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

Abstract

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- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu{\hbox {m}}$</tex></formula> InGaP/GaAs HBT, 0.5- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu{\hbox {m}}$</tex></formula> AlGaAs/GaAs enhancement- and depletion-mode HEMT monolithic microwave integrated circuit technology. A modified <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$m$</tex> </formula> -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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$({ P}_{1\ {\rm {dB}}})$</tex></formula> 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.