Multichannel receiver and AGC for optical links

Multi-channel, fully integrated CMOS optical receivers combining with spatially modulated photo detector (SMPD) array, transimpedance amplifiers, and limiting amplifiers are presented. It demonstrates scalable channel numbers with minimum area overhead and low cross talk of less than 0.1 dB. The receiver array is implemented in 0.18 μm CMOS and provides 20 Gbps throughput (5Gbps × 4). The conversion gain of each channel is 116 dB Ω, and the input sensitivity is about -11dBm for BER of less than 10-12. Besides, a 10 Gbps receiver with automatic gain control (AGC) for TIA is proposed. It tolerates 15 dB dynamic range, and the gain peaking can be improved by more than 3dB.