A measuring device and a measuring method for a terahertz superconducting transmission line

Abstract

The present invention discloses a novel device and method for measuring terahertz superconducting transmission lines. The device is primarily composed of a terahertz phase-locked signal source, a chip to be measured, a function generator, a detector readout circuit system, and a computer. To reduce the impedance matching requirements between the detector and the terahertz superconducting transmission line and obtain the detector's accurate received power, the present invention proposes a theoretical formula for high-precision measurement of the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line even when there is an impedance mismatch. The frequency spectra of the received power of the two detectors are compared to eliminate the frequency-dependent variation of the terahertz signal power in the optical path. A function generator is used to obtain the detector's accurate received power, thereby achieving measurement of the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line. The measurement device and method of the present invention provide more accurate measurement results and are easy to implement.

Description

Technical Field

[0001] The present invention relates to a measuring device and a measuring method for a terahertz superconducting transmission line, and belongs to the research field of terahertz technology. Background Art

[0002] Because terahertz superconducting transmission lines can achieve low transmission loss, they have a wide range of applications in low-loss signal transmission, such as in on-chip filters or feed networks for array antennas. There are three important technical parameters used to characterize the characteristics of terahertz superconducting transmission lines: the effective dielectric constant, which characterizes the phase transmission characteristics of signals in terahertz superconducting transmission lines and is closely related to the precise design of resonators or phase shifters. The second is the attenuation constant, which reflects the degree to which the amplitude of the signal in the terahertz superconducting transmission line attenuates with length. A smaller attenuation constant can meet the requirements of long-distance, low-loss signal transmission. The third is the characteristic impedance, which reflects the relationship between the voltage and current of the signal in the terahertz superconducting transmission line. If there is an impedance mismatch between the terahertz superconducting transmission line and other connected devices, reflections will occur, reducing the signal transmission efficiency.

[0003] Regarding the measurement of the three technical parameters mentioned above, due to factors such as the high signal frequency and extremely low ambient temperature (such as liquid helium temperature) in terahertz superconducting transmission lines, conventional measurement methods (such as using a vector network analyzer) are difficult to implement. Currently, the commonly used measurement method is to use quasi-optical technology. The quasi-optical technology uses an on-chip terahertz antenna to receive the output signal of the terahertz signal source and uses an on-chip integrated detector to perform measurements. There are two specific measurement methods:

[0004] 1) The terahertz signal received by the antenna is input into two channels after passing through a power splitter. The signal then passes through two different lengths of the transmission line to be tested before being received by detectors integrated into the channels. The power of the terahertz signals received by the two detectors is compared. The effective dielectric constant and attenuation constant of the terahertz superconducting transmission line are obtained by separately measuring the impedance mismatch and impedance matching of two different chips.

[0005] 2) The terahertz signal received by the antenna passes through a transmission line resonator made of a terahertz superconducting transmission line and is received by a single detector integrated on the chip. The effective dielectric constant of the terahertz superconducting transmission line is obtained by measuring the frequency intervals between the multiple harmonics of the resonator. The resonance curve of the resonator is then fitted to obtain the attenuation constant.

[0006] In principle, the first measurement method is simple and direct. It obtains the effective dielectric constant and attenuation constant by comparing terahertz superconducting transmission lines of different lengths. However, considering the errors in the chip manufacturing process, impedance matching will be difficult to achieve, which will lead to the inability to obtain an accurate attenuation constant. In addition, this measurement method requires the characteristic impedance of the terahertz superconducting transmission line to be determined in advance. Otherwise, it is impossible to design and manufacture a detector that matches the impedance of the terahertz superconducting transmission line.

[0007] The second measurement method mainly obtains the effective dielectric constant and attenuation constant of the terahertz superconducting transmission line by measuring the transmission line resonator. However, this measurement method does not eliminate the fluctuation of the terahertz signal power with frequency (for example, the output power of the terahertz signal source may be different at different frequencies and there may be standing waves in the optical path, etc.), and this measurement method cannot obtain the characteristic impedance of the terahertz superconducting transmission line. Summary of the Invention

[0008] The technical purpose of the present invention is to provide a novel measuring device and measuring method for terahertz superconducting transmission lines to solve the problems existing in the prior art.

