Josephson parametric amplifier based on multi-section quarter-wavelength impedance conversion line

Abstract

The invention discloses a Josephson parametric amplifier based on multiple sections of quarter-wavelength impedance conversion lines, which comprises input and output ports of the amplifier, the multiple sections of quarter-wavelength impedance conversion lines, superconductive Josephson junction nonlinear resonators and magnetic flux bias lines corresponding to the superconductive Josephson junction nonlinear resonators, wherein the plurality of sections of quarter-wavelength impedance conversion lines are formed by four sections of quarter-wavelength transmission lines which are prepared by adopting planar coplanar waveguide circuits. Besides, the Josephson parametric amplifier is prepared by adopting a lanthanum aluminate substrate, and compared with a common high-resistance silicon or sapphire substrate, the Josephson parametric amplifier has a higher relative dielectric constant, so that the reliability of a preparation process is improved. According to the invention, the impedance matching between the parameter amplifier and the external environment is realized by adopting a plurality of sections of quarter-wavelength impedance conversion lines, and meanwhile, the lanthanum aluminate substrate is innovatively adopted to prepare the parameter amplifier, so that the reliability and the yield of the preparation process are effectively improved; the prepared sample is continuously adjustable in a large frequency range and has excellent gain and bandwidth performance.

Description

Technical Field

[0001] The invention relates to the field of amplifiers, and in particular to a Josephson parameter amplifier based on multi-section quarter-wavelength impedance transformation lines. Background Art

[0002] Superconducting parametric amplifiers based on Josephson junctions have achieved noise performance close to the quantum limit and have been proven to be an important tool for superconducting quantum information processing. It has been widely used in single-shot readout, quantum feedback, vacuum squeezed state noise, and entangled microwave photon pairs. Although the previously reported Josephson parametric amplifier can provide sufficient gain and noise close to the quantum limit to meet the high-fidelity requirements of quantum information processing, its bandwidth is limited by the bandwidth of the external resonator, resulting in a bandwidth of about tens of megahertz when the gain exceeds 15dB.

[0003] Among the many schemes published so far, there are mainly two types of impedance transformation lines: the traditional single-section quarter-wavelength impedance transformation line and the impedance transformation line with a gradient structure. The traditional single-section quarter-wavelength impedance transformation line is relatively easy to prepare, but it can only achieve impedance matching within a fixed and small frequency range; the impedance transformation line with a gradient structure can achieve impedance matching within a larger frequency range, but its structural design is complex and requires high process precision.

[0004] Based on this, there is a need for a Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines with simple circuit plan design, high chip production yield, impedance matching over a large frequency range, and a gain of more than 15dB to achieve a bandwidth of several hundred megahertz. Summary of the invention

[0005] The purpose of the present invention is to provide a Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines.

[0006] The technical solution to achieve the purpose of the present invention is: a Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line, comprising an input and output port, a multi-section quarter-wavelength impedance transformation line, a superconducting Josephson junction nonlinear resonator and a flux bias line; one end of the multi-section quarter-wavelength impedance transformation line is connected to the input and output port, and the other end is connected to the superconducting Josephson junction nonlinear resonator; the other end of the superconducting Josephson junction nonlinear resonator is connected to the flux bias line, wherein:

[0007] The multi-section quarter-wavelength impedance transformation line comprises a first section quarter-wavelength impedance transformation line, a second section quarter-wavelength impedance transformation line, a third section quarter-wavelength impedance transformation line and a fourth section quarter-wavelength impedance transformation line. The four sections quarter-wavelength impedance transformation lines are all in the form of a planar coplanar waveguide transmission line. The characteristic impedances of the quarter-wavelength impedance transformation lines are Z1, Z2, Z3 and Z4 respectively. The impedances of the input and output ports and the superconducting Josephson junction nonlinear resonator are Z0, Z1 and Z2 respectively. L , then the characteristic impedance of each quarter-wavelength impedance transformation line is calculated according to It is determined by N=4, where N is the number of sections of the multi-section quarter-wavelength impedance transformation line.

