For simplicity of presentation, we will henceforth consider the assumption of impedance-matched blocs. When the bloc is considered impedance-matched, then the reflected wave b 1( t) at the input and the incident wave a 2( t) at the output are zero, so that, using the power wave formalism, the number of electrical variables is divided by two in (3.5). We thus adopt the definitions:
| (3.6) |  |
Even with the impedance-matching assumption, modeling RF and microwave blocs remains an unresolved task; there is currently no proven and practically effective theory for uniquely identifying the expression of (3.5). In order to have some insight into this expression, it is of interest to make a rough survey of the memory mechanisms in the modern RF and microwave circuits.
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