Patent ID: 7038557
Filing Date: 2006-05-02
Classification: H04B

Abstract:
1. An antenna duplexer comprising: an antenna terminal; a transmitting phase-shift circuit, one side of which is connected to said antenna terminal; a receiving phase-shift circuit, one side of which is connected to said antenna terminal; a transmitting filter connected to the other side of said transmitting phase-shift circuit and a transmitting terminal; and a receiving filter connected to the other side of said receiving phase-shift circuit and a receiving terminal; wherein said transmitting filter and/or said receiving filter is a composite filter, and said composite filter attains a characteristic having an attenuation pole at simultaneous transmission and reception time when transmission and reception are simultaneously performed, and controls respective impedances by said transmitting phase-shift circuit and said receiving phase-shift circuit to operate as a sharing unit and attains a characteristic where said attenuation pole is removed at non simultaneous transmission and reception time when transmission and reception are not performed simultaneously.