A signal processing device and a high-speed photoelectric detection system

Abstract

The application discloses a signal processing device and a high-speed photoelectric detection system, and relates to the technical field of signal processing. In view of the problem that current signal amplification schemes are not applicable to long-code digital high-speed signals, the application provides a signal processing device, which comprises a separation circuit and an amplification circuit. The input end of the separation circuit is connected with a long-code digital high-speed signal, and the separation circuit is used for separating high-frequency components in the long-code digital high-speed signal into one independent intermediate signal and separating low-frequency components and direct-current components into at least one independent intermediate signal. The input end of the amplification circuit is connected with the output end of the separation circuit, and the amplification circuit is used for respectively performing amplification processing on the intermediate signals and then outputting the intermediate signals. The device expands the application range of high-speed signal amplification processing, and can realize the amplification processing of the long-code digital high-speed signal containing high-frequency components, low-frequency components and direct-current components under the premise of ensuring information integrity.

Description

Technical Field

[0001] This application relates to the field of signal processing, and in particular to a signal processing device and a high-speed photoelectric detection system. Background Technology

[0002] In signal processing, a common process is signal amplification. However, for special signals like long-code high-speed digital signals, information is carried in high-frequency, low-frequency, and direct current (DC) components. Traditional signal amplifiers, when amplifying high-speed signals carrying DC components, experience a change in the quiescent operating point due to the presence of DC, causing the amplifier to malfunction. Furthermore, using AC coupling results in the loss of DC and low-frequency information. Therefore, neither of these methods is suitable for amplifying long-code high-speed digital signals. In other words, there is currently a technological gap in the amplification of such special signals. Utility Model Content

[0003] This application discloses a signal processing device and a high-speed photoelectric detection system for solving the problem of amplification and processing of special signals such as long-code digital high-speed signals, which carry information in high-frequency, low-frequency and DC components.

[0004] In a first aspect, this application provides a signal processing apparatus, comprising: a separation circuit and an amplification circuit; the input terminal of the separation circuit is connected to a long-code digital high-speed signal, and the separation circuit is used to: separate the high-frequency component, low-frequency component and DC component in the long-code digital high-speed signal into at least two independent intermediate signal outputs; the input terminal of the amplification circuit is connected to the output terminal of the separation circuit, and the amplification circuit is used to: amplify each intermediate signal separately and then output it.

[0005] In this device, the separation circuit can separately separate the high-frequency component, low-frequency component, and DC component of a long-code digital high-speed signal into one intermediate signal output, and separate the low-frequency component and DC component into at least one intermediate signal output. This signal separation process can effectively reduce the types of frequency information carried in the signal, processing the original long-code digital high-speed signal carrying three types of frequency information into an intermediate signal carrying one or two types of frequency information, and separating the high-frequency component from the low-frequency component and DC component. Therefore, the subsequent amplification circuit can use the corresponding amplification scheme when amplifying different intermediate signals. Based on this, this device can amplify each intermediate signal, that is, it can achieve amplification processing for special signals such as long-code digital high-speed signals that carry information in high-frequency, low-frequency, and DC components. This device expands the application range of high-speed signal amplification processing, enabling signal amplification processing even for long-code digital high-speed signals containing high-frequency, low-frequency, and DC components, while ensuring the integrity of the information.

[0006] In one possible implementation, the system further includes a merging circuit; the input of the merging circuit is connected to the output of each amplifier circuit, and the merging circuit is used to merge all the signals output by each amplifier circuit into a single signal output. In this implementation, the merging circuit reassembles the multiple signals split and amplified by the separation circuit and amplifier circuit into a single signal, so that subsequent circuits or systems can use it directly, thereby improving signal integrity and the versatility of the device.

[0007] In one possible implementation, the separation circuit includes: a first output terminal and a second output terminal; the separation circuit is used to: separate the low-frequency component and DC component of the long-code digital high-speed signal and output them as a first intermediate signal through the first output terminal; separate the high-frequency component of the long-code digital high-speed signal and output them as a second intermediate signal through the second output terminal; multiple amplification circuits include: a low-frequency amplification circuit and a high-frequency amplification circuit; the input terminal of the low-frequency amplification circuit is connected to the first output terminal of the separation circuit and is used to amplify the first intermediate signal; the input terminal of the high-frequency amplification circuit is connected to the second output terminal of the separation circuit and is used to amplify the second intermediate signal; the merging circuit includes: a first input terminal and a second input terminal; the first input terminal of the merging circuit is connected to the output terminal of the low-frequency amplification circuit, and the second input terminal of the merging circuit is connected to the output terminal of the high-frequency amplification circuit; the merging circuit is used to merge the amplified first intermediate signal and the second intermediate signal into a single signal output.

[0008] In this embodiment, the separation circuit is specifically configured as two separate paths: one outputs a low-frequency component and a DC component, i.e., the first intermediate signal; the other outputs a high-frequency component, i.e., the second intermediate signal. Correspondingly, low-frequency and high-frequency amplification circuits are provided, achieving optimal signal splitting. This splitting architecture utilizes the characteristic that the DC component and the low-frequency component can share the same amplification circuit, allowing the DC / low-frequency component and the high-frequency component to each employ the most suitable amplification strategy. It also reduces the complexity and difficulty in implementation caused by introducing too many amplification circuits, further improving the feasibility of this circuit in practical engineering applications.

