Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled...http://www.google.de/patents/US7526261?utm_source=gb-gplus-sharePatent US7526261 - RF power transmission, modulation, and amplification, including cartesian 4-branch embodiments
