Determination of bit-rate and sensitivity limits of an optimized p-i-n/HBT OEIC receiver using SPICE simulations

The sensitivity of an OEIC receiver depends essentially on the physical sources of device and circuit noise referred to its input, provided that the inter-symbol interference (ISI) makes no significant contribution. For well designed receivers, the latter situation can be realized only at an optimum bandwidth (f/sub 3 dB.opt/) for a given bit rate (B) or vice versa. In this paper, we have determined the relationship between the bit rate and the 3-dB bandwidth for negligible and pre-set levels of ISI for an optimized p-i-n/HBT transimpedance receiver with adjustable bandwidth. We have used SPICE simulations in the frequency domain to determine the effect of device and circuit noise, and SPICE transient analysis to determine the effect of ISI on the sensitivity. The ratio f/sub 3 dB.opt//B has been found to vary from 0.65 to 0.45 when B changes from 10 to 20 Gbps for the OEIC receiver used.