GaAs monolithic gain controllable amplifier for 2Gb/s optical transmission

Recently, ultra high-speed analog ICs for gigabit/s optical digital transmission have been investigated by mainly using Si-bipolar IC technologiest 1H2]. However, use of the GaAs-MESFET IC technologies is atractive for monolithic integration of repeater circuits operating at more than 2Gb/s because of their high-speed performance. For gain controllable amplifier used in multi-gigabit/s repeater, high gain and wideband characteristics are strictly required. To meet these requirements, we have developed a 4-stage gain controllable amplifier with new circuit configuration. In this paper, first, the new circuit configuration of the gain controllable amplifier is proposed. Next, circuit design and performance of the amplifier monolithieally integrated by using 0.7μm-gate GaAs-MESFET IC technology[3] are described.