[0009] In one possible implementation, the low-frequency amplifier circuit includes an operational amplifier and a variable gain amplifier. The input terminal of the operational amplifier is connected to the first output terminal of the discrete circuit, the output terminal of the operational amplifier is connected to the input terminal of the variable gain amplifier, and the output terminal of the variable gain amplifier is connected to the first input terminal of the merging circuit. In this implementation, the operational amplifier can provide stable input impedance and precise gain, while the variable gain amplifier allows for dynamic adjustment of the amplification factor according to signal characteristics or system requirements. The combination of the two enables high precision and high flexibility in the amplification of the low-frequency and DC component portions, adapting to input signals of varying strengths.

[0010] In one possible implementation, the system further includes: an analog-to-digital converter (ADC) circuit and a processing circuit; the input terminal of the ADC is connected to the first output terminal of the separation circuit, and the ADC circuit is used to detect the low-frequency gain of the first intermediate signal; the first input terminal of the processing circuit is connected to the output terminal of the ADC circuit, the second input terminal of the processing circuit is used to obtain the high-frequency gain, and the output terminal of the processing circuit is connected to the gain control terminal of the variable gain amplifier. In this implementation, by adding the ADC circuit and the processing circuit, a closed-loop automatic gain control loop is formed. The ADC circuit detects the actual gain of the first intermediate signal (low-frequency and DC components) in real time, while the processing circuit dynamically adjusts the amplification factor of the variable gain amplifier based on an external or preset high-frequency gain reference value. This ensures amplitude matching between the low-frequency and high-frequency signals during merging, effectively improving the quality and stability of the output signal.

[0011] In one possible implementation, the system further includes a conditioning circuit. This conditioning circuit is positioned between the first output of the splitting circuit and the first input of the merging circuit, and is used to condition the first intermediate signal to suppress fluctuations at the junction of the first and second intermediate signals. In this implementation, by placing a conditioning circuit between the first output of the splitting circuit and the first input of the merging circuit, the low-frequency + DC component can be conditioned before the low-frequency + DC component and the high-frequency component are merged. This effectively suppresses amplitude or phase fluctuations at the frequency domain junction of the first intermediate signal (low frequency and DC) and the second intermediate signal (high frequency). Since the two signals are processed by different amplifiers before merging, discontinuities or distortions are easily generated near the junction. The conditioning circuit can pre-compensate or post-correct these distortions, significantly improving the overall fidelity of the merged signal.

[0012] In one possible implementation, the conditioning circuit further includes: a first conditioning sub-circuit and a second conditioning sub-circuit; the input terminal of the first conditioning sub-circuit is connected to the first output terminal of the separation circuit, and the output terminal of the first conditioning sub-circuit is connected to the input terminal of the low-frequency amplifier circuit; the input terminal of the second conditioning sub-circuit is connected to the output terminal of the low-frequency amplifier circuit, and the output terminal of the second conditioning sub-circuit is connected to the first input terminal of the merging circuit. In this embodiment, the conditioning circuit is divided into a first conditioning sub-circuit (placed before the low-frequency amplifier circuit) and a second conditioning sub-circuit (placed after the low-frequency amplifier circuit). The first conditioning sub-circuit can optimize the signal quality entering the low-frequency amplifier circuit (such as impedance matching or filtering out out-of-band noise), while the second conditioning sub-circuit is used to correct the nonlinearity or residual fluctuations introduced by the low-frequency amplifier circuit itself. This two-stage conditioning structure has a stronger signal purification capability than single-stage conditioning, further improving the purity and stability of the low-frequency signal path. This better suppresses the amplitude or phase fluctuations of the first intermediate signal and the second intermediate signal at the frequency domain splicing point, further improving the overall fidelity of the merged signal.

[0013] In one possible implementation, both the first and second conditioning sub-circuits include one or more of the following: an RF phase shifter, an RF filter, and an RF isolator. In this implementation, the RF phase shifter is used to adjust the phase of the signal to optimize phase consistency when the two signals are combined. The RF filter is used to filter out unwanted frequency components and suppress spurious interference. The RF isolator prevents signal reflection and improves the stability of the low-frequency signal link used to transmit and amplify low-frequency + DC signals. These specific devices are all mature and reliable RF modules that can be flexibly selected or combined according to actual scenarios, making the conditioning sub-circuit in this circuit easier to implement in engineering.

[0014] In one possible implementation, the high-frequency amplifier circuit includes a low-noise amplifier or a transimpedance amplifier; the input terminal of the low-noise amplifier or transimpedance amplifier is connected to the second output terminal of the discrete circuit, and the output terminal of the low-noise amplifier or transimpedance amplifier is connected to the second input terminal of the merging circuit. In this implementation, the low-noise amplifier can amplify weak high-frequency signals while introducing extremely low additional noise, thus improving the signal-to-noise ratio. The transimpedance amplifier is suitable for converting current-type high-frequency input signals into voltage signals and amplifying them. Both can amplify the high-frequency signal components in common voltage and current signals, improving the integrity and purity of the high-frequency components during the amplification process.

