| 摘要 |
Method (800) for adjusting the center frequency of a balanced filter comprising at least four resonators, comprises the following steps: specifying (801) a nominal center frequency for the balanced filter when connected to a circuitry having a certain nominal impedance; determining (802) the actual center frequency of the balanced filter when connected to a circuitry having a certain actual impedance, comparing (803, 804) the actual center frequency of the filter to the nominal one, and adjusting (805, 806) the impedance ratio between the circuitry and the balanced filter within certain limits based on the comparison. A plurality of balanced filters (1610, 1620, 1630) on a substrate (1600) is characterized in that the total area of bulk acoustic wave resonators in the balanced resonators depends on the position of the balanced filter on the substrate. Further, the balanced filters have substantially the same actual center frequency.
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