Design and Analysis of a DC–43.5-GHz Fully Integrated Distributed Amplifier Using GaAs HEMT–HBT Cascode Gain Stage

Design and analysis of a dc-43.5-GHz fully integrated distributed amplifier (DA) using a GaAs high electron-mobility transistor (HEMT) heterojunction bipolar transistor (HBT) cascode gain stage is presented in this paper. The proposed DA is fabricated in a stacked 2-μmInGaP/GaAs HBT, 0.5-μmAlGaAs/GaAs enhancement- and depletion-mode HEMT monolithic microwave integrated circuit technology. A modifiedm-derived network and an HEMT–HBT cascode amplifier with inductive peaking technique are investigated to enhance the bandwidth of the DA. The bias networks of the DA are fully integrated in a single chip without off-chip bias-T or bias components. The measured average small-signal gain is 8.5 dB. The measured minimum noise figure is 4.2 dB. The measured maximum output 1-dB compression point( P_1\ dB)and the maximum output third-order intercept point are 8 and 18 dBm, respectively. Moreover, the DA is successfully evaluated with an eye diagram measurement, and demonstrates good transmission quality.