基于标准CMOS工艺的光接收机前置放大器设计

发布时间：2018-10-11 11:13

【摘要】：近年来,随着电信网、计算机网和因特网的快速发展,建立高速度、大容量的信息传输系统势在必行。以光波为载体、光纤为传输媒质的光纤通信具有容量大、传输距离远、功耗低、抗干扰和抗辐射等诸多优点,无疑成为信息高速公路的主流技术。但是此领域的芯片目前几乎都依赖进口,因此,开发具有自主知识产权、用于高速光纤传输系统的集成电路,对我国信息化建设具有重大意义。光接收机作为光纤通信系统的重要组成部分,是将光纤传输的光信号转换为电信号,再经放大、处理后恢复原信号的系统。前置放大器作为光接收机的关键部件,它在很大程度上决定着整个光接收机的性能,是将光检测器输出的微弱电流信号转换为电压信号并进行一定量的放大,然后输出给后续的主放大器。因此,前置放大器性能的改善对于光纤传输系统的改进具有很重要的意义。本论文基于0.18μm CMOS工艺,设计了一种带AGC功能的RGC输入光接收机跨阻前置放大器。此放大器在输入级采用RGC组态,有效地展宽了带宽、提高了跨阻；在增益级采用电压并联负反馈结构,同时嵌入自动增益控制技术AGC,除了扩大输入动态范围、也起到了提高跨阻与降低噪声的作用；为了实现前置放大器输出的单端信号能适应后续主放大器的双端输入,在输出级设计了一种单端转差分电路。仿真结果显示,当光接收机输入光功率为-10dBm、电源电压为1.8V、光检测器的寄生电容为0.5pF时,此跨阻前置放大器的跨阻增益为81dBΩ,-3dB带宽为2.25GHz,平均噪声电流谱密度约为6.0pA/Hz1/2,光灵敏度为-20dBm,输入电阻约为50Ω,内部功耗仅为58mV。相比传统的跨阻前置放大器,本设计的性能比如带宽、增益、灵敏度与功耗等都得到了不同程度的改善。
[Abstract]:In recent years, with the rapid development of telecommunication network, computer network and Internet, it is imperative to establish high speed and large capacity information transmission system. Optical fiber communication with optical wave as carrier and optical fiber as transmission medium has many advantages such as large capacity, long transmission distance, low power consumption, anti-interference and anti-radiation, etc., which undoubtedly becomes the mainstream technology of information highway. However, almost all chips in this field depend on imports. Therefore, it is of great significance to develop integrated circuits with independent intellectual property rights for high-speed optical fiber transmission systems in China. As an important part of optical fiber communication system, optical receiver is a system that converts optical signal transmitted by optical fiber into electric signal, then amplifies and recovers the original signal after processing. As the key component of the optical receiver, the preamplifier determines the performance of the whole optical receiver to a great extent, and converts the weak current signal from the optical detector to the voltage signal and amplifies the signal in a certain amount. It is then outputted to a subsequent main amplifier. Therefore, the improvement of preamplifier performance is of great significance to the improvement of optical fiber transmission system. Based on 0.18 渭 m CMOS process, a transresistive preamplifier of RGC input optical receiver with AGC function is designed in this paper. The amplifier adopts RGC configuration at the input stage, which effectively broadens the bandwidth and increases the cross resistance. At the gain stage, the amplifier adopts a voltage parallel negative feedback structure and embed the automatic gain control technology AGC, in addition to expanding the input dynamic range. In order to realize the single-terminal signal output of the preamplifier can adapt to the two-terminal input of the subsequent main amplifier, a single-terminal converter differential circuit is designed at the output stage. The simulation results show that when the input optical power of the optical receiver is -10 dBm, the power supply voltage is 1.8 V, and the parasitic capacitance of the optical detector is 0.5pF, The transresistance gain of the transresistance preamplifier is 81dB 惟, the 3dB bandwidth is 2.25 GHz, the average noise current spectral density is about 6.0 Pa / Hz / 2, the optical sensitivity is -20 dBm, the input resistance is about 50 惟, and the internal power consumption is only 58 MV. Compared with the traditional transresistive preamplifier, the performance of this design, such as bandwidth, gain, sensitivity and power consumption, has been improved in varying degrees.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TN929.1;TN432

【共引文献】