Signal conditioning circuit, method and signal processing device based on DC component adjustment

Abstract

The signal conditioning circuit, method and signal processing device based on DC component adjustment provided by the present application relate to the field of signal processing technology. In the present application, the DC component of the analog signal to be conditioned is adjusted through a coupling transformation module to form a first conditioned analog signal; the first conditioned analog signal is converted from single-ended to differential to form a second conditioned analog signal; the second conditioned analog signal is amplified to form a third conditioned analog signal; the voltage of the DC signal in the first conditioned analog signal is collected and a DC signal collection voltage is output; a DC signal feedback voltage is output based on the DC signal collection voltage; a DC signal conditioning voltage is provided to the coupling transformation module based on the DC signal feedback voltage, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is adjusted to the target voltage range. Based on the above content, the problem of difficulty in reliably processing analog signals existing in the prior art can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of analog signal processing, and in particular to a signal conditioning circuit, method and signal processing device based on direct current component adjustment. Background Art

[0002] With the development of radar, communication, electronic countermeasure and other fields, it is necessary to process RF microwave signals with wider bandwidth (DC ~ 20GHz) and higher rate (80GSa / s or higher) in broadband, high-speed signal acquisition and processing and test and measurement systems. It is difficult for RF devices to achieve full-band coverage. Generally, the signal is processed by segmentation and frequency division first, and then combined and output. Among them, the bandwidth of the existing mainstream signal acquisition and processing platform can only reach DC ~ 13GHz, and the sampling rate reaches 40GSa / s; higher bandwidth needs to be achieved through frequency conversion, and higher sampling rate needs to be achieved through interleaving technology. However, the spurious and noise caused by frequency conversion will reduce the accuracy and reliability of the system. Although time domain interleaving or frequency domain interleaving technology can improve the bandwidth and sampling rate of signal acquisition through error correction and compensation, various mismatch errors between multi-channel parallel interleaved sampling will affect the waveform reconstructed by the digital back-end, bring pressure to the digital back-end signal processing, and ultimately affect the sampling accuracy and functional technical indicators of the data processing platform. In order to solve the above technical problems, corresponding conditioning circuits are generally designed to condition the collected analog signals accordingly. However, the inventors have found that in the prior art, it is difficult to reliably condition the analog signals during the signal conditioning process. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a signal conditioning circuit, method and signal processing device based on DC component adjustment to improve the problem in the prior art that it is difficult to reliably process analog signals.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] A signal conditioning circuit based on DC component adjustment, comprising:

[0006] A coupling transformation module, wherein the coupling transformation module is used to receive the analog signal to be conditioned through the input end, perform DC component adjustment processing on the analog signal to be conditioned to form a first conditioned analog signal, and output the first conditioned analog signal through the output end;

[0007] A balun module, wherein the input end of the balun module is connected to the output end of the coupling transformation module, and the balun module is used to obtain the first conditioned analog signal, perform single-ended to differential conversion on the first conditioned analog signal to form a second conditioned analog signal, and output the second conditioned analog signal through the output end;

[0008] An operational amplifier module, wherein the input end of the operational amplifier module is connected to the output end of the balun module, and the operational amplifier module is used to obtain the second conditioned analog signal and perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal;

[0009] A voltage acquisition module, wherein the input end of the voltage acquisition module is connected to the output end of the coupling transformation module, and the voltage acquisition module is used to acquire the voltage of the DC signal in the first conditioned analog signal, and output the corresponding DC signal acquisition voltage through the output end;

[0010] A conditioning control module, wherein the input end of the conditioning control module is connected to the output end of the voltage acquisition module, and the conditioning control module is used to obtain the DC signal acquisition voltage and output a corresponding DC signal feedback voltage based on the DC signal acquisition voltage;

[0011] A voltage feedback module, wherein the input end of the voltage feedback module is connected to the output end of the conditioning control module, the voltage feedback module is used to obtain the DC signal feedback voltage, and provide a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage, the DC signal conditioning voltage is used as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to be within a predetermined target voltage range.

[0012] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the voltage acquisition module includes:

[0013] An operational amplifier, wherein a positive phase input terminal of the operational amplifier is connected to an output terminal of the coupling transformation module through a first resistor to obtain a voltage of a DC signal in the first conditioned analog signal, and a negative phase input terminal of the operational amplifier is grounded through a second resistor and connected to an output terminal of the operational amplifier through a third resistor to form a feedback loop;

[0014] A fourth resistor, wherein a first end of the fourth resistor is connected to the output end of the operational amplifier, and a second end of the fourth resistor serves as the output end of the voltage acquisition module, so that a DC signal acquisition voltage formed by the operational amplifier amplifying the DC signal of the first conditioned analog signal is output through the output end.

[0015] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the voltage acquisition module further includes:

[0016] A first magnetic bead, wherein a first end of the first magnetic bead is connected to a positive power supply terminal of the operational amplifier, and a second end of the first magnetic bead is used as a positive terminal connected to a power supply voltage;

[0017] A second magnetic bead, wherein a first end of the second magnetic bead is connected to the negative power supply terminal of the operational amplifier, and a second end of the second magnetic bead is used as a negative terminal connected to the power supply voltage.

[0018] In a preferred option of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the input end of the balun module is connected to the output end of the coupling transformation module through a fifth resistor to obtain the first conditioned analog signal, wherein the resistance value of the first resistor is in the kilo-ohm level, and the resistance value of the fifth resistor is in the ohm level.

