| 摘要 |
PROBLEM TO BE SOLVED: To set up the L and Q of coils to large values, to set up resistance to a small value and to reduce the thickness of an antenna by winding plural coils around a laminated magnetic core consisting of metallic thin plates and connecting these coils in parallel. SOLUTION: Plural metallic thin plates each of which has 25μm thickness are heated for 10min at 250 deg.C and quickly cooled and three treated thin plates are laminated to form a magnetic core 1 with 0.1mm thickness. A conductor with 0.1mm is wound around the magnetic core 1 as one layer 130 times to form a 1st coil 2 and a similar conductor with the same diameter is similarly wound around the core 1 as one layer 130 times to form a 2nd coil 3. These coils 2, 3 are connected in parallel to form an antenna. In the antenna having the two coils 2, 3 inductance L and Q are measured and a resistance(r) resulted from the core 1 is calculated, based upon the measured results. As compared with a coil obtained by winding a conductor with 0.15mm diameter as one layer and the parallel connection of two coils obrained by respectively winding two similar conductors with the same diameter around two magnetic cores as one layer, the L and Q of the coils 2, 3 in this antenna are sufficiently large, the resistance(r) is small and the thickness of the antenna can be reduced.
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