Signal conditioning circuit and method based on active balun and signal processing equipment

Abstract

The invention provides a signal conditioning circuit and method based on an active balun and signal processing equipment, and relates to the technical field of signal processing. The method comprises the following steps: performing direct-current component adjustment processing on a to-be-processed analog signal to form a direct-current component adjustment analog signal; performing single-ended to differential processing on the direct-current component adjustment analog signal to form a differential analog signal; performing signal amplification processing on the differential analog signal to form a target analog signal; collecting the voltage of a direct-current signal in the direct-current component adjustment analog signal, and outputting a corresponding direct-current signal collection voltage; outputting a corresponding differential conversion control voltage based on the DC signal acquisition voltage; differential conversion bias voltage is provided for the active balun unit based on the differential conversion control voltage, and the differential conversion bias voltage serves as the basis for single-end-to-differential processing. Based on the above content, the problem that the analog signal is difficult to process reliably in the prior art can be improved.

Description

Technical Field

[0001] The present application relates to the field of signal processing technology, and in particular to a signal conditioning circuit, method and signal processing device based on an active balun. 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 an active balun 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 an active balun, comprising:

[0006] A coupling transformation unit, wherein the coupling transformation unit is used to receive an analog signal to be processed through an input terminal, perform a DC component adjustment process on the analog signal to be processed to form a DC component adjusted analog signal, and output the DC component adjusted analog signal through an output terminal;

[0007] An active balun unit, wherein the input end of the active balun unit is connected to the output end of the coupling transformation unit, and the active balun unit is used to obtain the DC component adjustment analog signal, and perform single-ended conversion processing on the DC component adjustment analog signal to form a differential analog signal, and output the differential analog signal through the output end;

[0008] An operational amplifier unit, wherein an input end of the operational amplifier unit is connected to an output end of the active balun unit, and the operational amplifier unit is used to obtain the differential analog signal and perform signal amplification processing on the differential analog signal to form a target analog signal;

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

[0010] A differential conversion control unit, wherein an input end of the differential conversion control unit is connected to an output end of the voltage acquisition unit, and the differential conversion control unit is used to obtain the DC signal acquisition voltage and output a corresponding differential conversion control voltage based on the DC signal acquisition voltage;

[0011] A voltage feedback unit, wherein the input end of the voltage feedback unit is connected to the output end of the differential conversion control unit, the voltage feedback unit is used to obtain the differential conversion control voltage, and provide a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage, and the differential conversion bias voltage serves as a basis for the active balun unit to perform single-ended to differential processing.

[0012] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the voltage feedback unit includes:

[0013] A driving amplifier, wherein a non-phase input terminal of the driving amplifier is connected to an output terminal of the differential conversion control unit via a first resistor, and the driving amplifier is used to amplify the differential conversion control voltage output by the differential conversion control unit and output it to the linear controllable power supply;

[0014] A linear controllable power supply, wherein the input end of the linear controllable power supply is connected to the output end of the driving amplifier through a second resistor, and the linear controllable power supply is used to obtain the amplified differential conversion control voltage and perform voltage stabilization on the amplified differential conversion control voltage to form a differential conversion bias voltage;

[0015] A Schottky diode, wherein an anode of the Schottky diode is connected to the output end of the linear controllable power supply, and a cathode of the Schottky diode is connected to a DC bias voltage feedback control pin of the active balun unit to provide the differential conversion bias voltage;

[0016] 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;

[0017] A third resistor, wherein a first end of the third resistor is connected to the non-inverting input end of the driving amplifier, and a second end of the third resistor is connected to the output end of the driving amplifier;

[0018] A first magnetic bead, wherein a first end of the first magnetic bead is connected to a positive terminal of a power supply of the driving amplifier, and a second end of the first magnetic bead is used as a positive terminal connected to a power supply voltage;

[0019] A second magnetic bead, wherein a first end of the second magnetic bead is connected to the negative end of the power supply of the driving amplifier, and a second end of the second magnetic bead is used as a negative end connected to the power supply voltage.

[0020] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the linear controllable power supply includes:

[0021] A voltage stabilizing component, wherein an input end of the voltage stabilizing component is connected to the second resistor, and an output end of the voltage stabilizing component is connected to the anode of the Schottky diode;

[0022] A fourth resistor, wherein a first end of the fourth resistor is connected to the input end of the voltage stabilizing component, and a second end of the fourth resistor is connected to the cathode of the Schottky diode;

[0023] A fifth resistor, wherein a first end of the fifth resistor is connected to the input of the voltage stabilizing component, and a second end of the fifth resistor is grounded.

[0024] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the voltage stabilizing component includes:

[0025] An error amplifier, wherein a positive phase input terminal of the error amplifier is connected to the second resistor, and a negative phase input terminal of the error amplifier is used as a connection terminal for a reference voltage;

[0026] a first controller, wherein an input terminal of the first controller is connected to an output terminal of the error amplifier;

[0027] A first field effect transistor, wherein a gate of the first field effect transistor is connected to an output end of the first controller, a source of the first field effect transistor is grounded, and a drain of the first field effect transistor is connected to an anode of the Schottky diode.

