Patent ID: 7532086

Claim:
A digital attenuation apparatus comprising: a high frequency input means for receiving a high frequency signal; a first transmission means connected in series to the high frequency input means for matching an input impedance of the apparatus; a second transmission means connected in series to the first transmission means; a first switching means connected to the second transmission means and controlled and switched by a second voltage from outside; a third transmission means connected in series to the first switching means for matching an output impedance of the apparatus; a first resistive element connected to the first transmission means; a second resistive element connected to the third transmission means; a fourth transmission means connected to the first and second resistive elements; a second switching means connected in series to the fourth transmission means and controlled and switched by a control voltage from the outside, which is indicative of an inverted voltage of the second voltage; a fifth transmission means connected in series to the second switching means; and a third resistive element connected in series to the fifth transmission means and shorted to a ground.