Wideband resistor voltage divider and AC voltage ratio standard device

Abstract

The present invention relates to the field of proportional metering technology, and provides a wide-band resistor voltage divider and an AC voltage proportional standard device. The voltage divider mainly includes: a housing, an input coaxial socket, an output coaxial socket, and a resistor voltage divider structure with a shielding network arranged inside the housing; the pin of the input coaxial socket passes through the housing and is connected to the input end of the resistor voltage divider structure, and the pin of the output coaxial socket passes through the housing and is connected to the output end of the resistor voltage divider structure; wherein the resistor voltage divider structure includes: at least two resistor modules and at least three microstrip transmission modules; each resistor module is connected across two adjacent microstrip transmission modules. The present invention reduces the uncertainty of the optimal ratio difference and the uncertainty of the optimal angle difference, and has the advantages of wide bandwidth, high accuracy, and high integration.

Description

Technical Field

[0001] The present invention relates to the technical field of proportional measurement, and in particular to a broadband resistor voltage divider and an AC voltage proportional standard device. Background Art

[0002] Proportional measurement plays a crucial role in electrical measurement, primarily by addressing the issue of range expansion. Since measurement standards or measuring instruments often only have high accuracy within a certain range, accurate measurement of a wide range of electrical quantities requires the use of a proportional device. Proportional devices are typically manufactured as accessory-type dedicated proportional devices or proportional standard devices, serving as range extenders for various measuring devices. The use of proportional standard devices not only standardizes measuring instruments to a standard form, resulting in a simple and reliable structure, but also offers higher measurement accuracy than directly using instruments. This can particularly improve the insulation performance of circuits, protecting the safety of measuring instruments and users. With the advancement of measurement technology, proportional devices can now achieve higher accuracy than measuring instruments. Therefore, they can be used as primary standards, complemented by auxiliary measuring instruments, to complete testing tasks.

[0003] In modern electrical precision measurement, the use of ratios and proportional relationships to achieve measurement goals is widespread. Many precision measurements rely on voltage and current ratios. Various voltage proportional devices, shunts, variable resistors, variable capacitors, bridges, and attenuators are designed based on the principle of proportionality. For example, the calibration of inductive voltage dividers, bridge proportional arms, and strain gauge attenuators requires proportional standards for precision measurement. Among them, the AC resistor divider is an important electromagnetic device primarily used for AC voltage range expansion and is essential for broadening the AC voltage measurement range. AC proportional voltage dividers are applicable to all AC voltage measurement instruments, including AC voltage sources, AC voltmeters, AC / DC converters, measuring amplifiers, and phase meters. Whether using the AC / DC thermoelectric comparison method or the AC sampling measurement method, precision AC voltage and power measurement requires the use of an AC voltage divider to attenuate the measured AC voltage to a voltage that can be directly accepted by a digital data logger or thermoelectric converter.

[0004] With the improvement of measurement and testing levels, higher requirements are placed on the accuracy of AC voltage proportional devices, which are necessary for measurement and testing. These have objectively put forward new requirements for the development of AC proportional measurement technology. In some aspects, AC voltage proportional devices have become a bottleneck restricting the improvement of measurement and calibration levels.

[0005] Therefore, solving the calibration problem of broadband AC voltage proportional devices should be a key direction in electrical metrology research. However, existing AC voltage proportional devices have low stability, a narrow applicable frequency range, relatively large ratio and angle errors, and low accuracy. Summary of the Invention

[0006] Based on the above reasons, embodiments of the present invention provide a wide-band resistor voltage divider and an AC voltage ratio standard device.

[0007] A first aspect of an embodiment of the present invention provides a broadband resistor voltage divider, comprising: a housing, an input coaxial socket, an output coaxial socket, and a resistor voltage divider structure with a shielding network disposed inside the housing;

[0008] The pin of the input coaxial socket passes through the housing and is connected to the input end of the resistive voltage divider structure, and the pin of the output coaxial socket passes through the housing and is connected to the output end of the resistive voltage divider structure;

[0009] The resistor voltage-dividing structure includes: at least two resistor modules and at least three microstrip transmission modules; each resistor module is connected between two adjacent microstrip transmission modules.

