基于波导-微带探针阵列的Ka全频段功率合成放大器的设计

Design of a Full Ka-Band Power Combining Amplifier Based on Waveguide-Microstrip Probe-Array

采用基于波导-微带探针阵列的四路波导空间功率分配/合成结构,研制了一种Ka全频段1 W功率合成放大器。该模块中集成了驱动放大器以提高整个功放的增益。利用镜像原理,简化了具有对称性结构的波导-微带四探针功率分配/合成网络的仿真设计。在分析了屏蔽微带线相关寄生模式的基础上,合理设计腔体结构,保证了合成放大器在全频段内稳定工作。实测结果表明,在26.5~40 GHz的Ka全频段范围内,连续波饱和输出功率大于30.5 dBm,小信号增益大于40 dB。合成效率全频带内大于84%,36 GHz以下频段高于88%。

In this paper,a full Ka-band 1 W power-combined amplifier module is proposed,using a four-way waveguide spatial power divider/combiner based on waveguide-to-microstrip（Wg-Ms） probe-array transition.A driver amplifier is integrated in the module to improve the gain of the amplifier.By using the image theory,the design of power divider/combiner with symmetrical structure is simplified.Based on the analysis of the parasitic mode of shielded microstrip,the cavity structure is designed reasonably to guarantee the stable operation of the amplifier in the full band.The measured continuous wave saturated output power of the amplifier module is higher than 30.5 dBm over the entire Ka-band and the small signal gain is greater than 40 dB.The estimated active power combining efficiency over the full band is greater than 84%,and higher than 88% within 26.5 to 36 GHz.