Resonator filter with multiple cross-couplings

摘要

A filter device is provided for filtering signals. The filter device includes multiple series resonators, multiple shunt resonators and multiple cross-coupling circuits. The series resonators are connected in series between an antenna and one of a transmitter or a receiver. The shunt resonators are respectively connected between at least one of the series resonators and a ground voltage. The cross-coupling circuits are configured to bypass at least two series resonators of the multiple series resonators and at least one shunt resonator of the multiple shunt resonators.

主权项

1. A half-ladder filter having a passband, the filter comprising:
a plurality of series resonators connected in series between an input node and an output node; a plurality of shunt resonators respectively connected between a least one of the series resonators and a ground voltage; and a plurality of cross-coupling circuits comprising a corresponding plurality of capacitors, each cross-coupling circuit bypassing at least two series resonators of the plurality of series resonators and at least one shunt resonator of the plurality of shunt resonators, wherein the plurality of cross-coupling circuits cause a transmission zero to shift higher in frequency from an upper edge of the passband of the filter.