[0010] Optionally, the resistor voltage-dividing structure further comprises: welding a plurality of semicircular metal wires at equal intervals above each resistor module;

[0011] Each of the semicircular metal wires obtains a potential equal to that of the corresponding resistance module directly below it.

[0012] Optionally, the resistance voltage divider structure further includes: at least one fixed capacitor and at least one adjustable capacitor;

[0013] The fixed capacitor and the adjustable capacitor are both connected in parallel to the low-voltage arm of the resistance voltage divider structure.

[0014] Optionally, each of the microstrip transmission modules includes: a conductor plate, a dielectric substrate and a transmission microstrip;

[0015] The dielectric substrate is a fiber PCB board; the material of the transmission microstrip is copper foil;

[0016] Wherein, the resistance module is connected across two adjacent transmission microstrips.

[0017] Optionally, the rated power value of the resistance module is 3 times to 6 times the actual power consumed by the resistance module when the wide-band resistance divider operates at a rated input voltage.

[0018] Optionally, starting from the high-voltage side of the resistor voltage divider structure, the temperature coefficients between every two adjacent resistor modules are one positive and one negative.

[0019] Optionally, the broadband resistor voltage divider further includes: a buffer follower amplifier with a preset ratio;

[0020] The buffer follower amplifier is arranged at the output end of the resistor voltage divider structure.

[0021] Optionally, the output end of the broadband resistor divider adopts a double-shielded coaxial cable.

[0022] Optionally, the angular difference of the broadband resistor divider is tested by a square wave angular difference test method.

[0023] A second aspect of the embodiments of the present invention provides an AC voltage ratio standard device, comprising the wide-band resistor voltage divider as described in any one of the first aspect of the embodiments.

[0024] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0025] The voltage divider of this embodiment mainly includes: a housing, an input coaxial socket, an output coaxial socket, and a resistive voltage divider structure with a shielding network arranged inside the housing. The pin of the input coaxial socket passes through the housing and is connected to the input end of the resistive voltage divider structure, and the pin of the output coaxial socket passes through the housing and is connected to the output end of the resistive voltage divider structure. The voltage divider has the advantages of wide bandwidth, high accuracy, and high integration. The resistive voltage divider structure includes at least two resistor modules and at least three microstrip transmission modules. Each resistor module is connected across two adjacent microstrip transmission modules, reducing the uncertainty of the optimal ratio difference and the uncertainty of the optimal angle difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 1 is a schematic structural diagram of a broadband resistor voltage divider provided by an embodiment of the present invention;

[0027] Figure 2 1 is a schematic diagram of the geometric structure of a microstrip circuit provided by an embodiment of the present invention (a) and a diagram of electric and magnetic field lines (b);

[0028] Figure 3 1 is a schematic structural diagram of a voltage divider affected by parasitic capacitance provided by an embodiment of the present invention;

[0029] Figure 4 is a stray electric field diagram of a resistor module without a shielding cage provided by an embodiment of the present invention;

[0030] Figure 5 This is a stray electric field diagram of a resistor module with a shielding cage provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Those skilled in the art should be aware that the specific structures, dimensions, and proportions shown in the drawings of this application are used to illustrate the embodiments of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of the claims should be based on the claims.

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0033] See also Figure 1 , is a schematic diagram of the structure of the broadband resistor divider provided in this embodiment, and the following is combined with Figure 1 , the structure of the broadband resistor divider is explained.

[0034] The broadband resistor voltage divider of the present invention mainly comprises: a housing 1, an input coaxial socket 2, an output coaxial socket 3 and a resistor voltage divider structure with a shielding network arranged inside the housing 1 (such as Figure 1 4 and 5); the pin of the input coaxial socket 2 passes through the housing 1 and is connected to the input end of the resistor voltage divider structure, and the pin of the output coaxial socket 3 passes through the housing 1 and is connected to the output end of the resistor voltage divider structure.

[0035] The resistor voltage divider structure mainly includes: at least two resistor modules 4 and at least three microstrip transmission modules 5 ; each resistor module 4 is connected between two adjacent microstrip transmission modules 5 .

