Front-end amplifier circuit, circuit board and data acquisition equipment

Abstract

This application provides a front-end amplifier circuit, circuit board, and data acquisition device, relating to the field of electronic circuit technology. It solves the problem that the operating frequency of data acquisition devices in related technologies is limited, making it difficult to provide accurate signal measurement functions. The front-end amplifier circuit of this application can separate DC and low-frequency signals and high-frequency signals, thereby amplifying different components in the signal to be measured separately, expanding the operating frequency range of the circuit, and also amplifying the signal voltage, thereby achieving a better signal-to-noise ratio and voltage standing wave ratio, which is beneficial to improving the accuracy of signal measurement and providing more accurate signal measurement functions.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a front-end amplifier circuit, circuit board, and data acquisition device. Background Technology

[0002] In data acquisition equipment such as oscilloscopes, the front-end amplifier circuit plays a crucial role. Its main function is to amplify the measured signal to an appropriate range so that it can be processed by subsequent circuits, thereby enabling the detection of even weaker measured signals. To achieve this, it needs to have a low reflection coefficient, amplify the signal's current or voltage, and superimpose or eliminate DC components for processing by subsequent circuits.

[0003] However, in related technologies, the corresponding driving circuits constructed using MOSFETs and transistors to form the front-end amplifier circuit can only enhance the driving current but cannot increase the signal voltage. Furthermore, the circuit structure built with discrete components limits the operating frequency, preventing it from operating at higher frequencies and making it difficult to achieve a low voltage standing wave ratio (VSWR). Therefore, the limited operating frequency of the data acquisition equipment results in poor accuracy in detecting low-frequency signals, difficulty in adapting to high-frequency signals, and an inability to provide accurate signal measurement functions. Summary of the Invention

[0004] This application provides a front-end amplifier circuit, circuit board, and data acquisition device, which solves the problem that the operating frequency of data acquisition devices in related technologies is limited, making it difficult to provide accurate signal measurement functions. The solution of this application can separate and amplify DC, low-frequency signals, and high-frequency signals to achieve accurate measurement of different signals.

[0005] In a first aspect, this application provides a front-end amplifier circuit, which includes a signal input module, a low-frequency amplification module, a DC bias module, a radio frequency amplification module, and a signal output module.

[0006] The input terminal of the signal access module is connected to the signal receiving terminal to receive the signal to be measured. The signal access module is used to provide input impedance for the front-end amplifier circuit, and it is also used to separate DC and low-frequency signals and high-frequency signals in the signal to be measured.

[0007] The first input terminal of the low-frequency amplifier module is connected to the input terminal of the signal input module, and the second input terminal of the low-frequency amplifier module is connected to the impedance output terminal of the signal input module. The low-frequency amplifier module is used to amplify DC and low-frequency signals.

[0008] The output of the DC bias module is connected to the bias input of the low-frequency amplifier module. The DC bias module is used to provide a DC bias voltage to the low-frequency amplifier module to counteract the external bias voltage superimposed on the signal to be measured.

[0009] The input terminal of the RF amplifier module is connected to the impedance output terminal of the signal input module. The RF amplifier module is used to amplify high-frequency signals, and the amplification factor of the RF amplifier module is matched with the amplification factor of the low-frequency amplifier module.

[0010] The first input terminal of the signal output module is connected to the output terminal of the low-frequency amplifier module, the second input terminal of the signal output module is connected to the output terminal of the radio frequency amplifier module, and the output terminal of the signal output module is connected to the output signal terminal to provide the amplified measurement signal to the subsequent circuit.

[0011] Secondly, this application also provides a circuit board that includes the front-end amplifier circuit as described in the first aspect above.

[0012] Thirdly, this application also provides a data acquisition device, which includes the circuit board as described in the second aspect above.