[0019] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the voltage feedback module includes:

[0020] A linear controllable power supply, wherein the input end of the linear controllable power supply is connected to the output end of the conditioning control module, and the linear controllable power supply is used to obtain the DC signal feedback voltage and perform voltage stabilization processing on the DC signal feedback voltage to form a DC signal conditioning voltage;

[0021] A Schottky diode, wherein the anode of the Schottky diode is connected to the output end of the linear controllable power supply, and the cathode of the Schottky diode is connected to the DC bias voltage feedback control pin of the coupling conversion module to provide the DC signal conditioning voltage;

[0022] A first capacitor, wherein a first end of the first capacitor is connected to the cathode of the Schottky diode, and a second end of the first capacitor is grounded.

[0023] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the voltage feedback module further includes:

[0024] A driving amplifier, wherein the non-phase input terminal of the driving amplifier is connected to the output terminal of the conditioning control module through a sixth resistor, and the output terminal of the driving amplifier is connected to the input terminal of the linear controllable power supply through a seventh resistor, and the driving amplifier is used to amplify the DC signal feedback voltage output by the conditioning control module and output it to the linear controllable power supply;

[0025] An eighth resistor, wherein a first end of the eighth resistor is connected to the non-inverting input end of the driving amplifier, and a second end of the eighth resistor is connected to the output end of the driving amplifier.

[0026] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the voltage feedback module further includes:

[0027] A third magnetic bead, wherein a first end of the third magnetic bead is connected to the positive terminal of the power supply of the driving amplifier, and a second end of the third magnetic bead is used as a positive terminal connected to the power supply voltage;

[0028] A fourth magnetic bead, wherein a first end of the fourth magnetic bead is connected to the negative power terminal of the driving amplifier, and a second end of the fourth magnetic bead is used as a negative terminal connected to the power supply voltage.

[0029] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on DC component adjustment, the conditioning control module includes:

[0030] An analog-to-digital converter, wherein the input end of the analog-to-digital converter is connected to the output end of the voltage acquisition module, and the analog-to-digital converter is used to obtain the DC signal acquisition voltage and output a corresponding acquisition voltage digital signal based on the DC signal acquisition voltage;

[0031] A controller, wherein an input end of the controller is connected to an output end of the analog-to-digital converter, and the controller is used to obtain the collected voltage digital signal and output a corresponding feedback voltage digital signal based on the collected voltage digital signal;

[0032] A digital-to-analog converter, wherein the input end of the digital-to-analog converter is connected to the output end of the controller, the output end of the digital-to-analog converter is connected to the input end of the voltage feedback module, and the digital-to-analog converter is used to obtain the feedback voltage digital signal and output a corresponding DC signal feedback voltage to the voltage feedback module based on the feedback voltage digital signal.

[0033] On the basis of the above, the present application further provides a signal conditioning method based on DC component adjustment, which is applied to the above-mentioned signal conditioning circuit based on DC component adjustment. The signal conditioning method based on DC component adjustment includes:

[0034] Receiving the analog signal to be conditioned through the coupling transformation module, and performing a DC component adjustment process on the analog signal to be conditioned to form a first conditioned analog signal;

[0035] Acquire the first conditioned analog signal through the balun module, and perform single-ended to differential conversion processing on the first conditioned analog signal to form a second conditioned analog signal;

[0036] Acquire the second conditioned analog signal through the operational amplifier module, and perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal;

[0037] The voltage acquisition module acquires the voltage of the DC signal in the first conditioned analog signal, and outputs a corresponding DC signal acquisition voltage;

[0038] Acquire the DC signal acquisition voltage through the conditioning control module, and output a corresponding DC signal feedback voltage based on the DC signal acquisition voltage;

[0039] The DC signal feedback voltage is obtained through the voltage feedback module, and a DC signal conditioning voltage is provided to the coupling transformation module based on the DC signal feedback voltage, wherein the DC signal conditioning voltage serves as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to be within a predetermined target voltage range.

[0040] On the basis of the above, the present application also provides a signal processing device, including:

[0041] The above-mentioned signal conditioning circuit based on DC component adjustment;

[0042] An analog-to-digital conversion circuit, wherein the input end of the analog-to-digital conversion circuit is connected to the output end of the signal conditioning circuit based on DC component adjustment, and the analog-to-digital conversion circuit is used to perform analog-to-digital conversion processing on the third conditioned analog signal output by the signal conditioning circuit based on DC component adjustment to form a target digital signal.

[0043] The signal conditioning circuit, method and signal processing device based on DC component adjustment provided in the present application perform DC component adjustment processing on the analog signal to be conditioned through a coupling transformation module to form a first conditioned analog signal; perform single-ended to differential conversion processing on the first conditioned analog signal to form a second conditioned analog signal; perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal; collect the voltage of the DC signal in the first conditioned analog signal and output a DC signal collection voltage; output a DC signal feedback voltage based on the DC signal collection voltage; and provide a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to a target voltage range. Based on the above content, since the DC component of the conditioned analog signal is adjusted by the coupling conversion module before the single-ended to differential processing is performed, the voltage of the DC signal in the first conditioned analog signal output by the coupling conversion module is adjusted to a predetermined target voltage interval, so that the DC signal therein can be more easily adapted to the actual application scenario. For example, the amplitude of the DC signal (voltage) can be adjusted to 0V. When the amplitude of the input AC signal is very small, it needs to be amplified by a large multiple, so that the DC signal amplitude is not large relative to the AC amplitude, causing the signal amplitude input to the back-end module to exceed the safe input range; or the amplification factor is not enough, although the signal amplitude input to the back-end module is within the safe input range, the background noise of the circuit will drown out the small AC amplitude; or the range of the analog-to-digital converter relative to the back-end module is too small, and its range is not fully applied, resulting in too low resolution. In other words, based on the signal conditioning scheme provided by the present application, the reliability of the conditioning can be guaranteed, thereby improving the problem of difficulty in reliably processing analog signals in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings.

