基于功率合成器的北斗射频功率放大器设计

Beidou RF Power Amplifier Design Based on Power Combiner

针对当前应用于北斗卫星系统的射频功率放大器的小功率、低效率、高成本等缺点,本文提出一种基于功分合路器的改进型三级级联射频功率放大器设计方案。利用负载牵引法对末级功率放大器进行设计,利用集总参数与分布参数相结合的技巧对微带低通滤波器进行设计,利用小信号S参数法对前置级放大器进行设计。通过详细的理论分析和仿真优化,结合射频硬件电路和结构的设计要求,实际制作并实现稳定高效的30 W射频功率放大器设计。该方案可使低供电电压的小功率射频器件实现较大功率输出,并较好地兼顾线性度和效率。

Aiming at the shortcomings of low power,low efficiency and high cost of RF power amplifiers currently used in Beidou satellite system,an improved three-stage cascaded RF power amplifier design based on power split combiner was proposed. The final stage power amplifier was designed by load-pull method. The microstrip lowpass filter was designed by combining the lumped parameters and distribution parameters. The pre-amplifier was designed by the small-signal S-parameter method. Through detailed theoretical analysis and simulation optimization,combined with the design requirements of radio frequency hardware circuits and structures,a stable and efficient 30 W RF power amplifier design was actually produced and implemented. The scheme can use low-power radio frequency devices with low supply voltage to achieve higher power output,and better balance the linearity and efficiency.