Communication apparatus, electronic equipment with communication functions, communication function circuit, amplifier circuit and balun circuit

摘要

A communication apparatus includes, as a plurality of communication functions, an amplifier for amplifying a received signal or a transmitting signal, a balun for converting an unbalanced signal to a balanced signal or converting a balanced signal to an unbalanced signal and a mixer for converting a frequency. A gain reducing unit for reducing a gain of a specific frequency band is installed in at least one of the plurality of communication functions. A band rejection filter, for example, serves as a gain reducing unit and is disposed between a pair of transistors. A plurality of band rejection filters may be so arranged as to be distributed to the plurality of communication functions.