High Efficiency <i>D</i>-Band Multiway Power Combined Amplifiers With 17.5–19-dBm Psat and 14.2–12.1% Peak PAE in 45-nm CMOS RFSOI
Siwei Li, Gabriel M. Rebeiz
Abstract
This article presents fully integrated power amplifiers (PAs) with eight-way low-loss power combining for <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 applications in the GlobalFoundries CMOS 45RFSOI process. The eight-way power combining (four-way differential) common source (C.S.) and cascode amplifiers are implemented using four-stage differential PA unit cells as building blocks. The eight-way power combining network is composed of a four-way balun-short-transmission-line (balun-STL) combiner and a conventional quarter wavelength transmission line (QWL TL) combiner. The simulated two-stage eight-way combiner <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> (loaded) ohmic loss is only 1.1–1.4 dB at 130–150 GHz. The eight-way power-combining C.S. amplifier has a small-signal gain of 24 dB at 140 GHz with a 1.2-V supply and a 3-dB bandwidth of 131–150 GHz. The saturated output power (Psat) and output 1-dB compression point (OP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1 dB</sub> ) are 16.8–17.5 and 13–14.2 dBm at 130–150 GHz, respectively. The corresponding peak power-added efficiency (PAE) is 11.7%–14.2%. The eight-way power combining cascode amplifier achieves a small-signal gain of 24.8 dB at 135 GHz with a 3-dB bandwidth of 133–148 GHz. The corresponding Psat is 16.3–19 dBm at 125–150 GHz with a peak PAE of 6.5%–12.1%. To the best of our knowledge, these PAs achieve the highest Psat and OP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1 dB</sub> at the <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 in CMOS.