[0013] The front-end amplifier circuit of this application can separate DC and low-frequency signals and high-frequency signals, thereby amplifying different components in the signal to be measured separately, expanding the operating frequency range of the circuit, and also amplifying the signal voltage, thereby achieving a better signal-to-noise ratio and voltage standing wave ratio, which is beneficial to improving the accuracy of signal measurement and providing a more accurate signal measurement function. Attached Figure Description

[0014] Figure 1 A schematic block diagram of a front-end amplifier circuit provided in an embodiment of this application;

[0015] Figure 2 This is an equivalent circuit diagram of the signal access module in one embodiment of this application;

[0016] Figure 3 A schematic diagram of the circuit structure of a front-end amplifier circuit provided in an embodiment of this application. Detailed Implementation

[0017] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of this application and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, the accompanying drawings only show the parts related to the embodiments of this application, not all structures. Those skilled in the art, after reading this specification, should be able to conceive that any combination of technical features can constitute an optional implementation method, provided that the technical features do not contradict each other.

[0018] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects, not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. In the description of this application, "multiple" means two or more, and "several" means one or more.

[0019] As a component of data acquisition equipment such as oscilloscopes and data acquisition instruments, the front-end amplifier circuit plays a crucial role in enabling these devices to detect weak signals. In related technologies, the front-end amplifier circuit utilizes MOSFETs and transistors to construct corresponding drive circuits for front-end amplification.

[0020] However, this circuit can only increase the drive current, but cannot increase the signal voltage. Furthermore, the circuit structure built with discrete components limits its operating frequency, preventing it from operating at higher frequencies and making it difficult to achieve a low voltage standing wave ratio (VSWR). Therefore, the limited operating frequency of the data acquisition equipment results in poor accuracy in detecting low-frequency signals, difficulty in adapting to high-frequency signals, and ultimately, difficulty in providing accurate signal measurement functions.

[0021] To address this, embodiments of this application provide a front-end amplifier circuit. This front-end amplifier circuit can separate and amplify DC, low-frequency, and high-frequency signals to achieve accurate measurement of different signals. Figure 1 As shown, Figure 1 The schematic diagram of a front-end amplifier circuit provided in an embodiment of this application is shown. The front-end amplifier circuit includes a signal input module 101, a low-frequency amplification module 102, a DC bias module 103, a radio frequency amplification module 104, and a signal output module 105.

[0022] Specifically, the input terminal of the signal input module 101 is connected to the signal receiving terminal, which serves as the interface for external connection in the front-end amplifier circuit. It can receive the corresponding signal to be measured, thus connecting the signal to the front-end amplifier circuit. The first input terminal of the low-frequency amplifier module 102 is connected to the input terminal of the signal input module 101, and the second input terminal of the low-frequency amplifier module 102 is connected to the impedance output terminal of the signal input module 101. The output terminal of the DC bias module 103 is connected to the bias input terminal of the low-frequency amplifier module 102. Additionally, the input terminal of the radio frequency amplifier module 104 is also connected to the impedance output terminal of the signal input module 101.

[0023] The first input terminal of the signal output module 105 is connected to the output terminal of the low-frequency amplifier module 102, the second input terminal of the signal output module 105 is connected to the output terminal of the radio frequency amplifier module 104, and the output terminal of the signal output module 105 is connected to the output signal terminal.

[0024] Understandably, after the signal to be measured enters the front-end amplification circuit, the signal input module 101 separates the DC, low-frequency, and high-frequency signals within the signal to be measured. Furthermore, the signal input module 101 provides an input impedance to the front-end amplification circuit for impedance matching, thereby improving signal transmission quality and reducing signal distortion and interference. Correspondingly, the DC and low-frequency signals enter the low-frequency amplification module 102, where they are amplified. Moreover, the DC bias module 103 provides a DC bias voltage to the low-frequency amplification module 102 to counteract the external bias voltage superimposed on the signal to be measured, thus enabling the measurement of smaller signals.

[0025] The high-frequency signal enters the radio frequency amplification module 104, which amplifies the high-frequency signal. It is worth noting that the amplification factor of the radio frequency amplification module 104 matches that of the low-frequency amplification module 102, that is, the amplification factors of the two are equal, so that the measured signal provided by the front-end amplification circuit to the subsequent circuit is amplified according to the corresponding amplification factor.

[0026] As can be seen from the above scheme, the front-end amplifier circuit of this application can separate DC and low-frequency signals and high-frequency signals, thereby amplifying different components in the signal to be measured, expanding the operating frequency range of the circuit, and also amplifying the signal voltage, thereby achieving a better signal-to-noise ratio and voltage standing wave ratio, which is conducive to improving the measurement accuracy of the signal and providing a more accurate signal measurement function.

