Application of Microwave and Millimeter-wave Circuit Technologies to InGaP-HBT ICs for 40-Gbps Optical-transmission Systems

Application of microwave and millimeter-wave circuit technologies to InGaP-HBT ICs for 40-Gbps optical-transmission systems is demonstrated from two aspects. First, ICs for various important functions-amplification of data signals, amplification, frequency doubling, and phase control of clock signals - are successfully developed based on microwave and millimeter-wave circuit configurations mainly composed of distributed elements. A distributed amplifier exhibits >164-GHz gain-bandwidth product with low power consumption (P c ) of 71.2mW. A 20/40-GHz-band frequency doubler achieves wideband performance (40%) with low P c (26 mW) by integrating a high-pass filter and a buffer amplifier (as a low-pass filter). A compact 40-GHz analog phase shifter, 20- and 40-GHz-band clock amplifiers with low P c are also realized. Second, a familiar concept in microwave-circuit design is applied to a high-speed digital circuit. A new approach -inserting impedance-transformer circuits - to enable 'impedance matching' in digital ICs is successfully applied to a 40-Gbps decision circuit to prevent unwanted gain peaking and jitter increase caused by transmission lines without sacrificing chip size.