Patent ID: 8872601

Claim:
A circuit module comprising: a duplexer; and a circuit substrate on which the duplexer is mounted; wherein the duplexer includes: a duplexer main body; first, second and third external electrodes and a plurality of duplexer ground external electrodes provided on the duplexer main body; a first filter that outputs a signal input at the first external electrode to the second external electrode; a second filter that outputs a signal input at the third external electrode to the first external electrode; a ground conductor that is connected to the duplexer ground external electrodes and that is maintained at a ground potential; and the circuit substrate includes: a substrate main body; fourth, fifth and sixth external electrodes and a plurality of substrate top surface ground external electrodes that are provided on the substrate main body and that are respectively connected to the first, second and third external electrodes and the plurality of the duplexer ground external electrodes; seventh, eighth and ninth external electrodes and a substrate bottom surface ground external electrode provided on the substrate main body; a first signal path that connects the fourth external electrode to the seventh external electrode, a second signal path that connects the fifth external electrode to the eighth external electrode, and a third signal path that connects the sixth external electrode to the ninth external electrode; a first ground path that connects a portion of the plurality of the substrate top surface ground external electrodes to the substrate bottom surface ground external electrode; and a second ground path that is connected to the substrate top surface ground external electrode which is not connected to the substrate bottom surface ground external electrode and that is electromagnetically coupled to the second signal path or the third signal path.