Bulk acoustic wave resonator filters including rejection-band resonators
A BAW resonator filter can include a BAW resonator pass-band filter ladder, the BAW resonator pass-band filter ladder can be configured to pass frequency components of an input signal in a pass-band of frequencies received at an input node of the BAW resonator pass-band filter ladder to an output node of the BAW resonator pass-band filter ladder. A first rejection-band series resonator can be coupled in series between an input port of the BAW resonator pass-band filter ladder and the input node, the first rejection-band series resonator can have a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies. A second rejection-band series resonator can be coupled in series between an output port of the BAW resonator filter and the output node, the second rejection-band series resonator can have a second anti-resonant frequency peak in the rejection-band of frequencies.
1. A Bulk Acoustic Wave (BAW) resonator device comprising:
a BAW resonator pass-band filter circuit, the BAW resonator pass-band filter circuit configured to pass frequency components of an input signal in a pass-band of frequencies received at an input of the BAW resonator pass-band filter circuit to an output of the BAW resonator pass-band filter circuit; and
a first rejection-band series resonator included in the BAW resonator pass-band filter circuit coupled in series between the input of the BAW resonator pass-band filter circuit and the output of the BAW resonator pass-band filter circuit, the first rejection-band series resonator having a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies.
2. The BAW resonator device of claim 1 wherein the BAW resonator pass-band filter circuit comprises a ladder topology, a lattice topology, or a modified lattice topology.
3. The BAW resonator device of claim 2 wherein the BAW resonator pass-band filter circuit comprises the ladder topology, the BAW resonator filter circuit further comprising:
a second rejection-band series resonator coupled in series between the input of the BAW resonator pass-band filter circuit and the output of the BAW resonator pass-band filter circuit, the second rejection-band series resonator having a second anti-resonant frequency peak in the rejection-band of frequencies.
4. The BAW resonator device of claim 1 wherein the pass-band of frequencies is about 5.49 GHz to about 5.835 GHz.
5. The BAW resonator device of claim 1 wherein the rejection-band of frequencies is about 5.17 GHz to about 5.33 GHz.
6. The BAW resonator device of claim 3 wherein the first and second anti-resonant frequency peaks are in a range between about 5.17 GHz and about 5.33 GHz.
7. The BAW resonator device of claim 2 wherein the BAW resonator pass-band filter circuit comprises the ladder topology, the BAW resonator pass-band filter circuit further including:
a plurality of pass-band series resonators coupled in series withing the ladder topology, the pass-band series resonators having respective resonant frequency peaks in the pass-band of frequencies; and
a plurality of pass-band shunt resonators coupled in shunt within the ladder topology, the pass-band shunt resonators having respective anti-resonant frequency peaks in the pass-band of frequencies.
8. The BAW resonator device of claim 7 wherein the respective resonant frequency peaks of the pass-band series resonators and the respective anti-resonant frequency peaks of the pass-band shunt resonators are at about a center of the pass-band of frequencies.
9. A Bulk Acoustic Wave (BAW) resonator device comprising:
a BAW resonator pass-band filter circuit, the BAW resonator pass-band filter circuit configured to pass frequency components of an input signal in a pass-band of frequencies received at an input of the BAW resonator pass-band filter circuit to an output of the BAW resonator pass-band filter circuit; and
a first rejection-band shunt resonator included in the BAW resonator pass-band filter circuit coupled in shunt within the BAW resonator pass-band filter circuit, the first rejection-band shunt resonator having a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies.
10. The BAW resonator device of claim 9 wherein the BAW resonator pass-band filter circuit comprises a ladder topology, a lattice topology, or a modified lattice topology.
11. The BAW resonator device of claim 10 wherein the BAW resonator pass-band filter circuit comprises the ladder topology, the BAW resonator filter circuit further comprising:
a second rejection-band shunt resonator coupled in shunt within the BAW resonator pass-band filter circuit, the second rejection-band shunt resonator having a second anti-resonant frequency peak in the rejection-band of frequencies.
12. The BAW resonator device of claim 9 wherein the pass-band of frequencies is about 5.49 GHz to about 5.835 GHz.
13. The BAW resonator device of claim 9 wherein the rejection-band of frequencies is about 5.17 GHz to about 5.33 GHz.
14. The BAW resonator device of claim 9 wherein the first and second anti-resonant frequency peaks are in a range between about 5.17 GHz and about 5.33 GHz.
15. The BAW resonator device of claim 9 wherein the BAW resonator pass-band filter circuit comprises a ladder topology, BAW resonator pass-band filter circuit further including:
a plurality of pass-band series resonators coupled in series within the ladder topology, the pass-band series resonators having respective resonant frequency peaks in the pass-band of frequencies; and
a plurality of pass-band shunt resonators coupled in shunt within the ladder topology, the pass-band shunt resonators having respective anti-resonant frequency peaks in the pass-band of frequencies.
16. The BAW resonator device of claim 15 wherein the respective resonant frequency peaks of the pass-band series resonators and the respective anti-resonant frequency peaks of the pass-band shunt resonators are at about a center of the pass-band of frequencies.
17. A Bulk Acoustic Wave (BAW) resonator device comprising:
a first BAW resonator pass-band filter circuit configured to pass frequency components of an input signal of the BAW resonator filter in a first pass-band of frequencies received at an input port of the first BAW resonator pass-band filter circuit to an output port of the first BAW resonator pass-band filter circuit;
a first rejection-band series resonator coupled in series between the input of the first BAW resonator pass-band filter circuit and the output of the first BAW resonator pass-band filter circuit, the first rejection-band series resonator having a first anti-resonant frequency peak in a first rejection-band of frequencies that is less than the first pass-band of frequencies;
a second BAW resonator pass-band filter circuit, the second BAW resonator pass-band filter circuit configured to pass frequency components of an input signal in a second pass-band of frequencies received at an input of the second BAW resonator pass-band filter circuit to an output of the second BAW resonator pass-band filter circuit;
a first rejection-band shunt resonator included in the second BAW resonator pass-band filter circuit coupled in shunt within the second BAW resonator pass-band filter circuit, the first rejection-band shunt resonator having a first anti-resonant frequency peak in the first rejection-band of frequencies;
a switch configured to couple the input signal to the input port of the first BAW resonator pass-band filter circuit in a first state, and configured to couple the input signal to the input port of the second BAW resonator pass-band filter circuit in a second state.
18. The BAW resonator device of claim 17 wherein in the first state the first pass-band of frequencies is about 5.49 GHz to about 5.835 GHz and wherein the first rejection-band of frequencies is about 5.17 GHz to about 5.33 GHz.
19. The BAW resonator device of claim 17 wherein in the second state a second pass-band of frequencies is about 5.17 GHz to about 5.33 GHz and wherein a second rejection-band of frequencies is about 5.49 GHz to about 5.835 GHz.