| 摘要 |
Methods for matching adaptive hybrids ( 15 ) to lines ( 16 ) for making reflectograms of the lines ( 16 ) measure ( 1 ) input impedances (Z<SUB>meas</SUB>) of the lines ( 16 ), model ( 2 ) characteristic impedances of the lines ( 16 ) via physical models (Z<SUB>phymod</SUB>), estimate ( 3 ) parameters of the physical models (Z<SUB>phymod</SUB>) via cost functions which depend on the measured input impedances (Z<SUB>meas</SUB>), convert ( 30 ) the modelled characteristic impedances into impedance values ( 13 ), and set ( 31 ) the adaptive hybrids ( 15 ) with the impedance values ( 13 ). Unwanted near-end reflections are minimised and wanted reflections can be measured. The physical models depend on frequencies s, Bessel functions J<SUB>i </SUB>and parameters a<SUB>i </SUB>related to geometrical dimensions A, D and L and material constants sigma, epsilon and mu of the lines ( 16 ). The method may further model ( 6 ) characteristic impedances of the lines ( 16 ) via rational function models (Z<SUB>rafumod</SUB>) and estimate ( 7 ) parameters of the rational function models (Z<SUB>rafumod</SUB>) via further cost functions which depend on outcomes of the physical models (Z<SUB>phymod</SUB>).
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