Baseband injection provides a useful approach for use in linearizing power amplifiers. The challenge is the determination of the required baseband signal. In  a generalized formulation quantifying the baseband voltage signal, injected at the output bias port, to linearize the device behavior was introduced. This envelope domain based solution requires the determination of only a small number of linearizing coefficients. More importantly these coefficients should be stimulus, hence bandwidth independent. This property has been experimentally investigated using a 10W Cree GaN HEMT device under a 3-tone modulated stimulus at 1.5dB of compression. It will be shown that the linearization coefficients were invariant when varying the modulation bandwidth from 2MHz to 20MHz.
Ogboi, F. L., Tasker, P. J., Akmal, M., Lees, J., Benedikt, J., Ben Smida, S., Morris, K., Beach, M., & McGeehan, J. (2014). High bandwidth investigations of a baseband linearization approach formulated in the envelope domain under modulated stimulus. In 2014 44th European Microwave Conference (pp. 1305-1308). IEEE. https://doi.org/10.1109/EuMC.2014.6986683