A method for information frequency conversion and distribution based on the coherent injection locking phenomenon of superconducting frequency comb

Abstract

This invention discloses a method for information frequency conversion and distribution based on the coherent injection locking phenomenon of a superconducting frequency comb. Utilizing the coherent injection locking phenomenon of a superconducting microwave frequency comb, multiple amplitude-modulated, frequency-modulated, or phase-modulated signals with different carrier frequencies but the same modulation signal are generated simultaneously from a single amplitude-modulated, frequency-modulated, or phase-modulated signal. This method can receive information over a wide microwave frequency band and synchronously convert the information to multiple frequencies in real time, achieving frequency conversion and distribution of information with extremely low power consumption at low temperatures. Compared to mixing schemes, it does not require an external local oscillator signal, which is beneficial for high integration at low temperatures. It is suitable for information frequency conversion across multiple narrow frequency bands with a large frequency span, exhibits a certain degree of frequency selectivity, and the applicable frequency band of this invention can be precisely controlled by using superconducting microwave frequency combs with different fundamental frequencies. Information can be simultaneously distributed to multiple different frequency bands for real-time synchronous transmission of information between systems operating at different frequency bands.

Description

Technical Field

[0001] This invention belongs to the field of superconducting electronics, specifically relating to a method for information frequency conversion and distribution based on the coherent injection locking phenomenon of superconducting frequency combs. Background Technology

[0002] An on-chip superconducting microwave maser is an on-chip microwave source device that can operate at extremely low temperatures. This type of device consists of a superconducting Josephson junction and a superconducting microwave resonator. By coupling the Josephson junction and the microwave resonator to form a nonlinear system, when a DC bias voltage is applied to the Josephson junction, the microwave photons generated by the Josephson junction undergo up-conversion and down-conversion within this nonlinear system, causing the maser to radiate a microwave frequency comb signal. A frequency comb is a microwave or optical signal composed of a series of frequency components with equal frequency spacing and coherent phase in the frequency spectrum. Frequency combs can be used as high-precision "rulers" to measure frequency and time, and have wide and important applications in modern technology, such as optical clocks, precision spectroscopy, and optical communications. This type of superconducting microwave frequency comb device also exhibits a unique coherent injection-lock phenomenon. When a microwave signal with a frequency near a certain order frequency component of the frequency comb is injected into the device, the phases of all order frequency components in the maser signal spectrum become locked, and the maser peak narrows. Furthermore, in the injection-lock state, the frequency, phase, and amplitude of the injected signal simultaneously affect the frequency, phase, and amplitude of other order signals.

[0003] Information in superconducting detectors and superconducting quantum bit circuits is primarily in the form of microwave signals. Reading and processing these microwave signals typically requires obtaining information such as amplitude, frequency, and phase, which often necessitates frequency conversion of the microwave signal. Currently, the conventional frequency conversion method uses a mixer to mix the signal to be measured with a local oscillator signal to generate a signal of the desired frequency. This mixing process requires an external local oscillator microwave signal. If mixing is to be performed at low temperatures, whether the local oscillator microwave signal is generated directly at low temperatures or imported externally via microwave cables, additional heat will be introduced into the cooling system. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method for receiving information in a wide microwave frequency band, converting and distributing the information synchronously to multiple frequencies in real time, with extremely low power consumption, which is beneficial for low-temperature integration and realizes information frequency conversion and distribution based on the coherent injection locking phenomenon of superconducting frequency comb.

[0005] Technical Solution: To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses a method for information frequency conversion and distribution based on the coherent injection locking phenomenon of a superconducting frequency comb. It develops a new application approach for superconducting microwave frequency combs, utilizing the coherent injection locking phenomenon to simultaneously generate multiple amplitude-modulated, frequency-modulated, or phase-modulated signals with different carrier frequencies but the same modulation signal from a single amplitude-modulated, frequency-modulated, or phase-modulated signal. This method can receive information over a wide microwave frequency band and synchronously convert the information to multiple frequencies in real time, achieving information frequency conversion and distribution with extremely low power consumption at low temperatures. The specific steps are as follows:

[0007] S1: Fabricate a superconducting microwave frequency comb device with a suitable lasing frequency;

[0008] S2: Place the superconducting microwave frequency comb device at a low temperature to make the device generate a frequency comb signal;

[0009] S3: Inject the amplitude-modulated, frequency-modulated, or phase-modulated microwave signal that needs to be frequency-converted into the superconducting microwave frequency comb from the input end, so that the frequency comb is injected and locked.