[0009] To achieve the above objectives, the technical solutions provided by the present invention include:

[0010] A terahertz superconducting transmission line measurement device, comprising a terahertz phase-locked signal source, a chip to be measured, a function generator, a detector readout circuit system, and a computer, wherein:

[0011] The terahertz phase-locked signal source is used to transmit a terahertz signal of a set frequency;

[0012] The chip under test includes a receiving antenna, a power divider, and two thermal electron detectors. The receiving antenna is used to receive the terahertz signal emitted by the terahertz phase-locked signal source and send it to the power divider. The two signal output ends of the power divider are respectively connected to the thermal electron detectors integrated in the two channels through two sections of terahertz superconducting transmission lines with different lengths, and the terahertz signals divided into two paths are respectively sent to the corresponding thermal electron detectors. The signal output ends of the two thermal electron detectors are respectively connected to the signal input ends of the detector readout circuit system.

[0013] The function generator is connected to the two thermal electron detectors respectively, and outputs voltage signals for calibrating the received power of the two thermal electron detectors respectively, and the function generator and the terahertz phase-locked signal source do not work at the same time;

[0014] The output end of the detector readout circuit system is connected to a computer, and the response signals generated by the two thermal electron detectors to the received signals are converted into response data and sent to the computer;

[0015] The computer is used to implement:

[0016] When the terahertz phase-locked signal source outputs a terahertz signal of a set frequency, the response data of the two thermal electron detectors are recorded;

[0017] During the operation of the function generator, for any thermal electron detector, when its response data is equal to the response data of the terahertz signal of the set frequency output by the terahertz phase-locked signal source, the current output voltage of the function generator is recorded, and the received power of the current thermal electron detector at the output voltage is calculated, and the received power is used as the actual received power of the current thermal electron detector when the terahertz phase-locked signal source outputs the terahertz signal of the set frequency;

[0018] The received power ratio of the two thermal electron detectors corresponding to the set frequency is calculated using the actual received power, and based on the received power ratios of the two thermal electron detectors corresponding to different set frequencies obtained from multiple tests, a spectrum measurement result of the received power ratio of the two thermal electron detectors is generated;

[0019] Based on the relationship between the received power ratio and the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line, the spectrum measurement results of the received power ratio of the two thermal electron detectors were fitted with the least squares method to obtain the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line.

[0020] A method for measuring a terahertz superconducting transmission line, characterized by comprising the following steps:

[0021] S1) constructing a measurement device, the measurement device comprising a terahertz phase-locked signal source, a chip to be tested, a function generator, a detector readout circuit system, and a computer, the chip to be tested comprising a receiving antenna, a power divider, and two thermal electron detectors;

[0022] Setting a terahertz phase-locked signal source within the receiving range of a receiving antenna of the chip under test, connecting the output end of the receiving antenna to the input end of a power divider, connecting the two output ends of the power divider to two thermal electron detectors respectively through two sections of terahertz superconducting transmission lines of different lengths, connecting the output end of a function generator to the signal input ends of the two thermal electron detectors, connecting the output ends of the two thermal electron detectors to the input end of a detector readout circuit system, and connecting the output end of the detector readout circuit system to the input end of a computer;

[0023] S2) turning off the function generator, setting a target frequency range of the terahertz phase-locked signal source, and selecting a plurality of frequency points within the target frequency range;

[0024] S3) controlling the terahertz phase-locked signal source to output a terahertz signal of a set frequency, where the set frequency is one of the frequency points within the target frequency range, using a detector readout circuit system to respectively measure response data of the two thermal electron detectors to the terahertz signal of the current set frequency, and outputting the response data to a computer for recording and storage;

[0025] S4) resetting the frequency of the terahertz signal output by the terahertz phase-locked signal source, and repeating step 3) until the response data of the two thermal electron detectors at all frequency points within the target frequency range are obtained;

[0026] S5) turning off the terahertz phase-locked signal source, starting the function generator, and using the detector readout circuit system to measure the response data of the two thermal electron detectors to the voltage signal respectively;

