Trans-impedance amplifier and photoelectric receiver

Abstract

The invention discloses a transimpedance amplifier and a photoelectric receiver, and relates to the technical field of transimpedance amplifiers, the transimpedance amplifier comprises a first-stage main lumped amplifier, a first-stage secondary lumped amplifier, and a second-stage controllable gain distributed amplifier to an Nth-stage controllable gain distributed amplifier which are connected in sequence, and N is an integer greater than 2; the first-stage main lumped amplifier is used for converting an input optical signal into a voltage signal and outputting the voltage signal to the second-stage controllable gain distributed amplifier; the first-stage lumped amplifier is used for outputting a direct-current voltage signal to the second-stage controllable gain distributed amplifier; and the second-stage controllable gain distributed amplifier is used for amplifying the input voltage signal and then outputting the amplified voltage signal to the third-stage controllable gain distributed amplifier, and so on until the Nth-stage controllable gain distributed amplifier amplifies the input voltage signal and then outputs the amplified voltage signal. The trans-impedance amplifier provided by the invention can realize the targets of low noise and large bandwidth.

Description

Technical Field

[0001] The present invention relates to the technical field of transimpedance amplifiers, and in particular to a transimpedance amplifier and a photoelectric receiver. Background Art

[0002] With the popularization of applications such as 5G communications, big data, cloud computing, and AI technology, the demand for data transmission bandwidth is also increasing at an exponential rate. Since copper interconnects face bottlenecks that are difficult to break through in terms of transmission bandwidth, transmission distance, and energy efficiency, optical interconnects have become a research hotspot due to their advantages such as low loss, large bandwidth, and high energy efficiency. They have the trend and great potential to replace copper interconnects. The optoelectronic receiver in optical interconnects generally includes a detector optical chip and a transimpedance amplifier electrical chip, where the transimpedance amplifier determines the bandwidth, sensitivity, and power consumption of the receiver.

[0003] In the prior art, the two technical indicators of noise and bandwidth of traditional transimpedance amplifiers are mutually restricted. However, high-performance transimpedance amplifiers require low noise and large bandwidth. Therefore, it is urgent to solve the technical problem that the existing transimpedance amplifiers are difficult to achieve both low noise and large bandwidth. Summary of the invention

[0004] The embodiments of the present invention provide a transimpedance amplifier and a photoelectric receiver to solve the technical problem in the related art that the existing transimpedance amplifier is difficult to achieve both low noise and large bandwidth.

[0005] In a first aspect, a transimpedance amplifier is provided, comprising: a first-stage main lumped amplifier, a first-stage secondary lumped amplifier, a second-stage controllable gain distributed amplifier to an N-th-stage controllable gain distributed amplifier connected in sequence, wherein N is an integer greater than 2;

[0006] The first-stage main lumped amplifier is used to convert the input optical signal into a voltage signal and output it to the second-stage controllable gain distributed amplifier;

[0007] The first-stage lumped amplifier is used to output a DC voltage signal to the second-stage controllable gain distributed amplifier;

[0008] The second-stage controllable gain distributed amplifier is used to amplify the input voltage signal and output it to the third-stage controllable gain distributed amplifier, and so on, until the N-th-stage controllable gain distributed amplifier amplifies the input voltage signal and outputs it.

[0009] In some embodiments, the first stage main lumped amplifier comprises:

[0010] A current-to-voltage conversion unit, the current-to-voltage conversion unit is used to convert an input optical signal into a voltage signal;

[0011] An impedance conversion unit is connected to the current-voltage conversion unit and is used to convert the voltage signal converted by the current-voltage conversion unit into a preset target output impedance and output it according to the preset target output impedance.

