Analysis and experiment for drain bias dependence of IMD sweet spots in GaN HEMT power amplifier

A load network for Doherty amplifiers using an optimized impedance transformer

“…The Doherty amplifier has been known for its significant efficiency enhancement, as well as a good linearity, because of its load impedance modulation and third-order intermodulation (IM3) cancellation properties [1][2][3][4][5]. The IM3 performance of the Doherty amplifier has been known to be better than the class-AB amplifier, because the third-order complex power-series coefficients of the carrier and peaking amplifiers (g m3,C and g m3,P , respectively) can be optimized to be of equal magnitude and 180°out of phase using bias adjustment [4 -7].…”