Device and method for micro voltage signal measurement and null pointing

Abstract

The invention provides a device and a method for measuring and nulling a tiny voltage signal. The device comprises a nulling table, a quantum voltage device A and a quantum voltage device B, the quantum voltage device A and the quantum voltage device B comprise refrigeration equipment, a microwave driving source, a voltage / current bias source and a quantum voltage superconducting chip; the positive output end of the quantum voltage device A is connected with the negative output end of the quantum voltage device B and then connected to one end of the index table; the negative output end of the quantum voltage device A is connected with the positive output end of the quantum voltage device B and then connected with the system signal ground; by means of the device, the influence of quantum voltage steps is eliminated, adjustment and measurement are easier, and tiny signals are measured.

Description

Technical Field

[0001] This invention relates to the field of precision voltage signal measurement technology, and in particular to a device and method for measuring and zeroing minute voltage signals. Background Technology

[0002] Quantum voltage signals are currently the most stable voltage signals available. Based on the Josephson effect, they are the most accurate and stable voltage signals and are widely used in applications requiring high-precision voltage measurement, such as electrical metrology, aerospace, and power equipment. A quantum signal generation system mainly consists of a cooling device, a microwave driver, a voltage / current bias source, and a quantum voltage superconducting chip. The cooling device provides the quantum chip with an ambient temperature of 4.2K (or other chip-related temperatures). The microwave driver and bias source generate high-frequency, high-power microwave signals and electrical signals, respectively, which together drive the quantum chip to produce a stable and reliable quantum voltage signal.

[0003] Therefore, how to eliminate the influence of quantum voltage steps, make it easier to adjust and measure, and measure minute signals has become one of the existing technical problems that urgently need to be solved. Summary of the Invention

[0004] This invention provides an apparatus and method for measuring and zeroing minute voltage signals, which eliminates the influence of quantum voltage steps, making it easier to adjust and measure minute signals.

[0005] In a first aspect, a device for measuring and nulling minute voltage signals is provided, comprising: a null pointer, a quantum voltage device A, and a quantum voltage device B; wherein the quantum voltage devices A and B include a cooling device, a microwave drive source, a voltage / current bias source, and a quantum voltage superconducting chip;

[0006] The positive output terminal of quantum voltage device A is connected to the negative output terminal of quantum voltage device B, and then connected to one end of the index table.

[0007] The negative output terminal of quantum voltage device A is connected to the positive output terminal of quantum voltage device B, and then connected to the system signal ground;

[0008] The impedance Vx to be measured is connected to the other end of the null pointer.

[0009] In one implementation, quantum voltage device A is controlled to output quantum voltage V1, and quantum alternating voltage device B is controlled to output quantum voltage V2.

[0010] In one implementation, V2 and V1 are signals with the same frequency. The amplitude of the two signals is adjusted so that the null pointer indicates zero, that is, the signals are balanced, Vx = V2 - V1.

[0011] In one embodiment, the quantum voltage superconducting chip has a minimum voltage step of 70 microvolts, i.e., a minimum resolution of 70 μV.

[0012] In one embodiment, the quantum voltage superconducting chip has a driving frequency range of 17.5 GHz to 18 GHz.

[0013] In one implementation,

[0014] In one implementation,

[0015] Secondly, a method for measuring and zeroing minute voltage signals is provided, the method being applied to the aforementioned apparatus, comprising:

[0016] When initially measuring the value of Vx, quantum voltage devices A and B do not output signals, and the null pointer deflects to one side.

[0017] The voltage signal output by the quantum voltage device A is gradually approached, causing the null pointer to deflect from the initial deflection direction to the opposite direction.

[0018] Adjust the driving microwave frequency of quantum voltage device A to reduce the deflection angle. If the pointer is adjusted to zero, then Vx = V1.

[0019] If adjusting the output signal of quantum voltage device A does not reduce the deflection angle while keeping the pointer deflection direction unchanged, then start quantum voltage device B and output the minimum quantum step. At this time, the deflection angle will be closer to zero or deflected to the other side. Then, by adjusting the driving microwave frequency of quantum voltage device A, the pointer of the zero-point meter can be made closer to zero.

