A 150–175-GHz 30-dB <i>S</i> <sub>21</sub> Power Amplifier With 125-mW <i>P</i> <sub>out</sub> and 16.2% PAE Using InP HBT
Zach Griffith, Miguel Urteaga, Petra Rowell, Lan Tran
Abstract
We report a five-gain-stage 150–175-GHz solid-state power amplifier (PA, SSPA) monolithic microwave integrated circuit (MMIC) having modest 20–21-dBm output power <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {out}}$ </tex-math></inline-formula> , high gain, and high power-added efficiency (PAE). The transistor technology is 250-nm InP HBT. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{21}$ </tex-math></inline-formula> gain is 31.4 ± 1.2 dB from 100 to 178 GHz. The 3-dB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$S_{21}$ </tex-math></inline-formula> bandwidth is between 96 and 181 GHz. Typical return loss values for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert S_{11}\vert $ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vert S_{22}\vert $ </tex-math></inline-formula> exceed 8.5 and 10 dB, respectively. The dc power is 0.72 W. Across 150–175 GHz, the saturated output power <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {sat}}$ </tex-math></inline-formula> is 106–126 mW with 16–18-dB gain and 12.5%–16.2% PAE—peak values for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {out}}$ </tex-math></inline-formula> , gain, and PAE are at 170-GHz operation. The 1-dB gain compression <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {out}}$ </tex-math></inline-formula> (OP <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathrm {1\,dB}}$ </tex-math></inline-formula> ) is 30–60 mW. Across 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 (110–170 GHz), <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {sat}}$ </tex-math></inline-formula> is 82–126 mW with 9.1%–16.2% PAE. This work establishes a 1.62– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.89\times $ </tex-math></inline-formula> increase to PAE over 150–175 GHz operation at the output power and gain levels cited. It is also the highest RF output power demonstrated across the full 110–170-GHz WR6.5 waveguide band.