HELICAL ANTENNA AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a helical antenna for a cellular phone and so on and its manufacturing method in which a space between antenna elements and a cover over the periphery does not cause tilting and which is formed at an inexpensive cost. SOLUTION: This device comprises a bar shape core 25 which is a helical antenna element made of a conductive metallic plate being fixed by a bobbin 24 made of insulating resin, and a cover 26 made of insulating resin which is separately formed and covers over the periphery of the bobbin 24. An inner wall of a hole 26A of the cover 26 contacts with the peripheral surface of a projecting part of the antenna element 22 at the periphery of the bobbin 24. A protrusion 27 formed by thermal deformation of the internal wall around the contact caused by electromagnetic heating and so on, is clamped with a side of the protrusion of the antenna element 22 and the cover 26 is clamped with the core 25.