DC to 6-Ghz high-gain low-noise GaInP/GaAs HBT direct-coupled amplifiers with and without emitter-capacitive peaking

Abstract

High-gain shunt-series shunt-shunt wideband amplifiers with and without emitter-peaking capacitors are demonstrated by using GaInP/GaAs HBT technology. Experimental results show that the power gain is 28 dB front DC to 6 GHz for a wideband amplifier without emitter-peaking capacitors. On the other hand, a wideband amplifier with emitter-peaking capacitors can increase the gain bandwidth up to 8 GHz at the cost of lower input/output return loss. Both circuits have similar power and noise performance. The noise figures of both designs are less than 2.8 dB for frequencies below 6 GHz,. Op(1dB) and OIP3 are 7 and 20 dBin at 2 GHz, respectively. Total current consumption is 67 mA at 5-V supply voltage for both wideband amplifiers. (C) 2004 Wiley Periodicals, Inc.