Adjusted frequency temperature coefficient resonator

• US 7,868,522 B2
• Filed: 09/09/2005
• Issued: 01/11/2011
• Est. Priority Date: 09/09/2005
• Status: Expired due to Fees

• Current Assignee: Avago Technologies Wireless IP Singapore Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies Wireless IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Ruby, Richard C.
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Rosenau; Derek J
• Application Number:
  US11/223,386
• Publication Number:
  US 20070063622A1
• Time in Patent Office: 1,950 Days
• Field of Search: 310/312, 310/324, 310/346, 310/320
• US Class Current: 310/346
• CPC Class Codes: H03H 2003/021 the resonators or networks being of the air-gap type
• CPC Class Codes: H03H 2003/0407 Temperature coefficient
• CPC Class Codes: H03H 2003/0471 of a plurality of resonators at different frequencies
• CPC Class Codes: H03H 3/04 for obtaining desired frequency or temperature coefficient
• CPC Class Codes: H03H 9/02102 of temperature influence cutting angles H03H9/02015
• CPC Class Codes: H03H 9/585 Stacked Crystal Filters [SCF]
• CPC Class Codes: H03H 9/587 Air-gaps

Abstract

A temperature compensated pair of resonators. The temperature compensated pair of resonators comprises a first resonator configured to resonate at a first frequency and having a first frequency temperature coefficient and a second resonator configured to resonate at a second frequency and having a second frequency temperature coefficient. The second frequency is greater than the first frequency; the second frequency temperature coefficient is less than the first frequency temperature coefficient; and the first and the second resonators are fabricated on a common substrate.

Claims

1. A temperature compensated pair of resonators, comprising:

a first resonator comprising;

a first bottom electrode;

a first piezoelectric structure comprising a first piezoelectric layer, a second piezoelectric layer and an interstitial layer disposed between, and in contact with both the first piezoelectric layer and the second piezoelectric layer, wherein the interstitial layer comprises a stiffness coefficient versus temperature that is greater than a stiffness coefficient versus temperature of either of the first piezoelectric layer or the second piezoelectric layer;

a mass load layer disposed beneath the first bottom electrode; and

a first top electrode, wherein the first resonator has a first resonant frequency; and

a second resonator comprising a second bottom electrode;

a second piezoelectric structure; and

a second top electrode, wherein the second resonator has a second resonant frequency and a temperature coefficient of the stiffness of the mass load layer differs from a temperature coefficient of stiffness of the second top electrode.

2. The temperature compensated pair of resonators as recited in claim 1, wherein the mass load layer is an organic material.

3. The temperature compensated pair of resonators as recited in claim 2, wherein the organic material is selected from the group consisting of PMMA (Polymethyl-methacrylate), PY (Polyimides), and BCB (Benzocyclobutene).

4. The temperature compensated pair of resonators as recited in claim 1, wherein the mass load layer is a resin.

5. The temperature compensated pair of resonators as recited in claim 4, wherein the resin is a low-k material.

6. The temperature compensated pair of resonators as recited in claim 1, wherein the mass load layer is an oxide.

7. A temperature compensated pair of resonators, comprising:

a first resonator comprising;

a first bottom electrode;

a first piezoelectric structure comprising a first piezoelectric layer, a second piezoelectric layer and an interstitial layer disposed between, and in contact with both the first piezoelectric layer and the second piezoelectric layer, wherein the interstitial layer comprises a stiffness coefficient versus temperature that is greater than a stiffness coefficient verse temperature of either of the first piezoelectric layer or the second piezoelectric layer;

a mass load layer disposed beneath the first bottom electrode;

a first top electrode; and

another mass load layer disposed over the first top electrode, wherein the first resonator has a first resonant frequency; and

a second resonator comprising;

a second bottom electrode;

a second piezoelectric structure; and

a second top electrode, wherein the second resonator has a second resonant frequency and a temperature coefficient of the stiffness of the mass load layer disposed beneath the first bottom electrode differs from a temperature coefficient of stiffness of the second bottom electrode.

8. The temperature compensated pair of resonators as recited in claim 7, wherein the mass load layer is an organic material.

9. The temperature compensated pair of resonators as recited in claim 8, wherein the organic material is selected from the group consisting of PMMA (Polymethyl-methacrylate), PY (Polyimides), and BCB (Benzocyclobutene).

10. The temperature compensated pair of resonators as recited in claim 7, wherein the mass load layer is a resin.

11. The temperature compensated pair of resonators as recited in claim 10, wherein the resin is a low-k material.

12. The temperature compensated pair of resonators as recited in claim 7, wherein the mass load layer is an oxide.