Filter comprising inductor, duplexer using the filter and fabricating methods thereof

摘要

A filter using an air gap type film bulk acoustic resonator is provided. The present filter includes a substrate on which a first port, a second port, and a ground port are formed to be connected to an external terminal; at least one first film bulk acoustic resonator serially connecting the first port to the second port on the substrate; at least one second film bulk acoustic resonator parallel connected to an interconnection node formed between the first port and the second port; and at least one inductor serially connecting the second film bulk acoustic resonator to the ground port. The inductor included in the filter is fabricated with the first and second film bulk acoustic resonators as one body. Accordingly, a small-sized filter may be fabricated through a simplified process.