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

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 from 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. OP1dB and OIP3 are 7 and 20 dBm at 2 GHz, respectively. Total current consumption is 67 mA at 5-V supply voltage for both wideband amplifiers. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 67–69, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20377 [ABSTRACT FROM AUTHOR]