| 摘要 |
PURPOSE: To reduce the parasitic capacity by preparing a serial switch between every intermediate terminal and output terminal of a group and connecting the intermediate terminal to plural input terminals via at least a single serial switch used for every input terminal. CONSTITUTION: The signals sent from four signal sources are supplied to the input terminals IN1 to IN4 . A switching device has two intermediate terminals B1 and B2 to access the terminals IN1 to IN4 together with the serial switches SEa and SEb placed between a user equipment and both terminals B1 and B2 . The terminals B1 and B2 are connected to a signal source Z via the serial switches SE1 to SE4 each of which consists of three diodes. Furthermore, each of signal sources IN1 to IN4 is connected to the ground with AC via the matching impedances (Z1 .SH1 to Z4 , SH4 ) which are serial to a shunt switch. Thus, the same impedance is selected to the signal sources even when a connection line is selected and when no line is selected respectively. |
