WO2023010732A1

WO2023010732A1 - Temperature compensation broadband signal attenuation circuit and control method thereof

Info

Publication number: WO2023010732A1
Application number: PCT/CN2021/135780
Authority: WO
Inventors: 易军伟; 张守玉
Original assignee: 国仪量子(合肥)技术有限公司
Priority date: 2021-08-04
Filing date: 2021-12-06
Publication date: 2023-02-09
Also published as: CN113691236A; CN113691236B

Abstract

The present application relates to the technical field of signal processing, and in particular to a temperature compensation broadband signal attenuation circuit and a control method thereof. The temperature compensation broadband signal attenuation circuit comprises: a temperature acquisition assembly and a voltage-controlled capacitor; a switch assembly, which is used for enabling, when the state of the switch assembly is an attenuation control state, an attenuation ratio of the attenuation circuit to be 1:N; and a controller, which is connected to the temperature acquisition assembly, the switch assembly and the voltage-controlled capacitor, so as to control, when the attenuation ratio is 1:N and according to temperature information acquired by the temperature acquisition assembly, the current capacitance value of the voltage-controlled capacitor to enter a preset target capacitance value, such that an actual attenuation ratio of the attenuation circuit within a broadband is equal to 1:N. Therefore, the defects of an attenuation circuit in the related art can be eliminated, and interconnection with a control unit in a data acquisition system can be achieved, so that a calibration operation of the circuit is simplified, the accuracy and stability of a system are improved, the costs are low, and the circuit is simple and easy to realize.

Description

Temperature Compensation Broadband Signal Attenuation Circuit and Its Control Method

Cross References to Related Applications

This application is based on the Chinese patent application with the application number 202110893084.6 and the filing date is August 04, 2021, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated by reference into this application.

technical field

The present application relates to the technical field of signal processing, in particular to a temperature compensation broadband signal attenuation circuit and a control method thereof.

Background technique

A data acquisition card is a circuit board that digitizes analog signals and is generally used in signal acquisition systems, such as oscilloscopes. The input signal of the data acquisition card may be relatively large, and the driving ability is weak. In order to meet its voltage sampling range, a high-impedance input signal attenuation circuit needs to be introduced. A resistive attenuation circuit usually consists of two resistors whose resistance ratio is equal to the attenuation ratio, and the sum of the resistances is equal to the input impedance. However, due to the influence of parasitic parameters, the circuit bandwidth is very low, often only tens of kHz, which is difficult to meet the requirements of the acquisition card.

In related technologies, most oscilloscopes are equipped with passive probes, whose structure is similar to that of a traditional resistance attenuation circuit, the difference being that there are series resistors and compensation capacitors. By adjusting the capacitance of the capacitor, the impedance characteristics of the circuit are changed, so that within a bandwidth of about several hundred MHZ, the attenuation of the signal changes little, and the frequency response in the passband becomes flat, which meets the signal acquisition requirements.

However, the mechanically adjustable capacitor used in this type of attenuation circuit has a large temperature drift and is easily affected by mechanical vibration, resulting in inaccurate measurement. Therefore, it is not suitable for application in harsh measurement environments and needs to be solved urgently.

Contents of the invention

The application provides a temperature-compensated broadband signal attenuation circuit and its control method, which can not only eliminate the disadvantages of the attenuation circuit in the related art, but also can be interconnected with the control unit in the data acquisition system, simplify the calibration operation of the circuit, and improve the accuracy of the system. Sex and stability, low cost, simple and easy to implement.

The embodiment of the first aspect of the present application provides a temperature-compensated broadband signal attenuation circuit, including:

Temperature acquisition components and voltage-controlled capacitors;

A switch component, used to make the attenuation ratio of the attenuation circuit 1:N when the state of the switch component is in the attenuation control state; and

a controller, the controller is respectively connected to the temperature acquisition component, the switch component and the voltage-controlled capacitor, so that when the attenuation ratio is the 1:N ratio, according to the temperature acquisition component collected The temperature information controls the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio.

Optionally, when the state of the switch component is not in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:1.