[0010] S4: During injection locking, when the frequency or phase of the injected signal changes, the frequencies and phases of other signals must also change accordingly to satisfy the constraint of phase coherence of the frequency comb. When the amplitude of the injected signal increases, the energy of each signal converges more at the main peak, resulting in an increase in the amplitude of the main peak. After injection locking, the frequency, phase, and amplitude of each signal in the frequency comb change synchronously with the injection-locked signal. Each signal has a different carrier frequency but the same modulation signal relative to the injection-locked signal. This process realizes the real-time synchronous conversion and distribution of the information contained in the injected signal to multiple different frequencies.

[0011] S5: Pass the output frequency comb signal through a bandpass filter to extract the required frequency components;

[0012] S6: Based on the information modulation method of the microwave signal, the extracted frequency components are demodulated to obtain the modulated signal; due to the coherent injection lock phenomenon, the modulated signal of the injected signal is the same as the modulated signal of the extracted signal. This process realizes the demodulation of the original information at different frequencies.

[0013] Furthermore, in steps S1 and S2, the superconducting microwave frequency comb device includes a Josephson junction and a superconducting microwave resonator; the two ends of the superconducting microwave resonator are coupled to external microwave input and output lines respectively, and when a DC bias voltage is applied to the Josephson junction, the superconducting microwave frequency comb device radiates a microwave frequency comb signal.

[0014] Furthermore, in step S1, by controlling the resonator length within the superconducting microwave frequency comb device, superconducting microwave frequency combs with different lasing spectra can be realized, allowing for flexible selection of the operating frequency to adapt to different working scenarios.

[0015] Furthermore, in step S3, the superconducting microwave frequency comb device exhibits a coherent injection lock phenomenon. When a microwave signal with a frequency near a certain order frequency component of the frequency comb is injected into the device, the phases of each order frequency component in the lasing signal spectrum of the device are locked, and the lasing peaks become narrower. Moreover, in the injection lock state, the frequency, phase, and amplitude of the injected signal will simultaneously affect the frequency, phase, and amplitude of other order signals.

[0016] Furthermore, in step S5, the target frequency component is mixed to a low frequency using a mixer, and then the frequency component is extracted using a low-pass filter.

[0017] Furthermore, in step S5, a single target frequency component can be extracted using a bandpass filter, or multiple frequency components can be extracted simultaneously using multiple bandpass filters.

[0018] Furthermore, using the injection locking frequency distribution formula The precise frequencies of each order of the frequency comb signal are found in order to extract the target frequency components.

[0019] Furthermore, in step S6, according to the characteristics of the frequency comb signal, the frequency offset changes proportionally to the signal order. Therefore, for an FM signal, when the carrier frequency of the injected signal is unknown, but the maximum frequency offset of the original signal frequency modulation and the signal order corresponding to the extracted frequency components are known, the carrier frequency of the injected signal can be deduced by measuring the maximum frequency offset.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0021] (1) The method of the present invention can realize information frequency conversion and distribution at low temperature using only a single ultra-low power superconducting microwave frequency comb device when the original signal frequency and power are suitable. Compared with the mixing scheme, no external local oscillator signal is required, which is beneficial for high integration at low temperature.

[0022] (2) The method of the present invention is applicable to information frequency conversion of multiple narrow frequency bands with a large frequency span, has a certain frequency selectivity, and the applicable frequency band of the present invention can be precisely controlled by using superconducting microwave frequency combs with different fundamental frequencies.

[0023] (3) The method of the present invention can simultaneously distribute information to multiple different frequency bands, and can be used for real-time synchronous transmission of information between multiple systems with different operating frequency bands. A new application approach for superconducting microwave frequency combs has been developed.

[0024] (4) Compared with the mixing scheme, the present invention can eliminate the local oscillator signal, avoid the heat brought by the introduction or generation of microwave signals at low temperature, simplify the low temperature signal line, save the cooling power of the cooling system, and facilitate the integration of low temperature circuits. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of an on-chip superconducting microwave frequency comb sample.

