Analysis and design of an efficient, fully integrated 1–8 GHz traveling wave power amplifier in 180 nm CMOS

Abstract

Traveling wave amplifiers (TWAs) offer the advantage of broadband amplification and a closed set of equations that allow deriving the RF gain by means of treating TWAs as discrete transmission line approximations. Up to now, however, the significant losses associated with CMOS integrated inductors have been neglected. This work presents a new approach for determining the transmission line losses and phase constants that will bring about an enhanced gain prediction accuracy. The theory is verified by means of a realized design example. The working principle of the integrated DC supply inductor is discussed, whose performance is based on the inductors self-resonance effect. When applying a supply voltage Vdd of 2.4 V, the measured compression point P1 dB and the power added efficiency PAE at 2.4 GHz amount to 16.9 dBm and 19.6%, respectively. At 5.5 GHz, a value of 16.6 dBm for P1 dB and an associated PAE of 13.9% are achieved. The peak RF gain for these output power values reaches 11 dB, and values greater than 8 dB are obtained up to 7 GHz.