[0028] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the signal conditioning circuit based on active balun further includes:

[0029] A power-on timing control unit, wherein the power-on timing control unit is connected to the power supply end of the active balun unit, and the power-on timing control unit is used to control the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

[0030] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the power-on timing control unit includes:

[0031] A second field effect transistor, wherein a source of the second field effect transistor is connected to a positive terminal of an external power supply, and a drain of the second field effect transistor is connected to a positive power supply terminal of the active balun unit;

[0032] A second capacitor, wherein a first end of the second capacitor is connected to the source of the second field effect transistor, and a second end of the second capacitor is grounded;

[0033] a sixth resistor, wherein a first end of the sixth resistor is connected to the source of the second field effect transistor, and a second end of the sixth resistor is connected to the gate of the second field effect transistor;

[0034] A first triode, wherein the collector of the first triode is connected to the collector of the second field effect transistor;

[0035] a seventh resistor, wherein a first end of the seventh resistor is connected to the base of the first transistor, and a second end of the seventh resistor is grounded;

[0036] an eighth resistor, wherein a first end of the eighth resistor is connected to the emitter of the first transistor, and a second end of the eighth resistor is grounded;

[0037] A ninth resistor, wherein a first end of the ninth resistor is connected to the emitter of the first transistor, and a second end of the ninth resistor is connected to the negative power supply end of the active balun unit and the negative end of the external power supply;

[0038] a third capacitor, wherein a first end of the third capacitor is connected to a first end of the ninth resistor, and a second end of the third capacitor is connected to a second end of the ninth resistor;

[0039] Among them, after the positive and negative ends of the external power supply are powered respectively, the negative power supply end of the active balun unit is powered on through the negative end of the external power supply, and the first transistor is turned on based on the power supply of the negative end of the external power supply, so that the gate of the second field effect transistor is the negative voltage provided by the negative end of the external power supply, so that after the positive voltage provided by the positive end of the external power supply is applied to the source of the second field effect transistor, the second field effect transistor is turned on, so that the positive voltage provided by the positive end of the external power supply is applied to the positive power supply end of the active balun unit, thereby controlling the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

[0040] In a preferred embodiment of the present application, in the above-mentioned signal conditioning circuit based on active balun, the voltage acquisition unit includes:

[0041] An operational amplifier, wherein a positive phase input terminal of the operational amplifier is connected to an output terminal of the coupling conversion unit through a tenth resistor to obtain a voltage of a DC signal in the DC component adjustment analog signal, and a negative phase input terminal of the operational amplifier is grounded through an eleventh resistor and connected to an output terminal of the operational amplifier through a twelfth resistor to form a feedback loop;

[0042] a thirteenth resistor, wherein a first end of the thirteenth resistor is connected to the output end of the operational amplifier, and a second end of the thirteenth resistor serves as the output end of the voltage acquisition unit, so that a DC signal acquisition voltage formed by the operational amplifier amplifying the DC signal of the DC component adjustment analog signal is output through the output end;

[0043] 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 operational amplifier, and a second end of the third magnetic bead serves as a positive terminal connected to the power supply voltage;

[0044] A fourth magnetic bead, wherein a first end of the fourth magnetic bead is connected to the negative power supply terminal of the operational amplifier, and a second end of the fourth magnetic bead is used as a negative terminal connected to the power supply voltage.

[0045] On the basis of the above, the present application also provides a signal conditioning method based on an active balun, which is applied to the above-mentioned signal conditioning circuit based on an active balun. The signal conditioning method based on an active balun includes:

[0046] Receiving the analog signal to be processed through the coupling transformation unit, and performing a DC component adjustment process on the analog signal to be processed to form a DC component adjusted analog signal;

[0047] The DC component adjustment analog signal is obtained through the active balun unit, and the DC component adjustment analog signal is converted from a single-ended to a differential to form a differential analog signal;

[0048] Acquiring the differential analog signal through the operational amplifier unit, and performing signal amplification processing on the differential analog signal to form a target analog signal;

[0049] The voltage acquisition unit acquires the voltage of the DC signal in the DC component adjustment analog signal, and outputs a corresponding DC signal acquisition voltage;

[0050] The DC signal acquisition voltage is acquired through the differential conversion control unit, and a corresponding differential conversion control voltage is output based on the DC signal acquisition voltage;

[0051] The differential conversion control voltage is obtained through the voltage feedback unit, and a differential conversion bias voltage is provided to the active balun unit based on the differential conversion control voltage, wherein the differential conversion bias voltage serves as a basis for the active balun unit to perform single-ended to differential processing.

