| 摘要 |
PROBLEM TO BE SOLVED: To protect a MIM capacitor that is provided to an input/output terminal in series without exerting influences upon a transmission power property.SOLUTION: An ESD protection circuit is connected in parallel with a MIM capacitor C between a first terminal Va and a second terminal Vb. Schottky diodes Da1, ..., Dan are connected in series with each other, anodes are connected at a side of the first terminal Va and cathodes are connected at a side of the second terminal Vb. Schottky diodes Db1, ..., Dbm are connected in series with each other and connected in reverse parallel with Da1, ..., Dan. In the first terminal Va, a DC voltage is higher than that of the second terminal Vb in the state where an RF signal is not inputted to any one of the first and second terminals. The number of steps in Da1, ..., Dan is more than that of Db1, ..., Dbm. The number of steps in Db1, ..., Dbm is set in such a manner that, when the RF signal passes the MIM capacitor C, an amplitude of the RF signal is not attenuated to a predetermined RF signal amplitude.SELECTED DRAWING: Figure 3 |