[0012] In some embodiments, the current-to-voltage conversion unit includes a first resistor, a second resistor, a third resistor, a first transistor, and a second transistor;

[0013] A first end of the first resistor is connected to a power supply, and a second end of the first resistor is connected to a first end of the first transistor;

[0014] The first end of the second resistor is connected to the second end of the first transistor as an input end of the current-voltage conversion unit, the second end of the second resistor is connected to the third end of the second transistor, and the third end of the first transistor is grounded;

[0015] The first end of the second transistor is connected to a power supply, the second end of the second transistor is connected to the first end of the first transistor, the third end of the second transistor is connected to the first end of the third resistor, and the second end of the third resistor is grounded.

[0016] In some embodiments, the impedance conversion unit includes a fourth resistor and a third transistor, the first end of the third transistor is connected to a power supply, the second end of the third transistor is connected to the second end of the second transistor, the third end of the third transistor is connected to the first end of the fourth resistor as the output end of the current-voltage conversion unit, and the second end of the fourth resistor is grounded.

[0017] In some embodiments, the first transistor, the second transistor, and the third transistor are all NPN transistors.

[0018] In some embodiments, the first-stage sub-lumped amplifier has the same structure as the first-stage main lumped amplifier.

[0019] In some embodiments, the second-stage controllable gain distributed amplifier includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and M controllable gain units, where M is an integer greater than 1;

[0020] The M controllable gain units are connected in sequence, the first input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the first input end of the second controllable gain unit, the second input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the second input end of the second controllable gain unit, the first output end of the first controllable gain unit is connected to the first end of the fifth resistor and the first output end of the second controllable gain unit, the second end of the fifth resistor is connected to a power supply, the second output end of the first controllable gain unit is connected to the first end of the sixth resistor and the second output end of the second controllable gain unit, and the second end of the sixth resistor is connected to a power supply;

[0021] The first input end of the Mth controllable gain unit is connected to the first input end of the M-1th controllable gain unit and the first end of the seventh resistor, the second end of the seventh resistor is connected to the power supply, the second input end of the first controllable gain unit is connected to the second input end of the M-1th controllable gain unit and the first end of the eighth resistor, the second end of the eighth resistor is connected to the power supply, the first output end of the Mth controllable gain unit is connected to the first output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier, and the second output end of the Mth controllable gain unit is connected to the second output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier.

[0022] In some embodiments, each of the controllable gain units includes eight transmission lines and a controllable gain amplifier, and a first input terminal, a second input terminal, a first output terminal, and a second input terminal of the controllable gain amplifier are connected to two of the transmission lines.

[0023] In some embodiments, the Nth stage controllable gain distributed amplifier has the same structure as the second stage controllable gain distributed amplifier.

[0024] In a second aspect, a photoelectric receiver is provided, comprising the aforementioned transimpedance amplifier.

[0025] The beneficial effects brought about by the technical solution provided by the present invention include:

[0026] An embodiment of the present invention provides a transimpedance amplifier and a photoelectric receiver. The transimpedance amplifier is provided with a first-stage main lumped amplifier, a first-stage sub-lumped amplifier, a second-stage controllable gain distributed amplifier to an N-th stage controllable gain distributed amplifier connected in sequence. An external input optical signal first reduces the noise of a channel through the small bandwidth and high gain of the first-stage main lumped amplifier and the first-stage sub-lumped amplifier, and then expands the channel bandwidth through a multi-stage controllable gain distributed amplifier, thereby finally achieving the goal of low noise and large bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 An overall framework diagram of a transimpedance amplifier provided in an embodiment of the present invention;

[0029] Figure 2 An amplitude-frequency response diagram of a transimpedance amplifier provided by an embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the circuit structure of a first-stage main lumped amplifier provided in an embodiment of the present invention;

[0031] Figure 4 A schematic diagram of the circuit structure of a second-stage controllable gain distributed amplifier provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The embodiment of the present invention provides a transimpedance amplifier, which can solve the technical problem that the existing transimpedance amplifier is difficult to achieve both low noise and large bandwidth.

