圆形槽波导振荡器中径向盘厚度和阻抗的关系

为了实现具有较大阻抗的圆形槽波导与阻抗较小的有源器件之间的阻抗匹配,在W波段圆形槽波导振荡器中采用了径向盘结构,通过改变径向盘的厚度来调节输入阻抗的大小.用完全匹配层将圆形槽波导的开放边界截断为有限区域后,应用有限元法分析基于圆形槽波导的毫米波元件.为了避免传统的有限元方法所遇到的伪模式问题,选用了棱边元对圆形槽振荡器中的径向盘结构的输入阻抗进行数值计算.得出了频率在85～100GHz之间,对应于不同的径向盘厚度的输入阻抗.径向盘的厚度小于0.3mm时输入阻抗较小.计算结果为用于W波段圆形槽波导振荡器的径向盘的优化设计提供了依据.

Relationship between input impedance and radial disk thickness in circular groove guide oscillator

In order to match the widely different impedances between circular groove guide and millimeter wave semiconductor device, the radial disk structure is used in W-band oscillator based on circular groove guide. By varying the radial disk thickness, the input impedance can be changed. Perfectly matched layer (PML) is applied to truncate the open boundary of circular groove guide to fulfill the requirement of limited domain that the finite element method (FEM) can proceed. The input impedance from 85 to 100 GHz was calculated by tetrahedral edge element to eliminate spurious solutions. When thickness is less than 0.3 mm, the input impedance of the radial mount is relatively low. The numerical results that the impedance changes with the disk thickness are very useful for design and adjustment of W-band circular groove guide oscillators.