[0008] Furthermore, the characteristic impedance of the quarter-wavelength impedance transformation line is adjusted by changing the ratio of the center conductor width to the slot width of the transmission line. The higher the ratio of the center conductor width to the slot width, the lower the characteristic impedance of the planar coplanar waveguide transmission line. In addition, the characteristic impedance is also related to the chip substrate material. Under the condition that the ratio of the center conductor width to the slot width of the transmission line is constant, the larger the relative dielectric constant of the chip substrate used, the lower the characteristic impedance value of the transmission line.

[0009] Furthermore, a lanthanum aluminate substrate with a thickness of 500 μm was used for preparation.

[0010] Furthermore, the superconducting Josephson junction nonlinear resonator is formed by connecting a parallel plate capacitor and a nonlinear inductor in parallel, wherein:

[0011] The nonlinear inductor is a DC superconducting quantum interference device composed of two superconducting Josephson junctions connected in parallel. The input end of the parallel plate capacitor is connected to the fourth quarter-wavelength impedance transformation line, and the ground end of the DC superconducting quantum interference device is connected to the magnetic flux bias line.

[0012] Further, the working process is:

[0013] The microwave signal to be amplified is input into the input and output ports, and after being transmitted through a multi-section quarter-wavelength impedance transformation line, it is input into the superconducting Josephson junction nonlinear resonator;

[0014] A direct current and a pump signal are input to the flux bias line. By changing the direct current, the magnetic flux passing through the superconducting quantum interference device is adjusted, and its equivalent inductance is changed, thereby adjusting the operating frequency of the superconducting Josephson junction nonlinear resonator. The nonlinear inductance of the superconducting Josephson nonlinear resonator is used to achieve mixing between the input pump signal and the signal to be amplified, and the energy of the pump signal is converted into the energy required for amplifying the input signal. The amplified signal is reflected along the input transmission line and output through the input and output ports. A microwave circulator is connected to the input and output ports to achieve separation of the input and output signals.

[0015] Furthermore, the input and output ports, the multi-section quarter-wavelength impedance transformation lines and the magnetic flux bias lines are all made of niobium film with a thickness of 90nm to 120nm.

[0016] Furthermore, the upper plate of the parallel plate capacitor of the superconducting Josephson junction nonlinear resonator is aluminum, the dielectric layer is silicon nitride with a thickness of 200 nm, and the lower plate is niobium.

[0017] Furthermore, the DC superconducting quantum interference device uses a three-layer structure Josephson junction of aluminum-aluminum oxide-aluminum.

[0018] Furthermore, the multi-section quarter-wavelength impedance transformation line adopts laser direct writing lithography, the precision limit of laser direct writing lithography is about 1μm, and the gap width of the planar coplanar waveguide transmission line of the multi-section quarter-wavelength impedance transformation line reaches more than 3μm.

[0019] Furthermore, the central operating frequencies of the first quarter-wavelength impedance transformation line, the second quarter-wavelength impedance transformation line, the third quarter-wavelength impedance transformation line and the fourth quarter-wavelength impedance transformation line are the same.

[0020] Compared with the prior art, the present invention has the following significant advantages: 1) The design process of the Josephson parametric amplifier is simple. By sequentially connecting the quarter-wavelength impedance transformation lines of the same center frequency according to the specific characteristic impedance, the impedance matching between the environmental impedance of 50Ω and the characteristic impedance of the nonlinear resonator can be achieved. 2) The preparation process is simple. Compared with the impedance transformation line with a gradient structure, the design and preparation process are relatively simple, which reduces the process accuracy and links required for sample preparation and improves the yield and stability of sample preparation. 3) The preparation is carried out using a lanthanum aluminate substrate instead of a conventional high-resistance silicon substrate or sapphire substrate, which meets the accuracy required for sample preparation and makes the preparation process simpler and more stable. 4) Based on the design scheme of multiple quarter-wavelength impedance transformation lines, excellent gain-bandwidth characteristics can be obtained at multiple center frequencies, and an excellent gain-frequency coverage band is exhibited. 5) The design scheme based on multiple quarter-wavelength impedance transformation lines exhibits high gain and wide bandwidth characteristics at the design center frequency, achieving a gain of more than 15dB and a bandwidth of about 580MHz. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a circuit design diagram of a Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines.

[0022] Figure 2 It is a circuit design diagram of the multi-section quarter-wavelength impedance transformation line of the present invention.

[0023] Figure 3The invention provides a circuit design for the superconducting Josephson junction nonlinear resonator.

