when the impedance of a first circuit is deviated from a standard value , a second circuit is designed for generating a second reflected wave to cancel a first reflected wave generated by the first circuit . individual structural parts in a transmission line are intentionally designed to be deviated from a standard impedance reversely under a fine control . by this method , the impedance matching between the input and output impedance of the semiconductor element and the transmission line is achieved . as a result , the terminal impedance of the component of the semiconductor circuit and the semiconductor package substrate is adjusted to 50 ohm , so that a good signal property can be obtained .