TM模式同轴布喇格结构频率响应研究

Study on Frequency Response of TM Mode Coaxial Bragg Structure

摘要:

基于多波耦合理论，利用Fortran编程软件，以TM模式为工作模式，对工作在太赫兹频段的开正弦槽同轴布喇格反射器的频率响应进行了仿真研究。研究结果表明，在高频高阶TM模式下，竞争模式和所需工作模式带隙之间的带隙重叠可以通过初始相位差的逐渐增大得到明显改善；频响特性曲线的残存旁瓣可通过加窗技术得到有效抑制；加正圆锥或者倒圆锥渐变波纹时，工作模式影响较小，竞争模式会相应地偏离中心频带，对带隙重叠的分离也有一定的影响。研究为同轴布喇格反射器在太赫兹领域以TM模式工作提供了可能性。

Abstract:

Based on the modecoupling method and using TM mode as the working mode, the frequency response characteristics of a coaxial Bragg reflector with sinusoidal ripples were simulated with Fortran software. Results show that bandgap overlap between the competing and the desired working modes can be improved by increasing the initial phase difference. The residual sidelobes of the frequency response can be eliminated by applying Hammingwindow distribution. The bandgap overlap can be efficiently separated by using a coaxial Bragg structure with negative or positive cone ripple. This study offers an possibility for coaxial Bragg reflector to operate at terahertz frequency with TM mode.