[0027] In one embodiment, the signal access module includes a first resistor, a first capacitor, and a first inductor. Specifically, a first terminal of the first resistor is connected to a first terminal of the first capacitor, a second terminal of the first resistor is connected to a second terminal of the first capacitor, a first terminal of the first inductor is connected to a second terminal of the first capacitor, and the second terminal of the first inductor is grounded. The first terminal of the first resistor serves as the input terminal of the signal access module, the second terminal of the first resistor serves as the impedance output terminal of the signal access module, and the resistance value of the first resistor is matched to the equivalent input resistance of the RF amplification module. The inductance value of the first inductor is equal to the product of the capacitance value of the first capacitor and the square of the resistance value of the first resistor. The first capacitor is used to isolate DC and low-frequency signals and conduct high-frequency signals, and the first inductor is used to isolate high-frequency signals and conduct DC and low-frequency signals.

[0028] like Figure 2 As shown, Figure 2This is an equivalent circuit diagram of the signal access module in one embodiment of this application, wherein the first resistor R1 is connected in parallel with the first capacitor C1, and the first inductor L1 is connected in series with the first capacitor C1. Resistor R8 is the equivalent input resistance of the RF amplifier module. In the RF amplifier module, resistor R8 is equivalent to a resistor grounded at the input terminal of the RF amplifier module. Figure 2 In the circuit, resistor R8 is connected in parallel with the first inductor L1. The first resistor R1 is matched with resistor R8, thus making the input impedance of the circuit equivalent to the resistance value of the first resistor, thereby better matching the system and helping to measure the signal more accurately.

[0029] Furthermore, when the inductance of the first inductor equals the product of the capacitance of the first capacitor and the square of the resistance of the first resistor, the signal access module is equivalent to a resistor with a fixed resistance relative to the signal to be measured. It can be understood that after the signal to be measured enters the signal access module, under the AC-passing and DC-blocking effect of the first capacitor C1, high-frequency signals will pass through the first capacitor C1, while DC and low-frequency signals will pass through the first resistor R1. Additionally, under the DC-passing and AC-blocking effect of the first inductor L1, DC and low-frequency signals will pass through the first inductor L1, while high-frequency signals will pass through the resistor R8. Therefore, due to the presence of the first capacitor C1, DC and low-frequency signals can enter the low-frequency amplification module after passing through the first resistor R1; and due to the presence of the first inductor L1, high-frequency signals can enter the RF amplification module through the resistor R8.

[0030] Therefore, the signal access module can use the first capacitor to isolate high-frequency signals from the low-frequency amplification module, and use the inductor in parallel with the RF amplification module to isolate DC and low-frequency signals from the RF amplification module, thereby enabling the measurement of DC, low-frequency, and high-frequency signals, which helps to expand the operating frequency range of the circuit.

[0031] In one embodiment, the low-frequency amplification module includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an operational amplifier, thereby forming a differential amplifier circuit to process the low-frequency components in the signal to be measured, making the measurement of the low-frequency components more accurate.

[0032] Specifically, the first end of the second resistor is connected to the impedance supply terminal of the signal access module, the second end of the second resistor is connected to the first end of the third resistor, the second end of the second resistor is connected to the non-inverting input terminal of the operational amplifier, and the second end of the third resistor is grounded. The first end of the fourth resistor is connected to the input terminal of the signal access module, the second end of the fourth resistor is connected to the inverting input terminal of the operational amplifier, the first end of the fifth resistor is connected to the second end of the fourth resistor, the second end of the fifth resistor is connected to the output terminal of the operational amplifier, and the first end of the sixth resistor is connected to the output terminal of the operational amplifier.

[0033] Among them, the first end of the fourth resistor serves as the first input terminal of the low-frequency amplifier module, the first end of the second resistor serves as the second input terminal of the low-frequency amplifier module, the second end of the fourth resistor serves as the bias input terminal of the low-frequency amplifier module, and the second end of the sixth resistor serves as the output terminal of the low-frequency amplifier module. The resistance value of the sixth resistor is matched with the equivalent output resistance of the radio frequency amplifier module.

