The Verification of Linearizer for Wibro PAM

In this paper we designe the pre-distorter of linearizer for Wibro. The proposed pre-distorter apply with phase shifter and variable attenuator can be used to vary increasingly the phase and amplitude of signals to cancel inter-modulation distortion in the in-band spurious signal of power amplifiers. It’s also need to realize generator of inter-modulation distortion (IMD generator). A better approach makes a phase shifter have full variation in state not having variation level, variable attenuator have dynamic range broadly in state not having variation of phase, and IM generator is also made to generate components of inter-modulation distortion easily. We improved result of 12 dB that multi-carrier IMD characteristics is 25 dBc to 37 dBc in same state of 20% efficiency and 26 dB gain of PAM at 25 dBm output by applied with suggested pre-distorter. Index terms—pre-distorter, phase shifter, IM generator, variable attenuator, Wibro PAM.