[0036] Specifically, the broadband resistor divider of this embodiment can be made of A3 aluminum milling, and organically combines a resistor divider network (resistor module 4), a capacitor divider network, a shielding network, etc. It can conveniently divide the AC input voltage signal by a suitable value and output a constant AC voltage with a precise voltage division ratio, a small phase difference and a ratio difference.

[0037] For example, taking a certain proportional voltage divider as an example, this broadband resistor voltage divider adopts the following technical solution: it consists of an aluminum shell 1, an input coaxial socket 2, an output coaxial socket 3, a resistor element (resistance module 4), a shielding network PCB and a microstrip transmission strip (microstrip transmission module 5). The pins of the input coaxial socket 2 and the output coaxial socket 3 are welded to the inner end of the microstrip fracture of the microstrip transmission module 5, the shielding network is welded to the edge pad of the circuit board, and several resistor modules 4 are installed on the circuit board (the voltage divider ratio is different, and the number of resistors is different). Voltage divider capacitors can also be welded between the shielding networks, and the distance between the voltage divider resistors and the voltage divider capacitors is as far as possible.

[0038] The broadband resistor divider can divide the high-voltage AC signal into a low-voltage signal suitable for sampling. For example, the broadband resistor divider divides the AC signal with a maximum bandwidth of 600V into a 0.8V voltage signal suitable for sampling by the data collector through the voltage divider. In specific applications, the broadband resistor dividers with different ratios have different resistance values of the resistor network and different voltage-dividing capacitors. After the input AC voltage signal is divided by the resistors, a fixed AC voltage is output from the output end. This voltage has a strict proportional relationship, phase relationship, and ratio difference relationship with the input voltage. Its resistor module 4, capacitor network, shielding network, etc. ensure that these three relationships are accurately set.

[0039] This embodiment mainly studies the AC voltage ratio traceability technology in the range of 0.5V~1000V / 10Hz~1MHz, and obtains a high-accuracy broadband resistor voltage divider, and then establishes a resistive AC voltage ratio standard device based on the broadband resistor voltage divider. For example, the amplitude range of the calibrated broadband AC voltage is 0.5V~1000V, and the frequency range is 10Hz~1MHz. The nine voltage dividers of this embodiment can be used. The frequency of the resistor voltage divider in the 4V, 8V, and 15V ranges is 1MHz, the frequency of the resistor voltage divider in the 30V, 60V, 120V, and 240V ranges is 100kHz, and the frequency of the resistor voltage divider in the 480V and 1000V ranges is 10kHz. The optimal ratio error uncertainty finally obtained is 5×10 -6 , the optimal angular difference uncertainty is 6μrad, with high accuracy.

[0040] Since broadband resistor dividers are primarily used for sampling and measurement, AC resistor dividers must consider not only the voltage divider's stability and ratio error, but also the effects of the voltage divider's angular deviation. Furthermore, considering that the voltage divider's angular deviation can be calibrated using the half-voltage load recursion method, the voltage divider structure of this embodiment can adopt the most basic principle of series resistor voltage division, eliminating the need for a switch. This improves reliability and reduces the effects of switch leakage. Furthermore, to enhance the voltage divider's performance, reduce resistor load and temperature effects, mitigate the effects of leakage current caused by parasitic impedance, improve anti-interference capabilities, reduce the voltage divider's ratio error and angular deviation, and enhance its stability, the voltage divider of this embodiment employs effective shielding measures, such as the inclusion of a shielding network.

[0041] In one embodiment, the resistor voltage divider structure may further include: a plurality of semicircular metal wires welded at equal intervals above each resistor module 4; each semicircular metal wire obtains the same potential as the corresponding resistor module 4 directly below.

[0042] When designing the parameters of the voltage divider, factors such as the voltage coefficient, temperature coefficient, and power consumption of the resistor elements should be controlled, and efforts should be made to reduce the impact of these factors on the voltage divider measurement to within the allowable error range. Generally, most electronic components are directly soldered to the printed circuit board. However, according to the design requirements of the wide-band and wide-voltage range voltage divider, the insulation resistance of the printed circuit board is not large enough. Direct soldering will cause leakage current between the resistor pins and the circuit board. The main sources of voltage divider error are leakage current in the circuit and the influence of stray electric fields. In order to reduce the influence of leakage current and stray electric fields and keep the error within the allowable range, this embodiment adopts insulating brackets and equipotential shielding protection technology.