[0020] Repeat the adjustment operation, using different combinations of quantum steps to approximate the value of Vx, so that the null pointer points to zero. At this time, Vx = V2 - V1.

[0021] In one implementation, when reducing the deflection angle, it is necessary to ensure that the pointer does not deflect to the right, with the corresponding deviation value within tens of microvolts.

[0022] This invention provides an apparatus and method for measuring and zeroing minute voltage signals. The apparatus includes a zero-pointing meter, a quantum voltage device A, and a quantum voltage device B. Quantum voltage devices A and B each include a cooling device, a microwave drive source, a voltage / current bias source, and a quantum voltage superconducting chip. The positive output terminal of quantum voltage device A is connected to the negative output terminal of quantum voltage device B, and then connected to one end of the zero-pointing meter. The negative output terminal of quantum voltage device A is connected to the positive output terminal of quantum voltage device B, and then connected to the system signal ground. The impedance Vx to be measured is connected to the other end of the zero-pointing meter. This apparatus eliminates the influence of quantum voltage steps, making it easier to adjust and measure minute signals.

[0023] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1 A diagram of a device for measuring and zeroing minute voltage signals according to an embodiment of the present invention;

[0026] Figure 2 This is a method for measuring and zeroing minute voltage signals according to an embodiment of the present invention. Detailed Implementation

[0027] To eliminate the influence of quantum voltage steps and facilitate adjustment and measurement of minute signals, an apparatus and method for measuring and zeroing minute voltage signals are provided.

[0028] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0030] like Figure 1 As shown, an embodiment provides an apparatus for measuring and zeroing minute voltage signals, comprising:

[0031] 1. The voltage of the signal to be measured, Vx;

[0032] 2 refers to a zero meter, which is generally an analog meter header;

[0033] 3 and 4 are two independent quantum voltage devices A and B (including cooling equipment, microwave drive source, voltage / current bias source, quantum voltage superconducting chip, etc.), and the quantum voltage must be consistent, that is, different technical solutions cannot be used, such as mixing PJVS and JAWS.

[0034] The positive output terminal (+ terminal) of the quantum voltage device A is connected to the negative output terminal (- terminal) of the quantum voltage device B, and then connected to one end of the index table.

[0035] The negative output terminal (- terminal) of quantum voltage device A is connected to the positive output terminal (+ terminal) of quantum voltage device B, and then connected to the system signal ground.

[0036] The impedance Vx to be measured is connected to the other end of the null pointer.

[0037] The working principle of this invention is as follows: control quantum voltage device A to output quantum voltage V1, and quantum AC voltage device B to output quantum voltage V2. Note that V2 and V1 are signals of the same frequency. Adjust the amplitude of the two signals so that the zero pointer indicates zero, that is, the signals reach balance. At this time, it can be known that Vx = V2 - V1.

[0038] This invention targets the measurement or balance detection of weak voltage signals (nanovolt level / nV), employing a measurement device built with two quantum voltage signals. Compared to weak signal measurement devices such as lock-in amplifiers and nanovoltmeters, the device of this invention offers higher accuracy and stronger anti-interference capabilities. Lock-in amplifiers and nanovoltmeters are instruments specifically designed for measuring minute signals, but they contain active circuits for signal sampling, amplification, isolation, and filtering, introducing considerable interference. For example, commercially available nanovoltmeters only achieve sensitivity or resolution at the nanovolt level; based on their range error limit specifications, their error exceeds 100% when measuring a 10 nanovolt voltage signal. Therefore, lock-in amplifiers and nanovoltmeters can only provide a reference value for the measured minute voltage signal, carrying significant measurement uncertainty. Similarly, if a measurement device is built using only one quantum voltage signal, the measurement effect is inevitably affected by the quantum voltage step (according to the Josephson effect, quantum voltage signals appear in the form of step voltages). Figure 1 Depending on the manufacturing and driving methods of quantum voltage superconducting chips, the quantum voltage steps (i.e., the voltage difference between steps) range from tens of microvolts (μV) to 150 microvolts. This means that a single quantum voltage signal can only measure weak signals of tens of microvolts, which is significantly less than the requirements for nanovolt-level measurements. Dual-channel quantum signals, on the other hand, can use the difference between the two quantum voltage signals as a measurement reference, eliminating the influence of quantum voltage steps, making them easier to adjust and measure, and thus better suited for measuring minute signals.