[0034] It should be noted that, in one embodiment, the input impedance provided by the signal access module includes a first resistor. Correspondingly, the second and fourth resistors in the low-frequency amplification module are much larger than the first resistor. For example, the ratio of the resistance of the second resistor to the resistance of the first resistor and the ratio of the resistance of the fourth resistor to the resistance of the first resistor are both greater than or equal to 100, that is, the resistance of the second resistor and the resistance of the fourth resistor are both 100 times or more than the resistance of the first resistor.

[0035] Optionally, in one embodiment, the DC bias module includes a seventh resistor. The first terminal of the seventh resistor is connected to a DC bias voltage, and the second terminal is connected to the bias input terminal of the low-frequency amplification module. The DC bias voltage is matched to the external bias voltage, i.e., the DC bias voltage is equal to the external bias voltage. Therefore, the external bias voltage superimposed on the signal to be measured can be canceled out by the DC bias voltage, which is helpful for measuring small signals. Optionally, in another embodiment, the seventh resistor can be replaced by other devices, such as a Zener diode, to connect the corresponding DC bias voltage.

[0036] In one embodiment, the signal output module includes a second inductor and a second capacitor. Specifically, the first terminal of the second inductor is connected to the output terminal of the low-frequency amplification module, the first terminal of the second capacitor is connected to the output terminal of the radio frequency amplification module, and the second terminal of the second inductor is connected to the second terminal of the second capacitor.

[0037] The second inductor is used to conduct the amplified DC and low-frequency signals, and the second capacitor is used to conduct the amplified high-frequency signals. The reactance ratio of the second inductor and the second capacitor is matched with the reactance ratio of the signal access module.

[0038] Understandably, by utilizing the characteristics of the second capacitor and the second inductor, the signal output module can further separate the input signal. The signal passing through the second inductor retains the DC and low-frequency signals, while the signal passing through the second capacitor retains the high-frequency signals. Therefore, the second inductor is connected to the output of the low-frequency amplification module, and the second capacitor is connected to the output of the RF amplification module, thus enabling the input and output of the amplified signal. Therefore, through the signal output module, the front-end amplification circuit can receive amplified DC, low-frequency, and high-frequency signals, thereby providing the amplified measurement signal to the subsequent circuits, achieving a better signal-to-noise ratio and voltage standing wave ratio.

[0039] Figure 3The circuit structure diagram of the front-end amplifier circuit provided in one embodiment of this application is shown. In one embodiment, the signal access module in the front-end amplifier circuit includes a first resistor R1, a first capacitor C1 and a first inductor L1. The first end of the first resistor R1 is connected to the first end of the first capacitor C1, the second end of the first resistor R1 is connected to the second end of the first capacitor C1, the first end of the first inductor L1 is connected to the second end of the first capacitor C1, and the second end of the first inductor L1 is grounded.

[0040] The low-frequency amplification module includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and an operational amplifier U1. The first terminal of the second resistor R2 is connected to the second terminal of the first resistor; the second terminal of the second resistor R2 is connected to the first terminal of the third resistor R3; the second terminal of the second resistor R2 is connected to the non-inverting input of the operational amplifier U1; and the second terminal of the third resistor R3 is grounded. The first terminal of the fourth resistor R4 is connected to the first terminal of the first resistor; the second terminal of the fourth resistor R4 is connected to the inverting input of the operational amplifier U1; the first terminal of the fifth resistor R5 is connected to the second terminal of the fourth resistor R4; the second terminal of the fifth resistor R5 is connected to the output of the operational amplifier U1; and the first terminal of the sixth resistor R6 is connected to the output of the operational amplifier U1. Additionally, one terminal of the seventh resistor R7 is connected to the inverting input of the operational amplifier U1, and the other terminal of the seventh resistor R7 is connected to a DC bias voltage.

[0041] The RF amplifier module is marked by a dashed box in the figure. This part represents the equivalent input resistance (i.e., resistance R8) and equivalent output resistance (i.e., resistance R9) of the RF amplifier module.

[0042] In addition, the signal output module includes a second inductor L2 and a second capacitor C2. The first end of the second inductor L2 is connected to the output end of the low-frequency amplification module, the first end of the second capacitor C2 is connected to the output end of the radio frequency amplification module, and the second end of the second inductor L2 is connected to the second end of the second capacitor C2.

