| 摘要 |
PROBLEM TO BE SOLVED: To provide an FBAR filter having an unbalanced-balanced input/output structure which actually enables the mass production of the FBAR filter while enabling a filter circuit and a balun circuit to be disposed on a single chip. SOLUTION: In the FBAR filter having the unbalanced-balanced input/output structure for receiving an input of an unbalanced input signal, filtering it in a predetermined band and then outputting the filtered signal as a balanced output signal as a constitutive means for meeting said purpose, there are included a wafer, a filter circuit unit and a balun circuit unit. The filter circuit unit includes a plurality of FBAR resonators formed on a predetermined region on the top of the wafer. The balun circuit unit includes a plurality of metal layers electrically connected to one another to obtain a balun circuit and a plurality of dielectric layers each placed between the plurality of metal layers. The balun circuit unit is electrically connected to the filter circuit unit above a predetermined region of the wafer. COPYRIGHT: (C)2006,JPO&NCIPI
|