[0034] See also Figure 1 As shown, an embodiment of the present invention provides a transimpedance amplifier, comprising: a first-stage main lumped amplifier, a first-stage secondary lumped amplifier, a second-stage controllable gain distributed amplifier to an N-th-stage controllable gain distributed amplifier connected in sequence.

[0035] The first-stage main lumped amplifier is used to convert the input optical signal into a voltage signal and output it to the second-stage controllable gain distributed amplifier.

[0036] The first-stage sub-lumped amplifier is used to output a DC voltage signal to the second-stage controllable gain distributed amplifier. The DC voltage signal output by the first-stage sub-lumped amplifier is the same as the DC voltage signal in the voltage signal output by the first-stage main lumped amplifier (the voltage signal output by the first-stage main lumped amplifier generally also includes an AC small voltage signal).

[0037] The second-stage controllable gain distributed amplifier is used to amplify the input voltage signal and output it to the third-stage controllable gain distributed amplifier, and so on, until the N-th-stage controllable gain distributed amplifier amplifies the input voltage signal and outputs it.

[0038] Specifically, the first-stage main lumped amplifier and the first-stage secondary lumped amplifier are designed to be smaller than a preset bandwidth value (small bandwidth) and higher than a preset gain value (high gain), that is, the first-stage main lumped amplifier and the first-stage secondary lumped amplifier utilize small bandwidth and high gain to first reduce channel noise.

[0039] The design goal of the second-stage controllable gain distributed amplifier is gain adjustable and bandwidth expandable. That is, the second-stage controllable gain distributed amplifier expands the channel bandwidth of the voltage signal output by the first-stage main lumped amplifier and the first-stage secondary lumped amplifier, and improves the DC gain at the same time.

[0040] The design goal of the third-level controllable gain distributed amplifier is adjustable gain and further channel bandwidth expansion. And so on, until the N-level controllable gain distributed amplifier, the gain and bandwidth of the entire channel meet the requirements, and the overall goal of low noise and large bandwidth is finally achieved.

[0041] Assume N is 3, Figure 2 This is the amplitude-frequency response diagram of the transimpedance amplifier of the embodiment of the present invention. On the one hand, the first-stage lumped amplifier contributes most of the DC gain, and the concept of small bandwidth is adopted to reduce the noise of the transimpedance amplifier. On the other hand, the second-stage controllable gain distributed amplifier and the third-stage controllable gain distributed amplifier respectively provide a part of the adjustable DC gain, and perform peaking in different frequency bands to expand the bandwidth of the first-stage lumped amplifier, which is greatly improved from 3dB bandwidth 1 to 3dB bandwidth 2.

[0042] The transimpedance amplifier in the implementation of the present invention is provided with a first-stage main lumped amplifier, a first-stage sub-lumped amplifier, a second-stage controllable gain distributed amplifier to an N-th stage controllable gain distributed amplifier connected in sequence. An external input optical signal first reduces the noise of the channel through the small bandwidth and high gain of the first-stage main lumped amplifier and the first-stage sub-lumped amplifier, and then expands the channel bandwidth through the multi-stage controllable gain distributed amplifier, finally achieving the goal of low noise and large bandwidth.

[0043] As an optional implementation, in an embodiment of the invention, see Figure 3 As shown, the first-stage main lumped amplifier includes: a current-voltage conversion unit and an impedance conversion unit.

[0044] The current-to-voltage conversion unit is used to convert the input optical signal into a voltage signal. The impedance conversion unit is connected to the current-to-voltage conversion unit and is used to output the voltage signal converted by the current-to-voltage conversion unit according to a preset target output impedance.

[0045] Specifically, the current-voltage conversion unit includes a first resistor R1, a second resistor R2, a third resistor R3, a first transistor Q1, and a second transistor Q2. The impedance conversion unit includes a fourth resistor R4 and a third transistor Q3. The first transistor Q1, the second transistor Q2, and the third transistor Q3 may be NPN transistors.

