Acoustic wave filter and method of forming the same

• US 6,424,238 B1
• Filed: 01/08/2001
• Issued: 07/23/2002
• Est. Priority Date: 01/08/2001
• Status: Expired due to Fees

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Penunuri, David
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): TAKAOKA, DEAN O
• Application Number:
  US09/757,191
• Time in Patent Office: 561 Days
• Field of Search: 333/191, 333/187, 333/186, 333/188, 333/193, 333/194, 333/195, 333/196, 310/313.R, 310/313.B, 310/311
• US Class Current: 333/187
• CPC Class Codes: H03H 3/08 for the manufacture of resonators or networks using surface acoustic waves
• CPC Class Codes: H03H 9/605 consisting of a ladder configuration
• CPC Class Codes: H03H 9/6483 Ladder SAW filters

Abstract

An acoustic wave filter (10) and a method (30) of forming the acoustic wave filter (10) are disclosed. The acoustic wave filter includes a substrate (20) supporting a first die (18) and a second die (18). The first die (18) and second die (18) include either a Surface Acoustic Wave (SAW) resonator or a Bulk Acoustic Wave (BAW) resonator, wherein one of the resonators is configured as a series resonator (12) of the acoustic wave filter (10) and the other resonator is configured as a shunt resonator (14) of the acoustic wave filter (10).

Claims

1. An acoustic wave filter comprising:

a substrate;

a first die supported by said substrate, said first die having a first Surface Acoustic Wave resonator configured as a series resonator of said acoustic wave filter;

a second die supported by said substrate, said second die having a first Bulk Acoustic Wave resonator electrically coupled to said first Surface Acoustic Wave resonator and configured as a shunt resonator of said acoustic wave filter.

2. An acoustic wave filter as in claim 1, wherein said substrate is configured with cavities for receiving said first and second dies.

3. An acoustic wave filter as in claim 2, wherein said substrate is formed of a ceramic material.

4. An acoustic wave filter as in claim 2, wherein said substrate includes at least two ceramic layers.

5. An acoustic wave filter as in claim 1, wherein said first die has a second SAW resonator electrically coupled in a configuration selected from the group consisting of shunt and series resonators.

6. An acoustic wave filter as in claim 1, wherein said second die has a second BAW resonator electrically coupled in a configuration selected from the group consisting of shunt and series resonators.

7. An acoustic wave filter comprising:

a substrate;

a first die supported by said substrate, said first die having a first Bulk Acoustic Wave resonator configured as a series resonator of said acoustic wave filter;

a second die supported by said substrate, said second die having a first Surface Acoustic Wave resonator electrically coupled to said first Bulk Acoustic Wave resonator and configured as a shunt resonator of said acoustic wave filter.

8. An acoustic wave filter as in claim 7, wherein said substrate is configured with cavities for receiving said first and second dies.

9. An acoustic wave filter as in claim 8, wherein said substrate is formed of a ceramic material.

10. An acoustic wave filter as in claim 8, wherein said substrate includes at least two ceramic layers.

11. An acoustic wave filter as in claim 7, wherein said second die has a second SAW resonator electrically coupled to said first SAW resonator in a configuration selected from the group consisting of shunt and series resonators.

12. An acoustic wave filter as in claim 7, wherein said first die has a second BAW resonator electrically coupled to said first BAW resonator in a configuration selected from the group consisting of shunt and series resonators.

13. A method of forming an acoustic wave filter, said method comprising:

providing a substrate;

connecting a first die to said substrate, said first die having at least one Surface Acoustic Wave resonator configured as a series resonator of said acoustic wave filter;

connecting a second die to said substrate, said second die having at least one Bulk Acoustic Wave Resonator configured as a shunt resonator of said acoustic wave filter;

electrically coupling said at least one bulk acoustic wave resonator to said at least one surface acoustic wave resonator to form said acoustic wave filter.

14. A method as in claim 13, wherein said substrate is ceramic.

15. A method as in claim 13, wherein providing a substrate comprises:

providing a first ceramic layer and a second ceramic layer;

forming holes in said first ceramic layer; and

attaching said first layer to said second layer, thereby forming the holes into cavities for receiving said first and second dies.

16. A method of forming an acoustic wave filter, said method comprising:

providing a substrate;

connecting a first die to said substrate, said first die having at least one Surface Acoustic Wave resonator configured as a shunt resonator of said acoustic wave filter;

connecting a second die to said substrate, said second die having at least one Bulk Acoustic Wave Resonator configured as a series resonator of said acoustic wave filter;

electrically coupling said at least one bulk acoustic wave resonator to said at least one surface acoustic wave resonator to form said acoustic wave filter.

17. A method as in claim 16, wherein said substrate is ceramic.

18. A method as in claim 16, wherein providing a substrate comprises:

providing a first ceramic layer and a second ceramic layer;

forming holes in said first ceramic layer; and

attaching said first layer to said second layer thereby forming the holes into cavities for receiving said first and second dies.