[0045] Figure 1 A schematic diagram of a signal processing device provided in an embodiment of the present application.

[0046] Figure 2 A schematic diagram of a signal conditioning circuit based on DC component adjustment provided in an embodiment of the present application.

[0047] Figure 3 This is a schematic diagram of the application of the voltage acquisition module provided in the embodiment of the present application.

[0048] Figure 4 This is a schematic diagram of the application of the voltage feedback module provided in an embodiment of the present application.

[0049] Figure 5This is a schematic diagram of the application of the conditioning control module provided in an embodiment of the present application.

[0050] Figure 6 A schematic diagram of a frequency response characteristic curve of a DC component adjustment loop provided in an embodiment of the present application.

[0051] Figure 7 A schematic diagram of a frequency response characteristic curve of a signal conditioning circuit based on DC component adjustment provided in an embodiment of the present application.

[0052] Figure 8 A circuit diagram of a coupling transformation module provided in an embodiment of the present application.

[0053] Fig. 9 A circuit diagram of a balun module provided in an embodiment of the present application.

[0054] Fig.10 A circuit diagram of an operational amplifier module provided in an embodiment of the present application.

[0055] Fig.11 A schematic diagram of the steps included in the signal conditioning method based on DC component adjustment provided in an embodiment of the present application.

[0056] Icon: U1-operational amplifier, R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fourth resistor, L1-first magnetic bead, L2-second magnetic bead, D-Schottky diode, C-first capacitor, R6-sixth resistor, R7-seventh resistor, R8-eighth resistor, L3-third magnetic bead, L4-fourth magnetic bead. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0059] like Figure 1 As shown, an embodiment of the present application provides a signal processing device, wherein the signal processing device may include a signal conditioning circuit based on DC component adjustment and an analog-to-digital conversion circuit.

[0060] In detail, the signal conditioning circuit based on DC component adjustment can be used to perform corresponding conditioning (such as amplification and other processing) on ​​the received analog signal to be conditioned, thereby outputting a conditioned analog signal. The input end of the analog-to-digital conversion circuit is connected to the output end of the signal conditioning circuit based on DC component adjustment, and the analog-to-digital conversion circuit can be used to perform analog-to-digital conversion processing on the conditioned analog signal output by the signal conditioning circuit based on DC component adjustment (such as the third conditioned analog signal described later) to form a target digital signal.

[0061] Combination Figure 2 As shown, the embodiment of the present application also provides a signal conditioning circuit based on DC component adjustment, and the signal conditioning circuit based on DC component adjustment can be applied to the above-mentioned signal processing device. Among them, the signal conditioning circuit based on DC component adjustment can include a coupling transformation module, a balun module, an operational amplifier module, a voltage acquisition module, a conditioning control module and a voltage feedback module.

[0062] In detail, the coupling conversion module is used to receive the analog signal to be conditioned through the input end, and perform DC component adjustment processing on the analog signal to be conditioned to form a first conditioned analog signal, and output the first conditioned analog signal through the output end. The input end of the balun module is connected to the output end of the coupling conversion module, and the balun module is used to obtain the first conditioned analog signal, and perform single-ended to differential processing on the first conditioned analog signal to form a second conditioned analog signal, and output the second conditioned analog signal through the output end. The input end of the operational amplifier module is connected to the output end of the balun module, and the operational amplifier module is used to obtain the second conditioned analog signal, and perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal. The input end of the voltage acquisition module is connected to the output end of the coupling conversion module, and the voltage acquisition module is used to acquire the voltage of the DC signal in the first conditioned analog signal, and output the corresponding DC signal acquisition voltage through the output end. The input end of the conditioning control module is connected to the output end of the voltage acquisition module, and the conditioning control module is used to acquire the DC signal acquisition voltage, and output the corresponding DC signal feedback voltage based on the DC signal acquisition voltage. The input end of the voltage feedback module is connected to the output end of the conditioning control module. The voltage feedback module is used to obtain the DC signal feedback voltage and provide a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage. The DC signal conditioning voltage serves as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to a predetermined target voltage range. For example, in an application scenario, the DC signal can be adjusted to 0V (the corresponding range can be (-0.1, 0.1)V, etc.), so that in subsequent processing, the AC signal can be fully amplified without considering the interference problem of the DC signal caused by excessive amplification.

[0063] Based on the above content, since the DC component of the conditioned analog signal is adjusted by the coupling conversion module before the single-ended to differential processing is performed, the voltage of the DC signal in the first conditioned analog signal output by the coupling conversion module is adjusted to a predetermined target voltage interval, so that the DC signal therein can be more easily adapted to the actual application scenario. For example, the amplitude of the DC signal (voltage) can be adjusted to 0V. When the amplitude of the input AC signal is very small, it needs to be amplified by a large multiple, so that the DC signal amplitude is not large relative to the AC amplitude, causing the signal amplitude input to the back-end module to exceed the safe input range; or the amplification factor is not enough, although the signal amplitude input to the back-end module is within the safe input range, the background noise of the circuit will drown out the small AC amplitude; or the range of the analog-to-digital converter relative to the back-end module is too small, and its range is not fully applied, resulting in too low resolution. In other words, based on the signal conditioning scheme provided by the present application, the reliability of the conditioning can be guaranteed, thereby improving the problem of difficulty in reliably processing analog signals in the prior art.

