<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hui-Qi Bian</style></author><author><style face="normal" font="default" size="100%">Chao-Hai Du*</style></author><author><style face="normal" font="default" size="100%">Shi Pan</style></author><author><style face="normal" font="default" size="100%">Pu-Kun Liu*</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Terahertz frequency- and mode-insensitive broadband quasi-optical converter antenna system</style></title><secondary-title><style face="normal" font="default" size="100%">ournal of Infrared Millimeter and Terahertz Waves</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://link.springer.com/article/10.1007/s10762-018-0523-1</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">1065-1078</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Recently emerged multimode gyrotron, a high-power broadband terahertz radiator, encounters the challenge of efficiently converting a series of operating whispering-gallery modes (WGMs) into free-space Gaussian beams. To this demand, we propose a frequency- and mode-insensitive antenna capable of broadband multimode converting. For a single mode, to achieve broadband operation, special reflector configuration and large-radius launcher guarantee the system high robustness to frequency-induced wave number variation. Furthermore, for a series of operating WGMs, in order to achieve multimode operation, high-order mode indices guarantees familiar field patterns and ray trajectories. In particular, high-purity Gaussian beams are simultaneously achieved in different WGMs of broad continuous bands, including 351–361&amp;nbsp;GHz for TE11,2&amp;nbsp;mode, 375–385&amp;nbsp;GHz for TE12,2&amp;nbsp;mode, and 398–410&amp;nbsp;GHz for TE13,2&amp;nbsp;mode. The results are verified by both the vector diffraction theory and the method of momentum. This kind of mode converter will promote the development of multimode gyrotrons and other antenna-feeder systems for high-power terahertz applications.</style></abstract></record></records></xml>