[0027] S6) for the two thermal electron detectors, controlling the function generators to respectively output voltage signals of appropriate voltages so that the current response data of the thermal electron detectors is equal to the response data when a terahertz signal of a set frequency is input, and using a computer to calculate the received power of the current thermal electron detectors at the current output voltage of the function generator, and using the calculated power as the actual received power corresponding to the set frequency after calibration;

[0028] S7) adjusting the output voltage of the function generator and repeating step 6) to obtain the actual received powers of the two thermal electron detectors corresponding to all frequency points within the target frequency range, thereby obtaining spectrum data of the received power of each thermal electron detector within the target frequency range;

[0029] S8) Using a computer to calculate the ratio of received powers of the two thermal electron detectors at each frequency point, obtaining a spectrum measurement result, and performing a least squares fit on the spectrum measurement result based on a relationship between the received power ratio and the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line to determine the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line.

[0030] Based on the above solutions, improved or preferred solutions also include:

[0031] Furthermore, a detector readout circuit system is constructed using a room-temperature microwave readout circuit and two low-temperature low-noise amplifiers. The two thermal electron detectors are each connected to a low-temperature low-noise amplifier. The output signal is amplified by the corresponding low-temperature low-noise amplifier and sent to the room-temperature microwave readout circuit. The output end of the room-temperature microwave readout circuit is connected to a computer.

[0032] Furthermore, the thermal electron detector is a titanium thermal electron detector.

[0033] Furthermore, the voltage signal output by the function generator is a square wave signal.

[0034] Furthermore, the relationship is:

[0035]

[0036] Where r(f) is the received power ratio in functional form, f is the frequency of the output signal of the terahertz signal source, c is the speed of light in vacuum, and ε eff is the effective dielectric constant, α is the attenuation constant, Z0 is the characteristic impedance, Re represents the real part of a complex number, j represents the imaginary part of a complex number, tanh represents the hyperbolic tangent function, * represents the conjugate complex number, l1 and l2 are the lengths of the terahertz superconducting transmission lines in the two channels, and Z l1 With Z l2 are the equivalent impedances of the thermal electron detectors in the two channels, l1 and l2, Z l1 With Z l2 All can be obtained through measurement.

[0037] The beneficial effects of the present invention are:

[0038] The measuring device and measuring method of the present invention do not require impedance matching between the thermal electron detector in the chip to be measured and the terahertz superconducting transmission line. The equivalent impedances of the two thermal electron detectors can also be different. The present invention measures the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line by measuring the received power of the two titanium thermal electron detectors and fitting the spectrum of the power ratio, which can improve the accuracy of the measurement results. At the same time, the measuring device of the present invention has a simple structure and the data processing involved in the measurement method is easy to implement. Considering the application scenarios, the measuring device and measuring method proposed by the present invention are particularly suitable for measuring the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic diagram of the measuring device of the present invention;

[0040] Figure 2 Schematic diagram of the spectrum of the power ratio of terahertz signals received by two titanium thermionic electron detectors. DETAILED DESCRIPTION

[0041] The present invention will now be described in further detail with reference to the accompanying drawings.

[0042] The terahertz superconducting transmission line measurement device proposed in the present invention utilizes the impedance mismatch between the on-chip integrated detector and the terahertz superconducting transmission line. It is mainly composed of a terahertz phase-locked signal source, a chip to be tested, a function generator, a detector readout circuit system and a computer. The computer is installed with necessary data processing programs. When the chip to be tested is working, it is generally placed in a device that provides a low-temperature environment.

[0043] The measurement device and method of the present invention do not require impedance matching between the thermal electron detectors in the chip under test and the terahertz superconducting transmission line. The equivalent impedances of the two thermal electron detectors can also be different. The present invention measures the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line by measuring the received power of the two thermal electron detectors and fitting the spectrum of the power ratio.

[0044] The measurement of terahertz superconducting transmission lines in the present invention is divided into two parts:

[0045] First, a terahertz phase-locked signal source outputs a terahertz signal that is received by a receiving antenna on the chip under test. The receiving antenna sends the received terahertz signal to a power splitter. After passing through the power splitter, the terahertz signal is split into two signals, which are respectively input into two channels. The two channels use terahertz superconducting transmission lines of different lengths. The two signals pass through corresponding terahertz superconducting transmission lines and are received by thermal electron detectors in their respective channels. For the signal transmitted by the terahertz superconducting transmission line, the noise readout signal of the thermal electron detector will produce a response corresponding to the current received power.