[0064] It should be noted that the coupling transformation module can provide a signal amplification function while performing DC component adjustment processing on the input signal, that is, amplifying the input signal to a certain extent to facilitate processing by the back-end module.

[0065] The specific processing process of the coupling transformation module may be as follows:

[0066] Assuming that the amplitude of the input signal is Vin, and the magnitude of the reference DC bias signal of the coupling conversion module is Vg, after passing through the circuit with an amplification factor of k, the output voltage Vout is as follows:

[0067] Vout = k × (Vin - Vg) + Vb;

[0068] In the above formula, the DC bias voltage that needs to be adjusted by the coupling transformation module is Vg, so that the DC bias voltage Vb of the system as a whole is 0 in the collected Vout. The value of Vg at this time is the DC bias voltage value that needs to be configured, that is, Vg is adjusted so that Vb is compensated. After such processing, it can be ensured that the Vout output by the coupling transformation module is within the input voltage range allowed for the normal operation of the active balun in the subsequent stage. By adjusting the DC bias component of the input signal through the coupling transformation module, it plays a good role in balancing the processing of the input AC analog signal with the superimposed DC bias component, which is more conducive to the subsequent conditioning and acquisition circuit working in the most suitable amplitude-frequency range of the index, that is, even if the input signal is superimposed with a DC bias component, after processing and subsequent conditioning, the signal can still be adjusted back to adapt to the effective input range of the final analog-to-digital converter.

[0069] It should be noted that the balun module includes an operational amplifier. Therefore, in addition to converting a single-ended signal into a differential signal, it also has a certain differential gain characteristic. Based on this, while ensuring a good amplitude balance characteristic, it can also ensure excellent in-band flatness, and can effectively ensure the amplitude-frequency response characteristics of broadband and high-speed conditioning.

[0070] It should be noted that the specific structure of the voltage acquisition module is not limited and can be selected according to actual needs.

[0071] For example, in an alternative embodiment, in combination Figure 3 The voltage acquisition module may include an operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4.

[0072] In detail, the positive phase input terminal of the operational amplifier U1 is connected to the output terminal of the coupling transformation module through the first resistor R1 to obtain the voltage of the DC signal in the first conditioned analog signal. The negative phase input terminal of the operational amplifier U1 is grounded through the second resistor R2 and connected to the output terminal of the operational amplifier U1 through the third resistor R3 to form a feedback loop. The first end of the fourth resistor R4 is connected to the output terminal of the operational amplifier U1, and the second end of the fourth resistor R4 serves as the output terminal of the voltage acquisition module, so that the DC signal acquisition voltage formed by the operational amplifier U1 performing signal amplification processing on the DC signal of the first conditioned analog signal is output through the output terminal.

[0073] It is understandable that, in an alternative implementation, the voltage acquisition module may further include a first magnetic bead L1 and a second magnetic bead L2.

[0074] In detail, the first end of the first magnetic bead is connected to the positive power supply terminal of the operational amplifier U1, and the second end of the first magnetic bead is used as the positive end connected to the power supply voltage. The first end of the second magnetic bead is connected to the negative power supply terminal of the operational amplifier U1, and the second end of the second magnetic bead is used as the negative end connected to the power supply voltage.

[0075] It can be understood that, in an alternative embodiment, the input end of the balun module is connected to the output end of the coupling transformation module through a fifth resistor R5 to obtain the first conditioned analog signal, wherein the resistance value of the first resistor R1 is in the kilo-ohm level, and the resistance value of the fifth resistor is in the ohm level.

[0076] Based on the above circuit structure, in the initial state, the state of the input signal is unknown, and the amplitude of the AC component and DC component contained in it needs to be pre-sampled before it can be processed and calculated. After the input signal is amplified by the coupling conversion module, the AC component signal VAC is transmitted to the single-ended to differential active balun of the subsequent stage through a smaller (ohm level) resistor for subsequent conditioning; and the DC component signal VDC1 is transmitted to the positive input end of the operational amplifier U1 of the subsequent stage through a larger (kilo-ohm level) resistor. The operational amplifier U1 forms a positive feedback amplifier through an external resistor, which can ensure that a certain proportion of amplification is performed when the DC signal VDC1 is small, thereby improving the sensitivity of DC component signal detection. In addition, the DC component signal amplified by the operational amplifier U1 is VDC2, which can be sampled after passing through the resistor. Among them, in order to ensure that the possible small signal VDC1 is not interfered by the on-board power supply and clutter when amplifying it, the positive and negative power supplies of the operational amplifier U1 are powered by VDD and VEE on the board through a magnetic bead respectively.

[0077] It should be noted that the specific structure of the voltage feedback module is not limited and can be selected according to actual needs.

[0078] For example, in an alternative embodiment, in combination Figure 4 The voltage feedback module may include a linear controllable power supply, a Schottky diode D and a first capacitor C.

[0079] In detail, the input end of the linear controllable power supply is connected to the output end of the conditioning control module, and the linear controllable power supply is used to obtain the DC signal feedback voltage and perform voltage stabilization on the DC signal feedback voltage to form a DC signal conditioning voltage. The anode of the Schottky diode D is connected to the output end of the linear controllable power supply, and the cathode of the Schottky diode D is connected to the DC bias voltage feedback control pin of the coupling conversion module to provide the DC signal conditioning voltage. The first end of the first capacitor C is connected to the cathode of the Schottky diode D, and the second end of the first capacitor C is grounded. Based on this, a reliable DC signal conditioning voltage can be provided for the DC bias voltage feedback control pin of the coupling conversion module.

[0080] It is understandable that, in an alternative implementation, the linear controllable power supply may be an adaptive linear adjustable LCD output voltage (Adjustable LCD Output Voltage) circuit to achieve precise voltage control.

