Abstract

This paper proposes a method for performance improvement of multi-stacked CMOS millimeter-wave power amplifiers based on negative capacitance phase detuning, which can be generalized to other phase detuning techniques. It not only yields better inter-stage matching between stacks, but also offers the advantage of relaxed inter-stage phase rotation due to transistor parasitics. A x1.6 output power/gain and 7% efficiency improvement is observed as a result of the proposed technique. This is achieved because phase misalignment between stacks is minimized. The method is evaluated using simulations based on 28GHz PA in 45nm CMOS technology.