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US 12,407,320 B2Granted
Bridge filters
AssigneeRF360 Singapore Pte. Ltd.
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.
Claims18
An apparatus comprising:
- a filter circuit comprising:
- a first current balun comprising:
- a first terminal, a second terminal, a third terminal, and a fourth terminal, the first terminal coupled to a first port of the filter circuit, the third terminal coupled to a ground;
- 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;
- a filter core coupled between the first current balun and a second port of the filter circuit, the filter core galvanically coupled to the second terminal of the first current balun and to the fourth terminal of the first current balun, the filter core comprising:
- a first resonator coupled between the second terminal of the first current balun and a first node;
- a second resonator coupled between the fourth terminal of the first current balun and a second node;
- a third resonator coupled between the second terminal of the first current balun and the second node;
- and a fourth resonator coupled between the fourth terminal of the first current balun and the first node;
- a second current balun comprising:
- a first terminal coupled to the second port, a second terminal, a third terminal coupled to a ground, and a fourth terminal, the second terminal of the second current balun is coupled to the second node, and the fourth terminal of the second current balun is coupled to the first node;
- a first inductor galvanically coupled between the first terminal of the second current balun and the second terminal of the second current balun;
- and
- a second inductor galvanically coupled between the third terminal of the second current balun and the fourth terminal of the second current balun;
- an inductor coupled between the second terminal of the first current balun and the fourth terminal of the first current balun;
- and
- another inductor coupled between the second terminal of the second current balun and the fourth terminal of the second current balun;
- a resonant circuit coupled between the second terminal of the first current balun and a ground, the resonant circuit comprising:
- an inductor;
- and
- a capacitor coupled in parallel with the inductor between the second terminal of the first current balun and the ground;
- and
- a matching network coupled between the first port and the first current balun.
22 more elements
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 including a first node and a second node, 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, the first current balun comprising:
- a first terminal, a second terminal, a third terminal, and a fourth terminal, the first terminal coupled to the first port of the filter circuit, the third terminal coupled to a ground;
- 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 second current balun coupled between the second port and the filter core, the second current balun comprising:
- a first terminal coupled to the second port, a second terminal, a third terminal coupled to the ground, and a fourth terminal, the second terminal of the second current balun is coupled to the second node, and the fourth terminal of the second current balun is coupled to the first node;
- a first inductor galvanically coupled between the first terminal of the second current balun and the second terminal of the second current balun;
- and
- a second inductor galvanically coupled between the third terminal of the second current balun and the fourth terminal of the second current balun;
- an inductor coupled between the second terminal of the first current balun and the fourth terminal of the first current balun;
- and
- another inductor coupled between the second terminal of the second current balun and the fourth terminal of the second current balun;
- a first resonant circuit coupled between the second terminal of the first current balun and a ground, the first resonant circuit comprising:
- an inductor;
- and
- a capacitor coupled in parallel with the inductor between the second terminal of the first current balun and the ground;
- and
- a matching network coupled between the first port and the first current balun.
21 more elements
Dependencies are inferred from the claim text.