Bridge Filters
AssigneeRf360 Europe GmbH
InventorsEdgar Schmidhammer, Juha Sakari Ella
Life of this patent
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Abstract
An apparatus is disclosed for bridge filters. In example aspects, the apparatus includes a filter circuit with a current balun and a filter core. The current balun includes a first terminal coupled to a first port of the filter circuit, a second terminal, a third terminal, and a fourth terminal. The current balun also includes a first inductor galvanically coupled between the first terminal and the second terminal. The current balun further includes a second inductor galvanically coupled between the third terminal and the fourth terminal. The filter core is coupled between the current balun and a second port of the filter circuit. The filter core is galvanically coupled to the second terminal of the current balun and to the fourth terminal of the current balun.
Claims36
An apparatus comprising:
- a filter circuit comprising:
- a current balun comprising:
- a first terminal coupled to a first port of the filter circuit, a second terminal, a third terminal, and a fourth terminal;
- a first inductor galvanically coupled between the first terminal and the second terminal;
- and
- a second inductor galvanically coupled between the third terminal and the fourth terminal;
- and
- a filter core coupled between the current balun and a second port of the filter circuit, the filter core galvanically coupled to the second terminal of the current balun and to the fourth terminal of the current balun.
An apparatus comprising:
- a filter circuit comprising:
- a first port;
- a second port;
- a filter core coupled between the first port and the second port;
- and
- a current balun comprising:
- first means for galvanically coupling the filter core to the first port;
- and
- second means for galvanically coupling the filter core to a ground.
A method for operating a filter circuit, the method comprising:
- galvanically routing a first signal component of a first signal from a first port of the filter circuit to a first terminal of a filter core;
- electromagnetically routing a second signal component of the first signal from the first port to a second terminal of the filter core;
- propagating at least a portion of the first signal component through at least one first resonator of the filter core;
- propagating at least a portion of the second signal component through at least one second resonator of the filter core;
- electromagnetically routing the at least a portion of the first signal component from a third terminal of the filter core to a second port of the filter circuit as a part of a second signal;
- and
- galvanically routing the at least a portion of the second signal component from a fourth terminal of the filter core to the second port of the filter circuit as another part of the second signal.
An apparatus comprising:
- a filter circuit comprising:
- a first port;
- a second port;
- a filter core coupled between the first port and the second port, the filter core comprising a bridge filter including at least four acoustic wave resonators;
- a first current balun coupled between the first port and the filter core;
- and
- a second current balun coupled between the second port and the filter core.
Dependencies are inferred from the claim text.