[0052] In a preferred embodiment of the present application, in the above-mentioned signal conditioning method based on active balun, the signal conditioning circuit based on active balun further includes a power-on timing control unit, and the signal conditioning method based on active balun further includes:

[0053] The power-on timing control unit controls the power-on timing of the positive power supply terminal of the active balun unit to be later than the power-on timing of the negative power supply terminal of the active balun unit.

[0054] On the basis of the above, the present application also provides a signal processing device, including:

[0055] The above-mentioned active balun-based signal conditioning circuit;

[0056] 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 the active balun, and the analog-to-digital conversion circuit is used to perform analog-to-digital conversion processing on the target analog signal output by the signal conditioning circuit based on the active balun to form a target digital signal.

[0057] The signal conditioning circuit, method and signal processing device based on active balun provided in the present application perform DC component adjustment processing on the analog signal to be processed to form a DC component adjustment analog signal; perform single-ended to differential conversion processing on the DC component adjustment analog signal to form a differential analog signal; perform signal amplification processing on the differential analog signal to form a target analog signal; collect the voltage of the DC signal in the DC component adjustment analog signal, and output the corresponding DC signal collection voltage; output the corresponding differential conversion control voltage based on the DC signal collection voltage; provide a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage. Based on the above content, since the differential conversion bias voltage will be used as the basis for single-ended to differential processing, the reliability of single-ended to differential processing is higher, thereby ensuring the reliability of the output differential analog signal, so as to achieve reliable conditioning of the analog signal, thereby improving the problem of difficulty in reliably processing analog signals in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] 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.

[0059] Figure 1 A schematic diagram of a signal processing device provided in an embodiment of the present application.

[0060] Figure 2 A schematic diagram of a signal conditioning circuit based on an active balun provided in an embodiment of the present application.

[0061] Figure 3 This is a schematic diagram of an application of a voltage feedback unit provided in an embodiment of the present application.

[0062] Figure 4 This is a schematic diagram of the application of the linear controllable power supply provided in an embodiment of the present application.

[0063] Figure 5 A circuit diagram of a power-on timing control unit provided in an embodiment of the present application.

[0064] Figure 6 This is a schematic diagram of the application of the voltage acquisition unit provided in an embodiment of the present application.

[0065] Figure 7 This is a schematic diagram of the application of the differential conversion control unit provided in an embodiment of the present application.

[0066] Figure 8 A circuit diagram of a coupling transformation unit provided in an embodiment of the present application.

[0067] Fig. 9 A circuit diagram of an active balun unit provided in an embodiment of the present application.

[0068] Fig.10 A schematic diagram of the frequency response characteristic curve of the active balun unit provided in an embodiment of the present application.

[0069] Fig.11 A circuit diagram of an operational amplifier unit provided in an embodiment of the present application.

[0070] Fig.12 A schematic diagram of the steps included in the signal conditioning method based on active balun provided in an embodiment of the present application.

[0071] Icons: D-Schottky diode, C1-first capacitor, R1-first resistor, second resistor R2, R3-third resistor, L1-first magnetic bead, L2-second magnetic bead, R4-fourth resistor, R5-fifth resistor, Q1-first field effect transistor, L5-inductor, Q2-second field effect transistor, C2-second capacitor, C3-third capacitor, R6-sixth resistor, R7-seventh resistor, R8-eighth resistor, R9-ninth resistor, K-first transistor, U1-operational amplifier, R10-tenth resistor, R11-eleventh resistor, R12-twelfth resistor, R13-thirteenth resistor, L3-third magnetic bead, L4-fourth magnetic bead. DETAILED DESCRIPTION

[0072] 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.

[0073] 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.

[0074] 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 and an analog-to-digital conversion circuit based on an active balun.

[0075] In detail, the signal conditioning circuit based on the active balun can be used to perform corresponding conditioning (such as amplification and other processing) on ​​the received analog signal to be processed, thereby outputting a target 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 the active balun, and the analog-to-digital conversion circuit is used to perform analog-to-digital conversion processing on the target analog signal output by the signal conditioning circuit based on the active balun to form a target digital signal.

[0076] Combination Figure 2 As shown, the embodiment of the present application also provides a signal conditioning circuit based on an active balun, and the signal conditioning circuit based on the active balun can be applied to the above-mentioned signal processing device. Among them, the signal conditioning circuit based on the active balun may include a coupling transformation unit, an active balun unit, an operational amplifier unit, a voltage acquisition unit, a differential conversion control unit and a voltage feedback unit.

