Monolithic filters utilizing thin film bulk acoustic wave devices and minimum passive components for controlling the shape and width of a passband response
First Claim
1. A Multi-pole Bulk Acoustic Wave (BAW) filter, comprising:
- a first pair of ports;
a second pair of ports;
a first lead coupled between a first and a second one of said first pair of ports;
a second lead coupled between a first and a second one of said second pair of ports;
at least one BAW resonator coupled in series in said first lead;
at least a first Stacked Crystal Filter (SCF), said first SCF having first and second terminals coupled in said first lead, said first SCF also having a third terminal coupled in said second lead;
a plurality of impedance inverting elements, each individual one of said plurality of impedance inverting elements being coupled across said first and second leads; and
at least one inductive element, said at least one inductive element being coupled in parallel with said at least one BAW resonator, wherein said Multi-pole BAW filter yields a passband response having a center frequency fc.
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Accused Products
Abstract
There is provided a Multi-pole Bulk Acoustic Wave Resonator-Stacked Crystal Filter (Multi-pole BAWR-SCF) filtering circuit or device. In one embodiment the Multi-pole BAWR-SCF circuit comprises a first pair of ports, a second pair of ports, a first lead that is coupled between a first and a second one of the first pair of ports, and a second lead that is coupled between a first and a second one of the second pair of ports. The Multi-pole BAWR-SCF circuit also comprises at least one BAW resonator that is coupled in series in the first lead, and at least one Stacked Crystal Filter (SCF). The SCF has first and second terminals that are coupled in the first lead, and a third terminal that is coupled in the second lead. The Multi-pole BAWR-SCF circuit further comprises a plurality of impedance inverting elements and at least one inductive element. Each individual one of the impedance inverting elements is coupled across the first and second leads, and the at least one inductive element is coupled in parallel with the at least one BAW resonator. The Multi-pole BAWR-SCF circuit yields improved frequency response characteristics relative to those that are typically yielded by at least some conventional multi-pole filters, and includes a reduced number of passive components relative to the number of such components included in at least some conventional multi-pole filters.
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Citations
32 Claims
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1. A Multi-pole Bulk Acoustic Wave (BAW) filter, comprising:
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a first pair of ports; a second pair of ports; a first lead coupled between a first and a second one of said first pair of ports; a second lead coupled between a first and a second one of said second pair of ports; at least one BAW resonator coupled in series in said first lead; at least a first Stacked Crystal Filter (SCF), said first SCF having first and second terminals coupled in said first lead, said first SCF also having a third terminal coupled in said second lead; a plurality of impedance inverting elements, each individual one of said plurality of impedance inverting elements being coupled across said first and second leads; and at least one inductive element, said at least one inductive element being coupled in parallel with said at least one BAW resonator, wherein said Multi-pole BAW filter yields a passband response having a center frequency fc. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A Bulk Acoustic Wave (BAW) filter, comprising:
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a first substrate; a first conductive layer disposed on said first substrate; a first contact pad disposed on said first substrate; a second contact pad disposed on said first substrate; at least one BAW resonator disposed on said first substrate, said at least one BAW resonator being serially coupled between said first and second contact pads; at least one Stacked Crystal Filter (SCF) disposed on said first substrate, said at least one SCF being serially coupled between said first and second contact pads, said at least one SCF having a first terminal coupled to said first conductive layer; a second substrate; a second conductive layer disposed on said second substrate and being coupled to said first conductive layer; at least one inductor disposed on said second substrate, said at least one inductor being coupled in parallel with said at least one BAW resonator; and at least one impedance inverting element disposed on said second substrate, said at least one impedance inverting element having a first terminal serially coupled between said first and second contact pads, said at least one impedance inverting element also having a second terminal coupled to said second conductive layer. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A Multi-pole Bulk Acoustic Wave (BAW) filter, comprising:
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a first pair of ports; a second pair of ports; at least one BAW resonator coupled between said first pair of ports; at least one Stacked Crystal Filter (SCF) coupled between said first pair of ports, said at least one SCF having a terminal coupled between said second pair of ports, said at least one SCF also having at least one lumped element equivalent component; at least one impedance inversion means, each of said at least one impedance inversion means having a first end coupled between said first pair of ports and a second end coupled between said second pair of ports; and at least one tuning element, said at least one tuning element being coupled in parallel with said at least one BAW resonator, said at least one tuning element yielding a resonance at approximately a center frequency fc of the Multi-pole BAW filter for causing a passband of the Multi-pole BAW filter to have an increased bandwidth relative to a passband bandwidth of another filter that does not include the at least one tuning element; wherein said at least one lumped element equivalent component and said at least one impedance inversion means function to transform a terminating impedance of said Multi-pole (BAW) filter from a first impedance to a second impedance. - View Dependent Claims (27)
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28. A Bulk Acoustic Wave (BAW) filter, comprising:
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a first substrate; a first conductive layer disposed on said first substrate; a plurality of inductors disposed on said first substrate, each of said inductors having respective first and second terminal ends; and a plurality of impedance inverting elements disposed on said first substrate, each of said impedance inverting elements having respective first and second terminals, wherein the first terminal of each respective one of the impedance inverting elements is coupled to the first terminal end of a respective one of the inductors, and wherein the second terminal of each impedance inverting element is coupled to the first conductive layer, and further comprising, a second substrate; a second conductive layer disposed on said second substrate; a plurality of contact pads disposed on said second substrate; a plurality of BAW resonators disposed on said second substrate, each of said BAW resonators being serially coupled between said contact pads, each of said BAW resonators also being coupled to the second terminal end of a respective one of said inductors; and at least one Stacked Crystal Filter (SCF) disposed on said second substrate, said at least one SCF being serially coupled between said contact pads, said at least one SCF also having a first terminal coupled to said second conductive layer, wherein individual ones of the contact pads are coupled to the first terminal of a respective one of the impedance inverting elements and to the first terminal end of a respective one of the inductors. - View Dependent Claims (29, 30, 31, 32)
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Specification