[0026] Figure 2 This is a schematic diagram of information frequency conversion achieved by coherent injection locking of a superconducting microwave frequency comb.

[0027] Figure 3 A 4.39 GHz sinusoidal modulation signal was injected into a superconducting microwave frequency comb, and the frequency of the modulation signal was changed. The spectrum of each order of the frequency comb signal was measured. a is the spectrum when an amplitude-modulated signal was injected, and b is the spectrum when a frequency-modulated signal was injected.

[0028] Figure 4 This is a demodulation demonstration after frequency conversion of amplitude modulation information; a square wave modulated amplitude modulation signal with a carrier frequency of 6.58 GHz is injected, and the 5.1 GHz lasing signal from the laser is extracted, sampled, and demodulated; a is the sampled waveform and envelope; b is a comparison between the normalized demodulated signal and the original modulated signal.

[0029] Figure 5 This is a demodulation demonstration after frequency conversion of FM information; a sinusoidal modulated FM signal with a carrier frequency of 6.58GHz / 27.8GHz is injected, and the 4.39GHz lasing signal from the laser is extracted, sampled, and demodulated; a is a comparison between the normalized demodulated signal with the injected carrier frequency of 6.58GHz and the original modulated signal; b is a comparison between the normalized demodulated signal with the injected carrier frequency of 27.8GHz and the original modulated signal. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0031] Microwave frequency comb devices such as on-chip superconducting microwave masers exhibit a unique coherent injection-lock phenomenon. When a microwave signal is injected, and the frequency of this signal is near a certain frequency component of the maser signal, it can be observed that the phases of each frequency component in the signal spectrum generated by the maser are locked, and the maser peaks narrow. In the injection-lock state, the frequency, phase, and amplitude of the injected signal simultaneously affect the frequency, phase, and amplitude of other signals.

[0032] These superconducting microwave frequency comb devices are made of superconducting materials, exhibiting extremely low energy loss and simple fabrication processes. They generate microwave frequency comb signals with only DC bias. Utilizing the coherent injection-locking phenomenon of superconducting microwave frequency combs, information frequency conversion and distribution can be achieved at low temperatures. Under certain conditions, compared to traditional mixing methods, the local oscillator signal can be eliminated, facilitating high integration within cooling systems.

[0033] Example 1

[0034] The method for information frequency conversion and distribution based on the coherent injection locking phenomenon of superconducting frequency comb in this embodiment includes the following specific steps: S1~S6:

[0035] S1: Based on the application scenario, fabricate a superconducting microwave frequency comb device with a suitable lasing frequency. In this example, the lasing fundamental frequency is 750MHz.

[0036] S2: The superconducting microwave frequency comb device is placed at a low temperature, and the two ends of its superconducting microwave resonator are coupled to the external microwave input and output lines, respectively. A suitable DC bias voltage is applied across the Josephson junction to make the device generate a frequency comb signal.

[0037] S3: Inject the amplitude-modulated, frequency-modulated, or phase-modulated microwave signal that needs to be frequency-converted into the superconducting microwave frequency comb from the input end, so that the frequency comb is injected and locked.

[0038] S4: After injection locking, the frequency, phase, and amplitude of each order of the frequency comb signal change synchronously with the injected locking signal. Each order of signal has a different carrier frequency but the same modulation signal compared to the injected locking signal. This process enables the real-time synchronous conversion and distribution of the information contained in the injected signal to multiple different frequencies.

[0039] S5: Extract the desired frequency components from the output frequency comb signal.

[0040] S6: Based on the information modulation method of the microwave signal, the extracted frequency components are demodulated to obtain the modulated signal. Due to coherent injection lock-in, the modulated signal of the injected signal is the same as the modulated signal of the extracted signal. This process enables the demodulation of the original information at different frequencies.

[0041] Example 2

[0042] This embodiment, based on Embodiment 1, provides a more specific way to achieve the purpose of the present invention:

[0043] S1: Based on the application scenario, fabricate a superconducting microwave frequency comb device with a suitable lasing frequency.

[0044] A superconducting microwave frequency comb device is a superconducting device that can generate frequency comb microwave signals at extremely low temperatures. A frequency comb refers to a microwave or optical signal composed of a series of frequency components with the same frequency spacing and phase coherence in the spectrum.

