| 摘要 |
PROBLEM TO BE SOLVED: To provide an acoustic wave device capable of miniaturizing a filter, including a balun and enhancing design flexibility.SOLUTION: An acoustic wave device includes a common terminal Ant as an input terminal, a balun 20 that converts a signal input from the common terminal Ant into two antiphase signals, and outputs the antiphase signals, and a filter 30 that outputs the two signals input from the balun 20 as balanced output signals. The output impedance of the balun 20 is equal to the input impedance of the filter 30, and is larger than an output impedance of the filter 30. According to this structure, since the balun 20 is connected between the common terminal Ant and the filter 30, the input impedance of the filter 30 can be changed arbitrarily, and the degree of design freedom can be enhanced. In addition, increasing the input impedance of the filter 30, the filter 30 is miniaturized, and as a result, the acoustic wave device 100A as a whole can be miniaturized. |