Optionally, the attenuation circuit also includes:

a first resistor, one end of the first resistor is connected to the switch assembly, and the other end of the first resistor is grounded;

a second resistor, one end of the second resistor is connected to one end of the first resistor, and the other end of the second resistor is connected to the switch assembly;

a first capacitor, one end of the first capacitor is connected to one end of the first resistor, and the other end of the first capacitor is connected to the other end of the first resistor;

A second capacitor, one end of the second capacitor is connected to one end of the first capacitor, and the other end of the second capacitor is connected to the other end of the second resistor.

Optionally, the attenuation circuit also includes:

A third resistor, one end of the third resistor is grounded.

Optionally, the switch assembly includes:

first to eighth contacts;

The second contact is connected to the other end of the third resistor;

The third contact is connected to the signal input end;

The fourth contact is connected to the other end of the second resistor;

The fifth contact is connected to the other end of the first resistor;

The sixth contact is connected to the signal output end;

The seventh contact is connected to the other end of the third resistor.

Optionally, the switch component is a relay.

Optionally, the relay is a double-pole double-throw relay.

Optionally, a ratio of the sum of the first resistance and the second resistance to the first resistance is equal to the attenuation ratio.

Optionally, where,

The first capacitor and the second capacitor are compensation capacitors.

The embodiment of the second aspect of the present application provides a method for controlling a temperature-compensated broadband signal attenuation circuit, using the above-mentioned temperature-compensated broadband signal attenuation circuit, wherein the method includes the following steps:

When the state of the switch assembly is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N;

When the attenuation ratio is the 1:N ratio, control the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value according to the temperature information collected by the temperature acquisition component, so that the attenuation circuit is within a wide band The actual attenuation ratio is equal to the 1:N ratio.

Thus, when the state of the switch component is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N, and when the attenuation ratio is 1:N, the voltage-controlled capacitor is controlled according to the temperature information collected by the temperature acquisition component The current capacitance value enters the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio, which can not only eliminate the disadvantages of the attenuation circuit in the related technology, but also can be interconnected with the control unit in the data acquisition system , simplify the calibration operation of the circuit, improve the accuracy and stability of the system, low cost, simple and easy to implement.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic block diagram of a temperature-compensated broadband signal attenuation circuit provided according to an embodiment of the present application;

2 is a schematic structural diagram of a temperature-compensated broadband signal attenuation circuit according to an embodiment of the present application;

FIG. 3 is a flowchart of a control method of a temperature-compensated broadband signal attenuation circuit according to an embodiment of the present application.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, and are intended to explain the present application, and should not be construed as limiting the present application.

The following describes the temperature compensation broadband signal attenuation circuit and the control method thereof according to the embodiments of the present application with reference to the accompanying drawings. The application provides a temperature-compensated broadband signal attenuation circuit. When the state of the switch component is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N, and when the attenuation ratio is 1:N, the attenuation ratio is collected according to the temperature. The temperature information collected by the component controls the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio, which can not only eliminate the disadvantages of the attenuation circuit in the related technology, but also can It is interconnected with the control unit in the data acquisition system, simplifies the calibration operation of the circuit, improves the accuracy and stability of the system, is low in cost, simple and easy to implement.

Specifically, FIG. 1 is a schematic block diagram of a temperature-compensated broadband signal attenuation circuit provided by an embodiment of the present application.

As shown in FIG. 1 , the temperature compensation broadband signal attenuation circuit 10 includes: a temperature acquisition component 100 , a voltage-controlled capacitor C1 , a switch component 200 and a controller 300 .

Wherein, the switch assembly 200 is used to make the attenuation ratio of the attenuation circuit 1:N when the state of the switch assembly 200 is in the attenuation control state. The controller 300 is respectively connected with the temperature acquisition component 100, the switch component 200 and the voltage-controlled capacitor C1, so as to control the current capacitance value of the voltage-controlled capacitor C1 according to the temperature information collected by the temperature acquisition component 100 when the attenuation ratio is 1:N. Enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio.

Optionally, when the state of the switch assembly 200 is not in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:1.