[0046] Secondly, the voltage signal output by the function generator is received by the thermal electron detector. In response to the signal output by the function generator, the noise readout signal of the thermal electron detector will also produce a response corresponding to the current received power.

[0047] After the detector readout circuit system reads the noise readout signal of the thermal electron detector, the output data is finally sent to the computer for storage and data processing. The effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line are obtained by fitting the spectrum of the received power ratio of the two thermal electron detectors.

[0048] When a terahertz signal is input, the spectrum of the power ratio received by the two thermal electron detectors is related to two factors. The first is the power distribution ratio of the power divider, which is determined by the equivalent impedance of the two channels. The equivalent impedance of each channel can be obtained using the impedance equation of the low-loss transmission line; the second is the degree of loss of the terahertz signal in each channel after passing through the terahertz superconducting transmission line. The influence of the impedance mismatch between the thermal electron detector and the terahertz superconducting transmission line needs to be considered.

[0049] Based on the above considerations, the spectrum of the received power ratio r of the two detectors and the effective dielectric constant ε of the terahertz superconducting transmission line are finally obtained. eff , attenuation constant α and characteristic impedance Z0 are:

[0050]

[0051] Where r(f) is the ratio function of the received powers of the two detectors, f is the frequency of the output signal of the terahertz signal source, c is the speed of light in vacuum, Re represents the real part of a complex number, j represents the imaginary part of a complex number, tanh represents the hyperbolic tangent function, * represents the conjugate complex number, l1 and l2 are the lengths of the terahertz superconducting transmission lines in the two channels, and Z l1 With Z l2 are the equivalent impedances of the thermal electron detectors in the two channels, l1 and l2, Z l1 With Z l2 All can be obtained through measurement.

[0052] The effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line can be obtained by performing least squares fitting on the spectrum measurement results of the received power ratio of the two detectors using the above equation.

[0053] After receiving a terahertz signal or voltage signal, the thermal electron detector, although the received signal frequency is different, operates based on noise readout, so the received power corresponds to the response magnitude. However, because the readout circuit systems of the two detectors are not exactly the same (for example, the two low-temperature low-noise amplifiers are different), even if the two thermal electron detectors receive the same terahertz signal power, the output data of the detector readout circuit system will still be different. Therefore, it is necessary to use the voltage signal response measurement results to calibrate the two thermal electron detectors to obtain the precise received power when the terahertz signal is input, while eliminating the differences caused by the different detector readout circuit systems. Then, by repeatedly changing the output signal frequency of the terahertz phase-locked signal source, the spectrum of the received power ratio of the two detectors can be obtained. Finally, a fitting process is performed to obtain the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line.

[0054] The specific solution provided by the present invention is:

[0055] like Figure 1 The terahertz superconducting transmission line measurement device shown includes a terahertz phase-locked signal source, a chip to be measured, a function generator, a detector readout circuit system, and a computer, wherein:

[0056] The terahertz phase-locked signal source is used to transmit a terahertz signal of a set frequency, and when in use, it can be adjusted and placed in a suitable position to achieve a higher terahertz signal coupling efficiency;

[0057] The chip to be tested is composed of a receiving antenna, two sections of terahertz superconducting transmission lines, a 3dB T-junction power splitter and two titanium thermal electron detectors. The receiving antenna is used to receive the terahertz signal emitted by the terahertz phase-locked signal source and send it to the T-junction power splitter; the two signal output ends of the T-junction power splitter are respectively connected to the titanium thermal electron detectors integrated in the two channels through the two sections of terahertz superconducting transmission lines, and the terahertz signals divided into two paths are respectively sent to the corresponding thermal electron detectors. The two sections of terahertz superconducting transmission lines only differ in length; the signal output ends of the two titanium thermal electron detectors are respectively connected to the corresponding signal input ends of the detector readout circuit system;

[0058] The function generator is connected to the two titanium thermal electron detectors respectively, and is used to output a square wave voltage signal to the two titanium thermal electron detectors respectively, so as to calibrate the received power of the titanium thermal electron detectors at various frequency points according to the output voltage thereof. The function generator and the terahertz phase-locked signal source do not work simultaneously;

[0059] The detector readout circuit system consists of a room-temperature microwave readout circuit and two low-temperature low-noise amplifiers. The two titanium thermionic electron detectors in a low-temperature environment are each connected to a low-temperature low-noise amplifier. The low-temperature low-noise amplifier is used to amplify the response signal output by the titanium thermionic electron detector and send it to the room-temperature microwave readout circuit. The room-temperature microwave readout circuit then converts the response signal into computer-readable response data and sends it to the computer.

