SWITCHING DEVICE OF HIGH FREQUENCY SIGNAL

摘要

PURPOSE:To improve the attenuating performance in a low frequency region when a power supply is on, by providing a high pass filter to at least one of the input and output terminal sides. CONSTITUTION:A switching transistor 6 is turned off when a power supply is turned off during which the power supply voltage is not applied to a switch control terminal. A low pass filter is formed with inductance elements 1 and 2 and a capacitor 5. At the same time, a high pass filter consisting of a capacitor 13 and an inductance element 14 is connected to the side of an input terminal 3. Then the matching of impedance is set properly between these high and low pass filters. Thus the attenuating performance is improved in a low frequency region and when the power supply is turned on without deteriorating the inserting loss when the power supply is turned off. The same effect is obtained by providing a high pass filter at the side of an output terminal 4.