2.5Gb/s GaAs MESFET clock recovery and decision circuit

A 2.5Gb/s depletion-mode GaAs MESFET clock recovery and decision circuit are described, which are applied to the optical fiber communication. The circuit consists of a clock recovery circuit including a preprocessor, phase detector (PD), low-pass filter (LPF) and voltage controlled oscillator (VCO) and a decision circuit including a comparator and a latch. The SPICE simulation result confirms the high frequency 2.5GHz of the clock recovery and the high speed 2.5Gb/s of the decision circuit. The 2.5Gb/s decision circuit proved that it is able to deal with the input signal and produce a digital output signal after it being sampled by a clock signal.