表面粗糙度一直在電路中扮演中有重要的影響，其中對於導體損耗已有許多相關的模型被提出已用於不同的情況。在毫米波應用中，有波導管實驗 (180~230) 表示表面粗糙度可能會有明顯的效應。為了確認這個現象，現有的模型將會和毫米波波導管測量結果比較。
相關的文獻回顧中有2個模型被選出，分別是Huray的雪球堆積模型 (Snowball model) 和二階微擾法 (Small perturbation method to 2nd order) ，對於每一個模型都有對應的MABLAB程式計算並分析實驗結果。在最後實驗結果會另外和傳統的粗糙度模型Hammerstad-Bekkadel formula 做比較並用來輔助理解先前兩模型的差異。
在實驗中會設計一群可拆式長方型波導管 (Rectangular waveguides) 並用來量測表面粗糙度所造成的導體損耗，模型所需表面粗糙度相關的參數則是用alpha step和電子顯微鏡做測量。
最後將波導管實驗的導體損耗和模型算出的結果做比較並且提出概略但直觀的解釋以總結實驗結果。

Surface roughness is always plays an important role in circuit industries, many relevant models has been proposed and tested in a various conditions. In millimeter wave applications, it turns out that that the conductor loss due to the roughness may be significant in a waveguide environment. To verify this, the existing surface roughness models will be examined to find a suitable model for G band frequency to account for the extra conductor loss.
Before the experimental confirmation, a literature review on various models was done and there’re 2 models that finally were chosen to be tested, the snowball model and the small perturbation method to 2nd order (SPM2). For each theory a corresponding MATLAB program was written to analyze the experimental results. At last, the well-known surface roughness model, the Hammerstad-Bekkadel (H-B) formula will be served as an aid to generalize the observations from the measurement results.
For the experiments, a group of simple rectangular waveguides were designed to measure the additional conductor loss from the roughness. The surface parameters needed in both theories were obtained from alpha step and scanning electron microscope (SEM) measurements.
At last the evaluated power loss will be compared with the one obtained from S-parameter measurement and a straightforward point of view will be given to explain every observed phenomena in the results.

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