[0077] In detail, the coupling transformation unit is used to receive the analog signal to be processed through the input end, and perform DC component adjustment processing on the analog signal to be processed to form a DC component adjustment analog signal, and output the DC component adjustment analog signal through the output end. The input end of the active balun unit is connected to the output end of the coupling transformation unit, and the active balun unit is used to obtain the DC component adjustment analog signal, and perform single-ended to differential conversion processing on the DC component adjustment analog signal to form a differential analog signal, and output the differential analog signal through the output end. The input end of the operational amplifier unit is connected to the output end of the active balun unit, and the operational amplifier unit is used to obtain the differential analog signal, and perform signal amplification processing on the differential analog signal to form a target analog signal. The input end of the voltage acquisition unit is connected to the output end of the coupling transformation unit, and the voltage acquisition unit is used to acquire the voltage of the DC signal in the DC component adjustment analog signal, and output the corresponding DC signal acquisition voltage through the output end. The input end of the differential conversion control unit is connected to the output end of the voltage acquisition unit, and the differential conversion control unit is used to obtain the DC signal acquisition voltage, and output a corresponding differential conversion control voltage based on the DC signal acquisition voltage. The input end of the voltage feedback unit is connected to the output end of the differential conversion control unit, and the voltage feedback unit is used to obtain the differential conversion control voltage, and provide a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage, and the differential conversion bias voltage serves as the basis for the active balun unit to perform single-ended to differential processing.

[0078] Based on the above content, since the differential conversion bias voltage will be used as the basis for single-ended to differential processing, the reliability of single-ended to differential processing is higher, thereby ensuring the reliability of the output differential analog signal to achieve reliable conditioning of the analog signal, thereby improving the problem of difficulty in reliably processing analog signals in the prior art.

[0079] It should be noted that the specific structure of the voltage feedback unit is not limited and can be selected according to actual needs.

[0080] For example, in an alternative embodiment, in combination Figure 3 The voltage feedback unit may include a driving amplifier, a linear controllable power supply, a Schottky diode D, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a first magnetic bead L1 and a second magnetic bead L2.

[0081] In detail, the non-inverting input terminal of the driving amplifier is connected to the output terminal of the differential conversion control unit through the first resistor R1, and the driving amplifier is used to amplify the differential conversion control voltage output by the differential conversion control unit and output it to the linear controllable power supply. The input terminal of the linear controllable power supply is connected to the output terminal of the driving amplifier through the second resistor R2, and the linear controllable power supply is used to obtain the amplified differential conversion control voltage and stabilize the amplified differential conversion control voltage to form a differential conversion bias voltage. The anode of the Schottky diode D is connected to the output terminal 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 active balun unit to provide the differential conversion bias voltage. The first end of the first capacitor C1 is connected to the cathode of the Schottky diode D, and the second end of the first capacitor C1 is grounded. The first end of the third resistor R3 is connected to the non-inverting input terminal of the driving amplifier, and the second end of the third resistor R3 is connected to the output terminal of the driving amplifier. The first end of the first magnetic bead L1 is connected to the positive power terminal of the driving amplifier, and the second end of the first magnetic bead L1 is used as the positive end connected to the power supply voltage. The first end of the second magnetic bead L2 is connected to the negative power terminal of the driving amplifier, and the second end of the second magnetic bead L2 is used as the negative end connected to the power supply voltage.

[0082] It should be noted that the specific structure of the linear controllable power supply is not limited and can be selected according to actual needs.

[0083] For example, in an alternative embodiment, in combination Figure 4 , the linear controllable power supply may include a voltage stabilizing component, a fourth resistor R4 and a fifth resistor R5.

[0084] In detail, the input end of the voltage stabilizing component is connected to the second resistor R2, and the output end of the voltage stabilizing component is connected to the anode of the Schottky diode D. The first end of the fourth resistor R4 is connected to the input end of the voltage stabilizing component, and the second end of the fourth resistor R4 is connected to the cathode of the Schottky diode D. The first end of the fifth resistor R5 is connected to the input end of the voltage stabilizing component, and the second end of the fifth resistor R5 is grounded.

[0085] It should be noted that the specific structure of the voltage stabilizing component is not limited and can be selected according to actual needs.

[0086] For example, in an alternative implementation, the voltage stabilizing component may include an error amplifier, a first controller, and a first field effect transistor Q1.

[0087] In detail, the positive phase input terminal of the error amplifier is connected to the second resistor R2, and the negative phase input terminal of the error amplifier is used as a connection terminal for the reference voltage. The input terminal of the first controller is connected to the output terminal of the error amplifier. The gate of the first field effect transistor Q1 is connected to the output terminal of the first controller, the source of the first field effect transistor Q1 is grounded, and the drain of the first field effect transistor Q1 is connected to the anode of the Schottky diode D.

[0088] In an alternative implementation, the voltage stabilizing component may further include an inductor L5. The inductor L5 may also be a magnetic bead and may be connected to a power supply of the linear controllable power supply (eg, Figure 4 The VBATT in the circuit can be used to power various devices of the linear controllable power supply, such as powering the first controller, etc.) and the drain of the first field effect transistor Q1 to provide filtering.

[0089] On the basis of the above-mentioned embodiment, considering the power safety of the active balun unit, the signal conditioning circuit based on the active balun may further include a power-on timing control unit.

