A multi-octave power amplifier and related method provides an impedance matching unit configured to match impedances of a pair of balanced radio frequency (RF) signals applied thereto and output a pair of impedance-matched balanced RF signals, a converting unit configured to convert the pair of the impedance-matched balanced RF signals to an unbalanced RF signal and a compensation unit configured to compensate at least one rolled-off frequency component of the unbalanced RF signal and output a compensated RF signal.