TUNABLE HF FILTER HAVING PARALLEL RESONATORS

摘要

An RF filter is disclosed. In an embodiment, the RF filter includes series-interconnected basic elements, each basic element having an electroacoustic resonator and impedance converters interconnected in series between the basic elements, wherein the impedance converters are admittance inverters, wherein the resonators of the basic elements are parallel resonators only, and wherein at least one of the resonators is tunable.