High speed InP HBT driver IC for laser modulations

초록

High-speed IC for time-division multiplexing (TDM) optical transmission systems have been designed and fabricated by using InP heterojunction-bipolar-transistor (HBT) technology. The driver IC was developed for driving external modulators, featuring differential outputs and the operation speed up to 10 Gbps with an output voltage swing of 1.3 V-PP at each output which was the limit of the measurement. Because -3 dB frequency was 20 GHz, this circuit will be operated up to 20 Gbps. 1.3 V-PP differential output was achieved by switching 50 mA into a 50 Omega load. The power dissipation of the driver IC was I W using a single supply voltage of -3.5 V. Input and output return loss of the IC were better than 10 dB and 15 dB, respectively, from DC to 20 GHz. The chip size of fabricated IC was 1.7 x 1.2 mm(2).