Active Compensation of Higher Harmonics in a Switched-Mode RF PA

The estimate of total harmonic distortion (THD) correction capability was given when having non-ideal phase or amplitude alignment in active compensator of higher order harmonic components. The estimate of efficiency loss due to usage of harmonic compensator in a switch mode power amplifier (PA) was given. For example, efficiency of PA decreases by 7-10% when total harmonic distortion KTHD= 20% and active compensator used. Moreover, amplitude and phase deviation in the active compensator results in less compensation capability. Achievable higher harmonics level reduction is more than 40 dB, when amplitude deviates less than 1% or phase error is no more than 2.5 deg.