[0015] In one possible implementation, the separation and merging circuits include any one of a bias circuit, a current source mirror circuit, and a resistor network. In this embodiment, the bias circuit used is a standard component in microwave circuits for separating / merging DC / low-frequency and high-frequency signals, offering excellent performance; the current source mirror circuit is suitable for current-mode signal processing and has low power consumption advantages; and the resistor network is simple in structure and inexpensive. These solutions provide diverse implementation options for different application scenarios, balancing performance, power consumption, and cost.

[0016] Secondly, this application provides a high-speed photoelectric detection system, including a signal processing device and a photoelectric conversion module as described in any of the embodiments of the first aspect above, with the input terminal of the signal processing device connected to the output terminal of the photoelectric conversion module. This system includes the signal processing device provided in the first aspect, and therefore can achieve the same technical effects as the signal processing device in the first aspect. Specifically, this system can amplify various intermediate signals, that is, it can achieve amplification processing for special signals such as long-code digital high-speed signals that carry information in high-frequency, low-frequency, and DC components. This system expands the application scope of high-speed signal amplification processing; even for long-code digital high-speed signals containing high-frequency, low-frequency, and DC components, signal amplification processing can be achieved while maintaining information integrity. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This application provides an application architecture diagram for signal amplification. Figure 2 This is a structural diagram of a signal processing device provided in an embodiment of this application; Figure 3 A structural diagram of a signal processing device for two intermediate signals provided in an embodiment of this application; Figure 4 A schematic diagram illustrating the arrangement of two conditioning sub-circuits provided in an embodiment of this application; Figure 5 This is a structural diagram of another signal processing device provided in an embodiment of this application; Figure 6 A circuit schematic diagram of a signal processing device provided in an embodiment of this application; Figure 7 A voltage waveform diagram at a splicing point provided in an embodiment of this application; Figure 8 This is a structural diagram of a high-speed photoelectric detection system provided in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 10 - Signal processing device; 11-Separation circuit; 12-Amplification circuit; 13-Combination circuit; 14-Analog-to-digital conversion circuit; 15-Processing circuit; 121 - Low-frequency amplifier circuit; 122 - High-frequency amplifier circuit; 161 - First conditioning circuit; 162 - Second conditioning circuit; 1211 - Operational amplifier; 1212 - Variable gain amplifier; 20 - Photoelectric conversion module. Detailed Implementation

[0020] In the field of signal processing, a common signal amplification process is signal amplification. Systems or devices involving signal acquisition, such as oscilloscopes, photoelectric conversion probes, and photodetectors, typically include corresponding amplification circuits. Ignoring other signal processing circuits, the pre-amplifier stage is generally a signal acquisition circuit, and the post-amplifier stage is typically a signal output terminal or other circuits that require this signal as input. The signal acquisition circuit refers to the circuit that converts other forms of signals into electrical signals, which are easier to process later. In the oscilloscope, photoelectric conversion probe, and photodetector systems mentioned above, the signal acquisition circuit mainly refers to the photoelectric conversion module (converting optical signals into electrical signals). In other scenarios, the signal acquisition circuit can also take the form of a microphone (converting sound signals into electrical signals) or a Hall sensor (converting magnetic signals into electrical signals). The amplification circuit amplifies the signal acquired by the signal acquisition circuit, and after obtaining the expected output result, it outputs it through the signal output terminal. This signal output terminal can be the output terminal of the system itself or a port output to other modules in the system. For example… Figure 1As shown, for systems like oscilloscopes that involve signal display, the signal output terminal can be connected to the oscilloscope's internal display to visually display the acquired signal after it has been amplified by the signal amplification circuit.

[0021] However, depending on the target signal requiring amplification and the different amplification requirements, appropriate amplification circuits are needed to achieve the signal amplification. For example, different amplification circuits are required for high-frequency signals, low-frequency signals, or DC signals.

[0022] Among various signals, there exists a special type: long-code high-speed digital signals, which carry information in their high-frequency, low-frequency, and DC components. However, traditional signal amplifiers malfunction when amplifying high-speed signals carrying DC components because the presence of the DC signal causes a change in the static operating point. Using AC coupling, on the other hand, results in the loss of DC and low-frequency information. Therefore, none of these solutions are suitable for amplifying long-code high-speed digital signals, which are unique signals carrying information in their high-frequency, low-frequency, and DC components. This indicates a current technological gap in the amplification of such special signals.

[0023] To address the aforementioned problems, this application provides a signal processing device and a high-speed photoelectric detection system.

