Resonator-based filtering
View Patent ↗A filter may be constructed from multiple acoustic elements in parallel. A filtering method may comprise passing a signal to be filtered through such parallel acoustic elements. Such filtering may be applicable to communication devices.
1. A filter device, comprising:
one or more 2-port acoustic resonators coupled in parallel between a source node and a load node, each of the one or more 2-port acoustic resonators comprising:
an input terminal; and
a ground terminal; and
one or more 1-port acoustic resonators coupled in parallel with the one or more 2-port acoustic resonators between the source node and the load node, at least one of the one or more 1-port acoustic resonators comprising a 2-port acoustic resonator having an input terminal and a ground terminal and arranged to implement the 1-port acoustic resonator.
2. The filter device, as in claim 1 , wherein at least one of the one or more 2-port acoustic resonators comprises an Inter Digital Transducer (IDT).
3. The filter device as in claim 2 , wherein at least two acoustic resonators are acoustically coupled.
4. The filter device as in claim 3 , wherein the filter is designed to have an odd number of resonances.
5. The filter device as in claim 1 , wherein at least one of the one or more 2-port acoustic resonators includes a surface acoustic wave (SAW) device.
6. The filter device as in claim 1 , wherein at least one of the one or more 2-port acoustic resonators includes a dual-mode SAW (DIMS) resonator.
7. The filter device as in claim 1 , wherein at least one of the one or more 2-port acoustic resonators includes a bulk acoustic wave (BAW) device.
8. The filter device as in claim 1 , further comprising at least one impedance matching circuit coupled to the input node or to the output node.
9. A communication station comprising:
a transmit or receive device; and
the filter device as in claim 1 coupled to receive a signal from or to provide a signal to the transmit or receive device.
10. A filter device, comprising:
at least two acoustic elements coupled in parallel between a source node and a load node, wherein the at least two acoustic elements are arranged to filter a signal presented at the source node and output a filtered signal to the load node, the at least two acoustic elements including:
at least one two-port acoustic element coupled between the source node and the load node; and
at least one one-port acoustic element coupled in parallel to the at least one two-port acoustic element between the source node and the load node.
11. The filter device as in claim 10 , wherein one or more of the at least one one-port acoustic element comprises a two-port acoustic element arranged to implement a one-port acoustic element.
12. The filter device as in claim 10 , wherein at least one of the at least two acoustic elements comprises at least one Inter Digital Transducer (IDT).
13. The filter device as in claim 10 , wherein at least one of the at least two acoustic elements comprises a surface acoustic wave (SAW) device or a hulk acoustic wave (SAW) device.
14. The filter device as in claim 10 , further comprising at least one impedance matching circuit coupled to the source node or to the load node.
15. A communication station comprising:
a transmit or receive device; and
the filter device as in claim 10 coupled to receive a signal from or to provide signal to the transmit or receive device.
16. A method comprising:
directing an input signal into two or more parallel acoustic elements, the two or more parallel acoustic elements including at least one one-port acoustic element and at least one two-port acoustic element arranged to each other; and
combining outputs of the two or inure parallel acoustic elements to obtain a filtered output signal.
17. The method of claim 16 , wherein input signal is received from a component of a communication device.
18. The method of claim 17 , where in the component comprises a modulator or an antenna.
19. The method of claim 16 , further comprising:
forwarding the filtered output signal to a component of communication device.
20. The method of claim 19 , wherein the component comprises a modulator or an antenna.
21. The method of claim 16 , further comprising directing the input signal and/or the filtered output signal through at least one impedance matching element.
22. The method of claim 16 , wherein one or more of the at least one one-port acoustic element comprises a two-port acoustic element connected to implement a one-port acoustic element.