EP0949756A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Monolithic filters utilizing thin film bulk acoustic wave devices and minimum passive components for controlling the shape and width of a passband response
Assignee: Nokia Oyj
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Filing: 1999-04-08
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Granted: —
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Expires: 2019-04-08
Abstract
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.
Inventors
- 👤 Juha Ella
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 00:39
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/582; H03H9/586; H03H9/589; H03H9/0023; H03H9/0095; H03H9/02; H03H9/05; H03H9/0538; H03H9/0547; H03H9/542; H03H9/583; H03H9/585; H03H9/587; H03H9/588; H03H9/60; H03H9/605
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
161 words
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 f c .
Claim 2
Dependent Claim
192 words
A Multi-pole BAW filter as set forth in claim 1, wherein said at
least one BAW resonator includes a first BAW resonator and a second BAW
resonator, said impedance inverting elements include a first impedance
inverting element and a second impedance inverting element, and said at least
one inductive element includes a first inductive element and a second
inductive element, wherein each of said first BAW resonator and said first
impedance inverting element has a respective first terminal coupled to said
first port of said first pair of ports, said first BAW resonator also having a
second terminal coupled to said first terminal of said first SCF, said second
BAW resonator having a first terminal coupled to said second terminal of said
first SCF, said second BAW resonator also having a second terminal coupled
to said second port of said first pair of ports, said second impedance inverting
element having a first terminal coupled to said second port of said first pair of
ports, said first inductive element being connected in parallel with said first
BAW resonator, and wherein said second inductive element is connected in
parallel with said second BAW resonator.
Claim 3
Dependent Claim
156 words
A Multi-pole BAW filter as set forth in claim 2, wherein said first
inductive element has a first end coupled to said first port of said first pair of
ports, said first inductive element also having a second end coupled in said
first lead between said second terminal of said first BAW resonator and said
first terminal of said first SCF, said second inductive element having a
respective first end coupled in said first lead between said second terminal of
said first SCF and said first terminal of said second BAW resonator, said
second inductive element also having a respective second end coupled to said
second port of said first pair of ports, wherein said first impedance inverting
element has a second terminal coupled to said first one of said second pair of
ports, and wherein said second impedance inverting element has a second
terminal coupled to said second one of said second pair of ports.
Claim 4
Dependent Claim
27 words
A Multi-pole BAW filter as set forth in claim 2 or 3, wherein said
first SCF has equivalent parallel capacitances which function as further
impedance inverting elements.
Claim 5
Dependent Claim
218 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein said first terminal of said first SCF is coupled to said first port of said
first pair of ports, said third terminal of said first SCF is coupled to a first node
in said second lead, said second terminal of said first SCF is coupled to a first
terminal of said at least one BAW resonator, wherein said Multi-pole BAW
filter further comprises a second SCF, said second SCF having a first terminal
coupled to a second terminal of said at least one BAW resonator, said second
SCF having a second terminal coupled to said second port of said first pair of
ports, said second SCF also having a third terminal coupled to a second node
in said second lead, wherein said at least one impedance inverting element
includes a first impedance inverting element and a second impedance
inverting element, said first impedance inverting element having a first terminal
coupled in said first lead between said second terminal of said first SCF and
said first terminal of said at least one BAW resonator, said second impedance
inverting element having a first terminal coupled in said first lead between said
second terminal of said at least one BAW resonator and said first terminal of
said second SCF.
Claim 6
Dependent Claim
134 words
A Multi-pole BAW filter as set forth in claim 5, wherein said at
least one inductive element has a first end coupled in said first lead between
said second terminal of said first SCF and said first terminal of said at least
one BAW resonator, said at least one inductive element also having a second
end coupled in said first lead between said second terminal of said at least
one BAW resonator and said first terminal of said second SCF, wherein said
first impedance inverting element has a second terminal coupled to a third
node in said second lead, said third node being interposed between said first
and second nodes, and wherein said second impedance inverting element has
a second terminal coupled in said second lead between said third node and
said second node.
Claim 7
Dependent Claim
31 words
A Multi-pole BAW filter as set forth in claim 5 or 6, wherein each
of said first and second SCFs have equivalent parallel capacitances which
function as further impedance inverting elements.
Claim 8
Dependent Claim
37 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein said first SCF is tuned to yield a second harmonic resonance at a
frequency which is approximately equal to said center frequency f c .
Claim 9
Dependent Claim
29 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein each of said at least one BAW resonator and said first SCF includes
an acoustic minor structure.
Claim 10
Dependent Claim
25 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein said first SCF has equivalent parallel capacitances which function as
irnpedance inverting components.
Claim 11
Dependent Claim
62 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein said at least one inductive element yields a resonance at the center
frequency f c of the Multi-pole BAW filter, and functions to cause the passband
response to have an increased bandwidth relative to a passband bandwidth of
a filter that does not include the at least one inductive element.
Claim 12
Dependent Claim
23 words
A Multi-pole BAW filter as set forth in any preceding claim,
wherein each of said plurality of impedance inverting elements includes a
capacitor.
Claim 13
Dependent Claim
200 words
A Bulk Acoustic Wave (BAW) filter, comprising: 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.
Claim 14
Dependent Claim
19 words
A BAW filter as set forth in claim 13, wherein said second
substrate is disposed over said first substrate.