[0090] In detail, the power-on timing control unit is connected to the power supply end of the active balun unit, and the power-on timing control unit is used to control the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

[0091] It should be noted that the specific structure of the power-on timing control unit is not limited and can be selected according to actual needs.

[0092] For example, in an alternative embodiment, in combination Figure 5The power-on timing control unit may include a second field effect transistor Q2, a second capacitor C2, a third capacitor C3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a first transistor K.

[0093] In detail, the source of the second field effect transistor Q2 is connected to the positive end of the external power supply, and the drain of the second field effect transistor Q2 is connected to the positive power supply end of the active balun unit. The first end of the second capacitor C2 is connected to the source of the second field effect transistor Q2, and the second end of the second capacitor C2 is grounded. The first end of the sixth resistor R6 is connected to the source of the second field effect transistor Q2, and the second end of the sixth resistor R6 is connected to the collector of the second field effect transistor Q2. The first end of the seventh resistor R7 is connected to the base of the first transistor K, and the second end of the seventh resistor R7 is grounded. The first end of the eighth resistor R8 is connected to the emitter of the first transistor K, and the second end of the eighth resistor R8 is grounded. The first end of the ninth resistor R9 is connected to the emitter of the first transistor K, and the second end of the ninth resistor R9 is connected to the negative power supply end of the active balun unit and the negative end of the external power supply. A first end of the third capacitor C3 is connected to a first end of the ninth resistor R9 , and a second end of the third capacitor C3 is connected to a second end of the ninth resistor R9 .

[0094] Among them, after the positive and negative ends of the external power supply are powered respectively, the negative power supply end of the active balun unit is powered on through the negative end of the external power supply, and the first transistor K is turned on based on the power supply of the negative end of the external power supply, so that the gate of the second field effect transistor Q2 is the negative voltage provided by the negative end of the external power supply, so that after the positive voltage provided by the positive end of the external power supply is applied to the source of the second field effect transistor Q2, the second field effect transistor Q2 is turned on, so that the positive voltage provided by the positive end of the external power supply is applied to the positive power supply end of the active balun unit, thereby controlling the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

[0095] It should be noted that the specific structure of the voltage acquisition unit is not limited and can be selected according to actual needs.

[0096] For example, in an alternative embodiment, in combination Figure 6 The voltage acquisition unit may include an operational amplifier U1, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a third magnetic bead L3 and a fourth magnetic bead L4.

[0097] In detail, the positive phase input terminal of the operational amplifier U1 is connected to the output terminal of the coupling conversion unit through the tenth resistor R10 to obtain the voltage of the DC signal in the DC component adjustment analog signal, and the negative phase input terminal of the operational amplifier U1 is grounded through the eleventh resistor R11 and connected to the output terminal of the operational amplifier U1 through the eleventh resistor R11 to form a feedback loop. The first end of the thirteenth resistor R13 is connected to the output terminal of the operational amplifier U1, and the second end of the thirteenth resistor R13 serves as the output terminal of the voltage acquisition unit, so that the DC signal acquisition voltage formed by the operational amplifier U1 performing signal amplification processing on the DC signal of the DC component adjustment analog signal is output through the output terminal. The first end of the third magnetic bead L3 is connected to the positive power supply terminal of the operational amplifier U1, and the second end of the third magnetic bead L3 serves as the positive terminal 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 operational amplifier U1, and the second end of the fourth magnetic bead L4 serves as the negative terminal connected to the power supply voltage.

[0098] It should be noted that the specific structure of the differential conversion control unit is not limited and can be selected according to actual needs.

[0099] For example, in an alternative embodiment, in combination Figure 7 The differential conversion control unit includes an analog-to-digital converter, a second controller and a digital-to-analog converter.

[0100] In detail, the input end of the analog-to-digital converter is connected to the output end of the voltage acquisition unit, 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 second controller is connected to the output end of the analog-to-digital converter, and the second 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 second controller, and the output end of the digital-to-analog converter is connected to the input end of the voltage feedback unit, and the digital-to-analog converter is used to obtain the feedback voltage digital signal, and output the corresponding differential conversion control voltage to the voltage feedback unit based on the feedback voltage digital signal.

[0101] It should be noted that the model of the driving amplifier can be AD8051, which is mainly used for controlling and transmitting 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. The model of the error amplifier can also be AD8051. In addition, the specific types of the first controller and the second controller are not limited, for example, they can include, but are not limited to, various microcontrollers, DSP chips, FPGA chips, SOC chips, CPU chips, etc.

[0102] It should be noted that the specific types of the coupling conversion unit, the active balun unit and the operational amplifier unit are not limited. For example, the coupling conversion unit can be used to shield the DC signal and pass the AC signal. The specific structure is described below. The active balun unit 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, and can only reach the transmission of kilohertz-level frequency signals at the lowest). The specific structure is described below. The operational amplifier unit 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 active balun unit and the operational amplifier unit.

