Effect of random corrugation errors on reflection characteristics of coaxial Bragg structure with rectangular ripples

By using the mode-matching method, a theoretical model is presented to analyze the reflection characteristics of the coaxial Bragg structures corrugated with rectangular ripples, where the inner-rod and outer-wall ripples have random parameters due to fabrication error. Numerical simulations are carried out to investigate the effect of the errors of the corrugated depth, corrugated width, length of period and ripple position on the reflectivity frequency response for a coaxial Bragg structure which operates with TEM mode in the vicinity of 220 GHz. Numerical results reveal that, with a given range of error values, the random errors of corrugated width and ripple position have less influence on the reflection spectrum, while the random errors of corrugated depth and length of period critically affect the reflection properties of the example structure. Therefore, the manufacturing tolerances of these two parameters should be strictly controlled in accordance with the performance of the devices employed with coaxial Bragg structures. The theoretical model as well as the corresponding numerical code may provide engineering references for further applications of the coaxial Bragg structure with rectangular ripples.