本報告では，定在波同軸管法において，同軸構造の導体試料の内導体で生じる受動相互変調ひずみ(PIM)測定の感度を，内導体および外導体で消費される電力の観点から電磁界解析を利用して評価した.同軸構造の試料の内導体と外導体で消費される電力を計算するために，解析の上でそれぞれにポートを定義して，その両者の結合量を計算した.この際，内導体全面が外導体に覆われていると内導体に電力が印加されないため，外導体の長さを内導体よりも短くすることで内導体へ電力が印加されるようにした.結果として，本検討では外導体の長さが内導体の長さの0.8倍程度の場合に，各PIMに関連する周波数での内導体で消費される電力の量が大きくなることが確認できた.一方で，計算された結合量を利用して観測されるPIMレベルの変化の予測を行い，PIMレベルにおいても同様の傾向が見られることを確認した.%In this study, in the standing-wave coaxial tube method, the sensitivity of a passive intermodulation (PIM) measurement for an inner conductor of a coaxial line has been evaluated using an electromagnetic analysis in term of power consumption at the inner and the outer conductors. In order to calculate the power consumption, coupling strengthes between the coaxial tube and the specimen was obtained by definition of ports on the inner and the outer conductors. No power is consumed by the inner conductor when the outer condutor surrounds it. Therefore the inner condutor could be exited by the input powers by shortening the outer conductor. In the results, it was confirmed that the power consumption at the inner conductor was higher than that at outer conductor when a rate of the inner and the outer conductor was 0.8. On the other hand, the change of PIM levels was estimated using the coupling strengthes, and it was confirmed that the tendency of PIM levels was the same as that of the power consumption.
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