为了改善平面型功率合成放大器的性能,提出了一种基于双层平面电路的功率合成放大器设计方法.该放大器采用双层的平面功率分配/合成器结构以实现更高的集成度;为有足够的空间放置放大器芯片及其偏置元件,引入了直角微带转换头将放大器的位置引到电路的侧边;放大器的位置沿输入/输出轴向两边错开以提高散热性能.文中还设计、制作了一个包含4条支路的双层平面功率分配器和一个包含4个单元的双层平面功率合成放大器,并对其进行了测试,结果表明,该功率合成放大器在2.0~4.5GHz频带上的小信号增益为10~16 dB,在3 GHz时的饱和输出功率为25.9 dBm、功率合成效率为81%,说明这种设计方法是有效的.

In order to improve the performances of planar power-combining amplifiers,a power-combining amplifier based on the double-layer planar circuit is designed,which employs a double-layer planar power divider/combiner to improve the integration degree,introduces a right-angle microstrip bend to place the amplifiers and their biasing elements on the sides of the input-output axis to make enough room,and locates the amplifiers on the two sides of the input-output axis for heat dissipation.Afterwards,a four-path power divider and a four-element power-combining amplifier are designed,fabricated and tested.The results show that the proposed power-combining amplifier is of a small-signal gain of 10~16 dB over a wide bandwidth of 2.0~4.5 GHz,a saturated output power of 25.9 dBm at 3 GHz and a power-combining efficiency of 81%.It is thus concluded that the proposed design method is feasible.