Abstract: A reconfigurable ultra-wideband power amplifier based on filter-based biasing is proposed to accommodate the rapid development of 5G intelligent wireless communication systems. This paper designs a dual-band reconfigurable power amplifier based on the filter bias principle, reconfigurability theory and wideband input-output matching theory, which can operate in the continuous frequency band. The power amplifier operates in two frequency bands ranging from 0.7 GHz~2.2 GHz and 2.1 GHz~ 3.6 GHz, and the input and output are realized by a single-pole, single-throw switch and a single-pole, double-throw switch, respectively, based on PIN switches for switching the amplifier′s operating frequency band. Through the actual measurement, the amplifier in the range of 0.7 GHz ~2.2 GHz and 2.1 GHz ~3.6 GHz, the gain is 11.9 dB~13.6 dB and 10.7 dB~12.4 dB respectively; the power added efficiency (PAE) is 63.8%~72.7% and 60.3%~68.8% respectively; the saturation output power is about 41 dBm.The design takes into account the bandwidth, gain, PAE and output power of the amplifier to better suit the development of 5G wireless communication systems.