A Modified Boosting Transimpedance Amplifier with Channel Length Variation for Fiber Optical Communications

The design and simulation of a transimpedance amplifier (TIA) with different channel length is presented. The circuit consists of a Common Gate-Common Source (CG-CS) with an active feedback input stage followed by another Common Gate-Common Source stage. A series of different channel lengths (45 nm, 90 nm, 130 nm) were applied which are similar to the channel length modulation for a single channel length topology. In this work, the main focus is on obtaining the minimum input referred noise current and power consumption. The simulation results for this circuit were obtained as follows: Input referred noise current of (20.52 , 16.67 , 15.19 ) with a power consumption of (0.803 mW, 379.0 mW, 227.0 mW) corresponds to the above channel length series with a TIA gain of (44.02 dB, 43.00 dB, 44.08 dB) at a bandwidth of (1.58 GHz, 1.56 GHz, 1.30 GHz) on series with a constant supply voltage of 1V applied. The main motivation for above innovated results was to prove that the channel length variation behavior resembles the case of channel length modulation for a single channel length topology. Simulated results were achieved using LTspice software environment.