Patent ID: 8461942
Filing Date: 2013-06-11
Classification: H03H

Abstract:
1. A surface acoustic wave device comprising: a first filter and a second filter, each of them being a surface acoustic wave (SAW) filter including an odd number of at least three InterDigital Transducers (IDTs) respectively; an unbalanced terminal to which an unbalanced signal is input; a first balanced terminal from which a signal having a same phase as the unbalanced signal is output; and a second balanced terminal from which a signal having an opposite phase to the unbalanced signal is output, wherein one of electrodes of a first center IDT and one of electrodes of a second center IDT are commonly connected to the unbalanced terminal, the first center IDT and the second center IDT being one out of the odd number of IDTs and located at a center in the first filter and the second filter respectively; one of electrodes in each of two IDTs located on either side of the first center IDT is commonly connected to the first balanced terminal; one of electrodes in each of two IDTs located on either side of the second center IDT is commonly connected to the second balanced terminal; the number of electrode fingers of the first center IDT is an odd number; and the number of electrode fingers of the second center IDT is an even number, wherein the two IDTs located on either side of the first center IDT are separated from the first center IDT, and the two IDTs located on either side of the second center IDT are separated from the second center IDT, wherein the number of electrode fingers of an electrode, which is one of electrodes constructing the first center IDT and is connected to the unbalanced terminal, is greater than the number of electrode fingers of another electrode constituting the first center IDT.