A Q-band compact amplifier with +22 dB gain, ± 0.5 dB flatness over 40% Fractional Bandwidth in Tower 130 nm CMOS

This paper proposes an enhanced differential Cascode amplifier topology for mm-wave applications requiring wide-band amplification, flatness and compact integration area. It is here shown how to combine positive and negative feedbacks to improve drastically the stable gain of a Cascode amplifier. In addition with the use of compact 4th order transformers, a 2-stages amplifier with up to 11 dB gain per stage over 40 % fractional bandwidth and above fmax /2 is demonstrated while demonstrating as well one of the smallest core area (0.08 mm2). This topology presents currently a record small signal gain per stage at this technology node (fT/fmax of 87/90 GHz). The presented amplifier topology can be used repetitively and reliably to create wide-band amplifiers with state-of-the-art gain, flatness and return loss over small area. The circuit was realized using Tower's 130 nm CMOS.