Wherein, the attenuation control state can be ON state and OFF state, for example, in the ON state, the attenuation ratio is 1:N ratio; in the OFF state, the attenuation ratio is 1:1 ratio.

For ease of understanding, the temperature-compensated broadband signal attenuation circuit of the embodiment of the present application will be described in detail below with reference to FIG. 2 .

For example, as shown in FIG. 2, the controller 300 can be a sampling and control unit (Sampling And Control Unit, SACU), which collects temperature information of the attenuation circuit and outputs a control signal, and the switch component 200 can be K1.

Optionally, in some embodiments, the attenuation circuit 10 further includes: a third resistor R.

Optionally, in some embodiments, the switch assembly 200 includes: first to eighth contacts; the second contact 2 is connected to the other end of the third resistor R; the third contact 3 is connected to the signal input terminal Signal_IN; The fourth contact 4 is connected to the other end of the second resistor R2; the fifth contact 5 is connected to the other end of the first resistor R1; the sixth contact 6 is connected to the signal output terminal Signal_OUT; the seventh contact 7 is connected to the third The other end of the resistor is connected.

Optionally, in some embodiments, the switch assembly 200 can be a relay, and the relay is a double-pole double-throw relay, which can switch attenuation ratios of different ratios. For example, the attenuation ratio can be 1:1 or 1:N. More attenuation ranges can be achieved by using more relays.

Further, in some embodiments, the attenuation circuit 10 further includes: a first resistor R1, a second resistor R2, a first capacitor C2, and a second capacitor C3. Wherein, one end of the first resistor R1 is connected to the switch assembly 200 , and the other end of the first resistor R1 is grounded. One end of the second resistor R2 is connected to one end of the first resistor R1 , and the other end of the second resistor R2 is connected to the switch assembly 200 . One end of the first capacitor C2 is connected to one end of the first resistor R1, and the other end of the first capacitor C2 is connected to the other end of the first resistor R1. One end of the second capacitor C3 is connected to one end of the first capacitor C2, and the other end of the second capacitor C3 is connected to the other end of the second resistor R2.

Optionally, in some embodiments, the first capacitor C2 and the second capacitor C3 can be compensation capacitors, which are connected in parallel with the first resistor R1 and the second resistor R2 respectively, and can be used for rough compensation.

Optionally, the ratio of the sum of the first resistor R1 and the second resistor R2 to the first resistor R1 is equal to the attenuation ratio, that is:

Among them, N is the attenuation ratio.

In addition, the sum of the first resistor R1 and the second resistor R2 is equal to the DC input impedance R (generally 1MΩ or 10MΩ) of the attenuation circuit.

It should be noted that, further, in some embodiments, the temperature acquisition component 100 may be a temperature sensor R3, wherein the temperature sensor R3 may be any one of a platinum resistor, an NTC thermistor, or a temperature sensing chip. Assume that the first resistor R1, the second resistor R2, the first capacitor C2, the second capacitor C3 and the voltage-controlled capacitor C1 can be regarded as an attenuation unit (ATU), and the temperature sensor R3 (ie, the temperature acquisition component) is connected with the ATU Thermal coupling can accurately reflect the temperature information of the attenuation unit ATU.

The signal flow direction when the attenuation ratio of the attenuation circuit is 1:1 will be described in detail below in conjunction with FIG. 2 . Among them, the signal flow is as follows:

The controller 300 controls the switch assembly 200 to switch to the OFF state, the signal input terminal Signal_IN is input by the third contact 3 of the switch assembly 200, and the third contact 3 is usually connected to the second contact 2, so that the signal is directly loaded to the third resistor On R, the signal is connected to the sixth contact 6 through the seventh contact 7, so as to realize 1:1 attenuation, and the attenuation signal is output from the signal output terminal Signal_OUT.