[0081] It is understandable that, in an alternative implementation, in order to improve the reliability of voltage feedback, the voltage feedback module further includes a driving amplifier, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8.

[0082] In detail, the non-phase input terminal of the driving amplifier is connected to the output terminal of the conditioning control module through a sixth resistor, and the output terminal of the driving amplifier is connected to the input terminal of the linear controllable power supply through a seventh resistor. The driving amplifier is used to amplify the DC signal feedback voltage output by the conditioning control module and output it to the linear controllable power supply. The first end of the eighth resistor is connected to the non-phase input terminal of the driving amplifier, and the second end of the eighth resistor is connected to the output terminal of the driving amplifier.

[0083] It is understandable that, in an alternative implementation, the voltage feedback module further includes a third magnetic bead L3 and a fourth magnetic bead L4.

[0084] In detail, the first end of the third magnetic bead L3 is connected to the positive power supply terminal of the driving amplifier, and the second end of the third magnetic bead L3 is used as the positive end connected to the power supply voltage. The first end of the fourth magnetic bead L4 is connected to the negative power supply terminal of the driving amplifier, and the second end of the fourth magnetic bead L4 is used as the negative end connected to the power supply voltage.

[0085] For the above circuit, it should be noted that the DC signal feedback voltage output by the conditioning control module is amplified by the driving amplifier and its peripheral circuits, and then output to the linear controllable power supply through a resistor. The linear controllable power supply outputs the feedback voltage to the DC bias voltage feedback control pin of the coupling conversion module through a Schottky diode D. In this process, the positive and negative power supplies of the driving amplifier are each powered by a magnetic bead from the VS+ and VS- on the board to avoid power supply interference.

[0086] It should be noted that the specific structure of the conditioning control module is not limited and can be selected according to actual needs.

[0087] For example, in an alternative embodiment, in combination Figure 5 The conditioning control module includes an analog-to-digital converter, a controller and a digital-to-analog converter.

[0088] In detail, the input end of the analog-to-digital converter is connected to the output end of the voltage acquisition module, and the analog-to-digital converter is used to obtain the DC signal acquisition voltage, and output the corresponding acquisition voltage digital signal based on the DC signal acquisition voltage. The input end of the controller is connected to the output end of the analog-to-digital converter, and the controller is used to obtain the acquisition voltage digital signal, and output the corresponding feedback voltage digital signal based on the acquisition voltage digital signal. The input end of the digital-to-analog converter is connected to the output end of the controller, and the output end of the digital-to-analog converter is connected to the input end of the voltage feedback module, and the digital-to-analog converter is used to obtain the feedback voltage digital signal, and output the corresponding DC signal feedback voltage to the voltage feedback module based on the feedback voltage digital signal.

[0089] It should be noted that the DC component adjustment loop constructed by the above-mentioned voltage acquisition module, conditioning control module and voltage feedback module has a good gain frequency response characteristic, such as Figure 6 As shown, it has good flatness in the range of DC to 20 GHz. Wherein, VG refers to the DC bias voltage that needs to be adjusted by the coupling conversion module, that is, the above-mentioned Vg.

[0090] It should be noted that the above-mentioned signal conditioning circuit based on DC component adjustment has a good gain frequency response characteristic as a whole, such as Figure 7 As shown (where S(3, 1) and S(2, 1) correspond to the two ports of differential output), it also has good flatness in the range of DC to 20 GHz, i.e., (34.777-32.501) dB, which is less than 3 dB.

[0091] It should be noted that the model of the driving amplifier can be AD8051, which is mainly used to control and transmit circuit signals. Its main function is to output low-level signals to high-level signals, and to amplify signals, amplifying weak signals to a certain level for subsequent processing. In addition, the specific type of the controller is not limited, for example, it can include, but is not limited to, various microcontrollers, DSP chips, FPGA chips, SOC chips, CPU chips, etc.

[0092] It should be noted that the specific types of the coupling transformation module, the balun module and the operational amplifier module are not limited. For example, the coupling transformation module can be used to shield the DC signal and pass the AC signal. The specific structure is described below. The balun module can have the function of converting the single-ended signal into a differential signal and achieving a certain coefficient of gain (an active balun can convert the input single-ended signal into a differential signal, and the traditional transformer or balun is a passive device. Even if it can meet the transmission of high-frequency signals, it cannot meet the transmission of DC signals. The minimum can only reach the transmission of kilohertz-level frequency signals). The specific structure is described below. The operational amplifier module can be an operational amplifier circuit with adjustable gain (for example, it can be controlled by a controller through a serial port to amplify the input differential signal with variable gain to adapt to the conditioning and amplification of analog signals with a wide voltage input range, so that the analog signal amplitude output to the subsequent analog-to-digital converter is close to the full scale of the analog-to-digital converter, so that the analog-to-digital converter works in a state with the highest resolution and the best performance when the input signal amplitude is close to the full scale). The specific structure is described below. Wherein, two resistors are connected between the balun module and the operational amplifier module.

