Patent ID: 6411176
Filing Date: 2002-06-25
Classification: H01P

Abstract:
A duplexer comprising:a first external terminal; a second external terminal; an antenna terminal; a first frequency variable filter electrically connected between the first external terminal and the antenna terminal, and composed of at least two resonators and reactance elements electrically connected to respective ones of the resonators and capable of being voltage-controlled; a second frequency variable filter electrically connected between the second external terminal and the antenna terminal, and composed of at least one resonator and a reactance element electrically connected to the resonator and capable of being voltage-controlled; a predetermined reactance element of the first frequency variable filter being in an on state and another reactance element of the first frequency variable filter being in an off state, when the reactance element of the second frequency variable filter is in an on state, said predetermined reactance element of the first frequency variable filter being a reactance element connected to the resonator electrically connected in a position nearest to the antenna terminal.