[0039] The voltage measurement and null pointer device of this invention consists of two quantum voltage devices and a null pointer meter. The quantum voltage devices generate accurate, reliable, and programmable quantum voltage signals. Based on the type of their core device (quantum voltage superconducting chip), they can be divided into programmable quantum voltage devices (PJVS) and pulse-driven quantum voltage devices (JAWS), each with different peripheral driving source compositions. The quantum voltage signal output by a single quantum voltage device is consistent and possesses extremely high accuracy. The null pointer meter can be analog or digital, but its sensitivity must be in the nanovolt range.

[0040] This invention provides a solution for measuring weak voltage signals or judging circuit voltage balance. It can measure weak voltage signals at the nanovolt level or be used for judging the balance of bridge arms in various electromagnetic metrology, such as resistance bridges, right-angle bridges, and quantum impedance bridges. It can effectively reduce system errors, improve measurement accuracy, and enhance the technical indicators of application systems.

[0041] Based on the same technical concept, this application also provides a method for measuring and zeroing a small voltage signal. Since the method is applied to the above-mentioned device, the implementation of the method can be referred to the implementation of the device, and repeated details will not be described again.

[0042] The measurement and balancing methods are as follows:

[0043] (1) When initially measuring the value of Vx, quantum voltage devices A and B do not output signals, and the null pointer deflects to one side (Vx is input from the left, and the pointer deflects to the right);

[0044] (2) Controlling the output voltage signal of quantum voltage device A can gradually approach the null pointer, causing it to deflect from the initial deflection direction to the opposite direction (initially deflected to the right, then deflected to the left).

[0045] (3) Then adjust the driving microwave frequency of quantum voltage device A and reduce the deflection angle (note that the pointer meter should not deflect to the right, and the corresponding deviation value should be within tens of microvolts). If the pointer is adjusted to zero, Vx = V1.

[0046] (4) If adjusting the output signal of quantum voltage device A does not reduce the deflection angle (the corresponding deviation value is within tens of microvolts) while keeping the pointer deflection direction unchanged, start quantum voltage device B and output the minimum quantum step. At this time, the deflection angle will be close to zero or deflected to the other side. At this time, by adjusting the driving microwave frequency of quantum voltage device A, the pointer of the zero pointer can be made closer to zero.

[0047] (5) Steps (3) and (4) can be repeated to try to approximate the value of Vx with different combinations of quantum steps, so that the null pointer points to zero. At this time, Vx = V2 - V1.

[0048] To facilitate understanding, a specific example is given below:

[0049] A miniature voltage measurement and nulling device was built, realizing the function of capacitance proportional bridge balance determination:

[0050] 1. The voltage of the signal to be measured, Vx;

[0051] 2 refers to a zero meter, which is generally an analog meter header;

[0052] 3 and 4 are two independent quantum voltage devices A and B (including cooling equipment, microwave drive source, voltage / current bias source, quantum voltage superconducting chip, etc.). We use domestically produced quantum voltage superconducting chip, whose minimum voltage step is 70 microvolts (i.e., minimum resolution 70 μV).

[0053] The positive output terminal (+ terminal) of the quantum voltage device A is connected to the negative output terminal (- terminal) of the quantum voltage device B, and then connected to one end of the index table.

[0054] The negative output terminal (- terminal) of quantum voltage device A is connected to the positive output terminal (+ terminal) of quantum voltage device B, and then connected to the system signal ground.

[0055] The impedance Vx to be measured is connected to the other end of the null pointer.

