Sun Yunfei, He Juntao, Yuan Chengwei, Zhang Qiang
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, People's Republic of China.
Rev Sci Instrum. 2018 Aug;89(8):084701. doi: 10.1063/1.5035179.
A novel mode converter that can transform coaxial transverse electromagnetic (TEM) mode into circularly polarized TE (CPT) mode was developed and experimentally studied with high-power microwave (HPM). The mode conversion is realized by two steps. First, the TEM mode is converted into linearly polarized TE (LPT) mode by the webbed-shaped structure. Second, the LPT mode is transformed into the CPT mode with the insertion of circular-arc diaphragms in a circular waveguide. In this paper, the principle of a mode converter working at 1.57 GHz is demonstrated, as well as the experimental results. The experimental and simulation results are in good agreement. At the central frequency, the conversion efficiency is more than 99.5%, the measured axial ratio approximates to 1.39 dB, and the power handling capacity is in excess of 1.5 GW. These measured results meet the demand for narrow-band HPM source application.
一种能够将同轴横向电磁（TEM）模式转换为圆极化TE（CPT）模式的新型模式转换器被研制出来，并使用高功率微波（HPM）进行了实验研究。模式转换通过两个步骤实现。首先，通过网状结构将TEM模式转换为线极化TE（LPT）模式。其次，通过在圆形波导中插入圆弧形膜片将LPT模式转换为CPT模式。本文阐述了工作在1.57GHz的模式转换器的原理以及实验结果。实验结果与模拟结果吻合良好。在中心频率处，转换效率超过99.5%，测得的轴比约为1.39dB，功率处理能力超过1.5GW。这些测量结果满足窄带HPM源应用的需求。