Claim 15
Dependent Claim
180 words
A BAW filter as set forth in claim 13 or 14, wherein said at least
one BAW resonator includes a first BAW resonator and a second BAW
resonator, said at least one impedance inverting element includes a first
impedance inverting element and a second impedance inverting element, and
said at least one inductor includes a first inductor and a second inductor,
wherein each of said first BAW resonator and said first impedance inverting
element has a respective first terminal coupled to said first contact pad, said
first BAW resonator also having a second terminal coupled to a second
terminal of said at least one SCF, said second BAW resonator having a first
terminal coupled to a third terminal of said at least one SCF, said second BAW
resonator also having a second terminal coupled to said second contact pad,
said second impedance inverting element having a first terminal coupled to
said second contact pad, said first inductor being connected in parallel with
said first BAW resonator, and wherein said second inductor is connected in
parallel with said second BAW resonator.
Claim 16
Dependent Claim
22 words
A BAW filter as set forth in claims 13 to 15, wherein said at least
one impedance inverting element includes a capacitor.
Claim 17
Dependent Claim
53 words
A BAW filter as set forth in claims 13 to 16, and further
comprising a plurality of electrically conductive contacts coupled to said
second conductive layer, said plurality of contacts for coupling said second
conductive layer to ground, and wherein said first and second contact pads are
for being coupled to external circuitry.
Claim 18
Dependent Claim
40 words
A BAW filter as set forth in claims 13 to 17, wherein said first
conductive layer at least partially surrounds said first contact pad, said second
contact pad, said at least one BAW resonator, and said at least one SCF.
Claim 19
Dependent Claim
33 words
A BAW filter as set forth in claims 13 to 18, wherein said second
conductive layer at least partially surrounds said at least one inductor and said
at least one impedance inverting element.
Claim 20
Dependent Claim
62 words
A BAW filter as set forth in claims 13 to 19, wherein said first and
second conductive layers and said first and second substrates prevent
environmental contaminants from coming into contact with said at least one
BAW resonator, said at least one SCF, said first and second contact pads,
said at least one inductor, and said at least one impedance inverting element.
Claim 21
Dependent Claim
29 words
A BAW filter as set forth in claims 13 to 20, wherein said at least
one inductor is coupled to said at least one BAW resonator through solder
bumps.
Claim 22
Dependent Claim
31 words
A BAW filter as set forth in claims 13 to 21, wherein at least one
of said first and second substrates comprises one of Si, GaAs, glass, or a
ceramic material.
Claim 23
Dependent Claim
43 words
A BAW filter as set forth in claims 15 to 22, wherein at least a
portion of the first inductor is situated above said first BAW resonator, and at
least a portion of the second inductor is situated above said second BAW
resonator.
Claim 24
Dependent Claim
57 words
A BAW filter as set forth in claim 23, wherein the first impedance
inverting element is disposed in a plane that is above a plane in which said
first BAW resonator is disposed, and the second impedance inverting element
is disposed in a plane that is above a plane in which said second BAW
resonator is disposed.
Claim 25
Dependent Claim
21 words
A BAW filter as set forth in claims 13 to 24, wherein the at least
one inductor includes a spiral coil.
Claim 26
Dependent Claim
107 words
A Bulk Acoustic Wave (BAW) filter, comprising: 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; and 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 also
having a first terminal coupled to said first conductive layer.
Claim 27
Dependent Claim
110 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 26, and
further comprising: 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.
Claim 28
Dependent Claim
107 words
A Bulk Acoustic Wave (BAW) filter, comprising: 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.
Claim 29
Dependent Claim
109 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 28, and
further comprising: a first plurality of electrical contacts, individual ones of said first plurality
of electrical contacts being coupled to the second terminal end of
respective ones of the inductors; a second plurality of electrical contacts, individual ones of said second
plurality of electrical contacts being coupled to the first terminal end of a
respective one of the inductors and to the first terminal of a respective
one of the impedance inverting elements; and a third plurality of electrical contacts, individual ones of said third
plurality of electrical contacts being coupled to said first conductive
layer.
Claim 30
Dependent Claim
157 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 28 or 29,
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.
Claim 31
Dependent Claim
125 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 30, and
further comprising: a first plurality of electrical contacts, each of said first plurality of
electrical contacts being coupled between the second terminal end a
respective one of the inductors and a respective one of said BAW
resonators; a second plurality of electrical contacts, each of said second plurality of
electrical contacts coupling the first terminal end of a respective one of
the inductors and the first terminal of a respective one of the impedance
inverting elements, to a respective one of the contact pads; and a third plurality of electrical contacts, individual ones of said third
plurality of electrical contacts being coupled to said first conductive
layer for being coupled to ground.
Claim 32
Dependent Claim
28 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 31,
wherein the first plurality of electrical contacts have greater thicknesses than
thicknesses of the BAW resonators.
Claim 33
Dependent Claim
36 words
A Bulk Acoustic Wave (BAW) filter as set forth in claim 31 or 32,
wherein individual ones of the inductors are situated above the respective
ones of the BAW resonators to which the inductors are coupled.
Claim 34
Dependent Claim
222 words
A Multi-pole Bulk Acoustic Wave (BAW) filter, comprising: 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 f c 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.
Claim 35
Dependent Claim
38 words
A Multi-pole BAW filter as set forth in claim 34, wherein the Multi-pole
BAW filter includes a reduced number of impedance inversion means
and tuning elements relative to the number of such components included in
the another filter.
References Cited (Backward Citations)
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