[0024] The signal processing device 10 provided in this application, such as Figure 2 As shown, the system includes a separation circuit 11 and an amplifier circuit 12. The input of the separation circuit 11 is connected to a long-code digital high-speed signal. The separation circuit 11 is used to: separate the high-frequency component, low-frequency component, and DC component of the long-code digital high-speed signal into an independent intermediate signal, and to separate the low-frequency component and DC component into at least one independent intermediate signal. There are multiple amplifier circuits 12, each with its input connected to the output of the separation circuit 11. Each amplifier circuit 12 is used to: amplify its corresponding intermediate signal. In this text, "multiple" means at least two.

[0025] It should be noted that this embodiment does not limit the specific frequencies of the low-frequency and high-frequency components. However, it is readily understood that long-code digital high-speed signals contain two signal components with different frequencies. The higher-frequency signal component is the aforementioned high-frequency component (e.g., 40G~100G), and the lower-frequency signal component is the aforementioned low-frequency component (e.g., 10M and below). The DC component is the signal component whose signal form is a DC signal.

[0026] Furthermore, without separating any one of the high-frequency, low-frequency, and DC components into multiple outputs, the intermediate signals output by the separation circuit 11 can be 2 or 3 channels. When the intermediate signals are 2 channels, such as... Figure 2 As shown, one intermediate signal (i.e., the first intermediate signal) includes a low-frequency component and a DC component, and another intermediate signal (i.e., the second intermediate signal) includes a high-frequency component. When there are three intermediate signals, each of the three intermediate signals separately includes a low-frequency component, a DC component, and a high-frequency component. This embodiment does not impose any limitations on this, and the appropriate number of intermediate signal channels can be selected according to actual needs.

[0027] Furthermore, the specific implementation of the separation circuit 11 and the amplification circuit 12 needs to be adjusted according to the number of intermediate circuits. Specifically, when there are two intermediate signals, the separation circuit 11 only needs to separate the high-frequency component from the long-code digital high-speed signal (or separate the low-frequency component and DC component from the long-code digital high-speed signal). In this case, the separation circuit 11 can be selected with a circuit structure that can separate the high-frequency component (or the low-frequency component and DC component). When there are three intermediate signals, the separation circuit 11 needs to be selected with a circuit that can separate the low-frequency component, the high-frequency component, and the DC component separately, and at least two of them are required. Taking the separation of low-frequency component and high-frequency component as an example, the separation circuit 11 that can separate the high-frequency component is first used to separate one intermediate signal containing only the high-frequency component from the long-code digital high-speed signal; then, the separation circuit 11 that can separate the low-frequency component is used on the remaining signal containing the low-frequency component and the DC component to separate one intermediate signal containing only the low-frequency component; the remaining signal contains only the DC component, which is the third intermediate signal.

[0028] The specific implementation of amplifier circuit 12 is also adapted to the splitting of the intermediate signal. For example... Figure 2 As shown, when there are two intermediate signals, the amplifier circuit 12 should also have two channels: one for amplifying the first intermediate signal and the other for amplifying the second intermediate signal. The specific implementation of the two amplifier circuits 12 depends on the corresponding intermediate signals. For example... Figure 2 As shown, one amplifier circuit 12 is used to amplify the first intermediate signal containing low-frequency and DC components, so an amplifier circuit 12 structure for amplifying both low-frequency and DC components should be adopted. The other amplifier circuit 12 is used to amplify the second intermediate signal containing high-frequency components, so an amplifier circuit 12 structure for amplifying high-frequency components should be adopted. This embodiment does not limit the specific structure of the amplifier circuit 12; a suitable implementation scheme can be selected according to actual needs. The same principle applies to scenarios with three intermediate signals. In this case, the long-code digital high-speed signal is separated into three intermediate signals by the separation circuit 11, each containing a low-frequency component, a DC component, and a high-frequency component. Correspondingly, the amplifier circuit 12 should also have three channels, used to amplify the low-frequency component, the DC component, and the high-frequency component, respectively.

[0029] Subsequently, after being separated by the separation circuit 11 and amplified by the amplification circuit 12, the long-code high-speed digital signal can be output as multiple (2 or 3) amplified intermediate signals. To this end, this application also provides a further embodiment. Taking 2 intermediate signals as an example, ... Figure 3 As shown, the signal processing device 10 further includes a merging circuit 13. The input terminal of the merging circuit 13 is connected to the output terminal of each amplifier circuit 12, and the merging circuit 13 is used to merge all the signals output by each amplifier circuit 12 into one signal output.

[0030] The specific implementation of the merging circuit 13 should correspond to the number of separated and merged signals. Furthermore, the specific implementation of the merging circuit 13 can be considered the "inverse" circuit of the separation circuit 11. In this regard, this embodiment provides an optional embodiment where the separation circuit 11 and the merging circuit 13 include any one of the following: a bias tee, a current source mirror circuit, and a resistor network. All of the above structures can achieve signal separation (1 becomes N, N can be 2 or 3) or merging (N becomes 1). That is, the above structure has ports on both sides, one side having 1 port, corresponding to the output terminal during signal merging (outputting the merged amplified long-code digital high-speed signal) or the input terminal during signal separation (connecting the long-code digital high-speed signal to be amplified). The other side has the same number of ports as the number of intermediate signals, used as the input terminal during signal merging (connecting N intermediate signals) or as the output terminal during signal separation (outputting N intermediate signals). Therefore, based on the structures given in the above embodiments, by setting the input-output relationship of the two side ports, the separation circuit 11 and the merging circuit 13 of the above embodiments can be implemented. The circuit structure is simple, easy to implement, and highly reliable.

