| 摘要 |
PROBLEM TO BE SOLVED: To provide an in-cylinder helical antenna with a small contact area to a dielectric material having an excellent electric characteristic (helical antenna characteristic). SOLUTION: Inside an insolubility cylinder 10 having a helical groove on at least on a part of the inner face of which with a gate hole in the groove is inserted into an inner cylinder 2 having a straight pin section with the same outer diameter as the inner diameter of the cylinder. A soluble synthetic resin is injected from the gate hole to form a helical soluble synthetic resin layer, after the inside cylinder 2 is removed, the inner face of the cylinder is made rough, a plating catalysis is provided or after providing a plating catalysis, the soluble synthetic resin layer is disolved and removed to apply plating. |
