| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve isolation between ports of a front end module without enlarging an insertion loss. <P>SOLUTION: A front end module 1 is provided with an antenna port 2 to which an antenna is connected, receiving signal ports 3, 5, 7, transmitting signal ports 4, 6, a switching circuit 8 for switching a signal port to be connected to the antenna port 2, and a trap circuit 60. The trap circuit 60 is disposed to connect a signal route 61 between the receiving signal port 7 and the switching circuit 8, and a ground. The trap circuit 60 includes a diode 62 and a capacitor 63 which are serially connected. A control signal is applied to an anode of the diode 62 via an inductor 65. While the diode 62 is conducted, a serial resonance circuit is composed of an inductance component of the diode 62 and the capacitor 63. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
