Reactive Near-field to Far-field Transformation at 30 to 150MHz

抄録

In this paper, radiation patterns of a small loop antenna (l<λ/10) were estimated by reactive near-field (E- and H- field) obtained by FIT (Finite Integral Technique) analysis at 30 to 150MHz applying the equivalent theorem. Then, accuracy of estimation was examined by variations of sampling intervals of reactive near-field on a virtual closed surface S (L×L×L) divided into Δx=Δy=Δz. As a result, an estimated result at the condition of Δx=Δy=Δz=L/30 was good agreement with the simulation (MW-studio/CST) within 0.3dB difference. Moreover differences of estimated results, between the minimum interval (L/30) and the maximum interval (L), were within 3.05dB at 30MHz, 3.44dB at 75MHz, and 3.56dB at 150MHz.