A 2 5Gb/s depletion mode GaAs MESFET clock recovery and decision circuit is described,which applies 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 has proved to be able to deal with the input signal and produce a digital output signal after it being sampled by a clock signal.