[0031] As described above, the signal processing apparatus 10 provided in this application separates the high-frequency component, low-frequency component, and DC component of a long-code digital high-speed signal into a single intermediate signal output through a separation circuit 11, and also separates the low-frequency component and DC component into at least one intermediate signal output. This signal separation process effectively reduces the types of frequency information carried in the signal, processing the original long-code digital high-speed signal carrying three types of frequency information into an intermediate signal carrying one or two types of frequency information, and separating the high-frequency component from the low-frequency component and DC component. Furthermore, the subsequent amplification circuit 12 can use the corresponding amplification scheme when amplifying different intermediate signals. Based on this, the apparatus can amplify each intermediate signal, that is, it can achieve amplification processing for special signals such as long-code digital high-speed signals that carry information in high-frequency, low-frequency, and DC components. This apparatus expands the application scope of high-speed signal amplification processing, enabling signal amplification processing even for long-code digital high-speed signals containing high-frequency, low-frequency, and DC components, while ensuring the integrity of the information.

[0032] On the other hand, the above embodiments have already illustrated that the circuit structures in this device need to be adaptively configured according to the number of intermediate signals. To better illustrate the signal processing device 10 provided in this application, this embodiment takes two intermediate signals as an example scenario and further explains the specific structure of each circuit in the signal processing device 10.

[0033] like Figure 3 As shown, in one optional embodiment, the separation circuit 11 includes a first output terminal and a second output terminal. The separation circuit 11 is used to: separate the low-frequency component and the DC component in the long-code digital high-speed signal and output them as a first intermediate signal through the first output terminal; and separate the high-frequency component in the long-code digital high-speed signal and output it as a second intermediate signal through the second output terminal.

[0034] The plurality of amplifier circuits 12 include a low-frequency amplifier circuit 121 and a high-frequency amplifier circuit 122. The input terminal of the low-frequency amplifier circuit 121 is connected to the first output terminal of the separation circuit 11, and is used to amplify the first intermediate signal. The input terminal of the high-frequency amplifier circuit 122 is connected to the second output terminal of the separation circuit 11, and is used to amplify the second intermediate signal.

[0035] The merging circuit 13 includes a first input terminal and a second input terminal. The first input terminal of the merging circuit 13 is connected to the output terminal of the low-frequency amplifier circuit 121, and the second input terminal of the merging circuit 13 is connected to the output terminal of the high-frequency amplifier circuit 122. The merging circuit 13 is used to combine the amplified first intermediate signal and the second intermediate signal into a single output signal.

[0036] In this embodiment, the separation circuit 11 specifically splits the long-code digital high-speed signal into a first intermediate signal containing a low-frequency + DC component and a second intermediate signal containing a high-frequency component. Then, two amplification circuits 12, namely a low-frequency amplification circuit 121 and a high-frequency amplification circuit 122, amplify the first and second intermediate signals respectively. Finally, the merging circuit 13 combines the amplified first and second intermediate signals into a single output signal, thus obtaining the amplified long-code digital high-speed signal.

[0037] For the above structure, one possible specific embodiment of the low-frequency amplifier circuit 121 is as follows: Figure 5 As shown, the low-frequency amplifier circuit 121 includes an operational amplifier 1211 (OPA) and a variable gain amplifier 1212 (VGA). The input terminal of the operational amplifier 1211 is connected to the first output terminal of the split circuit 11, the output terminal of the operational amplifier 1211 is connected to the input terminal of the variable gain amplifier 1212, and the output terminal of the variable gain amplifier 1212 is connected to the first input terminal of the merging circuit 13.

[0038] Further such as Figure 5 and Figure 6 As shown, operational amplifier 1211 may also have a second input terminal, which is connected to a DC bias voltage Voffset. This DC bias voltage Voffset is used to compensate for any DC component that may exist in the output signal of the splitter circuit 11, or to provide a suitable DC operating point for the subsequent variable gain amplifier 1212. Specifically, operational amplifier 1211 adopts a differential input structure, with its non-inverting input terminal connected to the first output terminal of the splitter circuit 11, and its inverting input terminal connected to the DC bias voltage Voffset; or vice versa, set according to the signal polarity requirements. By adjusting the magnitude of the DC bias voltage Voffset, the static voltage at the output terminal of operational amplifier 1211 can be kept at a preset potential, reducing distortion in the subsequent variable gain amplifier 1212 caused by the input signal deviating from its linear dynamic range.

