DUAL-SPLIT PIEZOELECTRIC FILTER Russian patent published in 2015 - IPC H03H9/54 

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to electronic engineering and can be used for frequency selection of signals in radio receiving devices. A dual-split piezoelectric filter includes three in-series connected piezoelectric resonators; the first capacitor is connected to the first output of the first piezoelectric resonator; to the second output of the first piezoelectric resonator there connected is the second capacitor and the second piezoelectric resonator the second output of which is connected to the third capacitor and the third piezoelectric resonator, the second output of which is connected to the fourth capacitor, three inductance coils; the first inductance coil is connected to the first output of the first piezoelectric resonator; the second inductance coil is connected to the second output of the third piezoelectric resonator; the third inductance coil is connected to the second outputs of the second and the third capacitors; the second output of the third inductance coil is connected to a common bus; the fourth piezoelectric resonator and the fifth capacitor are connected parallel to the first piezoelectric resonator; the fifth piezoelectric resonator and the sixth capacitor are connected parallel to the second piezoelectric resonator; the sixth piezoelectric resonator and the seventh capacitor are connected parallel to the third piezoelectric resonator.

EFFECT: improvement of coordination with load resistances and provision of symmetrical amplitude-frequency characteristic (AFC) with increase of AFC squareness ratio.

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