[0103] In detail, combined Figure 8 In a specific application example, the coupling transformation unit 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 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 8Q12 in the figure) is connected from the positive power supply port through a resistor (such as Figure 8 R15 in the figure) provides positive power, the negative power port provides negative power, 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 coupling conversion unit is the output signal of the coupling conversion unit. 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 R17 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 R16 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.

[0104] In detail, combined Fig. 9 In a specific application example, the active balun unit 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 active balun unit 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. 9R27 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. 9 R26 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.

[0105] In the circuit of the active balun unit, 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 Q21 in the circuit) is divided by the ground voltage. Therefore, when the external power supply supplies power to the negative power port, its power loop is output in reverse, not output after input through the ground, so that the above-mentioned adaptive linear adjustable LCD output voltage circuit is required to power it (exemplarily, the negative power port can refer to the above-mentioned DC bias voltage feedback control pin, that is, the output end of the above-mentioned adaptive linear adjustable LCD output voltage circuit can be connected to the negative power port. In this way, due to the different sizes of the input signals, the requirements for its amplification factor are also different. Therefore, it is necessary to dynamically adjust the power supply of the negative power port, that is, the above-mentioned adaptive linear adjustable LCD output voltage circuit can be dynamically adjusted according to the collected DC signal collection voltage, that is, the above-mentioned differential conversion bias voltage is provided to the active balun unit, and the differential conversion bias voltage is used as the basis for the active balun unit to perform single-ended to differential processing). 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. 9The 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 tubes work well in the linear region, and the DC bias of their input signals needs to be close to 0V. Based on the above-mentioned active balun unit structure, its frequency response characteristic curve has a good flatness, such as Fig.10 .

[0106] In detail, combined Fig.11 In a specific application example, the operational amplifier unit may include a differential input port (such as Fig.11 VINP in), a differential input port (such as Fig.11 VINN in), a differential output port (such as Fig.11 VOUTP in), a differential output port (such as Fig.11 VOUTN in), two programmable impedance arrays and an amplifier (such as Fig.11 Q31 in ). Wherein, the differential analog signal (such as the aforementioned differential analog signal) is transmitted through the differential input port (such as Fig.11 VINP and VINN in the input operation amplifier unit), 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 accurate 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.11 Amplifier (such as Q31 in Fig.11 Q31 in) through the positive power supply port (such as Fig.11 VS+) and negative power supply port (such as Fig.11 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.11 C33 and C34 in the filter are used to filter it. Fig.11 The differential signal of Q31 in the circuit is fed through the RC feedback network (such as Fig.11 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.11 The VOUTP and VOUTN in the output differential signal (such as the target analog signal mentioned above).

[0107] Combination Fig.12The embodiment of the present application further provides a signal conditioning method based on an active balun, which can be applied to the above-mentioned signal conditioning circuit based on an active balun, wherein the signal conditioning method based on an active balun can include the following steps:

[0108] Step S110, receiving the analog signal to be processed through the coupling transformation unit, and performing a DC component adjustment process on the analog signal to be processed to form a DC component adjusted analog signal;

[0109] Step S120, obtaining the DC component adjustment analog signal through the active balun unit, and performing single-ended conversion on the DC component adjustment analog signal to form a differential analog signal;

[0110] Step S130, acquiring the differential analog signal through the operational amplifier unit, and performing signal amplification processing on the differential analog signal to form a target analog signal;

[0111] Step S140, collecting the voltage of the DC signal in the DC component adjustment analog signal through the voltage collection unit, and outputting the corresponding DC signal collection voltage;

[0112] Step S150, acquiring the DC signal acquisition voltage through the differential conversion control unit, and outputting a corresponding differential conversion control voltage based on the DC signal acquisition voltage;

[0113] Step S160: acquiring the differential conversion control voltage through the voltage feedback unit, and providing a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage.

[0114] The differential conversion bias voltage is used as a basis for the active balun unit to perform single-ended to differential processing. The specific implementation process of each of the above steps can refer to the relevant description above.

[0115] It is understandable that, in an alternative implementation, in order to ensure the safety of power supply, the signal conditioning circuit based on the active balun further includes a power-on timing control unit, and the signal conditioning method based on the active balun may further include the following steps:

[0116] The power-on timing control unit controls the power-on timing of the positive power supply terminal of the active balun unit to be later than the power-on timing of the negative power supply terminal of the active balun unit.