[0093] In detail, combined Figure 8 In a specific application example, the coupling transformation module may include an input port (such as Figure 8 VIN in), an output port (such as Figure 8 VOUT in), a positive power port (such as Figure 8 VS+ in), a negative power port (such as Figure 8 VS- in the ), a DC bias voltage feedback port (such as Figure 8 VG in the figure is used as the DC bias voltage feedback control pin mentioned above. The input signal passes through two diodes (such as Figure 8 D11 and D12 in the clamp are within the safe range of the positive power port and the negative power port, and the input signal is transmitted from the field effect tube (such as Figure 8 The gate input of Q11 in the figure is output to the next stage amplifier (such as Figure 8 Amplifier (such as Q12 in Figure 8 Q12 in the figure) is connected from the positive power supply port through a resistor (such as Figure 8 R11 in the figure provides positive power for it, the negative power port provides negative power for it, and the decoupling capacitor (such as Figure 8 C11 in the figure) is used as the positive power supply filter, and then passes through the amplifier (such as Figure 8 The signal output by Q12 in the figure is the output signal of the coupling conversion module. In addition, by adjusting the voltage of the DC bias voltage feedback port to make it equal to the DC bias voltage of the input signal, it can be made to pass through the resistor (such as Figure 8 R13 in) to the amplifier (such as Figure 8 The DC voltage of Q12 in the circuit is connected to the input signal through a resistor (such as Figure 8 R12 in) to the amplifier (such as Figure 8 Based on this, the DC voltage of the field effect transistor (such as Q12 in the positive power supply port) is offset. Figure 8 When the source of Q11 in Figure 8 Q11 in the circuit is turned on, and the AC component of the input signal is output to the subsequent amplifier (such as Figure 8 Q12 in the Figure 8 Q12) in the circuit amplifies the input AC signal to a certain extent.

[0094] In detail, combined Fig. 9 In a specific application example, the balun module may include a single-ended input port (such as Fig. 9 VIN in), a differential output port (such as Fig. 9 VOIUTP in), a differential output port (such as Fig. 9 VOUTN in), a positive power port (such as Fig. 9 VDD in), a negative power port (such as Fig. 9 The core components of the balun module are two field effect transistors (such as Fig. 9 Q21 and Q22 in the figure), and they are connected by the same positive power supply port through two resistors (such as Fig. 9 R22 and R23 in the figure) supply power to its gate and pass two decoupling capacitors (such as Fig. 9 The input signal passes through a resistor (such as C21 and C22) for positive power filtering. Fig. 9 R21 in the positive path), the power is divided into the positive path field effect tube (such as Fig. 9 The drain of Q22 in the figure and the field effect tube of the negative path (such as Fig. 9 In the positive path, the field effect transistor (such as Fig. 9 The source of Q22 in the Fig. 9 R27 in the output positive terminal signal, and the negative power supply port is connected through a resistor (such as Fig. 9 R25 in the figure provides negative power to its gate, which is supplied by a decoupling capacitor (such as Fig. 9 C24 in the figure) is its negative power supply filter; when the field effect tube (such as Fig. 9 When the source, negative power supply port, gate, and positive power supply port of Q22 in the positive path are turned on, the field effect tube (such as Fig. 9 Q22 in the circuit is turned on and the positive signal is output. In the negative path, the field effect tube (such as Fig. 9 The source of Q21 in the figure is grounded, and the drain is connected to the ground through a resistor (such as Fig. 9R26 in the output negative terminal signal, and the negative power supply port is connected through a resistor (such as Fig. 9 R24 in the figure provides a negative power supply to its drain, which is provided by a decoupling capacitor (such as Fig. 9 C23 in the figure) is its negative power supply filter; when the field effect tube (such as Fig. 9 When the gate of Q21 in the figure and the positive power supply port are turned on, the field effect tube of the negative path (such as Fig. 9 Q21) in the circuit is turned on and the negative terminal signal is output.

[0095] In the circuit of the balun module, the field effect tube (such as Fig. 9 The source voltage of Q22 in the circuit is provided by the positive power supply port through the field effect transistor (such as Fig. 9 Therefore, when the external power supply supplies power to the negative power port, its power loop is reversed and output, not input and then return through the ground, so the above-mentioned adaptive linear adjustable LCD output voltage circuit is needed to power it. At the same time, it can be found through this circuit that the field effect tube of the positive end path (such as Fig. 9 The source of Q22 in the positive path outputs a positive signal, and the field effect tube (such as Fig. 9 The drain of Q22 in the figure is connected to the field effect tube of the negative path (such as Fig. 9 The gate of Q21 in the negative path is connected; the field effect tube of the negative path (such as Fig. 9 The drain of Q21 in the circuit outputs a negative signal, and the source is grounded. The entire circuit is a symmetrical structure. Therefore, in order to ensure the output balance of single-ended to differential conversion, the two field effect transistors work well in the linear region, and the DC bias of their input signals needs to be close to 0V.

[0096] In detail, combined Fig.10 In a specific application example, the operational amplifier module may include a differential input port (such as Fig.10 VINP in), a differential input port (such as Fig.10 VINN in), a differential output port (such as Fig.10 VOUTP in), a differential output port (such as Fig.10 VOUTN in), two programmable impedance arrays and an amplifier (such as Fig.10 Wherein, the differential analog signal (such as the aforementioned second conditioned analog signal) is input through the differential input port (such as Fig.10VINP and VINN in the input operational amplifier module), the two signals are respectively controlled by corresponding programmable signals (for example, can be provided by a controller connected to the serial port) to control the programmable impedance array (a network composed of multiple adjustable impedances (usually composed of resistors or potentiometers). It can dynamically adjust the value of each impedance through the programmable signal to provide precise impedance matching to optimize signal transmission and minimize reflection) to match the input signal. The attenuated signal is output to an amplifier (such as Fig.10 Amplifier (such as Q31 in Fig.10 Q31 in) through the positive power supply port (such as Fig.10 VS+) and negative power supply port (such as Fig.10 The positive and negative power supplies connected to VS- in the figure are used to power the device, and the positive and negative power supplies are connected to a decoupling capacitor (such as Fig.10 C33 and C34 in the filter are used to filter it. Fig.10 The differential signal of Q31 in the circuit is fed through the RC feedback network (such as Fig.10 R31&C31 and R32&C32 in the circuit amplify and compensate the corresponding coefficients, and finally output the signal through the differential output port (such as Fig.10 VOUTP and VOUTN in the output differential signal (such as the third conditioned analog signal mentioned above).