[0043] In this design, the second resistor R2 and the fourth resistor R4 are both significantly larger than the first resistor R1. Furthermore, the first resistor R1 is matched with resistor R8, and the sixth resistor R6 is matched with resistor R9. Additionally, the reactance ratio corresponding to the first inductor L1 and the first capacitor C1 is the first reactance ratio value, and the reactance ratio corresponding to the second inductor L2 and the second capacitor C2 is the second reactance ratio value. The first reactance ratio value and the second reactance ratio value are equal. Specifically, both the first reactance ratio value and the second reactance ratio value are the square of the resistance value of the first resistor.

[0044] Understandably, under the influence of the first capacitor C1, high-frequency signals will pass through the first capacitor C1, while DC and low-frequency signals will pass through the first resistor R1. Similarly, under the influence of the first inductor L1, DC and low-frequency signals will pass through the first inductor L1, while high-frequency signals will pass through the resistor R8.

[0045] To address this, due to the presence of the first capacitor C1, DC and low-frequency signals can enter the low-frequency amplification module through the first resistor R1, and are further amplified by the operational amplifier U1 and the differential amplifier circuit formed by the corresponding resistors. Additionally, due to the presence of the first inductor L1, high-frequency signals can be connected to the radio frequency amplification module through resistor R8, thereby amplifying the high-frequency signals.

[0046] Similarly, based on the characteristics of the second inductor L2 and the second capacitor C2, the second inductor L2 is connected to the output terminal of the low-frequency amplifier module (i.e., the second end of the sixth resistor R6), and the second capacitor C2 is connected to the output terminal of the radio frequency amplifier module (i.e., one end of the resistor R9 in the figure), thereby realizing the input and output of the amplified signal.

[0047] Therefore, the front-end amplifier circuit of this application can separate DC and low-frequency signals and high-frequency signals, thereby amplifying different components in the signal to be measured separately, expanding the operating frequency range of the circuit, and also amplifying the signal voltage, thereby achieving a better signal-to-noise ratio and voltage standing wave ratio, which is beneficial to improving the measurement accuracy of the signal and providing a more accurate signal measurement function.

[0048] It should be noted that in some embodiments, the RF amplification module can use an RF amplification circuit, such as an operational amplifier in-phase RF amplification circuit or a low-noise amplification circuit, to amplify high-frequency signals; in addition, the RF amplification module can also use an RF amplifier to amplify high-frequency signals.

[0049] This application embodiment also provides a circuit board that includes the front-end amplifier circuit described in the above embodiment. Similarly, the circuit board can also separate DC and low-frequency signals and high-frequency signals, thereby amplifying different components in the signal to be measured, thereby expanding the operating frequency range. It can also amplify the signal voltage, thereby achieving a better signal-to-noise ratio and voltage standing wave ratio, which is beneficial to improving the accuracy of signal measurement and providing a more accurate signal measurement function.

[0050] This application also provides a data acquisition device, which can be an oscilloscope or a data acquisition instrument. The data acquisition device includes the aforementioned circuit board, thus enabling it to adapt to a wider operating frequency range and amplify different components of the signal to be measured, thereby amplifying the signal voltage and achieving a better signal-to-noise ratio and voltage standing wave ratio. This improves the accuracy of signal measurement and provides more precise signal measurement functionality.

[0051] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0052] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the appended claims.

