High-frequency composite part

摘要

A high-frequency composite part includes a high-frequency switch and an amplifier in a transmission circuit side among high-frequency parts constituting a PHS portable telephone. In the telephone, the high-frequency switch is used for switching between the connection of the transmission circuit Tx and an antenna, and the connection of a receiving circuit Rx and the antenna. The amplifier at the Tx side amplifies a signal to be transmitted which has been converted into an RF signal and passes through a filter at the Tx side, and sends it to the high-frequency switch. A high-frequency composite part may comprise: a multilayer board formed by laminating a plurality of dielectric layers; a high-frequency switch formed of a diode mounted on said multilayer board and a transmission line and a capacitor comprising interconnected electrodes formed on respective layers within said multilayer board; and an amplifier formed of a transistor mounted on said multilayer board and a transmission line and a capacitor comprising interconnected electrodes formed on respective layers within said multilayer board. In the high-frequency composite part, the amplifier may be comprised in a transmission circuit. The high-frequency composite part further may comprise a filter formed of a transmission line and a capacitor comprising interconnected electrodes formed on respective layers within said multilayer board. The multilayer board may comprise low-temperature baked ceramic material.