A frontend module includes an antenna terminal, and a duplexer including a first filter connected to the antenna terminal and a first terminal, configured to perform cellular communications within a 3.3 GHz to 4.2 GHz band, and a second filter connected to the antenna terminal and a second terminal, configured to perform Wi-Fi communications within a 5.15 GHz to 5.950 GHz band, wherein each of the first filter and the second filter includes an LC filter, and a portion of an operating time period of the first filter overlaps a portion of an operating time period of the second filter.