基于GaN宽带管芯的X波段功放设计

Design of An X Band Power Amplifier Based on GaN Broadband HEMT

本文在无大信号模型和静态I-V曲线下,应用小信号S参数,power tuned下的负载反射系数和线性模型,得到输出阻抗,应用宽带匹配进行阻抗设计。后加载偏置对S31进行仿真,并观测对S11的影响,从而保证扼流效果并且减小对匹配电路的影响。同时应用小信号S参数和输出阻抗得出输入阻抗,保证增益的平坦性。保证了在8-12GHz下,输出驻波VSWR<1.4,偏置隔离大于-30dB,小信号增益12.75dB,带内波动0.5dB。

A method to obtain output impedance and carry out impedance design by applying wideband match is put forward based on small signal S parameter, load reflection coefficient in power tuned and linear model （without large signal model and static I-V curve）. Simulation of S31 by adding load offset and observing impact on Sll is conducted to ensure choke effect and decrease impact on the match circuit; meanwhile to obtain input impedance by using of small signal S parameter and the output impedance, so as to ensure flatness of the gain. The method can guarantee that at the frequency of 8 - 12GHz, output VSWR 〈 1.4, offset isolation 〉 - 30dB, small signal gain is 12. 75dB, and in-band ripple is 0. 5dB.