Design And Simulation Of Preamplifier For10Gb/s Optical Receiver

The optical receiver circuit is an important feature for the optical interconnectionsystem. The preamplifier is a key component of the optical receiver and largelydetermines the performance of the entire optical receiver. The researchers’ studyfocuses on the bandwidth, gain and noise of the preamplifier, so the design andsimulation of the preamplifier for the10Gb/s optical receiver in0.13μm CMOS hasbeen done in this paper.Firstly, the low resistance, high resistance and transimpedance amplifier isintroduced in this paper, and the transimpedance amplifier due to the large bandwidthand high dynamic range is selected as the basic structure of the pre-amplifier circuit.RGC structure because of the advantages of the low input impedance and stable DCoperating point is used as the input of the transimpedance amplifier which can avoidthe parasitic capacitance of the optical detector impacting on the bandwidth of thepreamplifier. From the simulation results, the bandwidth using RGC structure is8.63GHz, and the bandwidth is improved by30.5%; when the parasitic capacitance ofthe optical detector ranges from0.2pF to0.3pF, bandwidth is essentially unchanged.And then, the bandwidth by using inductive shunt peaking and passive networkbandwidth matching technology is further expanded, and the improved preamplifiercircuit structure is achieved. Using Cadence Spectre to simulate, the results show thatwhen the optical detector capacitance is typically0.25pF and the voltage source is1.8V,the-3dB bandwidth of the preamplifier reaches8.43GHz, which is enhanced by13.5%,and it meets the requirement of the10Gb/s operating speed. The feedback resistor Rfisoptimized, which enhances the gain and reduces noise, and the gain of the circuit is upto60.2dB and the input referred noise current is36.3pA Hz. Finally, the improvedstructure of the pre-amplifier circuit is implemented with layout.