A 112-142GHz Power Amplifier with Regenerative Reactive Feedback achieving 17dBm peak Psat at 13% PAE

A two-way power-combining amplifier operating from 112-142GHz is presented. Integrated in Infineon’s 0.13μm SiGe-BiCMOS technology, it delivers 17dBm of peak saturated power to a 50Ω load at 13% PAE. Five fully-differential, transformer-coupled amplifier stages per path provide 34dB of forward transmission gain. Each 5-stage PA consists of capacitively gain-enhanced pre-drivers operated from 1.5V, followed by an inductively gain-enhanced cascoded driver powered by 3.3V. BJT models relevant at frequencies beyond 100GHz are evaluated to outline the trade-off between stability and gain exploited in this work. The design and layout of a folded, fully-differential, λ/4 power combiner is also presented, along with a full two-port characterization of the power-amplifier prototype.