| 摘要 |
A technique for realizing module size reduction while enhancing the anti-ESD characteristic of a low frequency band circuit without the need to add such an element as an ESD filter. In a diplexer included in a high-frequency power amplifier module, a composite grounding inductor with respect to an antenna terminal is formed of three inductors including a series inductor contained in a lowpass filter. Since an ESD signal contains main components thereof belonging to a frequency band of the order of a few hundreds of MHz or lower, the ESD signal is allowed to pass through a lowpass filter with little to no attenuation. Under this condition, a function for ESD filtering from the antenna terminal to an antenna switch circuit is provided by using the composite grounding inductor mentioned above and an electrostatic capacitor element, thereby suppressing passage of the ESD signal to the antenna switch circuit. |
