Patent ID: 7915972
Filing Date: 2011-03-29
Classification: H03H

Abstract:
1. A balance filter comprising: a first filter having first multimode surface acoustic wave (SAW) filters connected in parallel; a second filter that is connected to the first filter and includes one second multimode SAW filter; a first terminal connected to the first filter; and second terminals connected to the second filter, an input terminal of the balance filter being one of the first and second terminals, and an output terminal thereof being the other, electric signals transmitted from the first filter to the second filter or vice versa being in opposite phase, electric signals being input or output via the second terminals in opposite phase, wherein the first terminal is connected to the first filter from the side of the first filter closest to the second filter; and wherein an interdigital transducer (IDT) located in the center of the second filter has two electrodes, one of the two electrodes is connected to one of the second terminals, and the other is connected to another one of the second terminals.