Claims

1. A front-end amplifier circuit, characterized in that, include: The signal access module has its input terminal connected to a signal receiving terminal to receive the signal to be measured. The signal access module is used to provide input impedance to the front-end amplifier circuit and is also used to separate DC and low-frequency signals and high-frequency signals in the signal to be measured. A low-frequency amplification module, wherein the first input terminal of the low-frequency amplification module is connected to the input terminal of the signal access module, and the second input terminal of the low-frequency amplification module is connected to the impedance output terminal of the signal access module, and the low-frequency amplification module is used to amplify the DC and low-frequency signals; A DC bias module, the output of which is connected to the bias input of the low-frequency amplifier module, is used to provide a DC bias voltage to the low-frequency amplifier module to counteract the external bias voltage superimposed on the signal to be measured. The radio frequency (RF) amplification module has its input terminal connected to the impedance output terminal of the signal access module. The RF amplification module is used to amplify the high-frequency signal, and the amplification factor of the RF amplification module matches the amplification factor of the low-frequency amplification module. A signal output module, wherein the first input terminal of the signal output module is connected to the output terminal of the low-frequency amplification module, the second input terminal of the signal output module is connected to the output terminal of the radio frequency amplification module, and the output terminal of the signal output module is connected to the output signal terminal, for providing the amplified measurement signal to the subsequent circuit; The low-frequency amplification module includes a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and an operational amplifier. The first end of the second resistor is connected to the impedance supply terminal of the signal access module, the second end of the second resistor is connected to the first end of the third resistor, the second end of the second resistor is connected to the non-inverting input terminal of the operational amplifier, and the second end of the third resistor is grounded. The first end of the fourth resistor is connected to the input terminal of the signal access module, the second end of the fourth resistor is connected to the inverting input terminal of the operational amplifier, the first end of the fifth resistor is connected to the second end of the fourth resistor, the second end of the fifth resistor is connected to the output terminal of the operational amplifier, and the first end of the sixth resistor is connected to the output terminal of the operational amplifier. The first end of the fourth resistor serves as the first input terminal of the low-frequency amplifier module, the first end of the second resistor serves as the second input terminal of the low-frequency amplifier module, the second end of the fourth resistor serves as the bias input terminal of the low-frequency amplifier module, and the second end of the sixth resistor serves as the output terminal of the low-frequency amplifier module. The resistance value of the sixth resistor is matched with the equivalent output resistance of the radio frequency amplifier module.

2. The front-end amplifier circuit according to claim 1, characterized in that, The signal access module includes a first resistor, a first capacitor, and a first inductor; The first end of the first resistor is connected to the first end of the first capacitor, the second end of the first resistor is connected to the second end of the first capacitor, the first end of the first inductor is connected to the second end of the first capacitor, and the second end of the first inductor is grounded. Wherein, the first end of the first resistor serves as the input terminal of the signal access module, the second end of the first resistor serves as the impedance output terminal of the signal access module, and the resistance value of the first resistor is matched with the equivalent input resistance of the RF amplification module, and the inductance value of the first inductor is equal to the product of the capacitance value of the first capacitor and the square of the resistance value of the first resistor; the first capacitor is used to isolate the DC and low-frequency signals and conduct the high-frequency signals, and the first inductor is used to isolate the high-frequency signals and conduct the DC and low-frequency signals.

3. The front-end amplifier circuit according to claim 1, characterized in that, When the input impedance provided by the signal access module includes the first resistor, the ratio of the resistance of the second resistor to the resistance of the first resistor and the ratio of the resistance of the fourth resistor to the resistance of the first resistor are both greater than or equal to 100.

4. The front-end amplifier circuit according to claim 1, characterized in that, The DC bias module includes a seventh resistor, the first end of which is connected to the DC bias voltage, and the second end of which is connected to the bias input terminal of the low-frequency amplifier module. The DC bias voltage is matched to the external bias voltage.

5. The front-end amplifier circuit according to claim 1 or 2, characterized in that, The signal output module includes a second inductor and a second capacitor; The first end of the second inductor is connected to the output end of the low-frequency amplifier module, the first end of the second capacitor is connected to the output end of the radio frequency amplifier module, and the second end of the second inductor is connected to the second end of the second capacitor. The second inductor is used to conduct the amplified DC and low-frequency signals, the second capacitor is used to conduct the amplified high-frequency signals, and the reactance ratios of the second inductor and the second capacitor are matched with the reactance ratio of the signal access module.

6. The front-end amplifier circuit according to claim 5, characterized in that, When the signal access module includes a first inductor and a first capacitor connected in series, the reactance ratio corresponding to the first inductor and the first capacitor is the first reactance ratio value, and the reactance ratio corresponding to the second inductor and the second capacitor is the second reactance ratio value, and the first reactance ratio value is equal to the second reactance ratio value.

7. The front-end amplifier circuit according to claim 6, characterized in that, The signal access module further includes a first resistor connected in parallel with the first inductor, wherein the values ​​of the first reactance ratio and the second reactance ratio are both the square of the resistance value of the first resistor.

8. A circuit board, characterized in that, The circuit board includes the front-end amplifier circuit as described in any one of claims 1-7.

9. A data acquisition device, characterized in that, The data acquisition device includes the circuit board as described in claim 8.

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