[0043] Specifically, this embodiment utilizes a board-based space (cage-shaped) electric field confinement structure. While the grounded metal plate of a microstrip circuit blocks most electric field leakage, a small amount of electric field energy still radiates into space, requiring a method to confine this energy. A semicircular cage-shaped electric field confinement structure effectively addresses this problem. Specifically, multiple semicircular metal conductors are soldered at equal intervals above the soldered chip resistor (resistor module 4) on the PCB. These semicircular metal conductors utilize capacitor-assisted voltage division to achieve a potential identical to that of the resistor directly below.

[0044] The idea of the cage-shaped electric field confinement structure is derived from the equipotential ring shielding technology. It applies the on-board equipotential shielding ring to space to construct a spatial equipotential shielding ring. The electric field leaked from the copper foil (transmission microstrip) and resistor device (resistor module 4) on the PCB board, that is, the distributed capacitance, additional inductance, and PCB transmission line stray electric field, is confined within the shielding metal ring with the same AC potential. Without spatial electric field leakage, there is no leakage current, and there is no AC / DC difference, so higher AC characteristic indicators can be obtained. Figure 4 This is the stray electric field diagram of a resistor without a shielding cage simulated using ANSOFT MAXWELL 16.0 electromagnetic analysis software. Figure 5 This is a comparison of the spatial electric field distribution confined within the PCB and the cage-type shielding ring. It can be seen that the semicircular metal wire of this embodiment greatly reduces the leakage of the electric field.

[0045] In one embodiment, the resistor divider structure may further include: at least one fixed capacitor and at least one adjustable capacitor (not shown in the figure); the fixed capacitor and the adjustable capacitor are both connected in parallel to the low-voltage arm of the resistor divider structure.

[0046] Specifically, the present embodiment adopts a capacitor compensation technology for the phase angle error of the voltage divider. A major difference between an AC voltage divider and a DC voltage divider is the influence of the time parameters of the resistor and the various parasitic capacitances in the circuit on the phase angle error of the voltage divider. These parasitic capacitances include the parasitic capacitance of the resistor device, the parasitic capacitance of the resistor device to the ground, the input capacitance of the amplifier, the output lead of the voltage divider, and the input capacitance of the sampler. In order to reduce the phase angle error of the voltage divider and to reduce the influence of the parasitic capacitance introduced by the resistor, an appropriate small fixed capacitor can be connected in parallel to the low-voltage arm of the voltage divider. The voltage divider of the present embodiment can adopt a capacitor voltage divider design, which has a significant improvement on the phase angle error of the voltage divider.

[0047] The schematic diagram of the AC resistor divider affected by parasitic capacitance is shown in Figure 3 , where C0 is the load capacitance, C gi is the equipotential shielding capacitor, C is the compensation capacitor of the resistor, and C ri It is the stray capacitance in the space. This embodiment simplifies the design. riThe spatial stray capacitance can be ignored, and the focus is on the C0 load capacitance, C gi The contribution of the equipotential shielding capacitor and the C resistor compensation capacitor to the voltage divider's angular error can be determined through simulation experiments in this embodiment, and then adjusted in subsequent actual tests. To enable continuous adjustment of the angular error, the load capacitor C0 is connected in parallel with a fixed capacitor and a small adjustable capacitor in the low-voltage arm of the voltage divider. This significantly improves the phase angle error of the voltage divider, and the small adjustable capacitor allows for continuous adjustment of the angular error.

[0048] In one embodiment, each microstrip transmission module 5 may include: a conductor plate, a dielectric substrate and a transmission microstrip; the dielectric substrate is a fiber PCB board; the material of the transmission microstrip is copper foil; wherein the resistor module 4 is connected across two adjacent transmission microstrips.