[0024] Figure 4 It is a measurement circuit diagram of the parameter amplifier of the present invention.

[0025] Figure 5 It is a flux modulation phase spectrum diagram of the center frequency of the nonlinear resonator of the parametric amplifier of the present invention.

[0026] Figure 6 It is a gain frequency curve diagram of the parametric amplifier of the present invention at different center frequencies.

[0027] Figure 7 It is a gain frequency curve diagram of the parametric amplifier of the present invention at a center frequency of about 5.45 GHz. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] like Figure 1 As shown, a Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line includes an input and output port 101 of the amplifier, a multi-section quarter-wavelength impedance transformation line 102, a superconducting Josephson junction nonlinear resonator 103 and a corresponding magnetic flux bias line 104; one end 201 of the multi-section quarter-wavelength impedance transformation line is connected to the input and output port 101, and the other end 206 is connected to the superconducting Josephson junction nonlinear resonator 103; the other end of the superconducting Josephson junction nonlinear resonator 103 is connected to the magnetic flux bias line 104.

[0030] A microwave signal to be amplified is input into the input / output port 101, and after being transmitted through the multi-section quarter-wavelength impedance transformation line 102, it is input into the superconducting Josephson junction nonlinear resonator 103; at the same time, a direct current and a pump signal are input into the magnetic flux bias line 104, and the magnetic flux passing through the superconducting quantum interference device 303 is adjusted by changing the direct current, and its equivalent inductance is changed, thereby adjusting the operating frequency of the superconducting Josephson junction nonlinear resonator 103, and the nonlinear inductance of the superconducting Josephson nonlinear resonator is used to achieve mixing between the input pump signal and the signal to be amplified, and the energy of the pump signal is converted into the energy required for amplifying the input signal, and the amplified signal is reflected along the input transmission line and output through the input / output port 101, and a microwave circulator is connected to the input / output port 101 to achieve separation of the input and output signals.

[0031] like Figure 2As shown, the multi-section quarter-wavelength impedance transformation line 102 is composed of a first section quarter-wavelength impedance transformation line 202, a second section quarter-wavelength impedance transformation line 203, a third section quarter-wavelength impedance transformation line 204 and a fourth section quarter-wavelength impedance transformation line 205. Each of the above-mentioned quarter-wavelength impedance transformation lines is designed in the form of a planar coplanar waveguide transmission line, and its main feature is that the characteristic impedance of the transmission line can be adjusted by changing the ratio of the central conductor width to the slot width of the transmission line. The higher the ratio of the central conductor width to the slot width, the lower the characteristic impedance of the planar coplanar waveguide transmission line; in addition, the characteristic impedance of the transmission line is also determined by the chip substrate used by the parametric amplifier. Under the condition that the ratio of the central conductor width to the slot width of the transmission line is constant, the larger the relative dielectric constant of the chip substrate used, the lower the characteristic impedance value of the transmission line. The specific design parameter determination process is as follows: suppose that the characteristic impedances of each section of the multi-section quarter-wavelength impedance transformation line 102 are Z1, Z2, Z3, and Z4 respectively, and the impedances of the input and output ports and the superconducting Josephson junction nonlinear resonator are Z0=50Ω, Z2=50Ω, Z3=50Ω, and Z4=50Ω respectively. L =15Ω, where the characteristic impedance of the input and output ports can be equivalent to the external environment impedance value. The characteristic impedance of each impedance transmission line can be calculated based on It is determined by N=4, where N is the number of sections of the multi-section quarter-wavelength impedance transformation line.

[0032] like Figure 3 As shown, the superconducting Josephson junction nonlinear resonator is formed by parallel connection of a parallel plate capacitor 302 and a nonlinear inductor, wherein the nonlinear inductor adopts an equivalent inductor formed by a DC superconducting quantum interference device 303 formed by two superconducting Josephson junctions connected in parallel. The input end 301 of the parallel plate capacitor is connected to the fourth quarter-wavelength impedance transformation line 205, and the ground end 304 of the DC superconducting quantum interference device 303 is connected to the magnetic flux bias line 104. By changing the current input to the magnetic flux bias line 104, the magnetic flux passing through the superconducting quantum interference device 303 is adjusted, and its equivalent inductance is changed, thereby adjusting the operating frequency of the superconducting Josephson junction nonlinear resonator 103. In addition, the magnetic flux bias line 104 also has the pump signal energy required for the amplified microwave signal of the input parametric amplifier, and the pump signal is input into the DC superconducting quantum interference device 303 to achieve mixing between the input pump signal and the signal to be amplified.