[0046] The first end of the first resistor R1 is connected to a power supply, and the second end of the first resistor R1 is connected to the first end of the first transistor Q1. The first end of the second resistor R2 is connected to the second end of the first transistor Q1 as an input end of the current-voltage conversion unit, the second end of the second resistor R2 is connected to the third end of the second transistor Q2, and the third end of the first transistor Q1 is grounded.

[0047] The first end of the second transistor Q2 is connected to a power supply, the second end of the second transistor Q2 is connected to the first end of the first transistor Q1, the third end of the second transistor Q2 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is grounded.

[0048] The first end of the third triode Q3 is connected to a power supply, the second end of the third triode Q3 is connected to the second end of the second triode Q2, the third end of the third triode Q3 is connected to the first end of the fourth resistor R4 as the output end of the current-voltage conversion unit, and the second end of the fourth resistor R4 is grounded. In the embodiment of the present invention, the emitter follower is used as an impedance conversion unit to convert the output impedance into the transmission characteristic impedance of the subsequent distributed circuit.

[0049] Furthermore, the first-stage sub-lumped amplifier has the same structure as the first-stage main lumped amplifier, and the first-stage sub-lumped amplifier does not receive an optical signal, and directly outputs a DC voltage signal to the second-stage controllable gain distributed amplifier V n1 .

[0050] The first-stage lumped amplifier of the present invention is provided with an impedance conversion unit connected to a subsequent distributed amplifier, so that the output voltage signal can be output according to a preset target output impedance. At the same time, the first-stage lumped amplifier of the present invention has the characteristics of small bandwidth, high gain and low noise.

[0051] As an optional implementation, in an embodiment of the invention, see Figure 4 As shown, the second-stage controllable gain distributed amplifier includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and M controllable gain units, where M is an integer greater than 1.

[0052] The M controllable gain units are connected in sequence, the first input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the first input end of the second controllable gain unit, the second input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the second input end of the second controllable gain unit, the first output end of the first controllable gain unit is connected to the first end of the fifth resistor R5 and the first output end of the second controllable gain unit, the second end of the fifth resistor R5 is connected to a power supply, the second output end of the first controllable gain unit is connected to the first end of the sixth resistor R6 and the second output end of the second controllable gain unit, and the second end of the sixth resistor R6 is connected to a power supply.

[0053] The first input end of the Mth controllable gain unit is connected to the first input end of the M-1th controllable gain unit and the first end of the seventh resistor R7, the second end of the seventh resistor R7 is connected to the power supply, the second input end of the first controllable gain unit is connected to the second input end of the M-1th controllable gain unit and the first end of the eighth resistor R8, the second end of the eighth resistor R8 is connected to the power supply, the first output end of the Mth controllable gain unit is connected to the first output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier, and the second output end of the Mth controllable gain unit is connected to the second output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier.

[0054] Furthermore, each of the controllable gain units includes eight transmission lines (TL1-TL8) and a controllable gain amplifier U, and a first input terminal, a second input terminal, a first output terminal and a second input terminal of the controllable gain amplifier U are connected to two of the transmission lines.

[0055] The second to Nth controllable gain distributed amplifiers of the present invention do not require very high gains, but only require a relatively high bandwidth to expand the bandwidth of the overall transimpedance amplifier, thereby reducing the design difficulty of the controllable gain distributed amplifier.

[0056] Furthermore, the structure of the Nth stage controllable gain distributed amplifier is the same as that of the second stage controllable gain distributed amplifier.

[0057] An embodiment of the present invention further provides a photoelectric receiver, comprising the aforementioned transimpedance amplifier.

[0058] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0059] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0060] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A transimpedance amplifier, characterized in that: include: A first-stage main lumped amplifier, a first-stage sub-lumped amplifier, a second-stage controllable gain distributed amplifier connected in sequence to an N-th-stage controllable gain distributed amplifier, wherein N is an integer greater than 2; The first-stage main lumped amplifier is used to convert the input optical signal into a voltage signal and output it to the second-stage controllable gain distributed amplifier; The first-stage lumped amplifier is used to output a DC voltage signal to the second-stage controllable gain distributed amplifier; The second-stage controllable gain distributed amplifier is used to amplify the input voltage signal and output it to the third-stage controllable gain distributed amplifier, and so on, until the N-th-stage controllable gain distributed amplifier amplifies the input voltage signal and outputs it.