The signal flow direction when the attenuation ratio of the attenuation circuit is 1:N will be described in detail below in conjunction with FIG. 2 . Among them, the signal flow is as follows:

The controller 300 controls the switch assembly 200 to switch to the ON state, and the third contact 3 is connected to the fourth contact 4, so that the signal enters the attenuation unit ATU, and the signal passes through the second resistor R2, the second capacitor C3, the voltage-controlled capacitor C1 and the first A resistor R1 and the first capacitor C2 are connected to the fifth contact 5 of the switch assembly 200 after voltage division, the voltage division ratio is 1:N, the fifth contact of the switch assembly 200 is connected to the sixth contact 6 at this time, and the attenuation The signal is output by the signal output terminal Signal_OUT.

The following describes with examples the specific attenuation parameters in the figure.

Assuming that the parasitic capacitances of the second resistor R2 and the first resistor R1 are C3' and C2' respectively, then the impedance of the lower part of the attenuation unit ATU is:

Z2＝Z _R2 ||Z _C3 ||Z _C1 ||Z _C3' ;

The total impedance of the working part is:

Z1＝Z _R1 ||Z _C2 ||Z _C2' ;

Adjust the size of the voltage-controlled capacitor C1 through the sampling and control unit SACU, so that:

That is to say, the attenuation ratio of the attenuation circuit in the broadband is 1:N, and the temperature drift coefficient of the voltage-controlled capacitor is generally larger than that of the ordinary capacitor, which causes the impedance ratio of the circuit to change after the temperature changes. Therefore, in this embodiment of the present application, the temperature information of the temperature sensor R3 can be collected by the sampling and control unit SACU, and the closed-loop control voltage control capacitor C1 controls the voltage ControlSignal, so that the drift of the voltage control capacitor C1 and the second capacitor C3 and the first capacitor C2 maintain Consistent, ensuring that the attenuation ratio of the attenuation circuit remains unchanged in a wide temperature range. That is to say, the capacitance of the voltage-controlled capacitor C1 is controlled by an external control voltage signal. In the embodiment of the present application, the temperature information collected by the temperature acquisition component 100 controls the current capacitance value of the voltage-controlled capacitor C1 to enter the preset target capacitance value, thereby Fine-tune the voltage-controlled capacitor C1 to achieve fine compensation.

According to the temperature compensation broadband signal attenuation circuit proposed in the embodiment of the present application, when the state of the switch assembly is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N ratio, and when the attenuation ratio is 1:N ratio, according to the temperature The temperature information collected by the acquisition component controls the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio, which can not only eliminate the drawbacks of the attenuation circuit in related technologies, but also It can be interconnected with the control unit in the data acquisition system, simplifies the calibration operation of the circuit, improves the accuracy and stability of the system, is low in cost, simple and easy to implement.

Next, the control method of the temperature-compensated broadband signal attenuation circuit proposed according to the embodiment of the present application will be described with reference to the accompanying drawings.

As shown in Figure 3, the control method of the temperature compensation broadband signal attenuation circuit adopts the above-mentioned temperature compensation broadband signal attenuation circuit, including the following steps:

In step S301, when the state of the switch assembly is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N;

In step S302, when the attenuation ratio is 1:N ratio, the current capacitance value of the voltage-controlled capacitor is controlled to enter the preset target capacitance value according to the temperature information collected by the temperature acquisition component, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to 1:N ratio.

It should be noted that the foregoing explanations on the embodiment of the temperature-compensated broadband signal attenuation circuit are also applicable to the control method of the temperature-compensated broadband signal attenuation circuit in this embodiment, and details are not repeated here.

According to the control method of the temperature-compensated broadband signal attenuation circuit proposed in the embodiment of the present application, when the state of the switch component is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N ratio, and when the attenuation ratio is 1:N ratio According to the temperature information collected by the temperature acquisition component, the current capacitance value of the voltage-controlled capacitor is controlled to enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio, which can not only eliminate the problem of the attenuation circuit in the related art disadvantages, and can be interconnected with the control unit in the data acquisition system, simplify the calibration operation of the circuit, improve the accuracy and stability of the system, low cost, simple and easy to implement.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or N embodiments or examples in an appropriate manner. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present application, "N" means at least two, such as two, three, etc., unless otherwise specifically defined.

Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing a custom logical function or step of a process , and the scope of preferred embodiments of the present application includes additional implementations in which functions may be performed out of the order shown or discussed, including in substantially simultaneous fashion or in reverse order depending on the functions involved, which shall It should be understood by those skilled in the art to which the embodiments of the present application belong.

The logic and/or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium, For use with instruction execution systems, devices, or devices (such as computer-based systems, systems including processors, or other systems that can fetch instructions from instruction execution systems, devices, or devices and execute instructions), or in conjunction with these instruction execution systems, devices or equipment used. For the purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use in or in conjunction with an instruction execution system, device or device. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connection with one or N wires (electronic device), portable computer disk case (magnetic device), random access memory (RAM), Read Only Memory (ROM), Erasable and Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program can be printed, since the program can be read, for example, by optically scanning the paper or other medium, followed by editing, interpretation or other suitable processing if necessary. The program is processed electronically and stored in computer memory.

It should be understood that each part of the present application may be realized by hardware, software, firmware or a combination thereof. In the above embodiments, the N steps or methods may be implemented by software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: a discrete Logic circuits, ASICs with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

Those of ordinary skill in the art can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. During execution, one or a combination of the steps of the method embodiments is included.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, each unit may exist separately physically, or two or more units may be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. If the integrated modules are realized in the form of software function modules and sold or used as independent products, they can also be stored in a computer-readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims

A temperature-compensated broadband signal attenuation circuit, characterized in that it comprises:

Temperature acquisition components and voltage-controlled capacitors;

a switch component, configured to make the attenuation ratio of the attenuation circuit 1:N when the state of the switch component is in the attenuation control state; and

a controller, the controller is respectively connected to the temperature acquisition component, the switch component and the voltage-controlled capacitor, so that when the attenuation ratio is the 1:N ratio, according to the temperature acquisition component collected The temperature information controls the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value, so that the actual attenuation ratio of the attenuation circuit in the broadband is equal to the 1:N ratio.
The circuit according to claim 1, wherein when the state of the switch component is not in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:1.
The circuit according to claim 1, wherein the attenuation circuit further comprises:

a first resistor, one end of the first resistor is connected to the switch assembly, and the other end of the first resistor is grounded;

a second resistor, one end of the second resistor is connected to one end of the first resistor, and the other end of the second resistor is connected to the switch assembly;

a first capacitor, one end of the first capacitor is connected to one end of the first resistor, and the other end of the first capacitor is connected to the other end of the first resistor;

A second capacitor, one end of the second capacitor is connected to one end of the first capacitor, and the other end of the second capacitor is connected to the other end of the second resistor.
The circuit according to claim 1, wherein the attenuation circuit further comprises:

A third resistor, one end of the third resistor is grounded.
The circuit according to claim 4, wherein the switch assembly comprises:

first to eighth contacts;

The second contact is connected to the other end of the third resistor;

The third contact is connected to the signal input end;

The fourth contact is connected to the other end of the second resistor;

The fifth contact is connected to the other end of the first resistor;

The sixth contact is connected to the signal output end;

The seventh contact is connected to the other end of the third resistor.
The circuit of claim 1, wherein the switch assembly is a relay.
The circuit according to claim 6, wherein the relay is a double pole double throw relay.
The circuit according to claim 3, wherein the ratio of the sum of the first resistor and the second resistor to the first resistor is equal to the attenuation ratio.
The circuit of claim 3, wherein,

The first capacitor and the second capacitor are compensation capacitors.
A control method for a temperature-compensated broadband signal attenuation circuit, characterized in that the temperature-compensated broadband signal attenuation circuit according to any one of claims 1-9 is used, wherein the method includes the following steps:

When the state of the switch assembly is in the attenuation control state, the attenuation ratio of the attenuation circuit is 1:N;

When the attenuation ratio is the 1:N ratio, control the current capacitance value of the voltage-controlled capacitor to enter the preset target capacitance value according to the temperature information collected by the temperature acquisition component, so that the attenuation circuit is within a wide band The actual attenuation ratio is equal to the 1:N ratio.