| Project/Area Number |
05650362
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
情報通信工学
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| Research Institution | Musashi Institution of Technology |
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Principal Investigator |
ABE Miroru Musashi Institute of Technology, Dept.of Electronics and Communication Engineering, Associate Professor, 工学部, 助教授 (20061541)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Array-Antenna / Magnification of Phase difference / Frequency Multiplier / Directive Antenna / Miniaturization / Reduction of Spacing / Automatically Controlling in In-phase / Direction Finding Antenna / 指向性アンンテナ / 相互インピーダンス |
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| Research Abstract |
The method of multiplying each frequency in two signals can extend the phase difference between the signals. Applying this method to a receiving array, the spacing elements can be reduced and then an array for HF band becomes small effectively. By means of multiplying the receiving frequency by 4, the equi-spacing of the 2- and 4-elements array can be reduced to 9.6% and 6.4% of original spacing, respectively. This results are obtained not only by the frequency multiplying but also by the increment of the phase difference due to the mutual coupling between elements. The calculated receiving patterns with mutual coupling, using induced E.M.F.method and methods of Moment for monopole elements on the infinite ground plane, coincide with the measured values. In this case, we use a Phase Locked Loop as the frequency multiplier.
When the frequency doublers are applied to a 2-elements array controlled automatically in phase the spacing between the elements can be reduced to less than one-half of original spacing. However, when the array system receives a desirable arriving wave the system is influenced by undesirable arriving wave of the same frequency from null direction because of the nonlinearity of the frequency doubler.
The application of this method to a direction finding antenna is reasonable because of the detection of the arriving wave from only one direction.The spacing between elements can be reduced, though the accuracy of detecting angle is maintained. By means of multiplying the receiving frequency by 4, the spacing of 3-elements array can be reduced from 0.21lambda to 0.036lambda, where each element is placed on each summit of an equlateral triangle.
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