Piezoelectric film for low-loss surface acoustic wave filter

A piezoelectric film, surface acoustic wave technology, applied in electrical components, impedance networks, etc., can solve problems such as large insertion loss

Inactive Publication Date: 2013-04-03
LIYANG CITY PRODIVITY PROMOTION CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the insertion loss of the prior art surface acoustic wave filter devices is generally relatively large, and as the freq

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The Ti, Nb and Mn doped ZnO piezoelectric film was prepared on the diamond substrate material by physical vapor deposition, wherein the atomic percentage of Ti was 4%; the atomic percentage of Nb was 3%, and the atomic percentage of Mn was 3% , the piezoelectric constant d of the prepared doped ZnO piezoelectric film 33 is 150pC / N, and the resistivity ρ is 10 9 Ω cm, with a thickness of 250nm; on the doped ZnO piezoelectric film prepared above, an input IDT and an output IDT with a width of 600nm were fabricated by an electron beam direct writing process to obtain a surface acoustic wave filter device.

[0021] The frequency of the surface acoustic wave filter prepared above is 8GHz, and the electromechanical coupling coefficient is as high as 4.3% and the insertion loss is 13dB.

Embodiment 2

[0023] Adopt chemical vapor deposition method to prepare Ti, Nb and Mn doped ZnO piezoelectric film on diamond-like substrate material, the atomic percent of Ti is 4.5%; The atomic percent of Nb is 5%, and the atomic percent of Mn is 4.5%, The piezoelectric constant of the prepared ZnO piezoelectric film is d 33 is 190pC / N, and the resistivity ρ is 10 10 Ω cm, with a thickness of 350nm; on the doped ZnO piezoelectric film prepared above, an input IDT and an output IDT with a width of 500nm were fabricated by an electron beam direct writing process to obtain a surface acoustic wave filter device.

[0024] The frequency of the surface acoustic wave filter prepared above is 9GHz, and the electromechanical coupling coefficient is as high as 6.6% and the insertion loss is 11dB.

Embodiment 3

[0026] Ti, Nb and Mn doped ZnO piezoelectric thin films were prepared on sapphire substrate materials by sol-gel method, the atomic percentage of Ti was 2.5%; the atomic percentage of Nb was 4.6%, and the atomic percentage of Mn was 3.8%, The piezoelectric constant of the prepared doped ZnO piezoelectric film is d 33 is 240pC / N, and the resistivity ρ is 10 8 Ω cm, with a thickness of 300nm; on the doped ZnO piezoelectric film prepared above, an input IDT and an output IDT with a width of 300nm were fabricated by an electron beam direct writing process to obtain a surface acoustic wave filter device.

[0027] The frequency of the surface acoustic wave filter prepared above is 11 GHz, and the electromechanical coupling coefficient is as high as 6.2% and the insertion loss is 7 dB.

[0028] The beneficial effects of the present invention are as follows: the use of a new doped ZnO piezoelectric film has a large piezoelectric response and high resistivity, and the interdigital tr...

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Abstract

The invention discloses a piezoelectric film for a low-loss surface acoustic wave filter. The piezoelectric film is a ZnO piezoelectric film doped with Ti, Nb and Mn, wherein the atomic percentage of the Ti is 4.0-5.0%; the atomic percentage of the Nb is 3.0-5.0%; and the atomic percentage of the Mn is 3.0-4.0%. With the surface acoustic wave filter made of the piezoelectric film provided by the invention, the electromechanical coupling coefficient is high, the insertion loss is low, and the working efficiency is high.

Description

technical field [0001] The invention relates to a piezoelectric film, in particular to a piezoelectric film used for a filter. Background technique [0002] The surface acoustic wave filter is a special filter device made of piezoelectric materials such as quartz crystals and piezoelectric ceramics, using its piezoelectric effect and the physical characteristics of surface acoustic wave propagation. The so-called piezoelectric effect is the phenomenon that when the crystal is subjected to mechanical action, an electric field proportional to the pressure will be generated. Crystals with piezoelectric effect, when subjected to electrical signals, will also produce elastic deformation and emit sound waves, which can convert electrical signals into acoustic signals. Because this sound wave only propagates on the surface of the crystal, it is called surface acoustic wave. [0003] The surface acoustic wave filter has small size, light weight, reliable performance, and does not ...

Claims

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Application Information

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IPC IPC(8): H03H3/08
Inventor 梅欣张俊
Owner LIYANG CITY PRODIVITY PROMOTION CENT
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