[0039] Operational amplifier 1211 amplifies the first intermediate signal from separation circuit 11 and outputs it to variable gain amplifier 1212. Variable gain amplifier 1212 has a gain control terminal for receiving external gain control voltage or digital control signal to adjust its amplification factor in real time. This embodiment does not limit the source of the external gain control voltage or digital control signal; it can be input to variable gain amplifier 1212 by relevant personnel through a host computer or debugging device, i.e., the gain is manually adjusted; it can also be output by other processing devices with a preset gain adjustment program, or hardware circuits that can implement gain adjustment functions. Furthermore, the specific value of this amplification factor and the real-time adjustment scheme can be freely selected according to actual needs, and this embodiment does not impose any restrictions on this. The output terminal of variable gain amplifier 1212 is connected to the first input terminal of merging circuit 13 to output the amplified first intermediate signal to merging circuit 13.

[0040] In this embodiment, the operational amplifier 1211 provides stable input impedance and precise gain, while the variable gain amplifier 1212 allows for dynamic adjustment of the amplification factor according to signal characteristics or system requirements. The combination of these two features enables high precision and flexibility in the amplification of the low-frequency and DC components, adapting to input signals of varying strengths.

[0041] Furthermore, regarding how the VGA gain is adjusted in the above embodiments, this embodiment also provides an optional embodiment. For example... Figure 5 As shown, the device further includes an analog-to-digital converter circuit 14 and a processing circuit 15. The input terminal of the analog-to-digital converter circuit 14 is connected to the first output terminal of the separation circuit 11, and the analog-to-digital converter circuit 14 is used to detect the low-frequency gain of the first intermediate signal. The first input terminal of the processing circuit 15 is connected to the output terminal of the analog-to-digital converter circuit 14, the second input terminal of the processing circuit 15 is used to obtain the high-frequency gain, and the output terminal of the processing circuit 15 is connected to the gain control terminal of the variable gain amplifier 1212.

[0042] In this embodiment, the analog-to-digital conversion circuit 14 can be implemented using a device with analog-to-digital conversion capabilities, such as an analog-to-digital converter (ADC). As for the processing circuit 15, it can be implemented using a device with data processing capabilities, such as a central processing unit (CPU) or a microcontroller unit (MCU). For example... Figure 6 In one possible implementation shown, the analog-to-digital conversion circuit 14 is an ADC, and the processing circuit 15 is a CPU.

[0043] In this embodiment, the analog-to-digital converter circuit 14 is used to obtain the low-frequency gain of the first intermediate signal. It should also be noted that the signal processing device 10 provided in this application, as a device for signal amplification, is generally used as a front-end device for other devices utilizing this signal. That is, the subsequent stage of this signal processing device 10 is generally connected to a high-speed signal detection system such as an oscilloscope (or as part of a high-speed signal detection system). The output of this device is the amplified, long-code digital high-speed signal containing high-frequency components. Therefore, for the subsequent high-speed signal detection system, the high-frequency gain corresponding to the high-frequency components is known. Based on this, the high-frequency gain is also a known parameter that can be obtained by the processing circuit 15 and used to combine with the low-frequency gain obtained by the analog-to-digital converter circuit 14 to determine the VGA gain, thereby achieving VGA gain adjustment.

[0044] Furthermore, this embodiment also provides an optional implementation scheme for the specific implementation of the high-frequency amplifier circuit 122. For example... Figure 6 As shown, the high-frequency amplifier circuit 122 includes a low-noise amplifier (LNA) or a transimpedance amplifier (TIA). The input terminal of the LNA or TIA is connected to the second output terminal of the separation circuit 11, and the output terminal of the LNA or TIA is connected to the second input terminal of the merging circuit 13. It should be noted that whether an LNA or a TIA is used in this embodiment depends on the type of signal being amplified. For voltage signals, high-frequency components can be amplified using an LNA. For current signals, high-frequency components can be amplified using a TIA.

[0045] In this embodiment, the low-noise amplifier can amplify weak high-frequency signals while introducing extremely low additional noise, thus improving the signal-to-noise ratio. The transimpedance amplifier is suitable for converting current-type high-frequency input signals into voltage signals and amplifying them. Both can amplify the high-frequency signal components in common voltage and current signals, improving the integrity and purity of the high-frequency components during the amplification process.

[0046] Furthermore, the above embodiments provide an optional approach to the specific implementation of the low-frequency amplifier circuit 121. Based on the above embodiments, this embodiment also provides another optional embodiment for the low-frequency amplifier circuit 121. The low-frequency amplifier circuit 121 further includes a conditioning circuit. The conditioning circuit is disposed between the first output terminal of the separation circuit 11 and the first input terminal of the merging circuit 13, and is used to condition the first intermediate signal to suppress fluctuations at the junction of the first intermediate signal and the second intermediate signal.

