2006 Fiscal Year Final Research Report Summary
Research on Electromagnetic Measurement System Using Modulated Scattering Elements
| Project/Area Number |
17560300
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electron device/Electronic equipment
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| Research Institution | Tohoku University |
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Principal Investigator |
CHEN Qiang Tohoku University, Graduate School of Engineering, Associate Professor, 大学院工学研究科, 助教授 (30261580)
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| Project Period (FY) |
2005 – 2006
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| Keywords | antenna / measurement / electromagnetic field / radiation efficiency / radiation pattern / modulation |
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| Research Abstract |
It is required to measure the radiation efficiency of antennas of mobile phones and PHS accurately and rapidly, because the electromagnetic radiation from the antenna is partially observed by user's human body. In this research, a simultaneous measurement method using the parallel modulation technique has been proposed. The modulated probe element and the measurement system for radiation efficiency measurement have been developed for commercial use.
1. Accuracy improvement of the system. A directive antenna composed of a dipole and a reflector has been developed to increase the gain of the receiving antennas and improve the measurement accuracy. The frequency of local signal has bee adjusted to decrease the noise caused by the modulation. Furthermore, the mutual coupling analysis has been carried out to optimize the location of the probe array.
2. Broad bandwidth design of the system. The probe array has been designed to meet the requirement of the bandwidth of 800MHz-2.8GHz.
3. A 3-D antenna radiation measurement system has also been developed. The radiation efficiency of antennas has been measured by the system and the measurement results have been compared with the numerical results. It has been demonstrated that radiation efficiency of antennas can be measured rapidly with a satisfactory accuracy in about 16 seconds.
4. Phase measurement. It has been studied how to measure the phase information of the electromagnetic field. However, the investigation has found phase measurement difficult because of the delay effect of the feeding cables and modulation circuits of each probe. This part of research becomes the future work of challenge.
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