[0033] In this embodiment, the input and output ports 101, the multi-section quarter-wavelength impedance transformation line 102 and the magnetic flux bias line 104 are all made of niobium film with a thickness of 90nm to 120nm. The upper plate of the parallel plate capacitor 302 of the superconducting Josephson junction nonlinear resonator 103 is aluminum, the dielectric layer is silicon nitride, the thickness is 200nm, and the lower plate is niobium; the DC superconducting quantum interference device 303 uses a three-layer structure Josephson junction of aluminum-aluminum oxide-aluminum.

[0034] Furthermore, in the process of preparing the above-mentioned parametric amplifier, the input and output ports 101, the multi-section quarter-wavelength impedance transformation line 102, the lower plate of the parallel plate capacitor 302 and the flux bias line 104 are exposed by laser direct writing process and prepared by reactive ion etching. The dielectric layer of the parallel plate capacitor 302 is grown with silicon nitride by plasma enhanced chemical vapor deposition and prepared by laser direct writing exposure and reactive ion etching. The upper plate of the parallel plate capacitor 302 is prepared by laser direct writing exposure, electron beam thermal evaporation and stripping process. The DC superconducting quantum interference device 303 is prepared by laser direct writing or electronic book lithography and dual-angle electron beam thermal evaporation.

[0035] Furthermore, the precision limit of the laser direct writing lithography used in this scheme is about 1μm. In order to meet the preparation precision requirements of the parametric amplifier and improve the yield of the parametric amplifier, the gap width of the planar coplanar waveguide transmission line of the multi-section quarter-wavelength impedance transformation line 102 must meet the requirement of reaching more than 3μm.

[0036] Furthermore, the substrate of the parametric amplifier is usually a high-resistance silicon or sapphire substrate with a thickness of 430μm to 500μm. It is optimized to a lanthanum aluminate substrate with a thickness of 500μm and a higher relative dielectric constant than the high-resistance silicon or sapphire substrate. For the fourth quarter-wavelength impedance transformation line, the characteristic impedance needs to reach 18Ω, because it is necessary to increase the ratio of the center conductor width to the gap width of the planar coplanar waveguide transmission line, that is, while keeping the center conductor width of the transmission line unchanged, the width of the transmission line gap needs to be reduced; at the same time, in order to meet the process accuracy of laser direct writing lithography of 1μm, the transmission line gap width needs to be maintained above 3μm. Compared with the lanthanum aluminate substrate with a higher relative dielectric constant of the high-resistance silicon or sapphire substrate, the characteristic impedance of the transmission line can be further reduced while keeping the center conductor width and the gap width of the transmission line unchanged, so that the characteristic impedance of the fourth quarter-wavelength impedance transformation line reaches 18Ω while ensuring that the transmission line gap width needs to be maintained above 3μm. It meets the accuracy limit of laser direct writing lithography, while meeting the process preparation accuracy of the parametric amplifier, and improves the yield of the parametric amplifier chip.

[0037] Furthermore, the center operating frequencies of the first quarter-wavelength impedance transformation line 202, the second quarter-wavelength impedance transformation line 203, the third quarter-wavelength impedance transformation line 204 and the fourth quarter-wavelength impedance transformation line 205 are the same, thereby achieving impedance matching from the environmental impedance of 50Ω to the nonlinear resonator characteristic of 15Ω at the required center frequency.

[0038] Example

[0039] In order to verify the effectiveness of the scheme of the present invention, the following experimental design was carried out.

[0040] In this implementation sample, the designed parametric amplifier chip substrate is made of lanthanum aluminate, whose relative dielectric constant is 23.4, and the metal material used to design the impedance transformation line and the superconducting Josephson junction nonlinear resonator is made of niobium or aluminum, with a thickness of 90nm to 120nm. The length of each quarter-wavelength impedance transformation line of the designed multi-section quarter-wavelength impedance transformation line 102 is 2944μm, and the characteristic impedance of each quarter-wavelength impedance transformation line is 46Ω, 34Ω, 26Ω and 18Ω from left to right.