[0056] In this embodiment, the minimum voltage step of the quantum voltage superconducting chip is 70 microvolts (i.e., minimum resolution 70 μV). Its driving frequency range is 17.5 GHz to 18 GHz. According to the Josephson voltage calculation formula, by adjusting the driving frequency, the adjustable range of the microstep is 67.9 μV to 72.1 μV, following the operating steps:

[0057] (1) When initially measuring the value of Vx, quantum voltage devices A and B do not output signals, and the null pointer deflects to one side (Vx is input from the left, and the pointer deflects to the right);

[0058] (2) Controlling the output voltage signal of quantum voltage device A can gradually approach the null pointer, causing it to deflect from the initial deflection direction to the opposite direction (initially deflected to the right, then deflected to the left).

[0059] (3) Then adjust the driving microwave frequency of quantum voltage device A and reduce the deflection angle (note that the pointer meter should not deflect to the right, and the corresponding deviation value should be within tens of microvolts). If the pointer is adjusted to zero, Vx = V1.

[0060] (4) If adjusting the output signal of quantum voltage device A does not reduce the deflection angle (the corresponding deviation value is within tens of microvolts) while keeping the pointer deflection direction unchanged, start quantum voltage device B and output the minimum quantum step. At this time, the deflection angle will be close to zero or deflected to the other side. At this time, by adjusting the driving microwave frequency of quantum voltage device A, the pointer of the zero pointer can be made closer to zero.

[0061] (5) You can repeat (3) and (4) without operating and try to approximate the value of Vx with different combinations of quantum steps so that the null pointer points to zero. At this time, Vx = V2 - V1.

[0062] According to this embodiment, we obtain a stable null pointer device with the ability to measure minute voltage signals down to below 5nV and very small measurement uncertainty.

[0063] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0064] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for measuring and zeroing minute voltage signals, characterized in that, include: Refers to the zero meter, quantum voltage device A, and quantum voltage device B; The quantum voltage devices A and B include a cooling device, a microwave drive source, a voltage / current bias source, and a quantum voltage superconducting chip. The positive output terminal of quantum voltage device A is connected to the negative output terminal of quantum voltage device B, and then connected to one end of the index table. The negative output terminal of quantum voltage device A is connected to the positive output terminal of quantum voltage device B, and then connected to the system signal ground; The impedance Vx to be measured is connected to the other end of the null pointer.

2. The apparatus according to claim 1, characterized in that, Control quantum voltage device A to output quantum voltage V1, and quantum AC voltage device B to output quantum voltage V2.

3. The apparatus according to claim 2, characterized in that, V2 and V1 are signals with the same frequency. Adjusting the amplitude of the two signals until the zero pointer reads zero means that the signals are balanced, and Vx = V2 - V1.

4. The apparatus according to claim 3, characterized in that, The minimum voltage step of the quantum voltage superconducting chip is 70 microvolts, which means the minimum resolution is 70 μV.

5. The apparatus according to claim 4, characterized in that, The quantum voltage superconducting chip has a driving frequency range of 17.5 GHz to 18 GHz.

6. A method for measuring and zeroing minute voltage signals, said method being applied to the apparatus according to any one of claims 1 to 5, characterized in that, include: When initially measuring the value of Vx, quantum voltage devices A and B do not output signals, and the null pointer deflects to one side. The voltage signal output by the quantum voltage device A is gradually approached, causing the null pointer to deflect from the initial deflection direction to the opposite direction. Adjust the driving microwave frequency of quantum voltage device A to reduce the deflection angle. If the pointer is adjusted to zero, then Vx = V1. If adjusting the output signal of quantum voltage device A does not reduce the deflection angle while keeping the pointer deflection direction unchanged, then start quantum voltage device B and output the minimum quantum step. At this time, the deflection angle will be closer to zero or deflected to the other side. Then, by adjusting the driving microwave frequency of quantum voltage device A, the pointer of the zero-point meter can be made closer to zero. Repeat the adjustment operation, using different combinations of quantum steps to approximate the value of Vx, so that the null pointer points to zero. At this time, Vx = V2 - V1.

7. The method according to claim 6, characterized in that, When reducing the deflection angle, it is necessary to ensure that the pointer does not deflect to the right, and the corresponding deviation value is within tens of microvolts.

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