[0045] The superconducting microwave frequency comb used in this invention mainly consists of two parts: a Josephson junction 1 and a superconducting microwave resonator 2. The sample used in this embodiment is as follows: Figure 1 As shown.

[0046] The superconducting microwave resonator 2 is a half-wavelength coplanar waveguide resonator. The center conductor 3 of the resonator has a width of 16µm, the distance from the center conductor 3 to the ground plane 4 is 9µm, the resonator length is 10mm, and the corresponding resonant frequency is n×750MHz, where n is a positive integer. Each end of the resonator has a gap capacitor 5 (16µm on the left and 4µm on the right) for coupling to the outside environment. A DC bias line is connected in the middle of the resonator in the form of a toroidal inductor 6, which acts as a low-pass filter to prevent microwave energy leakage from the resonator.

[0047] Josephson junction 1 is located at one end of superconducting microwave resonator 2, with a junction area of ​​approximately 4µm. 2 Josephson junction 1 uses an aluminum junction, specifically an Al / AlO3 junction. x / Al three-layer structure. The two electrodes of Josephson junction 1 are connected to the center conductor 3 and the ground plane 4 of superconducting microwave resonator 2, respectively.

[0048] When a DC bias voltage is applied across Josephson junction 1, the device can radiate a microwave frequency comb signal, which appears as equally spaced spectral lines in the frequency domain. The frequencies of each order of the signal can be described by the following formula:

[0049]

[0050] Where m is the signal order (m=1, 2, 3…). Let m be the frequency of the m-th order signal. For frequency intervals, It is equal to the fundamental frequency of the superconducting resonator in the device.

[0051] Superconducting microwave frequency comb devices exhibit coherent injection lock-in. When a microwave signal with a frequency near a certain order component of the lasing signal is injected into the device, the phases of all frequency components in the lasing signal spectrum of the device lock, and the lasing peak narrows. The frequency distribution of each order of the frequency comb signal at this time can be described by the following formula:

[0052]

[0053] in, The order of the signal ( =1, 2, 3…), Let m be the frequency of the m-th order signal. For the injected signal frequency, The signal order corresponds to the frequency of the injected signal.

[0054] In the superconducting microwave frequency comb injection-locked state, changing the frequency, phase, and amplitude of the injected signal will cause the frequency, phase, and amplitude of other signals of different orders to change in real time.

[0055] The fundamental frequency of the superconducting microwave frequency comb device is determined by the superconducting microwave resonator within it. By controlling the resonator length, superconducting microwave frequency combs with different lasing spectra can be achieved. Therefore, the method of this invention allows for flexible selection of the operating frequency to adapt to different working scenarios.

[0056] S2: Place the superconducting microwave frequency comb device at a low temperature, and couple the two ends of the superconducting microwave resonator 2 to the external microwave input and output lines, respectively. Apply a suitable DC bias voltage across the Josephson junction 1 to make the device generate a frequency comb signal.

[0057] S3: Inject the amplitude-modulated, frequency-modulated, or phase-modulated microwave signal that needs to be frequency-converted into the superconducting microwave frequency comb from the input end, so that the frequency comb is injected and locked.

[0058] It is necessary to confirm that the injected signal can lock the phase of the superconducting microwave frequency comb. Successful injection locking can be determined by observing whether the peak linewidth of the frequency comb signal narrows and whether the frequencies of each order conform to the frequency distribution formula for locking. If the injected signal power is too low, it can be amplified before injection to meet the required injection locking power.

[0059] S4: During injection locking, when the frequency or phase of the injected signal changes, the frequencies and phases of other signals must also change accordingly to satisfy the frequency comb phase coherence constraint. When the amplitude of the injected signal increases, more energy from each signal converges at the main peak, leading to an increase in the main peak amplitude. Therefore, after injection locking, the frequency, phase, and amplitude of each signal in the frequency comb change synchronously with the injected locking signal. Each signal has a different carrier frequency but the same modulation signal relative to the injected locking signal. This process enables the real-time synchronous conversion and distribution of the information contained in the injected signal to multiple different frequencies.

[0060] S5: Extract the desired frequency components from the output frequency comb signal.

[0061] Available injection lock frequency distribution formula This is used to find the precise frequencies of each order of the frequency comb signal, so as to extract the target frequency component.

