平面链式功率合成放大器

Planar Chain Power Combining Amplifier

采用多端口平行微带线输出的功率合成放大器中,信号通道之间的距离可调范围较小,没有充足的空间放置单元放大器芯片及其偏置电路。本文针对这个问题,提出了一种微带平面链式功率分配/合成器结构。在该结构中,单元放大器的位置能够移到电路的侧边,各信号通道之间的距离可以根据需要进行选择。设计制作了一个包含4条支路的平面链式功率分配/合成电路;测试数据表明,其反射损耗在2.0～4.5 GHz的频带上小于13 dB,插入损耗小于0.8 dB。设计制作了一个包含4个单元放大器的平面链式功率合成放大器,在2.0～4.5 GHz频带上,其小信号增益为13～19 dB,与对应单元放大器的小信号增益吻合得较好。在3.2 GHz时的饱和输出功率为26.4 dBm,合成效率为85%。

The distance between signal paths is limited in the power combining amplifiers using parallel multi-port microstrip lines as the output ports. There is no enough room for the unit amplifiers and their biasing elements. With the problem, a planar chain power divider/combiner is presented in this paper. A four-path planar divider/combiner is designed and fabricated. Its measured results are given： the return loss is less than -13 dB on the wide bandwidth of 2.0-4.5 GHz. The insertion loss is less than 0.8 dB. Additionally, a four-element power combining amplifier is also designed and fabricated. Its small signal gain on the bandwidth of 2.0-4.5 GHz is 13- 19 dB, the saturated output power at 3.2 GHz is 26.4 dBm, and the power-combining efficiency is up to 85%.