[0097] Combination Fig.11 The embodiment of the present application further provides a signal conditioning method based on DC component adjustment, which can be applied to the above-mentioned signal conditioning circuit based on DC component adjustment, wherein the signal conditioning method based on DC component adjustment can include the following steps:

[0098] Step S110, receiving the analog signal to be conditioned through the coupling transformation module, and performing a DC component adjustment process on the analog signal to be conditioned to form a first conditioned analog signal;

[0099] Step S120, acquiring the first conditioned analog signal through the balun module, and performing single-ended to differential conversion processing on the first conditioned analog signal to form a second conditioned analog signal;

[0100] Step S130, acquiring the second conditioned analog signal through the operational amplifier module, and performing signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal;

[0101] Step S140, collecting the voltage of the DC signal in the first conditioned analog signal through the voltage collection module, and outputting the corresponding DC signal collection voltage;

[0102] Step S150, acquiring the DC signal acquisition voltage through the conditioning control module, and outputting a corresponding DC signal feedback voltage based on the DC signal acquisition voltage;

[0103] Step S160: acquiring the DC signal feedback voltage through the voltage feedback module, and providing a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage.

[0104] The DC signal conditioning voltage is used as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to be within a predetermined target voltage range.

[0105] For the specific implementation process of each of the above steps, please refer to the relevant description in the previous text.

[0106] In summary, the signal conditioning circuit, method and signal processing device based on DC component adjustment provided by the present application perform DC component adjustment processing on the analog signal to be conditioned through a coupling transformation module to form a first conditioned analog signal; perform single-ended to differential conversion processing on the first conditioned analog signal to form a second conditioned analog signal; perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal; collect the voltage of the DC signal in the first conditioned analog signal and output a DC signal collection voltage; output a DC signal feedback voltage based on the DC signal collection voltage; and provide a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to a target voltage range. Based on the above content, since the DC component of the conditioned analog signal is adjusted by the coupling conversion module before the single-ended to differential processing is performed, the voltage of the DC signal in the first conditioned analog signal output by the coupling conversion module is adjusted to a predetermined target voltage interval, so that the DC signal therein can be more easily adapted to the actual application scenario. For example, the amplitude of the DC signal (voltage) can be adjusted to 0V. When the amplitude of the input AC signal is very small, it needs to be amplified by a large multiple, so that the DC signal amplitude is not large relative to the AC amplitude, causing the signal amplitude input to the back-end module to exceed the safe input range; or the amplification factor is not enough, although the signal amplitude input to the back-end module is within the safe input range, the background noise of the circuit will drown out the small AC amplitude; or the range of the analog-to-digital converter relative to the back-end module is too small, and its range is not fully applied, resulting in too low resolution. In other words, based on the conditioning scheme provided by the present application, the reliability of conditioning can be guaranteed, and the problem of difficulty in reliably processing analog signals existing in the prior art can be improved.

[0107] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A signal conditioning circuit based on DC component adjustment, characterized in that: include: A coupling transformation module, wherein the coupling transformation module is used to receive the analog signal to be conditioned through the input end, perform DC component adjustment processing on the analog signal to be conditioned to form a first conditioned analog signal, and output the first conditioned analog signal through the output end; A balun module, wherein the input end of the balun module is connected to the output end of the coupling transformation module, and the balun module is used to obtain the first conditioned analog signal, perform single-ended to differential conversion on the first conditioned analog signal to form a second conditioned analog signal, and output the second conditioned analog signal through the output end; An operational amplifier module, wherein the input end of the operational amplifier module is connected to the output end of the balun module, and the operational amplifier module is used to obtain the second conditioned analog signal and perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal; A voltage acquisition module, wherein the input end of the voltage acquisition module is connected to the output end of the coupling transformation module, and the voltage acquisition module is used to acquire the voltage of the DC signal in the first conditioned analog signal, and output the corresponding DC signal acquisition voltage through the output end; A conditioning control module, wherein the input end of the conditioning control module is connected to the output end of the voltage acquisition module, and the conditioning control module is used to obtain the DC signal acquisition voltage and output a corresponding DC signal feedback voltage based on the DC signal acquisition voltage; A voltage feedback module, wherein the input end of the voltage feedback module is connected to the output end of the conditioning control module, the voltage feedback module is used to obtain the DC signal feedback voltage, and provide a DC signal conditioning voltage to the coupling transformation module based on the DC signal feedback voltage, the DC signal conditioning voltage is used as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to be within a predetermined target voltage range.

2. The signal conditioning circuit based on DC component adjustment according to claim 1, characterized in that: The voltage acquisition module comprises: An operational amplifier, wherein a positive phase input terminal of the operational amplifier is connected to an output terminal of the coupling transformation module through a first resistor to obtain a voltage of a DC signal in the first conditioned analog signal, and a negative phase input terminal of the operational amplifier is grounded through a second resistor and connected to an output terminal of the operational amplifier through a third resistor to form a feedback loop; A fourth resistor, wherein a first end of the fourth resistor is connected to the output end of the operational amplifier, and a second end of the fourth resistor serves as the output end of the voltage acquisition module, so that a DC signal acquisition voltage formed by the operational amplifier amplifying the DC signal of the first conditioned analog signal is output through the output end.