[0060] The computer is used to implement the following processes by running the data processing program:

[0061] 1) When the terahertz phase-locked signal source outputs a terahertz signal of a set frequency, record the response data of the two titanium thermionic electron detectors;

[0062] 2) During the operation of the function generator, for any titanium hot electron detector, when its response data is equal to the response data of the terahertz signal of the set frequency output by the terahertz phase-locked signal source, the current output voltage of the function generator is recorded, and the received power of the current titanium hot electron detector at the output voltage is calculated, and the received power is used as the actual received power of the titanium hot electron detector when the terahertz phase-locked signal source outputs the terahertz signal of the set frequency;

[0063] The received power ratio of the two titanium thermal electron detectors corresponding to the set frequency is calculated using the actual received power, and based on the received power ratios of the two titanium thermal electron detectors corresponding to different set frequencies obtained from multiple tests, a spectrum measurement result of the received power ratio of the two titanium thermal electron detectors is generated;

[0064] Based on the relationship between the received power ratio and the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line, the spectrum measurement results of the received power ratio of two titanium hot electron detectors were fitted with the least squares method to obtain the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line.

[0065] The method for measuring a terahertz superconducting transmission line based on the above measuring device specifically includes the following steps:

[0066] S1) constructing a measurement device, setting a terahertz phase-locked signal source at a suitable position within the receiving range of a receiving antenna of the chip to be measured, connecting the output end of the receiving antenna to the input end of a power divider, connecting the two output ends of the power divider to two titanium thermal electron detectors respectively through two sections of terahertz superconducting transmission lines of different lengths, connecting the output end of a function generator to the signal input ends of the two titanium thermal electron detectors, connecting the output ends of the two titanium thermal electron detectors to the input end of a detector readout circuit system, and connecting the output end of the detector readout circuit system to the input end of a computer;

[0067] S2) turning off the function generator, setting a target frequency range of the terahertz phase-locked signal source, and selecting multiple frequency points within the target frequency range;

[0068] S3) controlling the terahertz phase-locked signal source to output a terahertz signal at a certain frequency point, using a detector readout circuit system to respectively measure response data of the two titanium thermionic electron detectors to the terahertz signal of the current frequency, and outputting the response data to a computer for recording and storage;

[0069] S4) resetting the frequency of the terahertz signal output by the terahertz phase-locked signal source, and repeating step 3) until the response data of the two titanium thermionic electron detectors at all frequency points within the target frequency range are obtained;

[0070] S5) turning off the terahertz phase-locked signal source, starting the function generator, and using the detector readout circuit system to measure the response data of the two thermal electron detectors to the voltage signal respectively;

[0071] S6) controlling the function generator to output voltage signals of appropriate voltages to the two titanium thermal electron detectors, respectively, so that the current response data of the titanium thermal electron detector is equal to the response data of the titanium thermal electron detector at a certain frequency point, calculating the received power of the current thermal electron detector at the current output voltage of the function generator using a computer, and using the calculated value as the actual received power corresponding to the frequency point after calibration;

[0072] S7) adjusting the output voltage of the function generator and repeating step 6) to obtain the actual received power of the two titanium thermionic electron detectors corresponding to all frequency points within the target frequency range, thereby obtaining spectrum data of the received power of each titanium thermionic electron detector within the target frequency range;

[0073] S8) Calculate the received power ratio of the two titanium thermal electron detectors at each frequency point using a computer, and obtain the following: Figure 2 The spectrum measurement results shown are then fitted by the least squares method based on the relationship between the received power ratio and the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line to obtain the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line.