[0049] Specifically, this embodiment adopts a microstrip coaxial design. The AC resistor divider is essentially an extension of the DC resistor divider. The fundamental difference is that the AC voltage divider will generate an alternating electromagnetic field around the resistor. If this electromagnetic field is not bound, it will radiate in all directions, resulting in energy loss. This loss is actually stray radiation, which is reflected in the distributed capacitance and additional inductance of the resistor device, as well as the intrinsic stray parameters of the voltage divider transmission line. Since the voltage divider frequency of this embodiment reaches 1MHz, and it is hoped that the ratio difference and angle difference at higher frequencies are also very small, and in order to reduce stray radiation, this embodiment adopts a microstrip circuit design in the structural design to obtain the best AC characteristics within a certain frequency range, and to obtain the best transmission effect as much as possible, including power, amplitude, phase, etc.

[0050] A microstrip line is a strip conductor that is separated from the ground potential by a dielectric, and its other side is directly in contact with the air, with only one ground potential as a reference plane. The geometric structure of the microstrip line and the electric and magnetic field lines, such as Figure 2 As shown, each microstrip transmission module 5 comprises three parts: a conductor plate, a dielectric substrate, and a conductor strip. In this embodiment, the dielectric substrate must have low high-frequency dielectric loss, and the microstrip transmission line must have a smooth edge finish, thereby reducing attenuation. Due to the presence of the dielectric substrate, the energy of the alternating electric field is primarily concentrated in the substrate area. The grounded metal plate blocks stray leakage of the electric field, and the electric field energy radiated upward into space is relatively small. Specifically, in this embodiment, when the microstrip circuit is implemented using a specially designed and processed PCB board, the conductor plate is laid over a large area to form a balanced ground potential. The low-dielectric constant dielectric substrate is implemented using a special fiber PCB board with high insulation properties. The conductor transmission microstrip is implemented using a relatively narrow copper foil. A high-power, low-temperature-coefficient, high-precision chip-type precision voltage divider resistor (resistor module 4) is connected across two adjacent conductor strips.

[0051] Optionally, the rated power value of the resistance module 4 in this embodiment is 3 times to 6 times the actual power consumed by the resistance module 4 when the wide-band resistance voltage divider operates at the rated input voltage.

[0052] Optionally, in this embodiment, starting from the high-voltage side of the resistor voltage divider structure, the temperature coefficients between every two adjacent resistor modules 4 are one positive and one negative.

[0053] In order to meet the accuracy requirements of the wideband AC voltage divider, ensure that the voltage divider ratio remains unchanged, and make the voltage divider have good long-term stability, the resistor components used in the resistor divider in this embodiment should be selected based on the following technical indicators but not limited to the following technical indicators: accuracy, long-term stability, frequency response characteristics, temperature coefficient and power coefficient (humidity coefficient). At the same time, when selecting the resistance value, since the back-end sampler often uses a 1V range, the output voltage is generally set to 0.8V. At the same time, the output resistance should be much smaller than the input impedance of the sampling device, and the influence of power consumption should also be balanced. The appropriate current should be between 1mA and 10mA. Furthermore, after the resistor type is determined, this embodiment determines the various parameters of the required resistor based on the operating voltage, resistance value, power, temperature coefficient and voltage coefficient, and selects resistors with good consistency to form the main voltage divider branch through tests and screening such as specific stability, temperature coefficient, and AC parasitic inductance.

[0054] Specifically, this embodiment selects, ages, screens, and pairs the resistor module 4. First, the resistor module 4 can be made of chip resistors, such as precision alloy foil resistors and / or precision thin film resistors. These resistors have the characteristics of small time constants, low temperature coefficients, high resistance accuracy, and good long-term stability. Furthermore, under power-permitting conditions, this embodiment should select precision resistors with small package sizes and small distributed parameters. Second, the rated power value of the resistor module 4 should be at least 3 to 6 times the actual power consumed by the resistor when the voltage divider operates at the rated input voltage. If the rated power is too low, the temperature rise of the resistor will have a significant impact on the resistance value. If the rated power is too high, relatively large distributed stray parameters will be introduced.