[0117] In summary, the signal conditioning circuit, method and signal processing device based on active balun provided in the present application perform DC component adjustment processing on the analog signal to be processed to form a DC component adjustment analog signal; perform single-ended to differential conversion processing on the DC component adjustment analog signal to form a differential analog signal; perform signal amplification processing on the differential analog signal to form a target analog signal; collect the voltage of the DC signal in the DC component adjustment analog signal, and output the corresponding DC signal collection voltage; output the corresponding differential conversion control voltage based on the DC signal collection voltage; provide a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage. Based on the above content, since the differential conversion bias voltage will be used as the basis for single-ended to differential processing, the reliability of single-ended to differential processing is higher, thereby ensuring the reliability of the output differential analog signal, so as to achieve reliable conditioning of the analog signal, thereby improving the problem of difficulty in reliably processing analog signals in the prior art.

[0118] 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 an active balun, characterized in that: include: A coupling transformation unit, wherein the coupling transformation unit is used to receive an analog signal to be processed through an input terminal, perform a DC component adjustment process on the analog signal to be processed to form a DC component adjusted analog signal, and output the DC component adjusted analog signal through an output terminal; An active balun unit, wherein the input end of the active balun unit is connected to the output end of the coupling transformation unit, and the active balun unit is used to obtain the DC component adjustment analog signal, and perform single-ended conversion processing on the DC component adjustment analog signal to form a differential analog signal, and output the differential analog signal through the output end; An operational amplifier unit, wherein an input end of the operational amplifier unit is connected to an output end of the active balun unit, and the operational amplifier unit is used to obtain the differential analog signal and perform signal amplification processing on the differential analog signal to form a target analog signal; A voltage acquisition unit, wherein the input end of the voltage acquisition unit is connected to the output end of the coupling transformation unit, and the voltage acquisition unit is used to acquire the voltage of the DC signal in the DC component adjustment analog signal, and output the corresponding DC signal acquisition voltage through the output end; A differential conversion control unit, wherein an input end of the differential conversion control unit is connected to an output end of the voltage acquisition unit, and the differential conversion control unit is used to obtain the DC signal acquisition voltage and output a corresponding differential conversion control voltage based on the DC signal acquisition voltage; A voltage feedback unit, wherein the input end of the voltage feedback unit is connected to the output end of the differential conversion control unit, the voltage feedback unit is used to obtain the differential conversion control voltage, and provide a differential conversion bias voltage to the active balun unit based on the differential conversion control voltage, and the differential conversion bias voltage serves as a basis for the active balun unit to perform single-ended to differential processing.

2. The signal conditioning circuit based on active balun according to claim 1, characterized in that: The voltage feedback unit comprises: A driving amplifier, wherein a non-phase input terminal of the driving amplifier is connected to an output terminal of the differential conversion control unit via a first resistor, and the driving amplifier is used to amplify the differential conversion control voltage output by the differential conversion control unit and output it to the linear controllable power supply; A linear controllable power supply, wherein the input end of the linear controllable power supply is connected to the output end of the driving amplifier through a second resistor, and the linear controllable power supply is used to obtain the amplified differential conversion control voltage and perform voltage stabilization on the amplified differential conversion control voltage to form a differential conversion bias voltage; A Schottky diode, wherein an anode of the Schottky diode is connected to the output end of the linear controllable power supply, and a cathode of the Schottky diode is connected to a DC bias voltage feedback control pin of the active balun unit to provide the differential conversion bias 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; A third resistor, wherein a first end of the third resistor is connected to the non-inverting input end of the driving amplifier, and a second end of the third resistor is connected to the output end of the driving amplifier; A first magnetic bead, wherein a first end of the first magnetic bead is connected to a positive terminal of a power supply of the driving 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 end of the power supply of the driving amplifier, and a second end of the second magnetic bead is used as a negative end connected to the power supply voltage.

3. The signal conditioning circuit based on active balun according to claim 2, characterized in that: The linear controllable power supply comprises: A voltage stabilizing component, wherein an input end of the voltage stabilizing component is connected to the second resistor, and an output end of the voltage stabilizing component is connected to the anode of the Schottky diode; A fourth resistor, wherein a first end of the fourth resistor is connected to the input end of the voltage stabilizing component, and a second end of the fourth resistor is connected to the cathode of the Schottky diode; A fifth resistor, wherein a first end of the fifth resistor is connected to the input of the voltage stabilizing component, and a second end of the fifth resistor is grounded.

4. The signal conditioning circuit based on active balun according to claim 3, characterized in that: The voltage stabilizing component comprises: An error amplifier, wherein a positive phase input terminal of the error amplifier is connected to the second resistor, and a negative phase input terminal of the error amplifier is used as a connection terminal for a reference voltage; a first controller, wherein an input terminal of the first controller is connected to an output terminal of the error amplifier; A first field effect transistor, wherein a gate of the first field effect transistor is connected to an output end of the first controller, a source of the first field effect transistor is grounded, and a drain of the first field effect transistor is connected to an anode of the Schottky diode.

