Abstract:

To address the difficulty in combining low-frequency ultra-wideband power signals in a complex electromagnetic environment， this paper analyzed the causes of broadband resonance in the transmission line transformer during the application of broadband high-power combining and pointed out methods to improve low-frequency response， suppress in-band resonance， and enhance power capacity； it improved the broadband performance characteristics of the transmission line transformer model and developed a combiner covering 9 kHz~100 MHz with a loss of less than 0.6 dB and a power capacity of greater than 5 kW using the even-odd mode analysis method. This model and design method can guide the design of broadband high-power combiners in the VLF/VHF band and has a positive promoting effect on the development of low-frequency ultra-wideband high-power amplifiers and the research on high-permeability and low-loss magnetic materials.

Key words: transmission line transformer, ferrite, broadband combiner, even-odd mode analysis method, BALUN, parasitic parameter

摘要：

针对复杂电磁环境中低频超宽带功率信号合成困难的问题，分析了传输线变压器在宽带大功率合成应用时，发生宽带谐振的原因，指出了改善低频响应、抑制带内谐振、提升功率容量的方法，完善了传输线变压器模型的宽带性能特征，并采用奇偶模分析法研制了一种覆盖9 kHz~100 MHz，损耗小于0.6 dB，功率容量大于5 kW的合成器。此模型和设计方法可以指导VLF/VHF频段的宽带大功率合成器设计，对低频超宽带大功率功放的研制、高磁导率低损耗磁材料的研究具有积极的促进作用。

关键词: 传输线变压器, 铁氧体, 宽带合成器, 奇偶模分析法, 巴伦, 寄生参数