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US 12,407,331 B2Granted
Systems and methods for providing a tunable radio frequency bandpass filter with variable cross-coupling
AssigneeL3Harris Global Communications, Inc.
InventorDereck Bojanowski
Life of this patent
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Abstract
A bandpass filter comprising: a plurality of shunt resonators connected in series and configured to allow signals within a range of frequencies to pass; and a cross-coupling circuits connected to the plurality of shunt resonators and configured to generate a first transmission zeros in a low rejection band of the bandpass filter and generate a second transmission zero in a high rejection band of the bandpass filter.
Claims19
A bandpass filter, comprising:
- a plurality of shunt resonators coupled in series and configured to allow signals within a range of frequencies to pass;
- and
- a cross-coupling circuit connected to the plurality of shunt resonators and configured to generate a first transmission zero in a low rejection band of the bandpass filter and generate a second transmission zero in a high rejection band of the bandpass filter;
- wherein cross-coupling circuit comprises
- a first capacitor having a first variable capacitance tunable to concurrently adjust a position of the first transmission zero in the low rejection band relative to a center frequency of a passband of the bandpass filter and a position of the second transmission zero in the high rejection band of the bandpass filter relative to the center frequency, and
- a second capacitor having a non-variable capacitance limiting a distance by which the positions of the first and second transmission zeros can move away from each other.
3 more elements
A method for operating a bandpass filter, comprising:
- performing operations by the bandpass filter to allow signals within a range of frequencies to pass;
- tuning a first variable capacitance of a first cross-coupling circuit to concurrently adjust a position of a first transmission zero in a low rejection band of the bandpass filter relative to a center frequency of a passband of the bandpass filter and to adjust a position of a second transmission zero in a high rejection band of the bandpass filter relative to the center frequency;
- tuning a second variable capacitance of a second cross-coupling circuit to concurrently adjust a position of a third transmission zero in the low rejection band relative to the center frequency and to adjust a position of a fourth transmission zero in the high rejection band relative to the center frequency;
- and
- using a capacitor having a non-variable capacitance to limit a distance by which the positions of the first and second transmission zeros can move away from each other.
2 more elements
Dependencies are inferred from the claim text.