基于BiCMOS工艺的光接收机前端电路

Design and Realization of Optical Receiver Front-end Circuit in Standard SiGe BiCMOS

基于IBM 0.18μm SiGe BiCMOS工艺设计,实现了光接收机模拟前端,电路整体结构包括差分共射跨阻放大器(TIA)、限幅放大器(LA)以及输出缓冲级(Buffer)。采用SiGe异质结双极晶体管(HBT)作为输入级的差分共射跨阻放大器大大地减小了输入电阻,更好地展宽了频带。仿真结果表明,在1.8V电源电压供电下,驱动50Ω电阻和10pF电容负载时光接收机前端跨阻增益为74.59dB,带宽为2.4GHz,功耗为39.6mW。在误码率为10-9、输入电流为50μA的条件下,光接收机前端电路实现了3Gb/s的数据传输速率。实测结果表明,光接收机的-3dB带宽为1.9GHz。芯片面积为910μm×420μm。

An optical receiver front-end circuit is designed and fabricated in IBM 0. 18 /~m SiGe BiCMOS technology. The whole circuit consists of a transimpedance amplifier （TIA） with differential common-source configuration, four limiting amplifiers and an output buffer. SiGe heterojunction bipolar transistors （HBTs） with better high-frequency performance are used for the differential input pair, thus reducing the equivalent input resistance, and effectively expan- ding the bandwidth of the optical receiver. The simulation results indicate that the optical receiv- er terminated with 50 ~1 load resistance and 10 pF load capacitance has a transimpedance gain of 74.59 dB, and a --3 dB bandwidth of 2.4 GHz. The optical receiver successfully realizes 3 Gb/s data rate with a bit-error rate of 10-9 at incident current of 50/~A. The fabricated optical receiver has 910 /~mX420 /~m chip area, and consumes 39.6 mW at 1.8 V supply. The experimental re- sults show that the optical receiver front-end achieves a --3 dB bandwidth of 1.9 GHz.