[0055] This embodiment also performs temperature aging on the resistor module 4, such as newly purchased resistor elements, to accelerate the stabilization of the resistance value and screen out defective products, thereby improving the reliability of the resistors. For the voltage divider resistors, the temperature aging method generally uses multiple high and low temperature switching methods for aging, and the aging time is required to reach 150-200 hours. Then, this embodiment also screens the resistors to select qualified resistors to improve the reliability of the resistors. Specifically, the temperature coefficient is tested within a wide temperature range of 50°C. Unsatisfactory resistors with abnormal temperature curves are further eliminated, and good resistors with approximately linear temperature curves are retained. The temperature coefficient value of each resistor is recorded.

[0056] This embodiment also pairs the resistors. That is, starting from the high-voltage side resistor, the temperature coefficients of every two adjacent resistors must be one positive and one negative, and preferably completely offset, that is, the sum of the temperature coefficients is equal to 0. Only in this way can the local balance of the electric field be maintained, the accuracy of the voltage divider ratio difference and angle difference is improved, and the cumulative AC phase shift effect is avoided from destroying the voltage divider suppression ratio of the voltage divider capacitor.

[0057] Optionally, the broadband resistor voltage divider of this embodiment may further include: a buffer follower amplifier with a preset ratio; the buffer follower amplifier is arranged at the output end of the resistor voltage divider structure.

[0058] Specifically, this embodiment transforms the output impedance of a voltage divider. In a digital sampling system, the output of the voltage divider is connected to a sampling digital voltmeter or a high-speed data acquisition device. To accommodate the output load capacity of the standard source, the input impedance of the voltage divider must be sufficiently large (greater than 100kΩ), and therefore the output impedance of the voltage divider is also correspondingly high (greater than 1kΩ). However, the input impedance of the sampling device is limited (less than 1MΩ), and factors such as the connecting leads and the input capacitance of the sampling device (greater than 150pF) can significantly affect the proportional error and angular error of the voltage divider. To mitigate these effects, this embodiment utilizes sampling impedance transformation technology, namely, adding a 1:1 buffer follower amplifier output to the output of the voltage divider. Through impedance transformation, the output impedance of the voltage divider can be reduced to the milliohm level, greatly enhancing the impedance matching capability between the voltage divider output and the sampling digital voltmeter or high-speed data acquisition device.

[0059] Optionally, the output end of the broadband resistor voltage divider of this embodiment can adopt a double-shielded coaxial cable. In order to reduce the influence of external electromagnetic environment interference on the voltage divider, the voltage divider should adopt a shielding structure, and a metal shield should be designed outside the voltage divider circuit of different ranges. The high-voltage voltage divider adopts a double-shielded structure as a whole. In order to reduce the voltage coefficient of the AC-DC difference, for the high-voltage voltage divider, factors such as the dielectric loss of the resistor, the change of the resistance with temperature, and the change of the capacitance between the resistor and the outer sleeve or shield with temperature must also be considered. In order to compensate for the AC-DC difference at high frequency, the inner shield of the high-voltage voltage divider needs to be adjusted. In order to reduce the interference of the output lead of the voltage divider of the external electromagnetic environment in this embodiment, the output of the voltage divider can be connected to the output sampling digital voltmeter or high-speed data acquisition device using a double-shielded coaxial cable.

[0060] Optionally, the angular difference of the broadband resistor divider is tested by a square wave angular difference test method.

[0061] Because calibration of broadband resistor dividers is complex and there are currently no reliable verification procedures or calibration specifications in China, manufacturing broadband resistor dividers requires repeated fine-tuning and compensation of the high-voltage arm's resistance and low-voltage arm's capacitance. Therefore, it is crucial to conduct simple and quick testing to obtain reliable data.

[0062] Ratio error is relatively easy to test by measuring the AC voltage amplitude at the input and output terminals of the voltage divider. Measuring angular error is more difficult and requires a highly accurate phase standard. The square wave angular error rapid test method effectively solves this problem. Through Fourier series transform, a square wave can be viewed as a waveform formed by the superposition of low-order and high-order sine waves. The rise and fall times of a square wave are very short. For example, a 1MHz square wave typically has rise and fall times in the order of picoseconds. Using this method to test a voltage divider places extremely high demands on the divider's bandwidth. If the input and output square waves of the voltage divider overlap well on the oscilloscope screen, with no noticeable lag or lead, the angular error of the voltage divider is very small. Even if the input and output waveforms do not overlap, the approximate angular error can be calculated from the lead or lag time, facilitating adjustment.