[0041] The parallel plate capacitance value of the superconducting Josephson junction nonlinear resonator 103 is about 4.5 pF; the critical current of a single Josephson junction of its DC superconducting quantum interference device 303 is 1.8 μA, its inherent inductance is about 3.5 pH, and the maximum resonance frequency of the superconducting Josephson nonlinear resonator 103 is about 7.7 GHz.

[0042] like Figure 4 As shown, the actual device sample in this example is measured under the 30mK low-temperature test environment provided by the dilution refrigerator, and the actual measurement circuit diagram required. The microwave signal to be amplified generated by the vector network analyzer passes through the measurement circuit from room temperature to 30mK from the output port, enters through the microwave circulator port 1, and is connected to the input and output ports of the parameter amplifier after output from port 2. The signal is amplified by the amplifier and reflected back to the input and output ports. The reflected signal enters along the microwave circulator port 2 and is output from port 3. It is input into the vector network analyzer through the measurement circuit from 30mK to room temperature, and the S21 parameter of the vector network analyzer is read to obtain the S11 parameter of the parameter amplifier. The entire measurement system circuit design is reasonable and fully functional. Based on the complete measurement plan prepared by the system, the various performance characteristics of the prepared parametric amplifier can be well characterized, which further proves the excellence of the measurement system.

[0043] like Figure 5 As shown, the phase spectrum of the nonlinear resonator center frequency measured by the actual device sample in this embodiment changes with the bias current under the 30mK low temperature test environment provided by the dilution refrigerator. By changing the DC voltage value applied to the flux bias line 104, the center frequency of the superconducting Josephson junction nonlinear resonator 103 can be changed. The formula is used for fitting, and the red dotted line flux bias fitting curve is obtained. Its center frequency can be modulated from 7.7GHz to 4GHz, and its adjustable range of center frequency exceeds 3GHz, indicating that the superconducting Josephson nonlinear resonator 103 of the parametric amplifier works normally and shows excellent center frequency adjustable performance.

[0044] like Figure 6As shown in FIG. 1 , the gain bandwidth of the parametric amplifier at different center operating frequencies is measured for the actual device sample in the present embodiment under a 30mK low temperature test environment. By changing the DC voltage input to the flux bias line 104 and selecting a suitable pump signal frequency and power, the amplification effect of the parametric amplifier on the input microwave signal can be observed. By applying and turning off the pump signal, the S 21 By recording the changes of parameters before and after, the gain frequency curve of the parametric amplifier at different center frequencies can be obtained. The parametric amplifier can achieve gain curves at center frequencies of 4.95GHz, 5.05GHz, 5.22GHz, 5.45GHz, 6.04GHz, and 7.0GHz by selecting appropriate DC current signals and corresponding pump signals. The gain curve range covers the frequency range of 5GHz to 7GHz, and the bandwidth corresponding to the gain above 15dB is about 80MHz to 580MHz, proving that the parametric amplifier has an excellent gain frequency coverage band.

[0045] like Figure 7 As shown in FIG. 1 , the actual device sample in this embodiment is measured under a 30mK low temperature test environment, and the gain frequency curve is measured when the central operating frequency is about 5.45GHz. It can be seen that at this operating point, the bandwidth at which the gain reaches more than 15dB can reach about 580MHz. It is proved that at this operating point, the parametric amplifier can achieve the best working performance, meet the expected design goals, and meet the requirements of high gain and wide bandwidth, showing excellent working performance.

