Novel transit-time oscillator (TTO) combining advantages of radial-line and axial TTO
Xu Wei-Li, He Jun-Tao †, Ling Jun-Pu, Song Li-Li, Deng Bing-Fang, Dai Ouzhixiong, Ge Xing-Jun
       

Field distributions of different TM01 modes: (a) 0 mode, (b) π/2 mode, and (c) π mode.