2. The transimpedance amplifier according to claim 1, characterized in that: The first stage main lumped amplifier comprises: A current-to-voltage conversion unit, the current-to-voltage conversion unit is used to convert an input optical signal into a voltage signal; An impedance conversion unit, the impedance conversion unit is connected to the current-voltage conversion unit, and is used to output the voltage signal converted by the current-voltage conversion unit according to a preset target output impedance.

3. The transimpedance amplifier according to claim 2, characterized in that: The current-voltage conversion unit includes a first resistor, a second resistor, a third resistor, a first triode and a second triode; A first end of the first resistor is connected to a power supply, and a second end of the first resistor is connected to a first end of the first transistor; The first end of the second resistor is connected to the second end of the first transistor as an input end of the current-voltage conversion unit, the second end of the second resistor is connected to the third end of the second transistor, and the third end of the first transistor is grounded; The first end of the second transistor is connected to a power supply, the second end of the second transistor is connected to the first end of the first transistor, the third end of the second transistor is connected to the first end of the third resistor, and the second end of the third resistor is grounded.

4. The transimpedance amplifier according to claim 3, characterized in that: The impedance conversion unit includes a fourth resistor and a third transistor, the first end of the third transistor is connected to the power supply, the second end of the third transistor is connected to the second end of the second transistor, the third end of the third transistor is connected to the first end of the fourth resistor as the output end of the current-voltage conversion unit, and the second end of the fourth resistor is grounded.

5. The transimpedance amplifier according to claim 4, characterized in that: The first transistor, the second transistor and the third transistor are all NPN transistors.

6. The transimpedance amplifier according to claim 2, characterized in that: The first-stage sub-lumped amplifier has the same structure as the first-stage main lumped amplifier.

7. The transimpedance amplifier according to claim 1, characterized in that: The second-stage controllable gain distributed amplifier comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and M controllable gain units, where M is an integer greater than 1; The M controllable gain units are connected in sequence, the first input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the first input end of the second controllable gain unit, the second input end of the first controllable gain unit is connected to the output end of the first-stage main lumped amplifier and the second input end of the second controllable gain unit, the first output end of the first controllable gain unit is connected to the first end of the fifth resistor and the first output end of the second controllable gain unit, the second end of the fifth resistor is connected to a power supply, the second output end of the first controllable gain unit is connected to the first end of the sixth resistor and the second output end of the second controllable gain unit, and the second end of the sixth resistor is connected to a power supply; The first input end of the Mth controllable gain unit is connected to the first input end of the M-1th controllable gain unit and the first end of the seventh resistor, the second end of the seventh resistor is connected to the power supply, the second input end of the first controllable gain unit is connected to the second input end of the M-1th controllable gain unit and the first end of the eighth resistor, the second end of the eighth resistor is connected to the power supply, the first output end of the Mth controllable gain unit is connected to the first output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier, and the second output end of the Mth controllable gain unit is connected to the second output end of the M-1th controllable gain unit and the third-stage controllable gain distributed amplifier.

8. The transimpedance amplifier according to claim 7, characterized in that: Each of the controllable gain units includes eight transmission lines and a controllable gain amplifier, wherein a first input terminal, a second input terminal, a first output terminal and a second input terminal of the controllable gain amplifier are connected to two of the transmission lines.

9. The transimpedance amplifier according to claim 7, characterized in that: The structure of the Nth-stage controllable gain distributed amplifier is the same as that of the second-stage controllable gain distributed amplifier.

10. A photoelectric receiver, characterized in that: A transimpedance amplifier comprising any one of claims 1 to 9.

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