Patent ID: 7978024

Claim:
A multi-band duplexer comprising: an unbalanced multi-band port; a first balanced single-band port; a second balanced single-band port; a first unbalanced coupling arm conductively coupled to the unbalanced multi-band port; a second unbalanced coupling arm conductively coupled to the unbalanced multi-band port; an impedance matching circuit; a first pair of balanced coupling arms conductively coupled to the first balanced single-band port and electromagnetically coupled to the first unbalanced coupling arm; and a second pair of balanced coupling arms conductively coupled to the second balanced single-band port and electromagnetically coupled to the second unbalanced coupling arm, wherein the first and second unbalanced coupling arms are conductively coupled to the unbalanced multi-band port through a conductive unbalanced signal branch, and wherein the conductive unbalanced signal branch is electrically coupled between the unbalanced multi-band port and each of the first and second unbalanced coupling arms.