2001 Fiscal Year Final Research Report Summary
STUDY ON ACTIVE PHASED ARRAY ANTENNAS RADIATING HIGHER HARMONIC OUTPUT WAVE .
| Project/Area Number |
12650345
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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 |
電子デバイス・機器工学
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
NOGI Shigeji OKAYAMA UNIV., ELECTRICAL & ELECTRONIC ENG., PROFESSOR, 工学部, 教授 (10033250)
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| Co-Investigator(Kenkyū-buntansha) |
SANAGI Minoru OKAYAMA UNIV., ELECTRICAL & ELECTRONIC ENG., LECTURER, 工学部, 講師 (80226026)
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| Project Period (FY) |
2000 – 2001
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| Keywords | MICRO WAVE / MILLIMETER WAVE / ACTIVE ANTENNA / PHASED ARRAY / HIGHER HARMONICS / SYNCHRONIZATION / POWER COMBINING |
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| Research Abstract |
Output powers of microwave FETs decrease with increasing working frequency, and it is difficult at present to obtain output powers of fundamental oscillation using microwave FETs at more than 60 GHz. It has been confirmed in experiments at X band that at second harmonic output powers can be efficiently obtained in conparatively high output power level at frequencies where no output power can be yielded by fundamental oscillation. For this purpose, the load impedance is taken so that the fundamental oscillation output power is well suppressed and the second harmonic output power can be maximized. Next, in second harmonic active antenna arrays, appropriate mutual coupling between microstrip lines of adjacent antive antennas has been shown to be in the fundamental frequency with its phase of a multiple of 2π. This coupling can give not only relatively wide locking range which results in easy synchronization but also the maximum phase spacing between adacent active antennas. In the experiment of one dimensional array of 2, 3 and 4 second harmonic active antennas, we could attain the output beam sreering angle of 63, 73 and 81 degrees, respectively ; these beam steering angles correspond to the maximum phase differences of second harmonics of almost 350 degrees between adjacent active antennas. Since the maximum phase differences of fundamental oscillation between adjacent active antennas are 180 degrees, the maximum phase differences of second harmonics can be almost twice as large as in active antenna arrays with output waves of fundamental oscillation.
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