考虑寄生参数的高压GaN功率放大器漏极调制电路分析

Analysis of Drain Modulation for High Voltage GaN Power Amplifier Considering Parasitics

提出了一种适用于高压高功率GaN功率放大器的漏极调制电路。采用高压自举驱动电路并增加泄放开关管的方式以减小上升时间和下降时间。基于对寄生参数影响的分析及计算,提出了并联加电线的措施。此外,定量计算了提供脉冲大电流所需的储能电容容值。为了确保功率放大器的安全运行,提出了死区控制电路及时序控制电路。搭建了一台实验样机验证所提漏极调制电路设计的有效性,实验结果表明该样机的上升时间和下降时间均小于100 ns。

For high-voltage and high-power Gallium Nitride(GaN)power amplifiers,a drain modulation circuit with rapid rise and fall time is proposed in this paper.To decrease the rise and fall time,the high-side bootstrap drive circuit with an auxiliary discharge switch is proposed.The effect of the parasitics is analyzed based on calculation and the parallel bonding is proposed.The storage capacitance of power supply is calculated quantitatively to provide large pulse current.To ensure safe operation of the power amplifier,the circuit topology with the dead-time control and sequential control is proposed.Finally,a prototype is built to verify the drain modulation circuit design.The experiments prove that the rise time and fall time of the output pulse signal are both less than 100 ns.