基于模式组合与降阶原理的径向功率合成理论及方法研究

As one of the key technologies for the development of high mm-wave region, power-combining technique has found important value not only in traditional military and civil applications, but also in high-speed broadband wireless communication, high resolution imaging and other roaring new applications. The combining efficient of radial-line power-combining will not obviously decrease with the increasing of combining ports number. With this characteristic, radial-line combining technique has been extensively concerned, especially in high mm-wave region. However, the radial-line combining schemes at home and abroad still follow the conventional thought in microwave band, which result in only a few available spatially symmetric modes. Therefore, the higher the operation frequency is, the more difficult in structural realization, isolation of interference mode and combining efficiency are. To address the above problem, a principle of radial time symmetry is proposed for the first time. Based on this principle, techniques of mode superposition and equivalent boundary matching are proposed to increase the available mode types in radial-line mode sets, and improve the interference mode suppression and synthesis efficiency of radial-line combiner. Then, a means of voltage vector transfer matrix analysis is proposed to accurately analyse the exciting condition of operating mode, as well as the type and isolation of interference modes. Further, the instability of non-fully matched network and digital polarization power combining technique are researched. At last, we will verify the above theories and methods in 3 mm to 1 mm band. Research results of this project have great applied value in the development of radial-line power combining theory and technique, as well as in the development and application of high frequency system.

功率合成是开发毫米波高频段的关键技术，不论是在传统军事与民用领域，还是在飞速发展的高速宽带无线通信和高分辨成像等新领域都有重要的应用价值。径向合成技术具有合成效率不随路数增加而明显降低的特性，在高频段备受关注。然而目前国内外均沿用微波频段的研究思路，工作模极少，在更高频段还存在结构实现难、干扰模抑制差和合成效率低等问题，频率越高这些问题越明显。针对上述关键问题，本项目提出了径向时间对称性原理，可解决传统径向合成只能采用个别空间对称模的现状。提出了组合模和等效边界降阶技术，可提高干扰模抑制。提出了径向网络电压矢量转移矩阵分析方法，可精确分析模式激励条件、干扰模类型及抑制度。提出了解决非全匹配网络失配稳定性问题的途径，提出了数字极化功率合成技术。并拟将以上理论和方法进行验证和应用评估。本项目的研究成果对径向合成理论与技术的发展和高频段系统应用的开发有重要作用和意义。

功率合成是开发毫米波高频段的关键技术之一，尤其是径向功率合成的合成效率不随合成路数增加而明显降低，在高频段备受关注。然而目前国内外均沿用微波频段的研究思路，仅有个别工作模可以使用，在更高频段还存在结构实现难、干扰模抑制差和合成效率低等问题，频率越高这些问题越明显。针对上述关键问题，本项目提出组合模和降阶模理论及其构建方法，研究了径向网络电压矢量转移矩阵理论，推导出了组合模和降阶模的激励条件和合成支路的幅相关系。完成了一种220 GHz组合模功分网络的设计，初步证明了新的模式具有更好的高频适应性；采用组合模，在90~94 GHz频段完成了16路合成网络和合成功放的验证，径向合成网络具有最高94 %的效率，模式转换效率83 %。高次降阶模合成网络的合成效率大于90%。本项目提出的基于组合模和降阶模的径向功率合成方法具有重要的理论价值且切实可行，是实现毫米波高频段固态功率合成放大器的一种新思路。