal line near the g/4 feed line. Fig. 11 shows that the additional line (denoted by l8+l9+l10) and the lambdag/4 line (denoted by l 7) are combined into one double-feed resonator (double-feed resonator) structure. Fig. 12 shows that when S ₂₁ =0, eight transmission poles can be identified, six of which are generated by two tri-mode CLRs, and the remaining two are generated by two dual-feed resonators. The high band edge attenuation slope increases from 116.8dB/GHz to 276.1dB/GHz as compared to the filter using a conventional feed line in fig. 9; the low-frequency band edge attenuation slope is increased from 10.26dB/GHz to-81.8 dB/GHz. Fig. 13 (a) shows the current density distribution in the 5.5GHz passband, indicating that there is a current distribution on both the additional line and the lambdag/4 line. The additional wires act to compensate for the electrical length and when combined act as quasi-open loop resonators having half-wavelength resonant frequencies within a passband of about 5.5 GHz. FIG. 13 (b) shows the band-bottom edge transmission zero introduced at a frequency of 4.7GHz and its current density distribution; fig. 13 (c) shows that the higher band edge transmission zeros result from the higher spurious frequencies of the quarter wavelength resonance (10.06 GHz).

To further demonstrate this, we designed a fourteen stage filter according to the double feed resonator approach, with the geometric parameters shown in fig. 14 and the simulation results shown in fig. 15. When S ₂₁ = 0, fourteen transmission poles can be identified, of which twelve are generated by four tri-mode CLRs and the remaining two by two double feed line resonators. The filter has a high band edge attenuation slope of 518dB/GHz, from-3 dB (9.534 GHz) to-60 dB (9.644 GHz), and a low band edge attenuation slope of 104.2dB/GHz, from-3 dB (5.16 GHz) to-40 dB (4.805 GHz).

To verify the practical applicability of the design method of the present invention, we fabricated a filter with a dielectric constant of 9.8 using a 0.5mm thick YBCO/MgO superconducting substrate. A 600nm thick YBCO superconducting film was deposited on the MgO substrate. The filters were packaged in a box and measured at 68K at-20 dBm input power.

Fig. 16 shows a graph of simulated frequency response versus measured frequency response for a fourteen pole filter. From the figure, it can be seen that the measured passband is 5.16-9.54 GHz and the bandwidth is 59.6%. The maximum in-band insertion loss is about 0.5dB and the return loss is about-10 dB. The measurement result is well matched with the simulation result.

In summary, the embodiment of the invention provides a design method of a high-selectivity broadband superconducting filter based on a double feeder resonator method, which can compensate the electrical length by adding an extra line, can convert the traditional feeder into a resonator, and allows an extra transmission pole to be created in the passband, thereby enhancing the selectivity and bandwidth. A novel Connecting Line Resonator (CLR) is also proposed to obtain three resonant modes for filter design that can exhibit significant attenuation slope at the higher band edges. The design method of the high-selectivity broadband superconducting filter based on the double-feeder resonator method is adopted to design the secondary filter and the quaternary filter. The measurement result is well matched with the simulation result, and the method has obvious engineering practical value. Besides, the invention has compact structure, small volume, flexible design, easy integration and convenient circuit processing; suitable for various filter designs, including those with medium bandwidth and ultra-wideband requirements.

The foregoing has outlined rather broadly the more detailed description of embodiments of the invention, wherein the principles and embodiments of the invention are explained in detail using specific examples, the description of the embodiments being merely intended to facilitate an understanding of the method of the invention and its core concepts; those skilled in the art should appreciate that the conception and specific embodiment disclosed may be readily utilized as a basis for the designing of other structures for carrying out the same purposes of the present invention.

Claims

1. A high-selectivity broadband superconducting filter based on a double-feeder resonator method comprises a dielectric substrate and a high-temperature superconducting thin film layer positioned on the dielectric substrate; the method is characterized in that: the superconducting filter of the high-temperature superconducting film layer structure comprises a double feeder resonator and a plurality of connecting line resonators CLR; the input end and the output end of the superconducting filter are connected with double-feeder resonators by adopting 50 omega microstrip feeder lines, and a plurality of connecting line resonators CLR are arranged between the double-feeder resonators at the two ends; the coupling gap between the connecting double feeder line resonators and the connecting line resonators CLR is S, and the coupling gap between two adjacent connecting line resonators CLR is S _i; the connecting line resonator CLR is a three-mode resonator formed by connecting two microstrip lines, and a connecting line is arranged between the two microstrip lines; the superconducting filter is of a central symmetry structure.

2. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the minimum of the connecting wire resonators CLR is 1, and the maximum is not.

3. A high selectivity wideband superconducting filter based on a double feed resonator approach according to claim 1 or 2, characterised in that: the number of the connecting line resonators CLR is even or odd.

4. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the superconducting filter with the symmetrical structure adopts an odd mode method and an even mode method to analyze the resonance mode.

5. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: in the superconducting filter with the symmetrical structure, when two three-mode CLRs are reversely arranged and coupled through a gap s, cross coupling occurs between an odd mode and an even mode of the two CLRs, an additional transmission zero point is generated, and a very sharp skirt edge is displayed at the edge of a band.

6. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the superconducting filter with the symmetrical structure adopts a four-stage connecting line resonator, and converts a feeder into a resonator, and the double feeder resonator structure at the input end and the double feeder resonator at the output end generate two additional transmission poles.

7. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the position of the connecting line between the two microstrip lines of the connecting line resonator CLR is adjusted according to the broadband and performance of the resonator designed according to the requirement.

8. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the high-temperature superconducting film layer material is a superconducting material with the critical temperature above 77K and the resistance close to zero in a liquid nitrogen 77K refrigeration environment.

9. The high selectivity wideband superconducting filter based on the double feed resonator method of claim 1, wherein: the high-temperature superconductive film layer is made of yttrium barium copper oxide YBCO or bismuth strontium calcium copper oxide.

10. Use of a high selectivity wideband superconducting filter based on the double feed resonator approach as claimed in any one of claims 1-9, characterized in that: the superconducting filter converts a conventional feeder into a resonator by adding additional lines to compensate for the electrical length, allowing additional transmission poles to be created within the passband, thereby enhancing selectivity and bandwidth for various design filters, including designing filters with medium and ultra-wideband requirements.