Patent ID: 6928298

Claim:
A mobile communication device having a plurality of communication systems supporting different frequency bands, comprising: an antenna; a transmitter for each of the plurality or communication systems; a receiver for each of the plurality of communication systems; a diplexer transmitting transmission signals from the plurality of communication systems to said antenna, and distributing reception signals received via said antenna to the plurality of communication systems; a high-frequency switch for each of the plurality of communication systems, arranged to switch the signals between said transmitter and said receiver, said high-frequency switch being directly connected to said diplexer; a directional coupler extracting portions of the transmission signals, and sending the results to an automatic gain control circuit, said directional coupler being disposed between said antenna and said diplexer; and a high-frequency composite unit including a microwave circuit carrying the plurality of communication systems; wherein said high-frequency composite unit is defined by a multilayer substrate including a laminated body including a plurality of dielectric layers, the multilayer substrate having said diplexer, said high-frequency switches, and said directional coupler.