高阶耦合模倒圆锥双重正弦同轴结构频率响应

Frequency response of high order coupled mode in a coaxial Bragg structure with negative tapered-double-sinusoidal grooves operating at 0.35 THz

摘要:

为了形成带宽窄、品质因数Q高、选择性好的同轴布喇格反射器，提出一种倒圆锥型双重正弦同轴结构设计。基于耦合模式理论，在普通正弦槽结构的基础上，叠加刻蚀周期较小的辅助正弦分布，在导体内外壁上增加倒锥度，形成倒圆锥型双重正弦同轴布喇格结构。通过FORTRAN软件仿真得出，与普通正弦槽相比，倒圆锥型双重正弦同轴布喇格结构的工作模式和竞争模式的带宽更窄，品质因数Q得到提高，残余旁瓣现象得到抑制。同时，竞争模式的中心谐振频率点远离工作模式，带隙重叠进一步分离，频率选择性得到提高。该结构设计简单，方法合理，可以更好地分离工作模式和竞争模式，构建高品质因数Q、高功率的单一高次模谐振腔。

Abstract:

A negative tapered-double-sinusoidal grooves structure is proposed in order to form a coaxial Bragg reflector with narrow bandwidth, high quality factor Q and good selectivity. According to the coupling mode theory, on the basis of the ordinary sinusoidal groove structure, the auxiliary sinusoidal distribution with smaller etching period is superimposed, and the negative taper is added on the inner and outer walls of the conductor to form the negative tapered-double-sinusoidal grooves coaxial Bragg structure. Through FORTRAN software programming, compared with that of the ordinary sinusoidal grooves, the bandwidth of the working mode and the competing mode of the negative tapered-double-sinusoidal grooves coaxial Bragg structure gets narrower, the quality factor Q gets greater, and the residual side lobe phenomenon is suppressed. At the same time, the center resonant frequency point of the competition mode is far away from that of the working mode, the band gap overlap is further separated, and the frequency selectivity is improved. The structure design is simple and reasonable, which can better separate the working mode and the competition mode, and is favorable to construct a single high-order mode resonator with high quality factor Q and high power.