Optical receiver

Patent metadata

Field	Value
Publication number	US-11228823-B2
Application number	US-202016952912-A
Country	US
Kind code	B2
Filing date	Nov 19, 2020
Priority date	Jan 24, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

An optical receiver is disclosed, including an optoelectronic detector, a transimpedance amplification (TIA) circuit, a single-ended-to-differential converter, an I/O interface, and a controller. The optoelectronic detector, having bandwidth lower than required system transmission bandwidth, converts an optical signal into a current signal. The TIA circuit compensate gain for the received current signal based on a received control signal, to obtain a voltage signal, where a frequency response value of the current signal within first bandwidth is greater than that within the bandwidth of the optoelectronic detector, and any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector. The single-ended-to-differential converter converts the voltage signal into a differential voltage signal. The I/O interface outputs the differential voltage signal. The controller generates the control signal based on the differential voltage signal. The optical receiver disclosed can reduce costs while ensuring signal quality.

First claim

The invention claimed is:

1. An optical receiver, comprising:
an optoelectronic detector, the optoelectronic detector configured to convert a received optical signal into a current signal, wherein bandwidth of the optoelectronic detector is lower than a system transmission bandwidth requirement;
a transimpedance amplification circuit, the transimpedance amplification circuit configured to:
receive the current signal and a first control signal; and
perform transimpedance gain compensation for the current signal based on the first control signal to obtain a voltage signal, wherein a frequency response value of the current signal within first bandwidth of the transimpedance amplification circuit is greater than that within the bandwidth of the optoelectronic detector, wherein any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector, and wherein the first control signal is received from a controller;

a single-ended-to-differential converter, the single-ended-to-differential converter configured to:
convert the voltage signal into a differential voltage signal; and
send the differential voltage signal to an I/O interface and the controller, wherein the first control signal is generated based on the differential voltage signal; and

the I/O interface, the I/O interface configured to output the differential voltage signal.

2. The optical receiver according to claim 1 , further comprising the controller.

3. The optical receiver according to claim 2 , wherein the controller is configured to perform a plurality of sampling processing and perform the following operations in each of the plurality of sampling processing:
sending a control signal to the transimpedance amplification circuit;
sampling an upper level and a lower level of the received differential voltage signal to obtain a value of a sampling point; and
modifying the control signal based on a preset modification amount; and
wherein after performing the plurality of sampling processing, the controller is configured to:
use, as the first control signal, a control signal corresponding to a sampling point with a maximum value in a plurality of sampling points obtained after the plurality of sampling processing.

4. The optical receiver according to claim 2 , wherein the controller is configured to perform a plurality of detection processing and perform the following operations in each of the plurality of detection processing:
sending a control signal to the transimpedance amplification circuit;
using a first frequency as a boundary, and separately detecting energy of the differential voltage signal that has a frequency higher than the first frequency and energy of the differential voltage signal that has a frequency lower than the first frequency to obtain an energy difference, wherein the first frequency is 0.28/Tb, and wherein Tb is duration of each bit of the differential voltage signal; and
modifying the control signal based on a preset modification amount; and
wherein after performing the plurality of detection processing, the controller is configured to:
use, as the first control signal, a control signal corresponding to a minimum energy difference in a plurality of energy differences obtained after the plurality of detection processing.

5. The optical receiver according to claim 1 , further comprising an equalizer, wherein the equalizer is configured to:
receive the differential voltage signal from the single-ended-to-differential converter and a second control signal from the controller;
perform gain on the differential voltage signal based on the second control signal; and
send the differential voltage signal obtained after the gain to the controller and the I/O interface, wherein a frequency response value of the differential voltage signal after the gain within second bandwidth of the equalizer is greater than that within the first bandwidth, and wherein any frequency in the second bandwidth is higher than any frequency in the first bandwidth.

6. The optical receiver according to claim 1 , wherein the transimpedance amplification circuit comprises a fixed resistor, a first transistor, a second transistor, a variable resistance circuit, and an output port, and wherein:
the fixed resistor comprises two ports, wherein one port is grounded and the other port is connected to an emitter of the first transistor;
a base of the first transistor is configured to receive an input signal, and a collector of the first transistor is connected to an emitter of the second transistor;
a base of the second transistor is configured to receive a bias voltage signal, and a collector of the second transistor is connected to a first port of the variable resistance circuit, wherein the bias voltage signal is used to adjust a gain for the input signal;
the output port is located on a connecting line between the collector of the second transistor and the first port of the variable resistance circuit; and
the variable resistance circuit comprises three ports, wherein a second port of the variable resistance circuit is configured to receive a control signal, wherein a third port of the variable resistance circuit is grounded, and wherein the control signal is used to control a resistance value of the variable resistance circuit.

7. A receiving method, comprising:
converting, by an optical receiver, a received optical signal into a current signal by using an optoelectronic detector, wherein bandwidth of the optoelectronic detector is lower than a system transmission bandwidth requirement;
performing, by the optical receiver, transimpedance gain on the current signal based on a first control signal to obtain a voltage signal, wherein a frequency response value of the current signal within first bandwidth is greater than that within the bandwidth of the optoelectronic detector, and wherein any frequency in the first bandwidth is not lower than an upper cut-off frequency of the optoelectronic detector;
converting, by the optical receiver, the voltage signal into a differential voltage signal; and
generating a first control signal based on the differential voltage signal.

8. The method according to claim 7 , wherein generating the first control signal based on the differential voltage signal comprises:
performing a plurality of sampling processing, and using, as the first control signal, a control signal corresponding to a sampling point with a maximum value in a plurality of sampling points obtained after the plurality of sampling processing, wherein the following process is performed in each of the plurality of sampling processing:
performing transimpedance gain on the current signal based on a control signal to obtain the voltage signal, and converting the voltage signal into the differential voltage signal;
sampling an upper level and a lower level of the differential voltage signal to obtain a value of a sampling point; and
modifying the control signal based on a preset modification amount.

9. The method according to claim 7 , wherein generating the first control signal based on the differential voltage signal comprises:
performing a plurality of detection processing, and using, as the first control signal, a control signal corresponding to a minimum energy difference in a plurality of energy differences obtained after the plurality of detection processing, wherein the following process is performed in each of the plurality of detection processing:
performing transimpedance gain on the current signal based on a control signal to obtain the voltage signal, and converting the voltage signal into the differential voltage signal;
using a first frequency as a boundary, and separately detecting energy of the dif

Assignees

• Huawei Tech Co Ltd

Inventors

• Fu Shengmeng
• Xiong Yu
• Man Jiangwei
• Wang Chengyan
• Zeng Xiaofei
• Zeng Li

Classifications

• C22C38/54

  with boron · CPC title

• C22C38/52 Primary

  with cobalt · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C22C38/005

  containing rare earths, i.e. Sc, Y, Lanthanides · CPC title

• C22C33/02

  by powder metallurgy · CPC title