[0063] The broadband resistor divider of the above embodiment applies microstrip transmission theory, designs a board-based semicircular cage-shaped space electric field confinement structure, selects precision metal foil or metal film chip resistors, and adopts temperature aging technology, reliability screening technology, temperature coefficient matching technology, compensation capacitor fine-tuning technology, and square wave rapid test angle difference methods. It has the advantages of wide bandwidth, high accuracy, and high integration. It can be widely used in high-accuracy AC voltage and AC power measurement and testing needs to meet the verification and calibration of AC voltage, AC power, phase, etc., as well as other precision testing fields that require broadband and high-accuracy AC voltage signals. It can be extended to the design and development of metrology-grade equipment products such as AC standard resistors, AC shunts, pulse voltage dividers, pulse shunts, AC voltage sources, AC voltmeters, AC power sources, AC power meters, low-frequency phase meters, etc., and is widely used in electrical AC parameter measurement, precision testing, metrology-grade instruments and standard device development and other fields.

[0064] Based on the broadband resistor voltage divider of the above embodiment, this embodiment further provides an AC voltage ratio standard device, which includes any broadband resistor voltage divider of the above embodiment and has all the beneficial effects of the above broadband resistor voltage divider.

[0065] In addition, the features and benefits of the present invention are described by reference to exemplary embodiments. Accordingly, the present invention should clearly not be limited to these exemplary embodiments which illustrate some possible non-limiting combinations of features, which may exist alone or in other combinations of features.

[0066] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present invention are to be determined by the claims.

Claims

1. A broadband resistor voltage divider, characterized in that: include: A housing, an input coaxial socket, an output coaxial socket, and a resistor voltage divider structure with a shielding network arranged inside the housing; The pin of the input coaxial socket passes through the housing and is connected to the input end of the resistive voltage divider structure, and the pin of the output coaxial socket passes through the housing and is connected to the output end of the resistive voltage divider structure; The resistor voltage divider structure includes: at least two resistor modules and at least three microstrip transmission modules; each resistor module is connected between two adjacent microstrip transmission modules; The resistor voltage divider structure further includes: welding a plurality of semicircular metal wires at equal intervals above each resistor module; wherein each semicircular metal wire obtains the same potential as the resistor module directly below; and the plurality of semicircular metal wires constitute the shielding network; Each of the microstrip transmission modules includes: a conductor plate, a dielectric substrate and a transmission microstrip; the dielectric substrate is a fiber PCB board; the material of the transmission microstrip is copper foil; wherein the resistor module is connected across two adjacent transmission microstrips.

2. The broadband resistor voltage divider according to claim 1, wherein: The resistance voltage divider structure further includes: at least one fixed capacitor and at least one adjustable capacitor; The fixed capacitor and the adjustable capacitor are both connected in parallel to the low-voltage arm of the resistance voltage divider structure.

3. The broadband resistor voltage divider according to claim 1, wherein: The rated power value of the resistance module is 3 times to 6 times the actual power consumed by the resistance module when the wide-band resistance voltage divider operates at the rated input voltage.

4. The broadband resistor voltage divider according to claim 1, wherein: Starting from the high-voltage side of the resistor voltage divider structure, the temperature coefficients between each two adjacent resistor modules are one positive and one negative.

5. The broadband resistor voltage divider according to claim 1, wherein: The broadband resistor voltage divider further includes: a buffer follower amplifier of a preset ratio; The buffer follower amplifier is arranged at the output end of the resistor voltage divider structure.

6. The broadband resistor voltage divider according to claim 1, wherein: The output end of the broadband resistor voltage divider adopts a double-layer shielded coaxial cable.

7. The broadband resistor voltage divider according to claim 1, wherein: The angular difference of the broadband resistor voltage divider is tested by a square wave angular difference test method.

8. A resistance-type AC voltage ratio standard device, characterized in that: The invention comprises the broadband resistor voltage divider according to any one of claims 1 to 7.

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