Radio frequency designed a quadrature hybrid divider for the load-tolerant ICRF system on EAST

• Published in: Fusion engineering and design 2023-11, Vol.196, p.114026, Article 114026
• Main Authors: Yang, H., Yuan, S., Zhang, X.J., Liu, L.N., Qin, C.M., Chen, Y., Zhang, K., Wang, L., Chen, Q.Q., Qiu, S.C.
• Format: Article
• Language: English
• Subjects: Hybrid divider; ICRF; Load tolerant
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2023.114026

•The power divider is capable of effectively maintaining the stability of the ICRF system during long-pulse operation.•The power divider has a simpler structure and smaller size compared to those mentioned in previous literature, making it easier to manufacture and active water cooling.•The measurement results of the designed power divider show excellent reflection performance and isolation. A quadrature power divider designed for EAST uses a metal plate and coaxial line structure and operates at frequencies ranging from 27 to 45 MHz. The key parameters for the power divider, including central frequency, transmission coefficient, and phase dependence of output ports, are obtained through radio frequency simulation by CST MWS and optimized to achieve reflection and isolation levels below −24 dB with a bandwidth of 20 MHz. The power divider is tested at low power levels, confirming its reliability, and demonstrating a ±10 degree tolerance for phase management during synthesis. With its simple structure, excellent RF performance, and water cooling capability, the power divider is an important component for improving the stability of the ion cyclotron heating system.