Q波段高线性高效率GaN功率放大器MMIC

Q-Band GaN Power Amplifier MMIC with High Linearity and High Efficiency

针对卫星通信和5G毫米波通信应用,基于深亚微米GaN工艺,开发了一款高功率、高线性和高效率的功率放大器单片微波集成电路(MMIC)。根据器件的最大增益和负载牵引特性确定末级晶体管的总栅宽;根据增益要求采用4级放大器级联,前级、次前级、末前级和末级的栅宽比为1∶2∶4∶8;通过对末级和前三级栅极偏置电压分别加电,实现对各级电路增益分别调节,以提高放大器的线性度;输出匹配网络中包含了二次谐波调谐电路,以降低谐波分量,提高放大器的效率,并结合片外模拟预失真电路实现线性度提升。功率放大器MMIC芯片尺寸为2.6 mm×2.1 mm。测试结果表明,在37~42 GHz,放大器的饱和输出功率大于40 dBm,功率附加效率大于30%,功率增益大于18 dB,三阶交调失真(IMD3)@36 dBm小于-30 dBc。

Based on the deep submicronmetre GaN process,a high power,high linearity and high efficiency power amplifier monolithic microwave integrated circuit(MMIC)applied in satellite communication and 5G millimeter-wave communication was developed.The total gate width of the final stage transistor was determined by the maximum gain and loadpull characteristics of the device.A four-stage amplifier was adopted according to the gain requirement.The gate width ratio of transistors in the first,second,third and final stage is 1:2:4:8.By adjusting the gate bais voltages of the final stage and the first three stages respectively,the gain of each stage of the circuit can be adjusted separately to improve the linearity of the amplifier.The output matching network included the second harmonic tuning circuit to reduce the harmonic components and improve the efficiency of the amplifier,and the linearity improvement was realized with the off-chip analog pre-distortion circuit.The chip size of the power amplifier MMIC is 2.6 mm×2.1 mm.The test results show that at 37-42 GHz,the amplifier has a saturation output power greater than 40 dBm,a power added efficiency greater than 30%,a power gain greater than 18 dB,and a third-order intermodulation distortion(IMD3)@36 dBm greater than-30 dBc.