2005 Fiscal Year Final Research Report Summary
On Functional Modules Based on Integration of Acoustic Wave Devices and Semiconductor Circuitry
| Project/Area Number |
15360200
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Communication/Network engineering
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| Research Institution | Chiba University |
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Principal Investigator |
HASHIMOTO Ken-ya Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (90134353)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Masatsune Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (00009664)
OMORI Tatsuya Chiba University, Faculty of Engineering, Professor, 工学部, 助手 (60302527)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Surface Acoustic Wave / Module / Filter / Power Amplifier / Low-Noise Amplifier / Impedance Matching / Variable Filter / Copper Electrode |
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| Research Abstract |
This project was aimed at discussing possibilities of functional RF modules realized by the integration of RF acoustic wave devices and semiconductor circuitry from various aspects.
First, influence of RF acoustic wave devices to the power amplifier (PA) performances was investigated. It was shown that the impedance Z of RF filters significantly influences to the power added efficiency (PAE) of PAs at high power operation, and it was pointed out that Z variation must be suppressed to realize high PAE. It was also indicated that Z for harmonic frequencies is also important for the high PAE realization because non-linearity is obvious at high power operation. As a countermeasure, it was shown that Z variation can be fully suppressed by attaching two 90° hybrids to two RF filters, and effectiveness of this approach was demonstrated experimentally.
Then we discussed realization of new functional surface acoustic wave (SAW) devices by the use of Cu-electrode/15°YX-LiNbO_3-substrate configuration. It was shown that the influence of the bulk wave radiation can be suppressed by simply increasing Cu thickness. This technique is effective for the reduction of the filter insertion loss. Then use of weighted dummy electrodes and over-coating viscous materials were proposed for the suppression of unnecessary responses appeared in the filter passband.
Furthermore, we proposed new various functional devices such as various filters combining RF amplifiers and filters, and device configurations appropriate for the purposes were also discussed in detail from various aspects.
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