Acoustically coupled resonator notch and bandpass filters
A notch filter includes an inductor coupled between an input node and an output node, and a dual-resonator structure coupled between the input node, the output node, and ground.
1. A notch filter comprising:
a first dual-resonator structure having a top electrode coupled to an input node, an intermediate electrode, and a bottom electrode;
a second dual-resonator structure having a top electrode coupled to an output node, an intermediate electrode, and a bottom electrode;
a first inductor having a first end directly coupled to the input node and a second end coupled to the output node; and
a second inductor coupled between the intermediate electrode of the first dual-resonator structure and the intermediate electrode of the second dual-resonator structure.
2. The notch filter of claim 1 , wherein an additional intermediate electrode of the first dual-resonator structure and an additional intermediate electrode of the second dual-resonator structure are coupled to ground.
3. The notch filter of claim 1 , wherein the bottom electrode of the first dual-resonator structure and the bottom electrode of the second dual-resonator structure are coupled together.
4. The notch filter of claim 1 , wherein the first and second dual- resonator structures each comprise a coupled resonator filter.
5. The notch filter of claim 1 , wherein the first and second dual-resonator structures each comprise a film bulk acoustic resonator.
6. A notch filter comprising:
a first dual-resonator structure having a top electrode coupled to an input node, an intermediate electrode, and a bottom electrode;
a second dual-resonator structure having a top electrode coupled to an output node, an intermediate electrode, and a bottom electrode;
a first inductor having a first end coupled to the input node and a second end directly coupled to the output node; and
a second inductor coupled between the intermediate electrode of the first dual-resonator structure and the intermediate electrode of the second dual-resonator structure.
7. The notch filter of claim 6 , wherein an additional intermediate electrode of the first dual-resonator structure and an additional intermediate electrode of the second dual-resonator structure are coupled to ground.
8. The notch filter of claim 6 , wherein the bottom electrode of the first dual-resonator structure and the bottom electrode of the second dual-resonator structure are coupled together.
9. The notch filter of claim 6 , wherein the first and second dual-resonator structures each comprise a coupled resonator filter.
10. The notch filter of claim 6 , wherein the first and second dual-resonator structures each comprise a film bulk acoustic resonator.
11. A notch filter comprising:
a first dual-resonator structure having a top electrode coupled to an input node, an intermediate electrode, and a bottom electrode;
a second dual-resonator structure having a top electrode coupled to an output node, an intermediate electrode, and a bottom electrode;
a first inductor having a first end coupled to the input node and a second end coupled to the output node; and
a second inductor having a first end coupled between the intermediate electrode of the first dual-resonator structure and the intermediate electrode of the second dual-resonator structure and a second end coupled to ground, wherein the second inductor comprises an inductor component external to the first dual-resonator structure and to the second dual-resonator structure.
12. The notch filter of claim 11 , wherein an additional intermediate electrode of the first dual-resonator structure and an additional intermediate electrode of the second dual-resonator structure are coupled to ground.
13. The notch filter of claim 11 , wherein the bottom electrode of the first dual-resonator structure and the bottom electrode of the second dual-resonator structure are coupled together.
14. The notch filter of claim 11 , wherein the first and second dual-resonator structures each comprise a coupled resonator filter.
15. The notch filter of claim 11 , wherein the first and second dual-resonator structures each comprise a film bulk acoustic resonator.
16. A method comprising:
filtering a signal using a notch filter comprising a first dual-resonator structure having a top electrode coupled to an input node for receiving the signal, an intermediate electrode, and a bottom electrode; a second dual-resonator structure having a top electrode coupled to an output node for providing a filtered signal, an intermediate electrode, and a bottom electrode; a first inductor having a first end directly coupled to the input node and a second end directly coupled to the output node; and a second inductor coupled between the intermediate electrode of the first dual-resonator structure and the intermediate electrode of the second dual-resonator structure.
17. The method of claim 16 , wherein an additional intermediate electrode of the first dual-resonator structure and an additional intermediate electrode of the second dual-resonator structure are coupled to ground.
18. The method of claim 16 , wherein the bottom electrode of the first dual-resonator structure and the bottom electrode of the second dual-resonator structure are coupled together.
19. The notch filter of claim 16 , wherein the first and second dual-resonator structures each comprise a coupled resonator filter.
20. The notch filter of claim 16 , wherein the first and second dual-resonator structures each comprise a film bulk acoustic resonator.