[0074] In summary, the measurement device and measurement method proposed in the present invention, in order to reduce the impedance matching requirements between the detector and the terahertz superconducting transmission line and obtain the accurate received power of the detector, propose a theoretical formula that can still achieve high-precision measurement of the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line when the impedance mismatch occurs, and eliminate the frequency variation of the terahertz signal power in the optical path by comparing the spectrum of the received power of the two detectors. At the same time, a function generator is used to obtain the accurate received power of the detector, thereby achieving the measurement of the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line. The measurement device for achieving the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line proposed in the present invention is simple in structure, and the data processing involved in the measurement method is easy to implement. Considering the application scenarios, the measurement device and measurement method proposed in the patent of the present invention are particularly suitable for measuring the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line.

[0075] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A terahertz superconducting transmission line measurement device, characterized in that: It includes a terahertz phase-locked signal source, a chip to be tested, a function generator, a detector readout circuit system and a computer, wherein: The terahertz phase-locked signal source is used to transmit a terahertz signal of a set frequency; The chip under test includes a receiving antenna, a power divider, and two thermal electron detectors. The receiving antenna is used to receive the terahertz signal emitted by the terahertz phase-locked signal source and send it to the power divider. The two signal output ends of the power divider are respectively connected to the thermal electron detectors integrated in the two channels through two sections of terahertz superconducting transmission lines with different lengths, and the terahertz signals divided into two paths are respectively sent to the corresponding thermal electron detectors. The signal output ends of the two thermal electron detectors are respectively connected to the signal input ends of the detector readout circuit system. The function generator is connected to the two thermal electron detectors respectively, and outputs voltage signals for calibrating the received power of the two thermal electron detectors respectively, and the function generator and the terahertz phase-locked signal source do not work at the same time; The output end of the detector readout circuit system is connected to a computer, and the response signals generated by the two thermal electron detectors to the received signals are converted into response data and sent to the computer; The computer is used to implement: When the terahertz phase-locked signal source outputs a terahertz signal of a set frequency, the response data of the two thermal electron detectors are recorded; During the operation of the function generator, for any thermal electron detector, when its response data is equal to the response data of the terahertz signal of the set frequency output by the terahertz phase-locked signal source, the current output voltage of the function generator is recorded, and the received power of the current thermal electron detector at the output voltage is calculated, and the received power is used as the actual received power of the current thermal electron detector when the terahertz phase-locked signal source outputs the terahertz signal of the set frequency; The received power ratio of the two thermal electron detectors corresponding to the set frequency is calculated using the actual received power, and based on the received power ratios of the two thermal electron detectors corresponding to different set frequencies obtained from multiple tests, a spectrum measurement result of the received power ratio of the two thermal electron detectors is generated; Based on the relationship between the received power ratio and the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line, the spectrum measurement results of the received power ratio of the two thermal electron detectors were fitted with the least squares method to obtain the effective dielectric constant, attenuation constant and characteristic impedance of the terahertz superconducting transmission line.

2. The terahertz superconducting transmission line measuring device according to claim 1, characterized in that: The detector readout circuit system includes a room-temperature microwave readout circuit and two low-temperature low-noise amplifiers. The two thermal electron detectors in a low-temperature environment are each connected to a low-temperature low-noise amplifier. The output signal is amplified by the corresponding low-temperature low-noise amplifier and then sent to the room-temperature microwave readout circuit connected to the computer.

3. The terahertz superconducting transmission line measuring device according to claim 1, characterized in that: The thermal electron detector is a titanium thermal electron detector.

4. The device for measuring a terahertz superconducting transmission line according to claim 1, wherein: The voltage signal output by the function generator is a square wave signal.

5. A terahertz superconducting transmission line measuring device according to any one of claims 1 to 4, characterized in that: The relationship is: Where r(f) is the received power ratio in functional form, f is the frequency of the output signal of the terahertz signal source, c is the speed of light in vacuum, and ε eff is the effective dielectric constant, α is the attenuation constant, Z0 is the characteristic impedance, Re represents the real part of a complex number, j represents the imaginary part of a complex number, tanh represents the hyperbolic tangent function, * represents the conjugate complex number, l1 and l2 are the lengths of the terahertz superconducting transmission lines in the two channels, and Z l1 With Z l2 are the equivalent impedances of the thermal electron detectors in the two channels, l1 and l2, Z l1 With Z l2 All can be obtained through measurement.

