| Budget Amount *help |
¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1988: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1987: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Research Abstract |
So far, It has been a large problem that the measurements on electro-magnetic waves with a probe antenna had been influenced by reflected waves caused by the antenna stay which was ordinarily made of a rigid coaxial line. Because, when electromagnetic waves come to the antenna stay, they make the high frequency current flow on it which causes the second radiation, that is, " reflection". If no current flow were made on it, the bad influence of reflection would be taken off. Therefore, it was the antenna engineers' long-cherished desire to make the impedance of the stay rod higher in order to suppress the current flow and to get no interference on the antenna measurements.
It has been definitely shown by our research works that when some ferrite pipes is simply covered on the rod, its impedance becomes higher, and the bad wave reflection can be suppressed. So it was termed by us as "Microwave Magic Mantle ( 3m ).
Results obtained :
(a) A new probe antenna named as " Magnetic Dipole Antenna" has been developed. It is composed of a thin ferrite rod inserted in the small metallic loop covered with two metallic shield-fins and a quarter wavelength Balan. Those are set to the end of the antenna stay ( semi-rigid cable ). Also the characteristics of a ordinary loop antenna with a tuned balan, shield fins and 3M has been investigated.
(b) The characteristics of those probe antennas has shown a better 8-letter shape, compared with one without 3M.
(c) It has been cleared up by our investigation that the three important items are necessary at the design of such a probe antenna, those are the use of (1)3M, (2)the tuned Balan, and (3)the shield for the loop.
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