Design of High-Gain Sub-THz Regenerative Amplifiers Based on Double-<i>G</i> <sub>max</sub> Gain Boosting Technique
Dae‐Woong Park, Dzuhri Radityo Utomo, Byeonghun Yun, Hafiz Usman Mahmood, Jong-Phil Hong, Sang‐Gug Lee
Abstract
This article reports the concept of a double maximum achievable gain (double- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> ) core for the implementation of sub-terahertz high-gain amplifier design. The double- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> core is a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> core that adopts another linear, lossless, and reciprocal network that satisfies the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> condition onto an even number of cascaded transistor-level <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> cores. It is shown that the double- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> core, due to its regenerative nature, can achieve much higher gain per stage than that of the same number of cascaded <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> cores while satisfying the unconditional stability. Implemented in a 65-nm CMOS process, by adopting the proposed double- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$G_{\mathrm{ max}}$ </tex-math></inline-formula> core, 247- and 272-GHz two-stage amplifiers achieve the peak gain of 18 and 15 dB, the gain per stage of 9 and 7.5 dB, and the PAE of 4.44% and 2.37%, respectively, while dissipating 21.5 mW.