A <i>D</i>-Band SiGe Power Amplifier Using a Four-Way Coupled-Line Wilkinson Combiner
Sunil G. Rao, John D. Cressler
Abstract
This letter presents a four-way power-combined <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D$ </tex-math></inline-formula> -band silicon–germanium (SiGe) power amplifier (PA), which simultaneously achieves high output power and high efficiency. A 4-to-1 planar coupled-line Wilkinson combiner is used, which has low loss and provides broadband impedance transformation. The PA is designed in a 90-nm SiGe BiCMOS technology platform and operates over a bandwidth of 110–145 GHz, with 18.2 dB of gain. The design achieves a peak output power of 21.9 dBm at 130 GHz, with a power-added efficiency (PAE) of 12.5%. The PA maintains greater than 20-dBm output power with greater than 8.7% PAE, from 115 to 140 GHz. This work demonstrates the first silicon-based <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$D$ </tex-math></inline-formula> -band PA, which simultaneously achieves greater than 20-dBm output power and 10% PAE.