Abstract: This paper presents the design and the realization of a two-stage asymmetric continuous-mode class-B/ J Doherty power amplifier using Quasi-MMIC technology. When the impedance inverter network of carrier power amplifier is mismatched, the effect of non-infinity output impedance of peaking amplifier on the load impedance variation of the carrier stage is analyzed. Therefore, the impedance design space of continuous-mode class-B/ J Doherty amplifier is extended, which can increase bandwidth while maintaining high back-off efficiency. Moreover, this method is more universal because it is not necessary to extract packaging parameters of the die and select specific die. Based on this method, a quasi-MMIC continuousmode Class-B/ J Doherty power amplifier operating in 2. 3 - 2. 7 GHz frequency band is designed and fabricated. The measured results show that the output power is higher than 35 dBm, and the drain efficiency is higher than 36% around 8 dB back-off.