现代光通讯中的全集成CMOS限幅器及场强指示电路

A Fully Integrated CMOS Limiter and RSSI Circuits for Modem Optical Communications

针对各种光通信系统和射频通信系统中的应用,设计了一款限幅器及场强指示器(RSSI)电路,提出了一种新的直流漂移补偿方案,可使限幅器部分更加适合于全集成。对传统的RSSI电路作出了改进,大大提高了其工艺稳定性和温度稳定性。设计的限幅器具有72dB的电压增益,可以对载波为1.5MHz、带宽为1MHz的中频信号进行放大;RSSI部分的动态范围为80dBm,场强检测的误差小于±1dB。

This article introduces a limiter and received signal strength indicator（RSSI） circuit, which is used m optical and radio frequency communicatioin systems. A new DC offset cancellation technique is proposed in order to make the circuits more suitable for fully integrating. The traditional RSSI circuit is also improved for the purpose of stability under different process and variable temperature. The proposed limiter has 72 dB voltage gain and can amplify the 1.5 MHz intermediate frequency signal with 1 MHz bandwidth. The dynamic range of the RSSI circuit is 80 dBm and its error is less than ＋1 dB.