[0062] In addition to using a mixer to mix the target frequency component to a low frequency and then extracting it with a low-pass filter, a single target frequency component can also be extracted using a band-pass filter. This method does not require a mixer and multiple band-pass filters can be used to extract multiple frequency components simultaneously.

[0063] S6: Based on the information modulation method of the microwave signal, the extracted frequency components are demodulated to obtain the modulated signal. Due to coherent injection lock-in, the modulated signal of the injected signal is the same as the modulated signal of the extracted signal. This process enables the demodulation of the original information at different frequencies.

[0064] Based on the characteristics of frequency comb signals, the frequency offset varies proportionally to the signal order. Therefore, for FM signals, when the carrier frequency of the injected signal is unknown, but the maximum frequency offset of the original signal modulation and the signal order corresponding to the extracted frequency components are known, the carrier frequency of the injected signal can be deduced by measuring the maximum frequency offset. The following formula can be used for calculation:

[0065]

[0066]

[0067] in, Let m be the signal order corresponding to the injected signal frequency, and m be the signal order corresponding to the extracted frequency component. It is the maximum frequency deviation of the original signal frequency modulation. It extracts the maximum frequency offset of the signal. It is the carrier frequency of the injected signal. It extracts the signal carrier frequency.

[0068] Example 3

[0069] This embodiment provides a method for preparing a superconducting microwave frequency comb used in Embodiments 1 and 2, including steps S1 to S4:

[0070] S1: A 100 nm thick niobium (Nb) film is deposited on a sapphire substrate (C-direction, 650 µm thickness) using magnetron sputtering.

[0071] S2: Define the resonator pattern using standard photolithography, and then etch the niobium film using reactive ion etching to obtain the superconducting microwave resonator.

[0072] S3: LOR10B and AZ5214 photoresists are spin-coated sequentially, and then the floating bridge pattern is exposed by laser direct writing. The image is then placed in a developing solution for development. Because the underlying LOR10B photoresist is highly soluble in the developing solution, a hollow structure will appear in the bridge area, thus forming the floating bridge.

[0073] S4: An Al / AlO structure was obtained through electron beam double-angle evaporation. x For the / Al Josephson junction, in order to ensure good electrical contact between the electrodes at both ends of the Josephson junction and the superconducting microwave resonator, the oxide layer is removed by ion milling before double-angle evaporation.

[0074] Example 4

[0075] This embodiment provides the testing process and results of the present invention:

[0076] The on-chip superconducting microwave frequency comb device is placed inside a dilution refrigerator at an operating temperature of 20 mK. A DC bias of 189 µV is applied to the Josephson junction via a low-pass filter. The injected microwave signal is attenuated by approximately 75 dB before reaching the left input port of the superconducting microwave frequency comb. The microwave signal radiated by the device is connected to the output circuit from the right output port, passing through a 4-8 GHz bandpass filter, an infrared filter, a cryogenic microwave amplifier (+42 dB), and two room-temperature microwave amplifiers (+25 dB), before being connected to a spectrum analyzer or oscilloscope to measure the frequency or time domain of the signal.

[0077] The specific implementation method of the present invention is as follows: Figure 2 As shown, by injecting an amplitude-modulated (AM) or frequency-modulated (FM) signal with a carrier frequency near a certain order component of the frequency comb into the input terminal of the superconducting microwave frequency comb, and ensuring that the carrier frequency and power are appropriate, injection locking can be achieved. In the injection-locked state, the phases of all orders of the frequency comb signals are completely locked, and its linewidth is significantly narrowed to the measurement limit of the spectrum analyzer (1 Hz). Furthermore, the narrowing of the linewidth causes the originally dispersed signal energy to converge at the main peak, thereby significantly increasing the power of the lasing signal.

[0078] Due to coherent injection lock-in, in the injection-locked state, the frequency, phase, and amplitude of each order of the frequency comb signal change synchronously with the injected signal. In this state, each order component of the frequency comb also becomes the corresponding amplitude-modulated or frequency-modulated signal. Compared to the injection-locked signal, the carrier frequency is different, but the modulation signal is the same.