[0046] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present application. It should be noted that, for a person of ordinary skill in the art, several modifications and improvements may be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line, characterized in that: The invention comprises an input / output port (101), a multi-section quarter-wavelength impedance transformation line (102), a superconducting Josephson junction nonlinear resonator (103) and a magnetic flux bias line (104); one end (201) of the multi-section quarter-wavelength impedance transformation line is connected to the input / output port (101), and the other end (206) is connected to the superconducting Josephson junction nonlinear resonator (103); the other end of the superconducting Josephson junction nonlinear resonator (103) is connected to the magnetic flux bias line (104), wherein: The multi-section quarter-wavelength impedance transformation line (102) comprises a first section quarter-wavelength impedance transformation line (202), a second section quarter-wavelength impedance transformation line (203), a third section quarter-wavelength impedance transformation line (204) and a fourth section quarter-wavelength impedance transformation line (205), the four sections quarter-wavelength impedance transformation lines are all in the form of a planar coplanar waveguide transmission line, the characteristic impedances of the quarter-wavelength impedance transformation lines are respectively Z1, Z2, Z3 and Z4, the impedances of the input and output ports and the superconducting Josephson junction nonlinear resonator are respectively Z0, ... characteristic impedances of the quarter-wavelength L , then the characteristic impedance of each quarter-wavelength impedance transformation line is calculated according to It is determined by N=4, where N is the number of sections of the multi-section quarter-wavelength impedance transformation line.

2. The Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line according to claim 1, characterized in that: The characteristic impedance of the quarter-wavelength impedance transformation line is adjusted by changing the ratio of the center conductor width to the slot width of the transmission line. The higher the ratio of the center conductor width to the slot width, the lower the characteristic impedance of the planar coplanar waveguide transmission line. In addition, the characteristic impedance is also related to the chip substrate material. Under the condition that the ratio of the center conductor width to the slot width of the transmission line is constant, the larger the relative dielectric constant of the chip substrate used, the lower the characteristic impedance value of the transmission line.

3. The Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line according to claim 1, characterized in that: The lanthanum aluminate substrate with a thickness of 500 μm was used for preparation.

4. The Josephson parametric amplifier based on a multi-section quarter-wavelength impedance transformation line according to claim 1, characterized in that: The superconducting Josephson junction nonlinear resonator (103) is formed by connecting a parallel plate capacitor (302) and a nonlinear inductor in parallel, wherein: The nonlinear inductor is a DC superconducting quantum interference device (303) composed of two superconducting Josephson junctions connected in parallel, the input end (301) of the parallel plate capacitor is connected to the fourth quarter-wavelength impedance transformation line (205), and the ground end (304) of the DC superconducting quantum interference device (303) is connected to the magnetic flux bias line (104).

5. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 4, characterized in that: The working process is: The microwave signal to be amplified is input into the input / output port (101), and after being transmitted through a multi-section quarter-wavelength impedance transformation line (102), it is input into the superconducting Josephson junction nonlinear resonator (103); A magnetic flux bias line (104) inputs a direct current and a pump signal. By changing the direct current, the magnetic flux passing through the superconducting quantum interference device (303) is adjusted to change its equivalent inductance, thereby adjusting the operating frequency of the superconducting Josephson junction nonlinear resonator (103). The nonlinear inductance of the superconducting Josephson nonlinear resonator is used to achieve mixing between the input pump signal and the signal to be amplified, converting the energy of the pump signal into energy required for amplifying the input signal, and reflecting the amplified signal along the input transmission line and outputting it through the input / output port (101). The input / output port (101) is connected to a microwave circulator to achieve separation of the input and output signals.

6. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 1, characterized in that: The input and output ports (101), the multi-section quarter-wavelength impedance transformation lines (102) and the magnetic flux bias lines (104) are all made of niobium film with a thickness of 90nm to 120nm.

7. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 4, characterized in that: The upper plate of the parallel plate capacitor (302) of the superconducting Josephson junction nonlinear resonator (103) is made of aluminum, the dielectric layer is made of silicon nitride with a thickness of 200 nm, and the lower plate is made of niobium.

8. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 3, characterized in that: The DC superconducting quantum interference device (303) adopts a three-layer structure Josephson junction of aluminum-aluminum oxide-aluminum.

9. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 1, characterized in that: The multi-section quarter-wavelength impedance transformation line (102) adopts laser direct writing lithography, the precision limit of the laser direct writing lithography is about 1 μm, and the gap width of the plane coplanar waveguide transmission line of the multi-section quarter-wavelength impedance transformation line reaches more than 3 μm.

10. The Josephson parametric amplifier based on multi-section quarter-wavelength impedance transformation lines according to claim 1, characterized in that: The central operating frequencies of the first quarter-wavelength impedance transformation line (202), the second quarter-wavelength impedance transformation line (203), the third quarter-wavelength impedance transformation line (204) and the fourth quarter-wavelength impedance transformation line (205) are the same.

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