US Patent 10419039 Front end module and communication apparatus

A front end module that performs a CA method includes a signal path through which a signal of a first frequency band propagates, a signal path through which a signal of a second frequency band propagates, a switch module that includes antenna terminals and selection terminals and is connected to antenna elements, and a balun that is disposed at the signal path. First and second balanced terminals of the balun are connected to the selection terminals, and the balun causes a fundamental wave or harmonic of a transmission signal of the first frequency band input through an unbalanced terminal to branch into branch signals having opposite phases and outputs the branch signals to the first balanced terminal and the second balanced terminal.