[0079] Subsequently, it was verified that when using the coherent injection lock-in phenomenon of a superconducting frequency comb for information frequency conversion, the waveform information of the modulated signal can be preserved. An amplitude-modulated (AM) or frequency-modulated (FM) signal with a carrier frequency of 4.39 GHz was generated using a microwave source and input to the input terminal of the superconducting microwave frequency comb, scanning the frequency of the modulated signal. The amplitude modulation depth was fixed at 50%, and the maximum frequency deviation of the FM was fixed at 30 kHz. The spectrum of each order component of the frequency comb output signal was measured using a spectrum analyzer. Figure 3 As shown, Figure 3 In this context, 'a' represents the spectrum when an amplitude-modulated signal is injected. Figure 3 In the above, b represents the spectrum of the injected frequency-modulated signal. The signals of each order of the frequency comb also appear as amplitude-modulated or frequency-modulated signals modulated by the corresponding single-frequency sine wave, and the corresponding modulation frequency is equal to the modulation frequency of the injected signal. This indicates that when using this method for information frequency conversion, the waveform information of the modulated signal can be effectively preserved.

[0080] Next, a demonstration of demodulation after frequency conversion of amplitude modulation information was performed. A square wave modulated amplitude modulation signal with a carrier frequency of 6.59 GHz was generated using a microwave source, with an injection power of -65 dBm and a modulation depth of 60%, and input to the input of a superconducting microwave frequency comb. The 5.1 GHz component of the maser output frequency comb signal was mixed to 500 kHz, low-pass filtered to extract individual frequency components, and then sampled using an oscilloscope. The sampled signal was then demodulated through envelope detection and low-pass filtering to obtain the modulated signal. Figure 4 In this context, 'a' represents the sampled waveform and its envelope. Figure 4 In the diagram, 'b' represents the comparison between the normalized demodulated signal and the original modulated signal. It is observed that the demodulation result basically restores the corresponding square wave modulated signal.

[0081] After frequency conversion of amplitude modulation (AM) information, the demodulation effect is less than ideal due to the lasing device's insensitivity to changes in the injected signal amplitude and the noise in the test system. However, for modulated signals that can tolerate a certain amount of noise, such as square waves, demodulation can still be successfully performed after frequency conversion. If the noise in the test system is improved, the method of this invention has the potential to demodulate analog signals with even lower noise tolerance after AM information frequency conversion. Furthermore, by sampling lower-order signals or using bandpass filters, the above demodulation methods can eliminate the need for mixing to lower frequencies.

[0082] Finally, a demonstration of demodulation after frequency conversion of the FM information is presented. First, a 10kHz sine wave modulated FM signal with a carrier frequency of 6.59GHz is generated using a microwave source, with an injection power of -65dBm and a maximum frequency deviation of 100kHz, and input to the input of a superconducting microwave frequency comb. The 4.39GHz component of the maser output frequency comb signal is mixed to 500kHz, low-pass filtered to extract individual frequency components, and then sampled using an oscilloscope. The sampled signal is demodulated using a Hilbert transform to obtain the modulated signal. Figure 5 In the diagram, 'a' represents a comparison between the normalized demodulated signal and the original modulated signal when a 6.59 GHz carrier frequency signal is injected. Then, the injected signal carrier frequency is modified to 27.8 GHz, the injection power to -45 dBm, and other parameters and demodulation procedures remain unchanged. Figure 5 In the diagram, 'b' represents a comparison between the normalized demodulated signal and the original modulated signal when a 27.8 GHz carrier frequency signal is injected. It can be observed that after information frequency conversion, frequency modulation demodulation can effectively demodulate the modulated signal waveform. The method of this invention is more sensitive to frequency changes and is suitable for measuring frequency or phase changes of microwave signals at low temperatures. Currently, the highest injectable carrier frequency that can be demodulated experimentally is 27.8 GHz. Furthermore, by sampling lower-order signals or using bandpass filters, the above demodulation methods can eliminate the need for mixing to lower frequencies.

