Yadav Rana Pratap, Kumar Sunil, Kulkarni S V
Thapar University, Patiala, Punjab 147004, India and Institute for Plasma Research, Gandhinagar 382428, India.
Rev Sci Instrum. 2016 Jan;87(1):014703. doi: 10.1063/1.4939481.
Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.
本文介绍了基于带状线的1.5兆瓦、30 - 96兆赫超宽带高功率3分贝混合耦合器的设计和开发过程，并讨论了其在托卡马克离子回旋共振加热（ICRH）中的适用性。对于高功率处理能力，导体与地之间的间距需要非常大。因此，诸如带材宽度、带材厚度、耦合间隙和结等其他结构参数也会变大，这可能会达到最佳极限，此时诸如制造公差、不连续性以及更高TE和TM模式的激发等各种限制会变得突出，并显著恶化耦合线系统的期望参数。在设计的混合耦合器中，两条8.34分贝耦合线串联连接以获得3分贝的期望耦合，并且使用空气作为电介质。对于1.5兆瓦的功率处理能力，地与导体之间的间距取为0.164米。为了获得期望的间距，每个8.34分贝段的内部尺寸设计为3.6×1.0×40厘米，其中在1.5兆瓦混合耦合器的设计中已经显著地认识到、补偿并应用了这些限制，并在本文中进行了介绍。