[0047] Specifically, if we break it down according to the different types of transmitted signals, Figure 3 The separation circuit 11 and the merging circuit 13 can be divided into two signal links: a low-frequency signal link (including the low-frequency amplifier circuit 121) for transmitting low-frequency + DC components, and a high-frequency signal link for transmitting high-frequency components. The conditioning circuit in this embodiment is also located in the low-frequency signal link and can be situated anywhere within it; this embodiment does not impose any restrictions on this. Specifically, based on the above embodiment, the low-frequency signal link includes a low-frequency amplifier circuit; therefore, the conditioning circuit in this embodiment can be located before the low-frequency amplifier circuit 121, i.e., between the output of the separation circuit 11 and the input of the low-frequency amplifier circuit 121; or, it can be located after the low-frequency amplifier circuit 121, i.e., between the output of the low-frequency amplifier circuit 121 and the first input of the merging circuit 13; or, the conditioning circuit can include two sub-circuits, respectively located before and after the low-frequency amplifier circuit 121.

[0048] In this embodiment, by setting a conditioning circuit in the low-frequency signal link, amplitude or phase fluctuations of the first intermediate signal (low frequency and DC) and the second intermediate signal (high frequency) at the frequency domain splicing point can be effectively suppressed. Since the two signals are processed by different amplifiers before being combined, discontinuities or distortions are easily generated near the splicing point. The conditioning circuit can pre-compensate or post-correct the low-frequency + DC components, significantly improving the overall fidelity of the combined signal.

[0049] On the other hand, in addition to the above embodiments, this application also provides another optional conditioning solution. For example... Figure 4 As shown, the conditioning circuit further includes a first conditioning sub-circuit 161 and a second conditioning sub-circuit 162. The input terminal of the first conditioning sub-circuit 161 is connected to the first output terminal of the separation circuit 11, and the output terminal of the first conditioning sub-circuit 161 is connected to the input terminal of the low-frequency amplifier circuit 121. The input terminal of the second conditioning sub-circuit 162 is connected to the output terminal of the low-frequency amplifier circuit 121, and the output terminal of the second conditioning sub-circuit 162 is connected to the first input terminal of the merging circuit 13.

[0050] Compared with the previous embodiment, it is easy to see that this embodiment adopts a scheme in which the low-frequency component amplification circuit 121 is conditioned by conditioning sub-circuits (first conditioning sub-circuit 161 and second conditioning sub-circuit 162) before and after low-frequency component amplification. Pre-conditioning can optimize the signal quality entering the low-frequency amplification circuit 121 (such as impedance matching or filtering out-of-band noise), while post-conditioning is used to correct nonlinearity or residual fluctuations introduced by the low-frequency amplification circuit 121 itself. This two-stage conditioning structure has a stronger signal purification capability than single-stage conditioning, further improving the purity and stability of the low-frequency signal path. This better suppresses amplitude or phase fluctuations at the frequency domain splicing point between the first and second intermediate signals, further improving the overall fidelity of the combined signal.

[0051] Furthermore, this embodiment also provides an optional implementation scheme for the specific implementation of the first conditioning sub-circuit 161 and the second conditioning sub-circuit 162 (or the conditioning circuit that does not include two circuit parts as in the above embodiments). The first conditioning sub-circuit 161 and the second conditioning sub-circuit 162 (or the conditioning circuit) both include any one or more of the following: an RF phase shifter, an RF filter, and an RF isolator.

[0052] The radio frequency (RF) phase shifter is used to adjust the phase of the signal to optimize the phase consistency when merging the two signals. The RF filter is used to filter out unwanted frequency components and suppress spurious interference. The RF isolator prevents signal reflection and improves link stability. These specific devices are all mature and reliable RF modules, making the conditioning sub-circuit in this circuit easier to implement in engineering. Furthermore, all of the above devices can be used to condition low-frequency components, thereby suppressing fluctuations at the junction of the first and second intermediate signals. The specific devices selected to implement the conditioning sub-circuit can be flexibly chosen or combined according to the actual scenario; this embodiment does not impose any restrictions on this. Specifically, one optional example is as follows: Figure 6 As shown, both the first conditioning sub-circuit 161 and the second conditioning sub-circuit 162 are implemented through an RF filter.

[0053] In the above embodiments, a signal processing device 10 has been described in detail. This application also provides an embodiment corresponding to a high-speed photoelectric detection system. Figure 8 As shown, this embodiment provides a high-speed photoelectric detection system, including: a signal processing device 10 as provided in any of the above embodiments, and a photodiode (PD) module 20. The input terminal of the signal processing device 10 is connected to the output terminal of the photodiode (PD) module 20. The photodiode (PD) module 20 is used to convert optical signals into electrical signals. This electrical signal can be a long-code digital high-speed signal, which is amplified by the subsequent signal processing device 10.

[0054] Specifically, the high-speed photoelectric detection system provided in this embodiment can be a digital communication analyzer (DCA) sampling oscilloscope, a high-speed photoelectric probe, and a high-speed photodetector (with TIA).

[0055] Furthermore, since the system-related embodiments correspond to the device-related embodiments, please refer to the description of the device-related embodiments for the system-related embodiments, which will not be repeated here. However, it is readily apparent that since the high-speed photoelectric detection system provided in this embodiment includes the signal processing device provided in the above embodiments, it can achieve the same technical effects as the above signal processing device. Specifically, please refer to the embodiments in the device section above. In particular, even if the photoelectric conversion module in this system outputs a special signal such as a long-code digital high-speed signal, which carries information in high-frequency, low-frequency, and DC components, it can still be amplified and processed by the included signal processing device to ensure the information is complete for subsequent use. This fills the gap in the current field of signal processing for amplifying and processing special signals such as long-code digital high-speed signals.