[0083] In summary, this invention provides a method for information frequency conversion and distribution based on the coherent injection locking phenomenon of a superconducting frequency comb. Utilizing the coherence of the superconducting frequency comb, multiple amplitude-modulated, frequency-modulated, or phase-modulated signals with different carrier frequencies but the same modulation signal can be generated simultaneously from a single amplitude-modulated, frequency-modulated, or phase-modulated signal. This method can receive information over a wide microwave frequency band and synchronously convert the information to multiple frequencies in real time, with extremely low power consumption, which is beneficial for low-temperature integration.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for information frequency conversion and distribution based on superconducting frequency comb coherent injection locking phenomenon, characterized in that: By utilizing the coherent injection lock-in phenomenon of superconducting microwave frequency comb, multiple amplitude modulation, frequency modulation, or phase modulation signals with different carrier frequencies and the same modulation signal can be generated simultaneously from one amplitude modulation, frequency modulation, or phase modulation signal. This method enables information reception across a wide microwave frequency band and real-time synchronous conversion of information to multiple frequencies, achieving frequency conversion and distribution of information with extremely low power consumption at low temperatures. Specifically, it includes the following steps: S1: Fabricate a superconducting microwave frequency comb device with a suitable lasing frequency; S2: Place the superconducting microwave frequency comb device at a low temperature to make the device generate a frequency comb signal; S3: Inject the amplitude-modulated, frequency-modulated, or phase-modulated microwave signal that needs to be frequency-converted into the superconducting microwave frequency comb from the input end, so that the frequency comb is injected and locked. S4: During injection locking, when the frequency or phase of the injected signal changes, the frequencies and phases of other signals must also change accordingly to satisfy the constraint of phase coherence of the frequency comb. When the amplitude of the injected signal increases, the energy of each signal converges more at the main peak, resulting in an increase in the amplitude of the main peak. After injection locking, the frequency, phase, and amplitude of each signal in the frequency comb change synchronously with the injection-locked signal. Each signal has a different carrier frequency but the same modulation signal relative to the injection-locked signal. This process realizes the real-time synchronous conversion and distribution of the information contained in the injected signal to multiple different frequencies. S5: Pass the output frequency comb signal through a bandpass filter to extract the required frequency components; S6: Based on the information modulation method of the microwave signal, the extracted frequency components are demodulated to obtain the modulated signal; due to the coherent injection lock phenomenon, the modulated signal of the injected signal is the same as the modulated signal of the extracted signal. This process realizes the demodulation of the original information at different frequencies.

2. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In steps S1 and S2, the superconducting microwave frequency comb device includes a Josephson junction and a superconducting microwave resonator; the two ends of the superconducting microwave resonator are coupled to external microwave input and output lines respectively; when a DC bias voltage is applied to the Josephson junction, the superconducting microwave frequency comb device radiates a microwave frequency comb signal.

3. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In step S1, by controlling the resonator length within the superconducting microwave frequency comb device, superconducting microwave frequency combs with different lasing spectra can be realized, allowing for flexible selection of the operating frequency to adapt to different working scenarios.

4. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In step S3, the superconducting microwave frequency comb device exhibits coherent injection lock-in phenomenon. When a microwave signal with a frequency near a certain order frequency component of the frequency comb is injected into the device, the phases of each order frequency component in the lasing signal spectrum of the device are locked, and the lasing peaks become narrower. Furthermore, in the injection lock-in state, the frequency, phase, and amplitude of the injected signal will simultaneously affect the frequency, phase, and amplitude of other order signals.

5. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In step S5, the target frequency component is mixed to a low frequency using a mixer, and then the frequency component is extracted using a low-pass filter.

6. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In step S5, a single target frequency component is extracted using a bandpass filter, or multiple frequency components are extracted simultaneously using multiple bandpass filters.

7. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 6, characterized in that: Using the injection lock frequency distribution formula The precise frequencies of each order of the frequency comb signal are found to extract the target frequency components; where m is the signal order and f is the frequency of the signal. m f is the frequency of the m-th order signal. inj Let m be the frequency of the injected signal, and m be the signal order corresponding to the frequency of the injected signal.

8. The method for information frequency conversion and distribution based on the superconducting frequency comb coherent injection locking phenomenon according to claim 1, characterized in that: In step S6, according to the characteristics of the frequency comb signal, the frequency offset changes proportionally to the signal order. Therefore, for an FM signal, when the carrier frequency of the injected signal is unknown, but the maximum frequency offset of the original signal frequency modulation and the signal order corresponding to the extracted frequency components are known, the carrier frequency of the injected signal can be deduced by measuring the maximum frequency offset.

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