基于分集接收技术的可见光接收机前端电路  

Visible Receiver Front-End Circuit Based on Diversified Receiving Technology

作　　者：谢生 王续霏 毛旭瑞[2] 周高磊 闫冬 Xie Sheng;Wang Xufei;Mao Xurui;Zhou Gaolei;Yan Dong(School of Microelectronics,Tianjin University,Tianjin 300072,China;Institute of Semiconductors,Chinese Academy of Science,Beijing 10083,China;School of Electronical and Information Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学微电子学院天津市成像与感知微电子技术重点实验室,天津300072 [2]中国科学院半导体研究所,北京100083 [3]天津大学电气自动化与信息工程学院,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2020年第10期1062-1068,共7页Journal of Tianjin University：Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2017YFB0403603).

摘　　要：为了减弱噪声对可见光通信质量的影响,提高可见光通信系统的抗干扰性,基于台积电180 nm CMOS工艺,提出了一种抗噪能力较强的可见光接收机前端电路.电路主要包括跨阻放大器、限幅放大器、直流偏移消除网络和输出缓冲级.输入端对信号进行两路接收,通过印制电路板绘制把外部两个光电二极管相连,对接收到的光电流信号进行等增益合并,合并信号作为输入信号提供给光接收机模拟放大电路,这种设计实现了分集接收技术,提高了光通信系统的信噪比.跨阻放大器采用调节型共源共栅结构,共源结构作为反馈环路,降低芯片的输入阻抗,共漏结构提高了跨阻放大器的带负载能力.限幅放大器采用改进Cherry Hooper型限幅放大器结构,引入反馈电阻降低级间等效电阻,扩展有效带宽,并通过增加负载电阻为支路提供偏置电流,有效提高了电路的输出范围.测试结果表明,在电源电压为1.8 V、光电探测器等效电容为5 pF时,光接收机的跨阻增益为88 dBΩ,-3 dB带宽为510 MHz,在误码率小于3.8×10-3的条件下实现了600 Mb/s的数据传输.芯片功耗为43.62 mW,整体面积为624μm×823μm,当误码率为10-9时,基于分集接收的光接收机的灵敏度为-11.5 dBm.对比实验表明,分集接收技术降低了可见光通信的误码率,提高了通信质量,因此基于分集接收技术的光接收机有望应用于室内可见光通信系统领域.In this paper,a visible light receiver front-end circuit with strong anti-noise ability based on TSMC 180 nm CMOS technology is proposed to reduce the influence of noise on the quality of visible light communication and improve the anti-interference of visible light communication systems.The circuit mainly includes transimpedance amplifiers,a limiting amplifier,a DC offset elimination network,and a buffer.An input end receives signals in two ways,and two external photodiodes are connected via PCB drawing to realize an equal gain combination of received photocurrent signals.The combined signals are provided to the analog amplifier circuit of the optical receiver as the input signals.The design realizes diversity receiving technology and improves the signal-to-noise ratio of the optical communication system.The transimpedance amplifier adopts the regulated cascode structure,the common source structure is used as the feedback loop to reduce the input impedance of the chip,and the common drain structure improves the load capacity of the transimpedance amplifier.The improved Cherry Hooper limiting amplifier structure is adopted by introducing a feedback resistor to reduce the interstage equivalent resistance and expand the effective bandwidth.By increasing the load resistance,the bias current is provided to the branch,which can effectively improve the output range of the circuit.Experimental results show that when the power supply voltage is 1.8 V and the equivalent capacitance of the photodetector is 5 pF,the transimpedance gain of the optical receiver is 88 dBΩand the-3 dB bandwidth is 510MHz.With a bit error rate less than 3.8×10-3,a 600Mb/s data transmission is realized.The chip power consumption is 43.62mW and the overall area is 624μm×823μm;when the BER is 10-9,the sensitivity of the diversity-based receiver is-11.5 dBm.A comparative experimental study shows that diversity receiving technology can reduce the bit error rate of VLC,thus improving the communication quality.Therefore,the optical receiver based

关 键 词：半导体技术 可见光通信 光接收机 分集接收 

分 类 号：TN43[电子电信—微电子学与固体电子学]