Analysis and Design of Lossy Capacitive Over-Neutralization Technique for Amplifiers Operating Near fMAX.

This paper proposes a technique to enhance the maximum achievable power gain (GMAX) of the two-port active network (2PAN) in the near-ƒMAX region. This technique is based on using the optimized passive-linear-lossy-reciprocal (PLLR) embedding to increase the unilateral power gain (U) of the 2PAN and accordingly the GMAX. Due to the possibility to increase U, it shows the potential to improve the conventional gain-boosting approach which relies on the passive-linear-lossless-reciprocal (PLLLR) embedding and keeps the U constant. The concept itself is demonstrated on pseudo-differential NMOS pair using lossy capacitive feedback as the PLLR. This structure can serve as a basis for further gain optimization by implementing additional PLLLR embedding on top of it. Finally, by using the mentioned technique, a 190GHz amplifier is implemented in 28nm bulk CMOS technology, achieving 14.3dB of gain with 1.5dBm of PSAT and 2.6% of maximum PAE. [ABSTRACT FROM AUTHOR]