3. The signal conditioning circuit based on DC component adjustment according to claim 2, characterized in that: The voltage acquisition module also includes: A first magnetic bead, wherein a first end of the first magnetic bead is connected to a positive power supply terminal of the operational amplifier, and a second end of the first magnetic bead is used as a positive terminal connected to a power supply voltage; A second magnetic bead, wherein a first end of the second magnetic bead is connected to the negative power supply terminal of the operational amplifier, and a second end of the second magnetic bead is used as a negative terminal connected to the power supply voltage.

4. The signal conditioning circuit based on DC component adjustment according to claim 2, characterized in that: The input end of the balun module is connected to the output end of the coupling transformation module through a fifth resistor to obtain the first conditioned analog signal, wherein the resistance value of the first resistor is in the kilo-ohm level, and the resistance value of the fifth resistor is in the ohm level.

5. The signal conditioning circuit based on DC component adjustment according to claim 1, characterized in that: The voltage feedback module comprises: A linear controllable power supply, wherein the input end of the linear controllable power supply is connected to the output end of the conditioning control module, and the linear controllable power supply is used to obtain the DC signal feedback voltage and perform voltage stabilization processing on the DC signal feedback voltage to form a DC signal conditioning voltage; A Schottky diode, wherein the anode of the Schottky diode is connected to the output end of the linear controllable power supply, and the cathode of the Schottky diode is connected to the DC bias voltage feedback control pin of the coupling conversion module to provide the DC signal conditioning voltage; A first capacitor, wherein a first end of the first capacitor is connected to the cathode of the Schottky diode, and a second end of the first capacitor is grounded.

6. The signal conditioning circuit based on DC component adjustment according to claim 5, characterized in that: The voltage feedback module also includes: A driving amplifier, wherein the non-phase input terminal of the driving amplifier is connected to the output terminal of the conditioning control module through a sixth resistor, and the output terminal of the driving amplifier is connected to the input terminal of the linear controllable power supply through a seventh resistor, and the driving amplifier is used to amplify the DC signal feedback voltage output by the conditioning control module and output it to the linear controllable power supply; An eighth resistor, wherein a first end of the eighth resistor is connected to the non-inverting input end of the driving amplifier, and a second end of the eighth resistor is connected to the output end of the driving amplifier.

7. The signal conditioning circuit based on DC component adjustment according to claim 6, characterized in that: The voltage feedback module also includes: A third magnetic bead, wherein a first end of the third magnetic bead is connected to the positive terminal of the power supply of the driving amplifier, and a second end of the third magnetic bead is used as a positive terminal connected to the power supply voltage; A fourth magnetic bead, wherein a first end of the fourth magnetic bead is connected to the negative power terminal of the driving amplifier, and a second end of the fourth magnetic bead is used as a negative terminal connected to the power supply voltage.

8. The signal conditioning circuit based on DC component adjustment according to any one of claims 1 to 7, characterized in that: The conditioning control module comprises: An analog-to-digital converter, wherein the input end of the analog-to-digital converter is connected to the output end of the voltage acquisition module, and the analog-to-digital converter is used to obtain the DC signal acquisition voltage and output a corresponding acquisition voltage digital signal based on the DC signal acquisition voltage; A controller, wherein an input end of the controller is connected to an output end of the analog-to-digital converter, and the controller is used to obtain the collected voltage digital signal and output a corresponding feedback voltage digital signal based on the collected voltage digital signal; A digital-to-analog converter, wherein the input end of the digital-to-analog converter is connected to the output end of the controller, the output end of the digital-to-analog converter is connected to the input end of the voltage feedback module, and the digital-to-analog converter is used to obtain the feedback voltage digital signal and output a corresponding DC signal feedback voltage to the voltage feedback module based on the feedback voltage digital signal.

9. A signal conditioning method based on DC component adjustment, characterized in that: Applied to the signal conditioning circuit based on DC component adjustment according to any one of claims 1 to 8, the signal conditioning method based on DC component adjustment comprises: Receiving the analog signal to be conditioned through the coupling transformation module, and performing a DC component adjustment process on the analog signal to be conditioned to form a first conditioned analog signal; Acquire the first conditioned analog signal through the balun module, and perform single-ended to differential conversion processing on the first conditioned analog signal to form a second conditioned analog signal; Acquire the second conditioned analog signal through the operational amplifier module, and perform signal amplification processing on the second conditioned analog signal to form a third conditioned analog signal; The voltage acquisition module acquires the voltage of the DC signal in the first conditioned analog signal, and outputs a corresponding DC signal acquisition voltage; Acquire the DC signal acquisition voltage through the conditioning control module, and output a corresponding DC signal feedback voltage based on the DC signal acquisition voltage; The DC signal feedback voltage is obtained through the voltage feedback module, and a DC signal conditioning voltage is provided to the coupling transformation module based on the DC signal feedback voltage, wherein the DC signal conditioning voltage serves as a basis for the coupling transformation module to perform DC component adjustment processing, so that the voltage of the DC signal in the first conditioned analog signal output by the coupling transformation module is conditioned to be within a predetermined target voltage range.

10. A signal processing device, characterized in that: include: The signal conditioning circuit based on DC component adjustment according to any one of claims 1 to 8; An analog-to-digital conversion circuit, wherein the input end of the analog-to-digital conversion circuit is connected to the output end of the signal conditioning circuit based on DC component adjustment, and the analog-to-digital conversion circuit is used to perform analog-to-digital conversion processing on the third conditioned analog signal output by the signal conditioning circuit based on DC component adjustment to form a target digital signal.

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