5. The signal conditioning circuit based on active balun according to claim 1, characterized in that: The active balun-based signal conditioning circuit further includes: A power-on timing control unit, wherein the power-on timing control unit is connected to the power supply end of the active balun unit, and the power-on timing control unit is used to control the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

6. The signal conditioning circuit based on active balun according to claim 5, characterized in that: The power-on timing control unit comprises: A second field effect transistor, wherein a source of the second field effect transistor is connected to a positive terminal of an external power supply, and a drain of the second field effect transistor is connected to a positive power supply terminal of the active balun unit; A second capacitor, wherein a first end of the second capacitor is connected to the source of the second field effect transistor, and a second end of the second capacitor is grounded; a sixth resistor, wherein a first end of the sixth resistor is connected to the source of the second field effect transistor, and a second end of the sixth resistor is connected to the gate of the second field effect transistor; A first triode, wherein the collector of the first triode is connected to the collector of the second field effect transistor; a seventh resistor, wherein a first end of the seventh resistor is connected to the base of the first transistor, and a second end of the seventh resistor is grounded; an eighth resistor, wherein a first end of the eighth resistor is connected to the emitter of the first transistor, and a second end of the eighth resistor is grounded; A ninth resistor, wherein a first end of the ninth resistor is connected to the emitter of the first transistor, and a second end of the ninth resistor is connected to the negative power supply end of the active balun unit and the negative end of the external power supply; a third capacitor, wherein a first end of the third capacitor is connected to a first end of the ninth resistor, and a second end of the third capacitor is connected to a second end of the ninth resistor; Among them, after the positive and negative ends of the external power supply are powered respectively, the negative power supply end of the active balun unit is powered on through the negative end of the external power supply, and the first transistor is turned on based on the power supply of the negative end of the external power supply, so that the gate of the second field effect transistor is the negative voltage provided by the negative end of the external power supply, so that after the positive voltage provided by the positive end of the external power supply is applied to the source of the second field effect transistor, the second field effect transistor is turned on, so that the positive voltage provided by the positive end of the external power supply is applied to the positive power supply end of the active balun unit, thereby controlling the power-on timing of the positive power supply end of the active balun unit to be later than the power-on timing of the negative power supply end of the active balun unit.

7. The signal conditioning circuit based on active balun according to claim 1, characterized in that: The voltage acquisition unit comprises: An operational amplifier, wherein a positive phase input terminal of the operational amplifier is connected to an output terminal of the coupling conversion unit through a tenth resistor to obtain a voltage of a DC signal in the DC component adjustment analog signal, and a negative phase input terminal of the operational amplifier is grounded through an eleventh resistor and connected to an output terminal of the operational amplifier through a twelfth resistor to form a feedback loop; a thirteenth resistor, wherein a first end of the thirteenth resistor is connected to the output end of the operational amplifier, and a second end of the thirteenth resistor serves as the output end of the voltage acquisition unit, so that a DC signal acquisition voltage formed by the operational amplifier amplifying the DC signal of the DC component adjustment analog signal is output through the output end; A third magnetic bead, wherein a first end of the third magnetic bead is connected to the positive power supply terminal of the operational amplifier, and a second end of the third magnetic bead serves 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 supply terminal of the operational amplifier, and a second end of the fourth magnetic bead is used as a negative terminal connected to the power supply voltage.

8. A signal conditioning method based on active balun, characterized in that: The signal conditioning circuit based on active balun as described in any one of claims 1 to 7, wherein the signal conditioning method based on active balun comprises: Receiving the analog signal to be processed through the coupling transformation unit, and performing a DC component adjustment process on the analog signal to be processed to form a DC component adjusted analog signal; The DC component adjustment analog signal is obtained through the active balun unit, and the DC component adjustment analog signal is converted from a single-ended to a differential to form a differential analog signal; Acquiring the differential analog signal through the operational amplifier unit, and performing signal amplification processing on the differential analog signal to form a target analog signal; The voltage acquisition unit acquires the voltage of the DC signal in the DC component adjustment analog signal, and outputs a corresponding DC signal acquisition voltage; The DC signal acquisition voltage is acquired by the differential conversion control unit, and a corresponding differential conversion control voltage is output based on the DC signal acquisition voltage; The differential conversion control voltage is obtained through the voltage feedback unit, and a differential conversion bias voltage is provided to the active balun unit based on the differential conversion control voltage, wherein the differential conversion bias voltage serves as a basis for the active balun unit to perform single-ended to differential processing.

9. The signal conditioning method based on active balun according to claim 8, characterized in that: The active balun-based signal conditioning circuit further includes a power-on timing control unit, and the active balun-based signal conditioning method further includes: The power-on timing control unit controls the power-on timing of the positive power supply terminal of the active balun unit to be later than the power-on timing of the negative power supply terminal of the active balun unit.

10. A signal processing device, characterized in that: include: The signal conditioning circuit based on active balun according to any one of claims 1 to 7; 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 the active balun, and the analog-to-digital conversion circuit is used to perform analog-to-digital conversion processing on the target analog signal output by the signal conditioning circuit based on the active balun to form a target digital signal.

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