A polar linearisation system for RF power amplifiers

An new transmitter architecture for polar linearization of RF power amplifiers is presented. The architecture is adapted to digital transmitters which makes it possible to move some of the analog signal processing to the digital domain. An improvement of the varying loop-gain problem in feed back linearisation systems, that is easily incorporated in the new architecture is presented. This improvement increases the stability margin and reduces the variations of the bandwidth which leads to higher linearity of the system. Simulations documenting the improvements and showing important design constraints are presented