[0056] The above-described preferred embodiments have further detailed the purpose, technical solutions, and advantages of this application. It should be understood that the above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A signal processing device, characterized in that, include: Separating circuits and amplifying circuits; The input terminal of the separation circuit is connected to a long code type digital high-speed signal. The separation circuit is used to: separate the high-frequency component, low-frequency component and DC component in the long code type digital high-speed signal into an independent intermediate signal, and separate the low-frequency component and the DC component into at least one independent intermediate signal. The amplifier circuit comprises multiple circuits, and the input terminals of each amplifier circuit are connected to the output terminal of the separation circuit. Each amplifier circuit is used to amplify the corresponding intermediate signal.

2. The signal processing apparatus according to claim 1, characterized in that, Also includes: Combined circuits; The input terminal of the merging circuit is connected to the output terminal of each of the amplifier circuits. The merging circuit is used to merge all the signals output by each of the amplifier circuits into one signal output.

3. The signal processing apparatus according to claim 2, characterized in that, The separation circuit includes a first output terminal and a second output terminal; the separation circuit is used to: separate the low-frequency component and DC component in the long code digital high-speed signal and output them as a first intermediate signal through the first output terminal; separate the high-frequency component in the long code digital high-speed signal and output it as a second intermediate signal through the second output terminal; The plurality of said amplifier circuits include: a low-frequency amplifier circuit and a high-frequency amplifier circuit; The input terminal of the low-frequency amplifier circuit is connected to the first output terminal of the separation circuit, and is used to amplify the first intermediate signal. The input terminal of the high-frequency amplifier circuit is connected to the second output terminal of the separation circuit, and is used to amplify the second intermediate signal. The merging circuit includes a first input terminal and a second input terminal; the first input terminal of the merging circuit is connected to the output terminal of the low-frequency amplifier circuit, and the second input terminal of the merging circuit is connected to the output terminal of the high-frequency amplifier circuit; the merging circuit is used to merge the amplified first intermediate signal and the second intermediate signal into a single output signal.

4. The signal processing apparatus according to claim 3, characterized in that, The low-frequency amplifier circuit includes: an operational amplifier and a variable gain amplifier; The input terminal of the operational amplifier is connected to the first output terminal of the separation circuit, the output terminal of the operational amplifier is connected to the input terminal of the variable gain amplifier, and the output terminal of the variable gain amplifier is connected to the first input terminal of the merging circuit.

5. The signal processing apparatus according to claim 4, characterized in that, Also includes: Analog-to-digital conversion circuits and processing circuits; The input terminal of the analog-to-digital converter circuit is connected to the first output terminal of the separation circuit, and the analog-to-digital converter circuit is used to detect the low-frequency gain of the first intermediate signal. The first input terminal of the processing circuit is connected to the output terminal of the analog-to-digital converter circuit, the second input terminal of the processing circuit is used to obtain high-frequency gain, and the output terminal of the processing circuit is connected to the gain control terminal of the variable gain amplifier.

6. The signal processing apparatus according to claim 3, characterized in that, Also includes: Conditioning circuit; The conditioning circuit is located between the first output terminal of the splitting circuit and the first input terminal of the merging circuit, and is used to condition the first intermediate signal to suppress fluctuations at the junction of the first intermediate signal and the second intermediate signal.

7. The signal processing apparatus according to claim 6, characterized in that, The conditioning circuit includes: a first conditioning sub-circuit and a second conditioning sub-circuit; The input terminal of the first conditioning sub-circuit is connected to the first output terminal of the separation circuit, and the output terminal of the first conditioning sub-circuit is connected to the input terminal of the low-frequency amplifier circuit. The input terminal of the second conditioning sub-circuit is connected to the output terminal of the low-frequency amplifier circuit, and the output terminal of the second conditioning sub-circuit is connected to the first input terminal of the merging circuit. Both the first conditioning sub-circuit and the second conditioning sub-circuit include any one or more of the following: an RF phase shifter, an RF filter, and an RF isolator.

8. The signal processing apparatus according to claim 3, characterized in that, The high-frequency amplifier circuit includes: a low-noise amplifier or a transimpedance amplifier; The input terminal of the low-noise amplifier or the transimpedance amplifier is connected to the second output terminal of the separation circuit, and the output terminal of the low-noise amplifier or the transimpedance amplifier is connected to the second input terminal of the merging circuit.

9. The signal processing apparatus according to any one of claims 2 to 8, characterized in that, The separating circuit and the merging circuit include any one of the following: a bias circuit, a current source mirror circuit, and a resistor network.

10. A high-speed photoelectric detection system, characterized in that, It includes the signal processing device and the photoelectric conversion module as described in any one of claims 1 to 9, wherein the input terminal of the signal processing device is connected to the output terminal of the photoelectric conversion module.

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