6. A method for measuring a terahertz superconducting transmission line, characterized in that: The following steps are involved: S1) constructing a measurement device, the measurement device comprising a terahertz phase-locked signal source, a chip to be tested, a function generator, a detector readout circuit system, and a computer, the chip to be tested comprising a receiving antenna, a power divider, and two thermal electron detectors; Setting a terahertz phase-locked signal source within the receiving range of a receiving antenna of the chip under test, connecting the output end of the receiving antenna to the input end of a power divider, connecting the two output ends of the power divider to two thermal electron detectors respectively through two sections of terahertz superconducting transmission lines of different lengths, connecting the output end of a function generator to the signal input ends of the two thermal electron detectors, connecting the output ends of the two thermal electron detectors to the input end of a detector readout circuit system, and connecting the output end of the detector readout circuit system to the input end of a computer; S2) turning off the function generator, setting a target frequency range of the terahertz phase-locked signal source, and selecting a plurality of frequency points within the target frequency range; S3) controlling the terahertz phase-locked signal source to output a terahertz signal of a set frequency, where the set frequency is one of the frequency points within the target frequency range, using a detector readout circuit system to respectively measure response data of the two thermal electron detectors to the terahertz signal of the current set frequency, and outputting the response data to a computer for recording and storage; S4) resetting the frequency of the terahertz signal output by the terahertz phase-locked signal source, and repeating step 3) until the response data of the two thermal electron detectors at all frequency points within the target frequency range are obtained; S5) turning off the terahertz phase-locked signal source, starting the function generator, and using the detector readout circuit system to measure the response data of the two thermal electron detectors to the voltage signal respectively; S6) for the two thermal electron detectors, controlling the function generators to respectively output voltage signals of appropriate voltages so that the current response data of the thermal electron detectors is equal to the response data when a terahertz signal of a set frequency is input, and using a computer to calculate the received power of the current thermal electron detectors at the current output voltage of the function generator, and using the calculated power as the actual received power corresponding to the set frequency after calibration; S7) adjusting the output voltage of the function generator and repeating step 6) to obtain the actual received powers of the two thermal electron detectors corresponding to all frequency points within the target frequency range, thereby obtaining spectrum data of the received power of each thermal electron detector within the target frequency range; S8) Using a computer to calculate the ratio of received powers of the two thermal electron detectors at each frequency point, obtaining a spectrum measurement result, and performing a least squares fit on the spectrum measurement result based on a relationship between the received power ratio and the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line to determine the effective dielectric constant, attenuation constant, and characteristic impedance of the terahertz superconducting transmission line.

7. The method for measuring a terahertz superconducting transmission line according to claim 6, wherein: A detector readout circuit system is constructed using a room-temperature microwave readout circuit and two low-temperature low-noise amplifiers. Two thermal electron detectors are each connected to a low-temperature low-noise amplifier. The output signal is amplified by the corresponding low-temperature low-noise amplifier and sent to the room-temperature microwave readout circuit. The output end of the room-temperature microwave readout circuit is connected to a computer.

8. The method for measuring a terahertz superconducting transmission line according to claim 6, wherein: The thermal electron detector is a titanium thermal electron detector.

9. The method for measuring a terahertz superconducting transmission line according to claim 6, wherein: The voltage signal output by the function generator is a square wave signal.

10. A method for measuring a terahertz superconducting transmission line according to any one of claims 6 to 9, characterized in that: The relationship is: Where r(f) is the received power ratio in functional form, f is the frequency of the output signal of the terahertz signal source, c is the speed of light in vacuum, and ε eff is the effective dielectric constant, α is the attenuation constant, Z0 is the characteristic impedance, Re represents the real part of a complex number, j represents the imaginary part of a complex number, tanh represents the hyperbolic tangent function, * represents the conjugate complex number, l1 and l2 are the lengths of the terahertz superconducting transmission lines in the two channels, and Z l1 With Z l2 are the equivalent impedances of the thermal electron detectors in the two channels, l1 and l2, Z l1 With Z l2 All can be obtained through measurement.

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