Abstract: Under the demand of high integration、miniaturization and high performance for power amplifier in the transmit system, the compact and wideband GaN amplifier worked at integrated with switch was demonstrated in this paper. Based on the GaN power amplifier structure and matching optimization, the negative feedback circuits was adopted to reduce chip size and improve efficiency; and the amplifier-switch joint design method was adopted in this paper. The power amplifier and switches were cooperated designed to improve the chip function. The amplifier has reached the output power of more than 2 W and power added efficiency of more than 17%. In the meantime, the overall chip size has reduced to only 3.3 mm×2.5 mm. Compared the normal wideband amplifiers, the amplifier we demonstrated owns the advantages of small sizes、more integration and high power added efficiency, which has a promoting effect to the