EFFECTS OF RECONSTRUCTION FILTERS IN DIGITAL PREDISTORTION LINEARIZERS FOR RF POWER-AMPLIFIERS

The reconstruction filters are a major source of error in digital pred istortion linearizers for RF power amplifiers, This paper presents a m ethod that enables these filters to be designed for lowest filter comp lexity and minimum degradation of the linearizer performance. Furtherm ore, a method to choose an appropriate sampling rate for the predistor ter is presented, Different filter approximations and orders are exami ned for different amplifier configurations by means of simulation, Of the filters tried, low-ripple Chebyshev and Butterworth filters perfor m best. It is demonstrated that it is possible to account for reasonab le filter misalignment with only a small degradation in performance. I t is also shown that the effect on the modulation is small with respec t to intersymbol interference.